C4S Engine re-build and upgrade to 3.8L

Well, I had a valve seat destroy cylinder # 5 in my engine a few weeks back. I was driving casually and only in 1st gear when it happened. Pulled over when I lost power and cut the engine off. Wasn't sure what happened so I tried to re-start and heard the deadly mechanical clanking and immediately turned the key off.... Had the car flat bedded to my indy and waited to hear from them with their diagnosis. First I was told I had a possible conncecting rod failure as inspection from sump and oil filter seemed to show some metal shavings consistent with a rod. Well, this assumption was not the cause. Once we had the engine dismantled we uncovered the real culprit. Valve seat, as I mentioned above... So my # 5 cylinder was left with a crack / D chunk type failure see pics below and a damaged head on the 4-6 side. So I am left with an expensive re-build..... or replacement. I for 1 prefer to re-build an know what I have once the $ has been spent. In addition, I usually upgrade parts that fail on my machines. Fast forward 2 weeks.... Ive done a lot of research and made the decision to re-build and upgrade as I go. Hello 3.8 Nickies! The list of parts include but are not limited to: main bearings rod bearings all gaskets water pump 997 version coolant expansion tank air/oil separator drive belt LN deep sump kit LN chain tensioner LN low temp thermostat LN IMS triple row bearing upgrade LN Nickies 3.8 cylinder upgrade with forged JE pistons ARP rod bolts donor cylinder head Cleaning, machining, balancing of crankshaft assembly etc. etc. etc. For what its worth, I will contiune to update this thread as the process continues. I'm looking forward to learning a lot along the way.

Oh my, too bad. Keep us posted with pics and progress on your engine rebuild.

Excellant decision! Time to upgrade!

My condolences. I'm sure the rebuilt engine will be superb. Just like the PRESENT condition of your wallet!

Congrats on making the right decision! Keep the pics coming. Don't forget LNE billet IMS paddle, and if you can sport another $1500 for better rods. Who is doing the rebuild?

Logray, R&R rods may be included at some point.. All depends on hidden costs along the way. More pics to come. Local Indy is performing the rebuild. TuneRS they've worked with LN upgrades on numerous occasions. We are still in early stage. Case halves being sent off next week.

Change ALL those valve seats... Why? Because you'll find that the majority of them have less than one thousandth of crush holding them into the heads. This is a common issue with the 3.6 engines and it can recur if the seats are not removed and replaced with the proper interference fit. A few weeks ago I released this tech bulletin in one of our newsletters and had 3 emails from others that had the issue in the recent past.

Thanks Jake, they are on the list as well. Funny I have not heard more of this issue till it was too late. We appreciate all of your informative posts.

Wow. You were a tad bit unlucky....I had a valve seat break apart but I was lucky enough not to be driving (just idling) and I just turned the engine off very, very quickly. I've heard that rattle before on my VW which was a spun rod, so I wasn't going to wait any more than getting my hand to the key to kill it. I had all the valve seats replaced as well. And while I was in there and the really expensive stuff didn't happen, I had everything replaced (chain guides, gaskets, pumps, hoses, etc, etc.....tab came out to $10k; also had some extrude honing/machining done) Do you track your car often? I wonder what is the cause. The picture looks a lot worse than it was. Couple of nicks on the top but no scoring of the cylinder walls and the compression was still good.

Jyoteen, I track the car as often as possible! 10-12 events a year... Some multiple day events... I'm missing an event right as I'm typing this! Oh well, once the rebuild is complete I'll Be back and ready to battle. Looks like a similar situation as mine although no real cylinder damage. The chunked cylinder on mine forces me to upgrade but I might of elected to do the 3.8 either way. I need to do some searching here to find reviews on the upgrade. Anyone driving a 3.8?

it is scary to see how a few seconds of mishaps can break the engine. At least it seems you are in good hands with TunerRS, I need to go check them out. Did you get an idea of cost to rebuild so far ? I assume the important number is the price for a replacement engine, what number did you find out ? Looking forward to see you soon back on track.

Yeah Phil, I was hesitant to make this post as I do not wish to spread any fears of engine failures. The engine was strong and reliable with no signs of this pending valve seat issue. I suppose all the miles at the track took it's toll on my 10 year old motor. I had 69,000 miles and 20+ events since I bought it 2 years ago. I'm grateful the damage wasn't bad enough that I couldn't repair it. But, to answer your question it's going to cost well over $10,000 to fix. I had to buy a donor head since the valve seat smashed it up pretty good and that's when I lost compression. Porsche charges $4100 per head! I located one for $700 in really good condition. That is the only used part that will be used in the rebuild. All original parts will be ultrasonically cleaned, tested, balanced etc. When we are done I will have a new motor with all the LN updates included. Oh, did I mention it will be a 3.8?!!! I went to the shop yesterday to BS with the guys and saw the motor in pieces neatly stored on a it's own shelf unit. I took the ims bearing since LN is making a triple row assembly for me. The old bearing is in perfect condition, no play or wear whatsoever. Hardly a consolation at this point but I needed the distraction. So Phil, how was the event yesterday? Remo was there and drove in the intermediates for the first time. He said it was a bit competitive? Can't be nearly as dicey as the NASA 3-4 group we drove! How were the Toyos? They had to improve your times by 4 seconds or so.

I would put a V8 in it,recent write up in Grassroots

Valve seat failures are always silent.. With the 1/2 of one thousandth of interference fit that we see with the 3.6 heads its a wonder that more haven't failed sooner. We documented this mode of failure in 2009, but didn't see another case of it till this year when we had 3 of these cases.

Jake, have you seen this on a 3.4L head?

No, this is a 3.6 issue only. We have also seen it in the late Boxster heads from 2008 that utilize 3.6 valve sizes on the 3.4 engine with 3.6 head castings.

Thank you! Good to know.

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Argh that damn session at NASA that I did not record on tape... anyways, the weekend was good, with the Toyo88 I did shave 5 seconds off my time, 1.44 from 1.50, I'll post the video soon. Unfortunately in the intermediate group too many newbies who were not giving point by, but I found my way around Keep us posted on the rebuild, the car will be awesome when you are done.

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5 seconds eh? Thats a hell of an improvement. Looking forward to the track videos... Intermediate is a strange group. You have some rather quick guys out there with some experience and then you have others who are clueless. If you register for the Chin events you should be in the intermediate solo group. No newbs in that group for sure.

Did you look into sending your engine to Flat6 innovation to do the work ? I assume shipping is a killer but as they do that kind of work all the time, they might be faster and charge less hours in the end.

If you can wait until next summer...

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I have a couple of slots open immediately as one of our Grand Am racers decided not to build a pair of new race engines for 2012.. I haven't advertised the slots yet, so you better act quick :-)

These threads make me want to work for some extra cash to pay for a pro-active rebuild at flat6.

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Lots of people do this... We always have done more scheduled reconstruction work than repair work.

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Im aware of Flat6's great reputation but I am confident my local shop can rebuild the motor. Jake thanks for your offer also. If I was closer to you I would have towed the car over initially. In order to inspect all the parts to give an accurate quote on the rebuild the engine needed to be disassembled. I already have numerous hours into the job so far as a result. The case halves were sent to LN this week so in the meantime all good parts will be prepped and replacement parts are arriving already. LN has given me a turnaround time on the cylinder work of 6-8 weeks. Lets hope its closer to 6. Jake, what kind of gains have you seen in torque/HP for the 3.8 upgrade? Rev characteristics any different with the lighter weight forged pistons? My indy wants me to go to a lightweight flywheel but I dont want to hear any chatter and LN doesnt recommend them. Im not sure what the explanation is...? Ive searched the forum and havnt found an actual review. I will start a new thread once the car is done to give my impressions but Im really curious what your experience has been?

No problem.. I totally understand.. Even if we could build them all, I wouldn't want to. I have no idea what the builder of the engine will be doing to compliment the bore size/ displacement increases so I would be unable to throw any numbers out at you. With no rule book to follow and literally thousands of ways to design an engine package the results can vary widely. We never just increase the bore size with our builds, I work to compliment the difference in swept volume with cam timing alterations, CR increases and cylinder head work. Just the difference in the valve job and intake tract work under the seat can add a 15% new port flow with the 3.6 cylinder heads. Our engines don't just make more power, they also have instantaneous throttle response and make big torque, both of which I value more than a big peak HP number that LOOKS impressive on paper. I'll run down to the lab in a bit and see if I can grab some dyno graphs to put that into perspective. Please do not install a LWFW. We absolutely refuse to unless employing our billet crankshaft into a reconstruction. LN gave you very good information. Above all else your build should be focused on longevity.

Thanks for your response. I told him I wasnt interested. I drive the car daily and track it at least once a month and even if it was recommended I wouldnt install in on a street car. Also, I cant take irregular noises... rattles are unacceptable for me. Torque gain and increased throttle response would be terrific. The original setup was a bit too lazy for my taste. After spending the $ to re-cylinder and replace all wear items i hope to be left with a reliable package. I plan on keeping the car for a few more years until I can justify/afford a 997 GT3.

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Jake's project.. https://rennlist.com/forums/7559852-post19.html

Yeah I sent a PM last week to see if he could comment but no answer yet...

Lon is a busy guy and he doesn't often frequent forums. He has had our engine for over two years now. I have a list of folks that have our engines all over the country who have volunteered to chat with others.

Carey, I did get what I thought was your PM, and replied, but sonething didnt seem right so I must have screwed it up. Anyhow, the 3.8 Jake built is a wonder! People comment on the sound and often ask if its a turbo after they get a ride. Jake is correct, the torque makes the motor. Once up on the VCam, the thing keeps pulling all the way to red line and does not run out of breath in any gear. I've hit 154 on the main straight at Brainerd in 5th gear and its still pulling. Keep in mind that it is also a X51 and Jake had extra head work done and the ecu has been massaged by Protomotive. Not much I can't keep up with except modern turbos, cup cars, and GT3 RS's. In short, I can't reccommend his work enough!

No problem... Sounds like you've been having fun... Brainerd is a great track. I've watched numerous superbike races there over the years. Can't wait to get the car back on track with a fresh motor. Thanks for the follow up.

Anxious to see how this works out. My '02 3.6L C4S has been burning oil and just doesn't exhilarate like I think it should. Been eyeing the 3.8 upgrade. I'd like to see those dynos mentioned earlier...

Im still waiting on the engine cases to be returned from LN. My mechanic has a dyno shop next door. Once the motor is broken in Ill post up the dyno numbers. Hoping to be back on the road by mid February.

Carey, I Just brought a 2002 C4 Cab with the LN 3.8 engine. Let me tell you, I test drove 3.4's and 3.6's when I was looking to get a 996. All I can say is WOW. This thing is, hands down, faster than my 930. Tons of torque and power. The history on the 2002 C4 Cab, was the typical IM bearing, and the case was sent out to LN and the case was done by them and the customer wanted to bump it up to a 3.8 and they used the Nikasil and JE kit that they sell. I wish you could take my car out for a spin and you will see that you did the best thing by picking out that kit. DO NOT GET A ALUM FLYWHEEL!!!! My car has it and it has a new clutch. So it will have it for a while, due to the fact that I am not going to pay to replace it. The reason I would like to replace it, is it rattles like crazy. At a light, with the clutch out, sounds like my throw out bearing is going to fall out. Below 2000 rpm makes a terrible rattle. My 930 does the same with the Alum flywheel. Price you pay for quick response. Anyway. When you get it, brake it in slow. LN will give you instructions. Good luck and ENJOY. Robert

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On the contrary. The engine will thank you for not being nice to it. Don't baby it !!!!! The correct way to break it in is on a dyno... basically first startup is to get oil pressure quickly and hold higher than idle rpms for 15 or so min. Then the torture begins... including many near red line accelerations, allowing the engine to do the braking and not the dyno. Read through these for proper break in procedures: http://www.lnengineering.com/oil.html (search break in) http://www.lnengineering.com/support.html (section on break in) http://www.mototuneusa.com/break_in_secrets.htm http://www.aircooled.net/gnrlsite/re...s/engnbrkn.htm I'm almost to this point with my Nickies build !!!!

Im just going on what I was told 2 years ago on my 930 rebuild. This car had 8000 on the ln rebuild when I got it. The Ln paperwork/receipt stated brake in oil be changed in 500 miles. So i guessed it was a nice 500 miles. LOL.

Thanks guys, if you knew me you would know ive never babied anything that contains a motor. I rode superbikes for the first half of my life and only graduated to Porsche in last couple years. That being said, I plan to follow any directions given by LN as this build is quite costly and i expect to reap the rewards for being patient and rebuilding this motor the right way. oocb2, glad to hear first hand experience with the 3.8. I cant wait to aggravate some people at the track.The lightweight flywheel was never an option for me. Ive been advised against it by LN and Jake. I drive the car daily and even though there are some performance gains I couldnt listen to the chatter. logray, ive been following your build and cant wait to hear your impressions once your done. I think I speak for most here when I say we are quite impressed with your skill, accuracy and patience while you rebuild your own motor. The threads you've created should be archived here for others to read in my opinion.

If you have new lifters and new cams, as well as other new head hardware, if I remember right you should replace oil after first fire. If less new hardware in the heads, top off oil and change the filter after first fire, then change oil and filter again at 200 miles to non-synth mcycle oil. Don't switch to synthetic after at least 1k miles. You should read through all of those links though, there really is a wealth of great information. Or at least make sure you have an understanding with your engine builder as to what procedures they will be using if they are doing the initial firing and break in (and they should be using the recommended procedures). Once it's broken in, it's broken in. If you take er easy after that, well then that's just your driving style! :P

So one question is "Does Porsche use a non-synthetic oil for break-in at the factory?" My guess is that they fill up the engines with Mobil 1 0W40 on assembly and that is what is in the engine until the first oil change. And the manual that came with my car shows the first oil change at 15,000 miles! OUCH!! I think the LN procedures and the other write ups are probably great, but I am thinking that none of the factory engines had anything close. I also get a kick out the the oil recommendations in the manual. Temp Mineral Synthetic 50F+ 15W40 10W40 20W50 15W40 20W40 15W50 50F- 15W40 10W40 10W40 10W30 10W30 5W30 14F- 10W30 N/A 5W30 So no 0W40 at all, and listings for mineral and synthetic. And it goes on to say 10W40 or higher unless mostly below 32F then 5W30. There were TSB's after that date of my manual that had other listings including 0W40, but not in the manual. Interesting?

Sorry the formatting above is a little screwed up, cannot use tabs.

Doug as I remember watching the factory tour they do at least have every car on a rolling dyno and brought engine at redline before driving off. But as far as what oil they use, the only thing we have to go off of is I remember Jake saying he was dismantling a fresh crate engine, and it was not pretty...

Carey, I recently had my '03 C2's engine rebuilt by Jake and his guys at Flat 6. I live in Coconut Creek, not far from Tune RS. It looks like we do some of the same track events. It would be great to compare notes with you once you are back on the road. Best of luck with the rebuild.

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Thanks pal... I was at TuneRS yesterday and Taylor tells me he will have the cases back in a couple weeks. Im getting closer... Introduce yourself if you see me at the track. If all goes well I should be at Homestead with Chin at the end of Feb.

Sounds good. I'm signed up as an instructor on the Saturday of that Chin event. Chin Sebring on 12/5 was to have been my first track day with new motor but it rained on and off all day and I only got about 10 hot laps. Some guy in a Lexus lost it on the paint at start / finish, spun 75 yards before it hooked up at a 90 degree angle and went straight into the retaining wall (destroying about 10' of it) , went up in the air, landed back on the track spinning another 100 yards before again going into the wall nose first. Guy was ok, car was trashed. HOD at PBIR is next. See you at HMS.

Wet paint..... That mustve been pretty ugly... HMS has some issues with sheets of water running off the track in areas.