My 1999 C4 coupe engine rebuild is starting

Hello everyone about 3 weeks ago I purchased a 99 C4 coupe with a dead 3.4 . It had spun two bearings . Pulled the engine out , tore it down and now ready to send it to LN . Hopefully in the next two weeks . The plan is to build a Stage II 3.8 street/track performer . The heads will go to Len Hoffman for him to perform his magic 😊. The car is black over grey and a 6 speed . After I get the car running I will purchase a GT3 front bumper , side skirts and maybe a ducktail for the rear . Right now the only pic I have is her on my car trailer which just doesn't do her justice . I also have an 02 Boxster S with a 3.6 Jake Raby R51 in it . That mid engine chassis with 282 whp is a blast to drive , I expect the C4 will be just as thrilling . I will update this post as I make progress but as some of you know it's a long process . Keep the shiny side up 😁 ​​​​​

Good luck great selections of Porsche cars

Which cylinders were the bearings spun, assuming rods ? Any story on the motor ? Did it seem like it was just run low on oil (lack of maint) ? How did the cams and cam bearings look ?

Pictures of the rebuild in process, please!

Welcome to the club! Looking forward to the rebuild and any insight you can share along the way.

The car has 149000 miles and the previous owner did track the car , that " may " have lead to the failure . The inside of the engine was very clean and cams looked great . The main bearing nearest the crank pulley and the rod bearing next to it were what spun .

A little bit about my Porsche ownership history 😊. It all started with a 1974 911S Targa . Then a 1987 944S . Next was a 1983 911 SC and then I built a GT clone of a 914 on a 1975 chassis with a 3.0 911 engine . All were fun and lead me to my current two car stable . I am retired from Lockheed Martin but have a PT job with a local P car shop . It helps feed the passion 😁

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Thanks - did it have a deep sump on it ?

Tell us about your cars set-up. Aos, sump, oil levels, oil and water cooling, brakes, tires, what track, air temp. What did you think caused the failure.

Did it look this bad ?

Awesome. Another true Porschephile sharing the best bits with us! Take a look at UDIS if you want to be sure you won�t have spun bearings due to aeration. And 3rd radiator to help mitigate against spin bearings due to temp. The fact this engine made it to 140,000 miles and was clean is likely a testament to previous owners taking good care of their cars and likely doing proper oil change intervals!

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No

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No clue I just bought the car three weeks ago . The car is stock other than it has a ROW M030 suspension with Bilstein inserts . It has the 18" BBS two piece wheels I believe they are called Classics ?

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Thanks, good info. Have fun on the rebuild and hope to follow along.

No deep sump and probably Oem aos as well.

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Correct on both

Check with Charles at Engineering concerning 101mm bore in 3.4 case. IIRC there could be an issue within cylinder heads when going to that large bore.

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No issues Jake has built tons of 3.8 out of the 3.4 block . I discussed my build with Charles at LN this is quite routine for them . But thanks for the feedback .

I went back through some old threads, going to 3.8 in a 3.4 requires custom head gaskets and then recommend forged rods due to the amount of displacement increase. Hope this helps.

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This is true. I have one of those 3.4 → 3.8 FSI builds.

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Yep . I am ordering the correct head gaskets from LN along with their K1 forged rods . I appreciate all constructive feedback/comments .

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Just curious when was yours built ? What are your overall thoughts about the results of the build ? Do you remember what your HP and torque numbers were ?

Yesterday I dropped off the heads to Len Hoffman's shop . So another small step forward . He will clean and inspect the heads and then we will discuss the options .

This morning I ordered the FVD Brombacher X pipe for my exhaust renovation . Going to use stock headers , the x pipe and stock mufflers with a DIY version of the Fister mod .

Small update my FVD Brombacher X pipe was delivered today . I must say it is a piece of automotive art ! Unfortunately won't get to use it for quite a while but one more part checked off the list.

Small update: my block is at LN and has passed inspection so that is moving forward . Len Hoffman told me no issues with my heads so that's moving forward also . Today I dropped off my OEM headers and an exhaust bracket to a local powder coater . Never used this guy but talking to him he knows his stuff . He will bead blast then apply a silver Cerakote high heat finish . They should be ready to pick up next week . I may have him do some additional parts will see what the headers look like . I will post a pic when I get them back .

Welcome, and thank you for sharing. Looking forward to following this build. I had to re-fresh the bottom end in my 3.4 car last year, caught it very early on- number 6 rod bearing starting to show wear. Liners were in good condition, no scoring good compression- however my car was only at about 68k miles at the time. Kudos to your 3.8 build.

Another progress update - this morning I picked up my headers and an exhaust bracket that I had high temp Cerakote finished locally . They came out good . Also found out this morning that LN Engineering is done machining my block and it's shipping to the plater this week . All good stuff 😁

Awesome so far. interested in the 3.4 to 3.8 conversion. love to see how well it performs. Do they have to change the crank to get the displacement? (I understand that the 3.8 had a longer stroke)

^^^ No they use the stock crank . So the displacement increase is via the bore . I have driven many 3.8 996's so I know what she will do . With 350-360 HP at the crank or more with a solid linear torque curve it will perform quite well . And that is with stock camshafts but with reworked heads. And other mods I can't talk about 😋

Small update : today I received the price quote from Len Hoffman for the rework of the heads . Between the larger valves and his porting work he says there will be a 14% increase in flow . That should make some good overall performance . Also heard from LN Engineering my block should ship around 4/15 from the plater back to LN . The balance of internal parts from LN along with my block should ship by the end of April . It's all slowly coming together 😁

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How much is the quote as I'm planning on having him do the same?

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Sorry I am not willing to share the price . I am getting special pricing for a variety of reasons .

Woohoo yesterday my block and internal parts arrived from LN . So now I have to get pistons/rods balanced that will happen the end of this month . Len said my heads will be ready to pick up end of next week . It's all coming together . The guy building my engine will be ready the middle of June . My goal is to get it back in the car in July and break it in . Then Dyno tune and enjoy 😁

Another step forward happens today , I will be driving to Len Hoffman's shop this morning to pick up my heads ! 🙂 . The heads are the last of the " big items " needed before the build can start . Next week the rods/pistons get balanced and then my engine builder buddy starts the build mid June .

Today I had a friend balance the rods and pistons . Only had to take 2/10 of a gram off one piston so very happy with the Mahle Motorsport pistons . The Carrillo rods were perfect out of the box . So basically I am done with all the hard stuff now onto assembly . My mechanic friend that is building the engine will be ready mid June . Can't wait to see the completed engine 😁

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Is this pretty common, to have so many cooks do a rebuild? I'm hoping not to ever need a rebuild but if it does, can't I just buy an engine and have my Indy install it? I know there are not racks of completed engines, like at the grocery store, but can you just have the pistons and rods, polishing and blueprinting all done by one person or shop? Is the reason you are having this done because that's how to get the best result? For an average Joe, all this is not needed right? I'm thinking of just buying a rebuild off of eBay and bolting it in. Won't that work? Thank you.

^^^ It depends on what you want . In my case I wanted to eliminate all the known weaknesses of the 996 engine AND I wanted more performance . So to achieve that the block went to LN and the heads to Len Hoffman . And by balancing parts like crankshaft/flywheel/pressure plate/rods/pistons to race spec you get a very smooth rotating mass . Yes you can purchase a used engine or new short block if that's what you want to do . My dad instilled in me the mantra " do it right or not at all " . I stick to that advice as much as possible it never lets me down .

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if you plan on tracking it or just like buff horses, sounds reasonable. It's only money. As long as our other responsibilities and what not are taken care of, hell, a man needs a hobby. I'm kind of the same mind, but perhaps a bit more budget limited. I could have bought a later model but to me the newer the 911 the less they remind me of the car I dreamed of as a youth. So much more fun sometimes to refurb and renew and make it your own for sure. Enjoy!

Finally the day has come ! All parts are in hand and the guy building my engine is now ready . Tomorrow morning I will deliver everything to the builder and will wait to hear on progress and completion . My original goal of making it go vroom 😁 in July is still a possibility . For those of you that have gone down this path you know how much planning and research is needed . I am very happy to be at this point . Next milestone will be the install . Then the initial firing up and break in miles . Then Dyno and fine tuning . Can't wait 😋

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I've had my FSI Stage I for close to a year now and one of the extras offered, and gladly taken, was Race Level Dynamic Balancing Tolerances, set to .2 Oz/In. from .5 Oz/In. My '99 C4 Cab just purrs and runs like a skalded cat when needed.

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Mine is headed to FSI any day now for a Stage II build. I opted for the race level balancing too. I chose every Stage II option because I didn�t want any regrets. I still wonder if I should have gone with an R build, but I�m pretty happy with my choices.

Dropped everything off at the builder this morning . He says if no surprises it may be done by next weekend ! Oh boy getting closer 😋

Woohoo I received a text last night from the engine builder , all he has left to do is install the intake manifold and dress out the wiring harness . I will be picking it up around 1:00 today . I have to admit I had a hard time sleeping last night 😋 . I will snap a pic of the mummy shrink wrapped monster 😁

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Excited for you! Don't know how much you would be willing to share after its completed, but would love to see a flow chart of decisions/steps you went thru as you pieced the parts and procedures together that you needed to do before handing everything over to your engine builder.

^^^ It's not a very exciting story 😁 . For the last 4+ years I have worked PT at FSI as a test driver . So when I am not driving I am learning the ins and outs of the builds . So in a nutshell here is the path I took . 1. Engine block and IMS shaft sent to LN Engineering for the Nicky cylinders and other voodoo they do 😋 2. LN also supplied all gaskets and bearings/pistons/rods . Basically all internals . 3. When I received all the bearings they were sent out to a specialist for thermal coatings. 4. Because of proximity I then drove my heads to Len Hoffman's shop in Watkinsville Georgia. He did a complete " big valve " restoration and performance porting . 5. Once everything was back in my hands I delivered everything to the engine builder . I did some additional stuff like IPD plenum/GT3 throttle body. Went with larger 24 lb per hour injectors. Had OEM headers coated inside and out with Cerakote . Also purchased a catless x-pipe from FVD Brombacher . Will run stock mufflers for now I may change those at some point . That's how I got here. Obviously working at FSI is a HUGE advantage. Having Jake just a text away for advice is priceless . His knowledge base on these engines is truly amazing . Next step obviously is to mate engine/transmission and get it installed .

Picked up the engine this afternoon , here are a few mummy teaser pics . Heading to the shop tomorrow to offload the engine there until I can get some help for the install . Overall today was a great day . More pics to follow as I make progress .

Mummy motor.

The mummy shows it's pretty face 😋

Today I did some prep work before engine install . Pulled the front bumper and cleaned a LOT of debris between the condensers and the radiators . Then I installed a 3rd radiator to help keep her cool . Then I pumped out about 12 gallons of old fuel and installed a new fuel filter . Will be adding Seafoam then top off with fresh fuel . I am hoping to install the engine in the next two weeks .

Engine/transmission going in this afternoon . Yesterday we mated the transmission to the engine and took care of some ancillary items . Added an underdrive pulley while access was easy . Installed a UAOS a friend of mine had on hand but he only had the box . I was able to fab up the various hoses and modified/sealed a new AOS . Made it a gravity drain into the oil filler neck . Happy with how it looks . So it will be a late evening of work today but well worth the effort . May not fire her up until tomorrow we will just have to see how it goes . It's been a long journey and I am ready for the next phase 😁

The timeline of your rebuild has been very similar to mine. However, I�ve been stuck for over a month waiting for ARP hardware. Being told maybe September... We�re you able to source them from somewhere or go back together with OEM? Thanks!

^^^ I was able to get mine from LN , I think I was just lucky .

At approximately 8:30 tonight the Porsche sprang to life with it's new DNA running through it's veins 😁. All went as expected but did have an initial scare with oil pressure . But the tried and true bang your fist on the dash made the oil pressure gauge spring to life 😋. Engine sounds great and strong . I have a quick video but open headers don't do her justice . I have a few pics to post but I will be busy the next few days . Hope to drive her this weekend.

Here is a short video of the initial start up . Open headers so kind of wonky sounding 😋 https://drive.google.com/file/d/1K8H...w?usp=drivesdk

Awesome - congrats on getting it completed. Looks like your video requires an approval. You may want to make it public in the settings.

I " think " I corrected the access issue . I am not very tech savvy 😋

Sure did. It sounds great!

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Great . And thank you it has been a lot of work .

Drove her about 40 miles today and slowly working out small issues . Electronics don't like sitting idle for 1 1/2 years but they are all starting to wake up . I am driving without the front bumper as I wanted to make sure the 3rd radiator I added wasn't leaking . So far everything is dry . She looks like a mad max car 😁 .

Thought I would update . So I have 215 miles on the car with no issues . Front bumper is installed and she's running cool . Next Wednesday we will strap her to the chassis dyno and see what she can do . So far the only check engine light is for the SAI . I eliminated it and that will be turned off electronically next week . Looking forward to see what she can do .

Plans have changed , going on the dyno Monday . Might be hard to sleep well Sunday night 😁

Just did the first baseline dyno pulls, did two pulls and have 304.92 HP and 282.30 tq at the wheels . Running rich up top so there is more in her . Will start tuning tomorrow morning when air is cooler . Will finish her up tomorrow and report final results .

Final numbers are in , made 318 HP and 290 lb ft of torque at the wheels . Pulls very strong and sounds good . Sprung a leak on a brake hardline ☹️ so repairing that at the moment . Overall I am very happy , Jake says 388 HP at the crank which is very respectable . Hope my small journey has been helpful . Probably going to be away from the forum for a while , going to go enjoy this bad boy 😋

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Impressive numbers. Can you post the curves? I am curious on what the graphs look like. With 14% improvement in flow at the heads you must have gone with Lens stage 2 package?

This morning did one final tweek to get rid of a bobble from 2000-2200 rpm . Now she's smooth as silk from idle to 7300 . You can feel the Vario Cam kick in and she presses you back into the seat . She is a blast to drive . Now I will start the visual restoration she needs a good clay bar session along with some minor paint touch up . A Singer style mini ducktail is coming tomorrow via the brown truck . Next will be some sort of front spoiler lip . Fun times . Here are some pics of the " black beotch " .

Awesome!!

Looks good! Polish the headlights and it will look 100% better!

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Polishing the headlights is on the to do list. The pics make them look better than they really are . They are quite faded . But Porsche used very high quality lexan and they will look like new when done . But the interior lenses are burned on both so will probably convert to bi-xenon. Thanks for the feedback .

Update: car has been running great with no issues . On Thursday I met Jake at the shop he sold me a used LN 2 quart extended sump with X51 baffles . I am cleaning it up then will drill and tap for an oil temp sensor . I am getting close to the next oil change so will do it all together . Happy 4th of July