Hardback

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.

Barn996

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

Byprodriver

Excellant decision! Time to upgrade!

Joe Lapin

My condolences.

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

logray

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?

Hardback

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.

Flat6 Innovations

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.

Hardback

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.

jyoteen

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.

Hardback

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?

philooo

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.

Hardback

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.

Chaos

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

Flat6 Innovations

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.

logray

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