'04 Carrera C4S M96/03 DIY Engine Rebuild

Backstory It started with a ticking sound coming from the engine on the passenger side, which was driving me crazy. Every time I pulled into my garage it was there. Much more noticeable after the car was warmed up. When I bought the car I had done an inspection, but shame on me for not doing a PPI, which may have caught this. The sound did not happen when I inspected it, maybe it needed to warm up more first. Everything else on the car was perfect, no RMS issues, new AOS, clutch, IMS solution installed, engine mounts, tires, all good. At any rate, I started noticing the tapping sound not long after I took possession of the car and started driving it any distance. I brought it to a local Porsche 'expert' shop that told me it was nothing to worry about, and that I should use a different oil weight. A few weeks later I noticed it was spattering oil on my garage floor upon start. This was coming out the driver side exhaust, which meant the 456 passenger side of the engine. Some googling led me to to this site, where I learned that this was a somewhat common issue with the M96 engine,. Also that it was often mis-diagnosed as 'noisy lifters'. I had to know for sure and got a borescope and take a look. (Inexpensive endoscope on Amazon endoscope on Amazon I used for the video below of my #6 cylinder) Cylinder #6 - Endoscope Wow - bad cylinder scoring. Huge bummer. Googling and reading more about this I found that this has occurred with other 996 engines, some with much less mileage then my own. I spent a lot of time here on Rennlist reading about this and I now know much, much more about 996 engines than I ever thought I would! So, after a depressing few days I decided that I was going to fix this before bigger issues occurred. Options for Fixing 1. Sell the car, pass on to some other poor buyer. PO did this to me but was not an option for me ethically/morally. 2. Sell it as a known issue, take a loss, and move on. Another non-option for me, I really like the car and want to keep it. 3. Buy a used engine off eBay. Risky, prices are not much less than doing a rebuild, and don't address the underlying problem. 4. Buy a rebuilt engine. There are a few suppliers: RND Engines - too pricey Vertex Auto - also too pricey MB Motorsports - this is not a comment at all on their quality, etc. but I didn't like the idea of steel cylinders in an aluminum block 5. Send it out for rebuild. I've learned there are very few shops out there there that should be trusted to do this, Flat6Innovations would be my first choice. But at around 20-28K this was far too expensive for me. 6. Porsche crate motor (expensive!) or a much less expensive short block and use my own cylinder heads. Again, neither of these would address the original problem. 7. Rebuild/fix the engine myself. Still expensive! but not as much as other options, and comes with bonus of bigger engine and a challenging project. So rebuild it is! I am not a mechanic, but have worked on engines, and am very mechanical/handy. So I wanted to get as much information as I could before I started this to fully understand what I was getting into. I started by getting the Bentley Service Manual Bentley Service Manual and reading lots of threads others had posted on rebuilds. Here are some links I found very useful Ahsai (Fantastic guide, and he has also graciously helped me with some questions I've had) https://rennlist.com/forums/996-foru...engine-39.html Logray https://rennlist.com/forums/996-foru...he-finale.html Redneck Rebuild https://www.6speedonline.com/forums/...ld-thread.html Flat 6 Assembly http://www.flat6innovations.com/inde...ngine-assembly IxOmega Build https://www.lxomega.com/projects/cars/911/indexA.html Boxster 996 https://dorkiphus.net/porsche/showthread.php?t=33667 And these videos: You Tube You Tube You Tube You Tube You Tube Rebuild Goals I paid a pretty fair price for the car but it didn't make sense to me to pour nearly what I paid for it into the rebuild. So I wanted primary to keep costs as low as possible, without sacrificing build quality. I also wanted to do this myself for the experience, but also to keep the costs down. I was really interested in the rebuild class offered by The Knowledge Gruppe (Jake Raby) but the price didn't fall into my goals and I just could not justify it. I did sign up for their online course, but it unfortunately got cancelled. Rebuild Costs As I looked into this I found different approaches taken by others. I hope this doesn't turn into a flame war, but I'm going to list the options I came across: 1. Cylinder re-sleeving: Aluminum sleeves - Hartech (UK), LN Engineering Nickes Iron sleeves - MB Motorsports, others (google them) 2. Cylinder Re-boring and re-plating: Millenium Technologies Yes, you can re-bore and re-plate the cylinders, and I called up Millenium to get a quote for this. They gave me a very reasonable price to re-bore to 97mm, replate and match with Wossner pistons, rings, etc. This was extremely interesting but in the end I decided to go with the LNE Nickies because: Goal for me was to keep the car long-term. I was concerned with the decreased cylinder wall thickness, and out-of-round issues, as well as the fact that D-Chunking was not addressed. Iron sleeving - this is not a comment on quality or durability, but I just did not like the idea of using iron sleeves. Maybe irrational, but just my preference. Again, I hope this does not start a debate. I spent a good amount of time putting this all together, so I wanted to give others an idea of what the looks like. Breakdown attached as html file. Tools Cost You will need the right tools. Some are obvious, but just so there are no surprises, here is what I got: Engine Stand. Harbor Freight has a lot of choices I didn't want to spend the money and have not needed it so far: 996 Engine Yoke High jack stands. I used these: Harbor Freight 6 ton jack stands and they were high enough to get the engine out Floor Jack and Transmission Jack. I had a floor jack, and got the transmission jack at Harbor Freight again Cam Timing Tools (thanks Ahsai!). These from eBay are specific to my M96/03 3.6L VarioCam Plus. A 3.4L engine will need different tools Cam Alignment Tools. Again, eBay and specific to my engine Rear Main Seal Tool - you may be able to install without this tool, but for $60 I felt this was worth it For filing the rings, yo will need a ring squaring tool ring squaring tool and also a http://www.ebay.com/itm/332104328874 Ring Compressor - you could use a cheap spring type one, but why take the risk for this price? When it is time to refill the coolant back into your engine, you will need an Airlift type cooling system filler Airlift type cooling system filler Optional, but recommended to get the Durametric Tool I hope you are adding this up because, yes, the tools alone are expensive. Other Items/ Costs If were were looking at my parts list carefully you may have noticed things like new knock sensors, MAF sensor, and injector work. Basically, if you are going to tear down the engine then you need to replace all of that, along with new chains, seals, gaskets, chain guides, etc. Also, all of the engine bolts are stretch bolts, which means they cannot be re-used. You could opt to go with lower cost OEM replacement bolts, but I went with the ARP bolts, which are re-usable. Also, if you've had scored cylinders and are seeing oil come out the tail pipe, it means the cats are probably coated with that same soot and need to be replaced. I opted to replace mine with an x-pipe and did not list that cost in my sheet, but you should be aware of it. Final note is that you might be able to rebuild with re-bore/re-plating and get away with re-using some of these items, but I went this route because I wanted to go for long term reliability. Engine removal / teardown There are enough posts and videos out there about removing the engine so I'm not going to post on that. It took me about 4 hours total, and the most difficult part was removing the A/C compressor back bolt. One 'trick' I recommend is to remove the intake throttle body and intake tube. Took me about an hour fiddling with that bolt before I did that, but afterwards it took about 3 minutes. I've disassembled everything and have sent out my block to LNE for re-sleeving, and am patiently waiting for them to be completed. I also sent out my heads to Len Hoffman at Hoffman Automotive , who did an unbelievable job cleaning, pressure testing, porting, and R&R on the valves. I've also spent lots of time cleaning parts. Lots. Of. Time. To help with this, I got an Ultrasonic Cleaner off eBay . Yup, another tool expense. I got the 15L one and it worked great, but some parts I had to do 1/2 at a time. If I had gotten the 20L all of those parts would have fit right in. Next post I'll upload some disassembly photos, more to come....

Thanks for sharing! Any specialty tools needed? Did you take pictures of the rebuild?

From your itemized parts and service spreadsheet I noticed you had the rotating assembly balanced. May I ask the shop name that performed the work? And what were the exact parts that were balanced? I will be starting a similar thread soon. My block and heads are currently with LN and Hoffman.

Ahsai (Fantastic guide, and he has also graciously helped me with some questions I've had) ^^^^ This guy! Keep him close. He knows...

Assuming metal moved through your engine, I would suggest changing all hydraulic actuators/tensioners so you don’t reintroduce metal. You left out cam sprockets (intake and exhaust) because there is a good possibility warn sprockets will hasten wear on the new chains and go downhill from there. You also left out lifters (approx $2,500]. You should cut valve seats if you are doing guides. Then You will need to check spring pressures and shim accordingly. And you should replace the rod bushings - almost certain you will be able to measure wear. If you are going to spend a significant amount of money, you should go all the way because not doing so, just changes the weak link to something else.

I have not had this done yet, but have had this work quoted out from a shop local to me . The parts involved include everything that rotates: crankshaft / rods / pistons / pins / rings / rod bearings dual mass flywheel / clutch / clutch / plate Ahsai did an amazing job of balancing his pistons / rods / wrist pins / rings. I was really keen on doing this myself but since the entire thing needs to be balanced on the crank with the DMF, etc. I decided not to spend money/time with a piston balancer and scale, etc. and to just send the whole thing out for that. For that, I called quite a few places around me to understand what it involved. What I found is interesting. Most places only balance to within 1 gm. In fact they only wanted me to send them a single piston / rod / wrist pin / ring set. Nope. I finally found the shop I linked above, who happens to live close to me. This guy is the real deal - he has an ultra precision shop with some unbelievable tooling (Rottler F67A / H85A / VR10 - more fun stuffI learned about), and will balance the entire assembly to within .1 gm. This is likely better than it came from the factory and I hope I will have a ridiculously smooth running engine in the end.

Wow thanks for sharing. Really looking forward to this.

Head job was completely redone, valve seats, guides, pressure tested, ported, everything. From speaking with a few folks its debatable whether the lifters need replacement or not. These had interestingly been replaced by the PO not too long ago. Visual inspection shows no wear whatsoever, and there doesn't seem to be a lot of info on tolerances for these. Lastly, if they give me an issue I figure I can always replace them later.

I rebuilt my engine about 2 yrs ago. I did not add all my receipts, but I think I spent between 15-20k very happy with it. Now is the time to install the "insurance policy " parts and make it a better reliable engine. I chose not to do anything to increase horsepower, just reliability. I went this route because of a very respected person in the collector car community. there is no end to performance mods and money to be spent. Went for reliability

It will be a fun, rewarding project. Just be aware that there is absolutely no info in Bentley regarding tear down or build up of the bottom end of the engine. Splitting the case halves and reassembly are tricky, so make sure you somehow get good info on this important build.

P.S. : Nickies are definitely the way to go, and can increase displacement at no extra cost.

Yes, I did discover that! Almost useless for a bottom end rebuild. I ended up googling and buying the PDF version of the the 'technical shop manual' for that, and also went through the forum links I posted several times.

Does the .pdf you bought have the bottom end info? If so, could you send me a link to where you bought it?

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I too would be interested!

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FYI, Hartech uses Nikasil coated alloy sleeves, not iron. (not a flame, just clarification)...besides, now I'm subscribed Looking forward to seeing your results. I would REALLY like to try this one day myself. Thanks for posting!

I went here eManuals Online Search for your model year, etc. I bought two manuals: one is titled 'Technical Manual 996 Carrera Repair' and watermarked with www.workshopmanuals.co.uk the other is titled '2001-2005 Porsche 911 (996.2) Service Manual'

Thanks, I corrected that part

This is already a great resource thread! Thanks for sharing. Looking forward to more.

Related data point: I’m just finishing a rebuild of the 3.6 in my 997 to a 3.8. New sleeves, JE Pistons, heads redone, bearings, chains, guides, AOS, IMSB, etc. I just fired the car for the first time in eighteen months about a week ago, and I’m the process of chasing down a bunch of issues (O2 sensors, cam solenoids, etc). Apparently leaving a car apart for over a year is not a recipe for happy parts. I’ve not yet totaled my parts, but I think my costs are around 10k. From memory, machine shop bill with pistons was about $4500. Gaskets, bearings, IMSB, AOS, yada, yada were about $5k. If there is interest, I’ll post a shopping list. One huge help to me was a fellow forum member and Raby school grad who I convinced to provide, notes, tools and consultation services for a generously low price. Also, the guys at Coventry Motorcar in Connecticut were super helpful in ordering parts, offering suggestions, and Durametric help. Props to Eastwood’s Machine for case artwork. Oh, and the reason for rebuild was low compression (rings, no visible scoring) in #6. Leak down was 20%, enough for the car to skip at idle. I bought the car in this condition.

My car has been making that knocking noise for 24k miles now (60k to 84k). I use about 1 QT of oil every 1300 miles. It never appears to be spitting oil out the tail pipe. The UOA have been pretty normal. I don't drive it that hard. I keep the rpms around 3k for most of my drive and rarely use WOT or exceed 5.5k rpms. I guess I know the engine has been on the way out for a while and trying to get another year out of it before I get a new engine or rebuild.

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Are both needed or is one more detailed than the other?

Good luck with the rebuild, please keep us updated with the progress. If you haven't looked already I would recommend Jim Ellis (Porsche Atlanta) for parts, they were by far the cheapest for the top end refresh I just did on my car for lifter issues. I'd suggest you have a look at your intake lifters to ensure its the updates part and #, I did a post about misfire/lifter issues that details the difference. Peace of mind if your car already has the new parts fitted.

Engine Removal There are lots of guides on how to drop the engine so I'm not going to document any of that. But I will note a few things I found: 1. Removing the bolt behind that A/C compressor is much, much easier if you first remove throttle body and intake pipes. After removing the throttle intake, unscrew 2 clamps each side on the rubber connecters at the end of the horizontal intake pipe and push the connectors to the middle. Then lift out the intake pipe. After that you can use your left hand to guide the socket onto the bolt and remove it. Took me an hour of fiddling before I figure this out, then another 5 mins once I did. 2. Fuel line disconnect: (04 C4S) - don't disconnect anything on the fuel rail. Instead there is a single main fuel line on the upper left that unclips. The line leads off into a Y connection at the back of the engine, which splits off to each fuel rail. After lowering the engine about 4 inches you will easily see the connector, and can unclip it at the top left, near the cooler reservoir. The whole thing took me about 4 hours to drop, and now that I've done it once I think I could do it in under 2 the next time. She's going to need a really good cleaning. Top view, intakes removed. Rear view, flywheel shot.

Just a few more glamour shots before I got it up onto the engine stand. Another view from the top. 123 head side had some kind of leak in the past I think, oil was dry. Up on the engine stand. 456 side was very clean. Bottom view, tilted on its side.

Oil pump on 123 side. Opposite end with 123 side up. Cam cover removed. Sprockets and timing chain. Opposite view of camshafts, 123 side.

456 side cams. Cylinder Scoring Finally, we get to the interesting part, and the whole reason I'm doing all this! I was surprised to find cylinder #4 had the most scoring. #6 is where most of the sound came from and the one I scoped, but this had worse scoring. #5 had no issues, as expected. And #6. You can see where I scraped off some carbon deposits on the piston head with a screwdriver. Also matches up with why oil was spitting out my driver side exhaust onto my floor. At one point I thought I would drive this one more summer and fix it next year, but I'm glad I'm doing this now before more downstream issues occur = more $$$ to fix. That oil blowing by was ending up in my cats (at least the right one) and so they also need to be replaced.

View of the crankcase half on the engine stand with the crank carrier removed. The crank carrier is quite heavy, so what I did was re-attached 4 of the head bolts into it at the top and then tied rope across them. The rope was then attached to a hoist to lift it out. I will post photos of this when I re-assemble it. The crankcase carrier out with the IMS attached. Shot of the IMS solution spin-on adapter that was already in place. Just another shot of the crankcase, showing the oil pan area. This is what the crank carrier looks like with the bearings removed And another shot. These both will get cleaned up before reassembly.

If I may add, the AC's third bolt can be easily accessed through the temp sensor hole on top with a crows foot. No need to take the throttle body off unless you plan to anyway.

Connecting rods removed. I decided to re-use these and not upgrade to Carillos because I don't intend to track my convertible. They are quite fine for street use and 3.6 to 3.8 upgrade, but NOT for 4.0 upgrade or any track use. These will also get cleaned up really good. Bearings have not been removed yet, but will get discarded and replaced. Be careful and keep the two halves paired together. Crankshaft is near perfect. Hard to believe it has over 100K on it. Once I get my cylinder blocks back from LNE with the new pistons and rings, I will send this out along with them for balancing and polishing. Then I will finally be able to start with the assembly process! The cylinder heads were sent out a while back and I've received them back already. Will post some photos of those next.

I found this really interesting piece of plastic in the bottom nozzle of the oil sprayer in the middle of the 456 side. The oil feeds up into this hole and out the other side to the two sprayer holes. What is most interesting is that there was no wear/issues with cylinder 5. It also just fell right out, so it was not jammed in there. (You also can see the old thrust washers in the background there). Here is another photo of it. The worst part of this is that right after I took these photos I picked it up with a pair of pliers to put into a jar and it snapped out, forever gone. I felt really stupid, but another reason I'm glad I decided to go ahead and do this now. I carefully inspected all other areas of the engine and did not find anything else like this, so not really sure what it was or where it came from.

Was that a Fram oil filter I saw? Oh, the humanity ....

LOL - yes, it is, but that was a fresh filter I put that on after I drained out all the oil and removed the Bosch one that was there. I didn't want anything from the filter to drain back into the case after got it on the stand and turned it over.

This is the filter that was on there, and the one you want to use with the IMS adapter: Amazon Amazon

Closeup of piston from #4 cylinder And #6

Ok, thats going to be it for a while. I'm off to Mt Hood for a week of skiing and hopefully when I return my cylinders will be back and I can start the assembly process. I didn't document this as much as I had hoped to - tough to grab your phone and take photos when you are wearing nitrile gloves and covered in oil. For assembly though, this should be much cleaner so hopefully I can do a better job at that part. More to come in the next weeks...

Subscribed. Loiks good so far. Are you getting the crankshaft runout measured?

Yes, and thanks for the reminder on that. I actually did measure the axial play before I disassembled the crank carrier assembly, and will also do this after the sub-assembly is put back together. This is the tool I used (thanks again Harbor Freight). Mount it on the crank carrier, push the crankshaft all the way to the opposite direction of the flywheel and then zero the indicator. Then pull the crank outward and measure the distance. Mine measured at 0.052. Here is the excerpt from one of the workshop manual PDFs' I referenced earlier.

I hope you mean 0.052mm and not 0.052 in. That HF tool has an inch scale.

Correct, I converted it from the .002in reading to .052mm

Great post and smart move going ahead with the rebuild now and doing it yourself is a great way to get even more personal with the m96. Is scoring typically more prevalent on the 456 side, if so, why?

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More knowledgable will drop in, but I've read: yes 456 side more common and related to some increased forces on that side due to engine design. But, what do I know...just enough to be dangerous!

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The piston pins are offset in the factory pistons. It is theorized that the offset is not optimal on the bank 2 side since Porsche opted to use one piston for both sides, meaning one bank (2 in this case), doesn't have the correct offset. They did this on the Cayenne V8 as well and eventually came up with a piston that was specific for the Cayenne/Panamera that used bank specific offsets. In fact, the same piston is used between the six and eight cylinder engines.

Charles, when was this change made?

Great thread. Looking forward to more pics.

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very interesting, had no idea there were different piston pin offsets for bank 1 and 2. How much deviation in the offsets are we talking about, thousandths of a mm? Do you know if the 997.1 has the same issue as I believe borescoring is also quite prevalent on those engines.

Don't quote me on this, but I think 2012 or 2013 might have been the first year with different pin offsets that are bank specific - I think it was whatever year Porsche stopped using the VW 6 cylinder and came out with their own 6 cyl for the Panamera and Cayenne. I can't find my notes and the sample pistons I purchased from Porsche to see what differences they made from model to model are squirreled away somewhere I can't find them. I think the 9A1 piston has a .060" offset- again, those samples are hidden away somewhere.

Update It took much longer than I hoped, partly due to me being busy, and also because of a huge stupid mistake (more on that later), but I finally got my car back together and on the road this weekend. It runs unbelievably smooth and strong and I couldn't be happier with the result. Here is the first batch of updates detailing the assembly process. Head work The first thing to come back from being sent out were the heads, done by Len Hoffman of Hoffman Automotive. He did a fantastic job, pressure testing, new valves, guides, springs. I opted to have stage I port work done also. I can't believe how clean the heads came back - they look brand spanking new. Heads look amazing! Work done by Len Hoffman from Hoffman Automotive. Exhaust ports cleaned up Stage I port work New valves, springs, and guides.

The head took about 7 weeks to come back. The next step was to balance out the rotating assembly and I was hoping I could same some time and do it while waiting for the crankcase to come back from LNE. However I realized that the pistons, wrist pins, etc. were also needed and those would not get back to me until the crankcase was completed. So the hardest part of all this was the waiting for those parts to come back. Crankcase halves with new LNE nickie sleeves The crankcase took about 8 weeks to get back to me. I was dying waiting for it all to get back, but I was very happy with the result. LNE does some awesome work and their service was awesome. Big box arrives with crankcase Wow, that looks nice. The other side. One thing to note if you send out your crank like I did to LNE is to remove ALL parts from the crankcases. I removed everything EXCEPT the spacer sleeve (pic below) used to hold the AC compressor, as I thought it was pressed in and did not come out. When I got to that part of the assembly I realized I did not have that part and was stuck. Fortunately LNE was accommodating and sent me one that they had in their shop. AC Compressor sleeve on crank that I forgot to remove, and discovered only when I got to that part of the assembly.

Balancing the rotating assembly Now that all my parts were back it was time to send out the rotating assembly for balancing. As mentioned, this had to be done serially (after I got all the parts back), so I was in for another two week wait. I sent the parts to Performance Automotive Technology which is local to me. This guy did an awesome job. He is really meticulous and I has some good discussions with him about engine rebuilding and some of the unbelievably accurate machinery he has. He also has some really cool projects going on that he showed to me. Here are the parts I sent to him for balancing: 1. Crankshaft, bolts 2. Dual Mass Flywheel 3. Clutch pressure plate, friction disc, bolts 4. Piston rods 5. Pistons 6. Wrist pins 7. Rings He balanced everything out to .1 (1/10) of a gram! Pistons and rods balanced Comparison of original weight to new JE pistons. All pistons were set to 393.3g. You can see where the weight was removed on this one. Top comparison Bottom comparison Side comparison. The new pistons do not ust a stopper pin on the middle ring groove, and they also have grooves above the compression ring. Side comparison - look at the scoring on that original piston!

Ring gapping Next step is to gap the rings. I first put the crankcase halves and all parts into my upstairs playroom which has a nice temp control (crank cases are 45lbs each, so carrying them up to the third floor was good exercise). Cylinder halves placed into a room set at 72 degrees. Will come back tomorrow and do the ring gapping. Right on the money.

Before I checked the gap for each ring, I carefully inspected the ends of each ring for any burrs some magnifying glasses. I was amazed at the consistency and quality of the rings - there was not a single burr found. Ring square used to position ring in the cylinder for measurement. Ring square removed. Gap was measured at 0.020 All the ring gaps came in above the minimum of 0.015, and they were consistently around 0.020 thousandths. I could not believe this at first and had to go back and re-measure them twice. They all came out within .001 of each other. This was the case for both the compression and the oil rings. So no ring filing necessary!

Looking forward to watching your assembly! Thanks for documenting

Love the shinny parts. Is it a 3.6 or 3.8?

Wrist pin fun Next step is to pre-assemble the 1,2 and 3 piston assemblies. I wanted to get lots of practice getting those tricky wrist pins in, so I practiced on my old pistons first. It seems silly, but the hardest part I had was actually getting the clips into the tube and placed correctly. It took me about an hour of frustration before I figured out the easiest way for me to do it quickly and consistently. Also make note that these clips can un-spring and fly out of that tube very easily and end up anywhere, so do not do this near your engine if it is partially assembled! 1. Grease is crucial - put some assembly grease inside the tube 2. Press the clip into the tube vertically (clip gap pointing straight up) then rotate it horizontally until the entire thing is inside the tube diagonally. Keep the clip gap and tube gap aligned. 3. Use a flat-blade screwdriver to hold the gap side in the tube, and gently pry up the other side until it is horizontal 4. Clip aligned in tube and ready for insertion.

Next step is to place the rod into the tube. Mine has a screwed **** at the end allowing me to adjust the depth that the rod extends past the end of the tube. I did not take a picture of it, but the rod has a small notch at the end which accommodates the wrist clip and fits exactly inside the hole for the piston wrist pin. I adjusted the depth so that it extended just enough to push the clip out of the tube, into the piston hole right up to the depth of the wrist pin. Wrist clip insertion tool. The other end has a **** allowing me to adjust how far this end will extend beyond the tube, and into the hole where the wrist pin sits. Here you can see the pin inserted correctly into the piston. Looking closely at the hole you can see an outer bevel. The insertion tool fits perfectly into that bevel. Adjusting the **** controls how deep the rod extends beyond, and thus into the hole. I set it so that it will push the clip to the right depth right against the wrist pin and into the notch made for the wrist clip. It's hard to make out in that photo but the clip site perfectly in the notch, right against the wrist pin. I practiced this a few times and with a firm sharp shove on the **** the clip goes right in and sits perfectly.

Don't forget to clean your parts. Again. and. again......and again. Here is what the rod journals looked like after the first wipe down after coming back from balancing. I had already cleaned them previously in an ultrasonic cleaner.

After getting pistons 1,2 and 3 assembled with the rods I placed the bearings into the journals. The shop manual notes that it is important to orient the notches for the journals towards the bottom of the engine, so that they pick up lubrication. After inserting the bearings I drew arrows to point in the down direction to make sure I oriented them correctly later when I put them onto the crankshaft. Note the notches for the journals. Also note that with these forged cracked rods the two halves only align in one direction, so don't get them mixed up. (Actually not difficult to do because they are not actually flat, and when aligned correctly the two halves fit perfectly) Arrow drawn to indicate notches on the bottom half.

Notches for bearings. Bearing in upper half. Note how uneven the break in the two halves are - pretty easy to keep them aligned properly. And the bottom part with bearing installed.

I forgot to mention earlier that after I did the disassembly I got a 15L ultrasonic cleaner off eBay for cleaning the parts. That size worked but in retrospect I wish I had gone with the 20L model, which would have been large enough for all the parts (one at a time). For the carrier assembly for example I was able to clean the top and bottom a half at a time. First one end with about 1/4 sticking out, and then the other end with the now clean end sticking out. For cleaner I just used water and Dawn dish detergent, with temp at 45d C. Parts came out super clean! After that I patted then with a shop towel and then used my air compressor to blow out any remaining water. Next up - assembling the crankcase carrier assembly!

Crankcase carrier assembly Again cleaned the journals with acetone and Kim Wipes until they came perfectly clean. Bearing placed in bottom carrier. Crankshaft aligned for insertion. Crankshaft placed into bottom carrier. I did not take a photo because my hands were greasy, but don't forget to put lots of assembly grease on those bearings before placing the crankshaft. More grease applied and top half placed. End shot of two halves. I used ARP bolts for the carrier halves. They came with a neat diagram indicating the torquing sequence, and instructions on how to properly lubricate and torque them. Adding the ARP grease to the threads and underside of the bolt heads before assembling. Torqued the bolts according to the sequence, in three parts. 17, then 34 ft lbs initial. Then final torque to 50 ft lbs.

After torquing I gripped the crankshaft at the flywheel side and rotated it to see how it felt. It rotated smooth as silk, felt like it was being held by warm butter. Important note! I forgot to mention a rather important step above - mounting the thrust bearings in the bottom carrier. I did not take a photo of these, but they must be installed with the depressions facing outward. The mount right in the middle of the carrier on either side of the center journal. Again, add assembly grease before placing the crankshaft onto the carrier. Next step is to check the axial free play. Axial free play measurement. Push the crankshaft inward (here to the left), and then zero out the dial. Now push (pull) the crankshaft outwards and measure the free play. .0023in = .058mm. According to workshop manual: Crankshaft Endplay New Installation 0.05-0.24 mm Wear Limit 0.28 mm So all looks good.

That looks great, thanks for the thread

Assembly continued Next step was to attach the 4,5,6 piston rods to the crankshaft / carrier assembly, along with the IMS shaft. Again, ARP bolts used for the piston rods and remember to keep the bearing slots aligned towards the bottom. Remember to orient the piston rods in the right direction when attaching to the crankshaft. ARP bolts used again, greased and torqued to the right specs. Note that in this picture the bottom is actually currently facing to the back, so the bearing keys need to be facing up also (reverse of how it is showing in the photo). Rods attached and torqued, IMS shaft attached with new chain, guide and tensioner. Again, here you can see the 456 rods on the crank. The assembly is upside down, so the journal keys should be oriented up, towards the IMS shaft. This engine already had an IMS solution in place. I sent it back with my crankcase to LNE to have it refurbed and re-pinned.

Hi Space- great job on the build, thanks for documenting. Where did you get the specifications for building the bottom end?

Hi Coopduc. This was a rebuild of an M96/03 3.6L engine to a 3.8 LNE. I pulled together specs from a variety of places: 1. Bentley Workshop Manual 2. eBay DVD for Porsche 996 98-04 Workshop Manual 3. Online purchase of 2001-2006 996.2 Service Manual

Next step is to place the carrier assembly into the 123 side crankcase. That assembly is heavy so you'll want to use a lift to carefully lower it down. I of course did not have the Porsche special mounting tool, so I improvised, which worked great: Saved my head bolts from the teardown with some rope and used them to mount my special carrier tool. The carrier now sitting in the crankcase. Make sure to rotated and line up that IMS properly with the hole for the oil feed.

Now from underneath, use another one of those leftover head bolts and a socket to secure the carrier assembly. Use the original bolt on the far side (you can see it near the chain). This will secure the carrier in place so it may now be rotated.

Now that it is secured, you can turn it back facing up and insert the 1,2,3 pistons. Definitely want to use a tapered ring compressor for these, lube it up with assembly grease and the pistons slide right in (put some grease inside the cylinder also). I had already purchased one previously, but I also got one back along with my crank halves and other parts from LNE. Don't bother with one of the cheap band-style ones, you will waste your time and maybe even damage something. And don't forget to first clean the cylinder walls again with Kim Wipes and acetone.

Used a torque angle gauge on the piston rod bolts, again using ARP grease and tightened up to the proper specs. You can also see the pulley is mounted here finger tight so that I could rotate the crank while inserting the pistons and positioning them for tightening. I skipped some photos here of mating the top and bottom crank halves. This is the part where you have to apply a thin bead of Drei bond and then get it all together within 5 minutes. I got some help here because you have to make sure the chain come up through the top half, and the piston rods (sans pistons) fit up into the top crankcase. Note the KimWipes and rubber bands I used earlier to protect the cylinder walls for this step. Also make sure to lay everything out first, set your torque gauge, and open to the page showing the bolt tightening sequence (or memorize it). 5 minutes is actually a long time, but it seems like you are going to run out of time when you get to this step.

Nice pics. It's interesting your pistons are so much lighter than mine. Mine are ~401g each. Do you know how much your wrist pins weigh? Mine are ~89g each.

Out of sequence, but here is more cleaning of the piston journals prior to assembling the bearings in prep for insertion into the 123 side.

Hi Ahsai. I unfortunately did not think to weigh my wrist pins. I do recall holding both the old and the new and not feeling a significant difference though. The balancer did note that he was very impressed with the balance of the crankshaft as well as the consistency of the rod weights. They were within 1g of each other from the factory. He got them down to .1 gram.

Next step is to install the shaft sealing gasket. I used the 'special tool' that I found on this thread (I think from Ahsai - thanks!). Home depot 1 1/2" cap and a washer. Then use the pulley bolt to draw on the gasket. Don't use any oil or grease, and make sure to clean the engine surface with acetone again first. Also make sure no gasket material (drei bond) is in there.

^Oh yea, that's how I did it too. No worries about the weight. I was just curious if LN has changed the design of the pistons. Yours is definitely ~7g lighter than mine. My stock rods are within 0.6g of each other from the factory so it's pretty good but of course the more important part is balancing between the reciprocating mass and rotational mass.

4,5 6 Piston Attachment Time for the scary part, assembling the 4,5,6 pistons and attaching the wrist pins. I suggest doing a bit of practice first on the bench. The tool I had was a bit of a disappointment because the plastic wrist pin insertion rod did not fit. It was too big. However, it's not too difficult to get the wrist pin in there, you just have to work with it a bit. Tools I used for this. Note the endoscope I bought originally to verify the scoring that caused me to take on this crazy project. This is the wrist pin insertion rod. I had a hard time reading the markers on the pulley and used an erasable marker to number them. You can see it extending into the cylinder. You should be able to use this to insert it through the piston and into the rod as shown here. That lets you line them up for inserting the wrist pin. However, this rod does not fit into the piston. With some finagling I managed to get them to line up and get the wrist pins in.

This part did make me a little nervous, but I had practiced enough to get the feel of inserting those clips correctly and so felt confident about it. I did not take any pictures attaching the clips, but I did use my endoscope to verify proper insertion. First clip successfully inserted. 2 for 2 The last one was a piece of cake I was really paranoid about this part and I found the photos difficult to verify. So I used the endoscope to take video to make sure those clips were in right. https://www.youtube.com/watch?v=tbtR...ature=youtu.be I did this for all three but am only posting one here.

Is it normal to allow the rod to touch the bore? I thought it was bad to do that

To touch the cylinder? No. There is a thin layer of assembly grease on the wall and the rod is not riding up and down on it, just resting there.

Next step was to install the IMS Solution. I made two mistakes here that I had to correct. First one was I had slightly mis-aligned the slot with the hole where the oil feed goes. I had to drill out the hole a little to accommodate the nut. Second mistake (easily fixed), I noticed right after I took this photo. There is an elbow that goes on the oil adapter so the line does not feed directly onto it like in the photo. The elbow comes off at 90 degrees and tilted up so that the oil line fits more naturally. Turned the assembly upside down and installed the oil sumps back in the crankcase. This is the next special tool I created for dealing with the pulley bolt. I actually created this when I was removing it. Simple piece of 3/4 plywood and a four ft 2x4 attached with five 2" screws. The 2x4 sits on the ground and use a 5/16" bolt in the 3 holes. I measured and located the three holes to align with the holes in the pulley (use your high school bisecting skills with a protractor to get the holes exact). This worked really well and was much better than buying a $225 tool that would not get much use. The pulley bolt is a one-time stretch bolt, so you will need a new one for assembly.

I taped up all the holes to keep out any stray dirt, dust, etc. You may have noticed the 6mm sheet of plastic which I called my 'Car O.R'. I hung fit from the ceiling to floor and split my 2-car garage in two so I could use the other side. This side stayed closed for the entire 3 months. I mounted an air cleaner off ebay ( like this one ) to the ceiling and ran it 24x7 to ensure my work area was dust free. Re-attaching the other parts and its starting to look like an engine again! I actually spent a lot of time figuring out how to assemble the chain guides inside the crankcase correctly. I had missed taking photos of those during the dis-assembly, and it is not well-documented how those parts are assembled. For the 3.6L engine the parts are not symmetrical, and it is not obvious (at least was not to me) how they fit.

Cylinder head assembly Next up was attaching those shiny new cylinder heads. I did not take a photo of this, but the head gasket is installed between this and the crankcase. Don't forget to install the dowel pins in the crankcase first (like I did). More ARP bolts and nice diagram with torque specs and tightening sequence. Took a while applying the ARP grease to the bolt threads, washers, and underside of the bolts. Tightened in two equal steps of 30 and then 60 ft lbs. This is a photo of the mis-sized gasket that came with my gasket kit. When I got to this point I had to wait another week for the right gaskets to come in.

Both heads attached. Starting to look more like an engine. I got tired of fishing that chain out of the engine and used a rubber band and an old wrist pin to keep it from going back down into the block.

Cams, lifters and timing Time to assemble the cams and set the timing. This procedure is different for the 3.4 and 3.6 engines, and is pretty well documented in the Bentley manual. Start by locking the pulley at Cylinder 1 TDC. Input camshaft placed under chain with cam lobes near chain pointing inward (456 side). Notice how all cam lobes sit flat across all 6 lifters. The other one will do the same, the cam lobes near the chain also point inwards. Yep, I got to do this all over again after realizing that I missed the bolts in the middle of the lifter carrier. To get the second cam in, remove the sprocket and place the cam under the chain. Again, make sure the cam lobes near the chain point toward the inside. Now you can fit the sprocket onto the cam and on the chain. Attach the bolts finger tight to the sprocket. Align cam slots horizontally and attach the cam clamping tool. Nut in the middle only needs to be finger tight. Next attach the cam bearing clamps, finger tight on the screws. See here the orientation of the cam lobes near the chain that are pointing towards each other. When you do the 123 side its the cam lobes on the end AWAY from the chain, and they face outwards. Also note the screws I missed in the middle of the bearing carrier. It may have been Ok to add those at this point but I took it apart and re-did the whole process anyways. Only took about 10 mins. For the camshaft caps, E = Eintake (Intake) and A = Auspuf (Output/Exhaust). 1 is on the chain and 2 is in the middle. After the bearing caps are in, attach the chain guide bolts finger tight, then tighten the bearing caps and finally tighten the guide bolts. Then tighten the sprocket bolts and remove the cam clamping tool. Next step is to insert the chain tensioner back in. I didn't take a photo of this but the last step is to use the special tool (you need the actual one here - tool 9685, which you can find on eBay) that slides over the nut on the above left camshaft, and sits in the cutout on the right. It has a hole on the left side that holds the cam (thin hex bolt) and lets you torque that nut to 37 ft lb plus 110 deg. Timing is done. The 123 side is the same, the only difference is that the camshaft lobes AWAY from the chain point outward. (For 456 they are the lobes NEAR the chain). Again, those cams will fit perfectly flat across all six lifters when aligned properly.

I was still waiting for those gaskets to come in so I did the oil pan cover next. Thin line of drei bond and follow the tightening sequence. Those are a lot of bolts to tighten down in that 5 minute period so get everything ready before hand.

Another belly shot. You can now see the corrected oil line and barely make out the elbow (blue aluminum) going to the spin on adapter. Also forgot to mention that I did upgrade the hex billet oil drive bit in the oil pump when I re-assembled that. This was from LNE and I thought it was cheap insurance from that drive bit ever having an issue.

Spark plug gaskets came in, so finally putting the cam head covers on. More drei bond application. Careful to not apply too thick a bead, you don't want 'gasket seepage' into the crankcase, which could break off little pieces of gasket and might clog up oil galleys. Take note of orientation of the scavenge oil pumps on each side. There is a slot in the pump that aligns with the slot in the cylinder head. The other side I was able to dis-assemble and re-assemble after cleaning, but this side is new because I broke a screw while taking it apart. I probably didn't need to dis-assemble it but it gave me something to do while waiting for all my parts to come back in. 123 side done.

RMS Installation For this I could have assembled another special tool as others have done, but I've read a few posts about bad RMS installs and so I asked LNE if they had an install tool. I don't think it's something they do as normal course but they were awesome and offered to rent me the tool. It was well worth it and made the job really easy. Started by cleaning those surfaces again with acetone. The RMS has a PFTE surface so you don't want any grease or oil. Lay the tool down on top of the seal, leaving the plastic inner ring in place. You can see how the ring fits nicely onto the tool. Snug the ring up and seat it in the tool. Place it onto the crankshaft. Thread the middle bolt finger tight. Attach the housing, and finger tighten the screws. Slowly tighten the center bolt to draw it into the engine. You will feel a definite stop when it is done, does not need a lot of force. Don't remove it right away, leave it in place for 2 hours so the gasket can seat properly. Then remove it. This is a super-high quality tool and made this job really easy and foolproof. I'm glad I was able to use it and also glad that I did not have to buy it, I think it goes for over $600. Thank you LN Engineering for renting it to me!

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We continuous improve our designs as we get access to older parts that have been returned to us for freshening up. Likewise, new forgings and machining processes become available to us and we take advantage of them. In fact we are testing two new piston designs now.

Great thread! We're working to make rebuilding the M96 engine more DIY-friendly like offering more tool rentals and help through our new support ticketing system. We can't teach you how to build an engine, but threads like this help to show that with the right guidance and training, like classes from The Knowledge Gruppe, you don't need to be afraid of the M96 engine, and they can be built right without bankrupting you.

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Thanks Charles for the info amd that makes sense. Btw, I've put 8k miles on my LN 3.8 with IMSS now. It's running smooth and strong with no issues whatsoever.

This is some good stuff! Thanks for sharing.

Finishing tasks Almost done, few more assembly tasks before getting the engine back in. New Dual Mass Flywheel, clutch, pressure plate and throwout bearing. I thought I took a photo of the last 'special tool' but now can't find it. To torque up the flywheel to the crankshaft there is a Porsche special tool that holds the flywheel gears fixed. I didn't want to buy that tool so improvised by first threading some transmission bolts in and then threading some pressure plate bolts into the flywheel finger tight. I then got a piece of speaker wire and secured it to the pressure plate bolts and transmission bolts. Go around the flywheel and do this in several places (I used one continuous piece of wire) and it wont move, allowing the flywheel bolts to be torqued on. I originally had hoped to re-use the clutch and flywheel because the clutch only has 20K miles on it and shows very little wear, and the DMF was also in fairly good shape with no play in it. But I decided in the end to just replace them all so I wouldn't have to do this again for a long time. At the same time I upgraded to an EPS clutch with 30% more surface area .

Last thing was to re-attach the transmission. You can see the transmission jack I used for the rear half, and the engine is sitting on a dolly. Time to dock that engine back home. I used a floor jack under the front, right under the engine mount bracket, and simultaneously raised the transmission jack. I made some plumb bobs with bolts and string to help me line up the engine mounts before raising the engine back in.

I'm a day or two out from putting mine back in...Thanks for the inspiration! Great job too!

Exhaust upgrade My original cats needed to be replaced because on the 456 side the cat converter had separated inside and was rattling, plus it had gotten quite polluted with soot and oil from the scored cylinder. I really did not want to spend a fortune on replacing these so I first looked for some used ones. I finally decided to go with a new 200 cell SS X-Pipe on eBay and took a chance on it not causing CEL issues. At the same time I decided to replace my headers with some eBay SS headers . I know there is a lot of controversy over these but I kept my old ones just in case fitment or other issues came up. Lastly, to avoid any possibility of CELs due to the 200 cell cats I bought these mini cats . Sure looks pretty with those shiny exhaust pieces (I already had purchased the Fister Exhaust). When I was waiting for all my parts to come back I painted the sway bar yellow for fun. Fluid filling After finally getting the engine back in the next thing was to fill all the fluids: A. Power steering fluid: Pentosin CHF-11 B. Gasoline. After disassembly I had drained out all the gas from the fuel tank as I knew it would be sitting for a long time. This is pretty easy to do. Just locate and remove the fuel pump relay in the panel under the drivers footwell and jumper pins 30 and 87 with a wire. First attach a hose to the fuel line in the engine bay and put it into a gas can. Fuel pumps right out. C. Oil. I used 9 qts of Joe Gibbs HR5 break-in oil. D. Antifreeze. Make sure you use an airlift system airlift system to evacuate all the air and leave no pockets. I used 3 gallons of https://www.carpartsdiscount.com/coolant-antifreeze-1-gallon-pink-g40/porsche~boxster.html?3593=1300753&3671=1002&r=2&gclid=CjwKCAjwoMPcBRAWEiwAiAqZhygld6HXIfibfVjJzqB6V4heyIU3ZaD6hXgNgMLOCbmQu1-6SFlA7RoCJXwQAvD_BwE mixed with 3 gallons of distilled water. Engine startup Finally, the moment of truth! I had bought a http://www.durametric.com/buyus.aspx to be able to monitor and check everything. First, I turned on the ignition and waited 30 seconds. Then I turned the key to let the crank turn a few times to get some oil pressure up. Turned it off and then on again until it just started, then turned it off. Repeated this 4 more times. Then started it up. Problem #1 When the engine started I noticed right away that it was not idling smoothly. I let it run about 30 seconds to log info and then turned it off to see what was wrong. Durametric had logged several CELs. CEL P0300 Cylinder misfire CEL P0301 Cylinder 1 misfire CEL P0344 Camshaft position sensor It took me some time to figure out, but I realized that while re-installing the engine I had cracked the crank ventilation tube going from side B to side A, attaching to the AOS. This was was the original tube that I had not replaced, and had gotten brittle with age. It had a large crack in it on the 456 side, and I also found that it had become dis-lodged from the AOS. Sigh. The only way to replace that sucker was to remove the engine. Had to order a new hose and drop the engine again to replace it. Worst part of that was draining the antifreeze fluid. In retrospect I may have been able to get to it by just lowering the engine a few inches (which is possible without disconnecting everything). 2nd attempt Following Saturday I spent getting the engine back out and replacing the vent tube. I was able to get it out and back in on the same day, but it took me all day to do it. On Sunday it was time to start her up again. Problem remains Again, the engine started up and ran rough. It ran better than the first time, but was something was still not right. I logged some more data and turned if off again. I had a few thoughts: 1. Issue with the O2 sensors and not able to regular AF mixture properly 2. Issue with the coils (which I had not replaced) 3. Some issue with the new 200 cell exhaust system I had put in 4. Something I did wrong during assembly. Timing of bank 1 perhaps? The injectors were completely rebuilt back to specs by Witchhunter Performance so I felt confident it was not those. This had me really worried. I did not have a lot of experience with how to read Durametric values or understand how the DME worked. So I spent a lot of time googling on those CEL codes. Lots of threads on this forum relating to them, and I found this guys video which was extremely helpful in understanding how an ECU works: You Tube I suspected something wrong with my O2 sensors, so I hooked up the Durametric and logged these values. O2 sensor voltage ahead of Bank 1 - Blue O2 sensor voltage ahead of Bank 2 - Red Not good. You can see that Bank 2 switches up and down like it is supposed to but Bank 1 sensor is just all over the place. So first thing I did was replace the Bank1 pre-cat O2 sensor. Fired it up and tried again. No difference. Next thing was to replace the coil for Cylinder 1. I tried that and again, same thing. Now I was getting really worried. I then realized that the down header coming from cylinder 1 was cold, so obviously not firing. This could only mean no spark or no fuel. I pulled the plug and discovered that it was dry, indicating no fuel. Since I did not suspect the newly rebuilt injector, I thought it was a wiring issue to the injector. It was time to pull out the Bentley manual and start tracing the wiring. That Bentley manual is worth the money, I highly recommend getting it if you plan on working on this car. I was worried that the wiring harness had a break in it somewhere so I started to test continuity from the injector socket back to the round connector on the right side of the engine. As I traced through the wiring diagram I realized that the colors for the cylinder 1 injector wires did not match the diagram, which really confused me. I then checked the ones for cylinders 2 and 3. Those matched. It was then that I realized the really, really stupid mistake I had made. I had swapped the connections between the cylinder 1 injector and the changeover valve. After thinking a bit I then remembered being distracted during the time I had assembled those connections. Problem solved I put things back together again and started the engine and this time all was right with the world. The engine was running much smoother and this is what the O2 sensors now looked like: Time to get her on the road and break her in! Initial drive was about 150 miles along varying country and highway roads with hills and various load conditions, including engine braking and stints of steady and uneven RPMS, but keeping under 4K. I still have not yet reached the 500 mile mark, and plan to change over the oil to Joe Giggs HR10 at that point for the next 3K miles. The engine is running very smoothly and the torque is fantastic. No CELs or issues and I am so glad to be rid of that slapping sound. In the end this project was very rewarding being able to do a 100% teardown and rebuild. I also am happy I learned quite a lot about these engines as well as the fundamentals of engine management and diagnosing ECU issues. If I can do this then you can also. You just have to take your time and be able to read and follow instructions. I ended up spending more than I had wanted to on this rebuild. There are some parts that I might have re-used (clutch, some exhaust parts) if I really wanted to reduced the cost. You can look at the inventory list I posted at the beginning of this post to get an understanding of the parts you will need and costs you will incur.

Congrats on the successful rebuild! The extra torque and smoothness are what I love about the 3.8

Well done, sir! You give DIY home garage folks hope for the future...and lots of great study material. Cheers!

Congrats on success!

Same here...congratulations! Thanks for taking us along on the journey. Now go out and do some miles with smiles.

Wow congrats, now enjoy an awesome car

nice build..where did u buy all ur parts from? also ductile iron sleeves should not be a problem..honda,nissan, toyotas,subarus, go over 200k miles on iron liners on aluminum blocks.. somebody should make a book on m96/97 engine rebuilds..step by step

I started by using an online parts diagram like this one to get the OEM part numbers I needed. I listed all the parts I needed and put them into a spreadsheet so I could price shop them. You can google for that OEM part number and get a lot of listings. I was focused on keeping my rebuild costs down so I entered the lowest price I found, and then grouped them all by vendor. I tried to stick to OEM porsche parts but did not always. These vendors are the ones that I found had best prices on the various parts (often with big discrepancies between them): SonnenPorsche Warehouse33 AutohausAZ FCPEuro I also found a few parts on eBay and Amazon (muffler parts and I got a great deal on a new DMF).

I dropped mine as one unit, but would it be easier to mount the motor then tranny separate? I'm working solo with 2 floor jacks and jack stands.

I can�t imagine that doing them separately and mounting the tranny to the engine would be easier. Lifting them in as one unit is very straight forward.

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Thanks, that confirms my thinking as well. Sorry for the drift O n S...

I've heard that it can be done but I don't think I'd attempt it myself. Its easy enough to do together with a transmission jack and a floor jack. I used a floor jack cross beam which made it more stable and easier to lower and raise the engine: Floor Jack Cross Beam

Crossed 500 miles this weekend and changed the oil over to BR40 for the next 2500K. The car runs so smoothly and the power and torque are really intoxicating. I'm wondering if anyone that has done a 3.6 to 3.8 build has any idea of the HP and torque gains - rough numbers?

i read somewhere that torque is what really changes.. something like 10ftlbs per .1 liters.. so about 20ftlbs more.. also remenber most builds end up with better mods.. better exhaust or headers and the gt3 tb and ipd plenum.. so alot of the power u are gonna feel is from that.. the bigger displacement just amplifies it.. someday i would like a 4.0l build on my 3.6 if it ever blows..unless they make a dfi engine swap something easy for the 997.1

Congrats, I just finished putting 1000 km on my rebuilt 3.6l - 3.9l. Where are you feeling the extra torque and power? I am just now starting to break the 5000 rpm limit and finding the car seems to have way more hp at the top end seemed pretty normal below 4000 rpm. Also fuel consumption is 1l/100 km more when driving it to conserve fuel but seems to actually be better on fuel consumption when driving it harder.

Thanks. Probably more of a 'seat of the pants' thing or maybe because it is running so much more smoothly, but it seems to pull a lot stronger up to 4K. I haven't gone above that so can't yet on feel in the upper range.

I just bought my 04 C4S coupe last Friday and I've been going back through the pages of threads here on Rennlist. What an amazing job you did, just incredible. Dave

Thanks but I have to admit to standing on the shoulders of giants here on Rennlist. Many thanks to others before me when there was a lot less docs/information on how to do this. The good news is that this is not as daunting as it seems, and there are folks here on this forum that are willing to help out (including myself).

Update - I've passed the break-in period (3k miles) and I am so happy with the results. The torque between 4-6k is really intoxicating. I wish I had put this on a dyno before so that I can compare before and after. I'm considering doing a dyno in the spring just so I can get an idea of what the HP/torque numbers are: 3.6 to 3.8L Stage I porting when I had the heads rebuilt X-Pipe 200 cel cats eBay SS headers (sorry for the haters) Anyone have any idea of what should be expected for the 3.6 to 3.8 upgrade in terms of hp/torque?

This is an awesome thread, I saw you posted a link to it in another thread I am watching and I think this will really be helpful to him as I fear he is going to need to do this as well. I did read this whole thread but I dint see what you said the total cost was, do you mind sharing? Thanks

Sure, take a look at the first post in this thread - there is an attachment with the items broken down. I chose to replace many other items that I *could* have left (clutch, dual mass flywheel, etc.) which would have brought the cost down. I also added a new exhaust (x-pipe and SS headers). In short, I did not skimp, but I also did not splurge. All in this cost me around 15K

Great job, I love these threads. I did the chain guides and lifters on my 3.6. I would have loved to do a full rebuild but at 50k miles and no issues I didn't think it worth it. Hopefully others will get the confidence to undertake more DIY jobs on these great cars. PS. I am glad I wasn't the only one that didn't take good notes on the chain guides, when I disassembled mine it looked obvious......not so obvious when you come to reassemble!,

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Thanks, I didn't see the link but once you mentioned it i ent back and looked. Its amazing how those little numbers add up to one big *** number! Again great job, God I hope I never find myself in that position. You must have felt like a new man when completed. You probably learned a little about Porsche engines but a lot about yourself.

Update: Just went through 10K miles with no issues and have been now running up the engine to full power. The extra torque and pull is awesome, the engine really boots! I did remove the Fister D's that combined with the 200 cel X-Pipes were just a bit too loud for my taste (and my neighbors as well). With just the cross pipes there is a really nice sound that is louder than stock but not too loud. I couldn't be happier with the rebuild and would recommend this to anyone in this unfortunate situation. Also I'm fully on the Joe Gibbs oil change regimen (DT40) and plan to stick with that - (can't beat the price from LNE).

Impressive! What did your chain guide/wear pads look like?

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Good to read! Here's to many trouble free miles...

I wish I had taken photos of those. All the guides were showing wear for sure. The paddles had the least amount of wear, but had definite tracks in them. The pads on the cam heads were the worst, about half way through the material.

Update and bump. Went through 25K miles post-build and engine still running strong and trouble-free. Purrs like a kitten and revs smooth as butter. For anyone else in this situation - you can do it yourself if you are handy and can read instructions.

Wonderful follow up !! ( and great documentation of the DIY build !!)