DSOMC6

That just sux!

Pull the valley cover off. That should give you a quick view as to what's going on.

C7&7

Yeah. I think just taking the intake manifold off would give a good look at the valves as well.

JUIC3D

Damn Sean, really sorry to hear that. I hope everything turns out ok, but by the looks of those valves...

taken19

Yeah, it sucks but I told my wife I bought this car to break it. I drove the **** out of it the past two weekends. A ran a 1:47 lap at homestead on heat cycled tires that don't have much life left in them. I've taken about 5 seconds off my lap times in the past few weeks.

This was inevitable, just hoping it would have happened later than this. Only got about a year (7 track days) out of this head and cam setup. Already looking into a dry sump LS3...

taken19

I will do that next and post pics.

JUIC3D

Grand sport drysump or ARE/Airaid(however you spell it)?

I'm honestly surprised to hear of the motor letting go so soon-that doesn't inspire confidence in my own, but I don't put quite the same amount of stress on it that you do.

I'm glad to see your attitude is on the up and up though--this is a good excuse to build it bigger stronger and faster

JUIC3D

I can't see Hinson or anyone footing the bill for a new motor. I know the C5R is a tough chain, but I don't think it comes with any guarantee

66biskwik

Especially if it hapened at the track. Like any other race parts, warranty is up when you close the hood.

1fastbob

Not to wish the OP any bad luck.....but.....I'll bet you have cracked pistons as well as the bent valves you already know about. The problem either was broken timing chain, broken camshaft or loose or broken cam gear. I surely hope I am wrong. I think road racing is much harder on valve trains than drag racing.

Best of luck with it.

Bob

taken19

Not sure about the dry sump as they add quite a bit of $$$ to the bottom line. Called Hinson this morning - they haven't heard of any issues with the Katech C5R chain like this. Brian does have a full wet sump LS3 motor with 16k miles for $5k and a dry sump LS3 with 1600 miles for $7k - not bad prices. Kinda wanted to do this build on my own, not just swap motors. Then again, I build my last motor and look how long that one lasted, lol!

I also doubt I will see any reimbursement, but I think it would be worth finding out the cause of the failure. The motor has 15-20 hrs of track time on it (4500-6500 rpm)- not much when comparing to other successful motor builds. And I don't push rpm too high, usually shifting between 5800-6300.

The wife knew a spare motor was in the near future, she didn't know that it would be installed so quickly...

Pulled the intake and all intake valves look fine. Looks like 6 or 7 exhaust valves are bent but not broken. That is what is giving the gap between valve stem and rocker. Maybe pistons aren't too bad and cylinder walls probably ok. Heads will be off next.

I think I could sell my Spin ported FAST intake, injectors, UD pulley and headers and recoup some of the cost (maybe $1500 or so).

taken19

Bob, I'm thinking you're right. Pistons definitely contacted the exhaust valves, but won't know the extent til heads come off.

Just happy it did this with open field in front of me and not a wall

1fastbob

Yes, wall would not have been good. I really hope your damage is minimal.

taken19

Trying to look at the bright side... I may be able to start with a clean slate and build a road course specific motor, not a drag strip motor that drives on the track.

JUIC3D

Good luck with the head removal. I'm really curious to see what lurks behind the timing cover.

taken19

Can probably have the heads off this week. Engine cover sometime next week. Expecting the worst but hoping for the best.

glenB

Because my experience, and, talking with the folks at ATI and Cloyes at the PRI Show

cheap underdrive pulley = broken chain

Some disagree, but, compile all the threads with broken chains and add up the ones with UD pullies Vs those that didn't, and they all broke the same way, usually when downshifting after high RPM

Just sayin'

Sorry for your luck

When redoing, check the Cloyes set up. They use the same C5R chain but a diffrent set of gears and it takes out the slop you get when using the OEM gear set. It's as tight as a Gen 3 set up. Greatly reduces chain whip.

But don't take my word for it, call them 479-646-1662 Ext 228 7:30 - 2:30 CST M-F

JUIC3D

My LS3 had a tensioner and the chain was very tight as well.

Does that not cure any potential for slop?

taken19

Glen, thanks for the info. I will definitely give them a call. The guys in AutoX/RR section are saying the same thing. Good lesson learned I guess and I suppose I got lucky it happened with 100yards of grass in front of me and not a tire wall or something much harder.

I should have the heads off this week and engine cover off next week to determine the scope of damage and possible the cause.

I appreciate the contact info.

glenB

Not from what I've seen.

The Cloyes setup has a different pitch to the teeth. It will cause a little noise, similar to the Gen3

GMs pitch on the teeth is to reduce noise, but it makes for a sloppy chain, hence the tensioner. The Cloyes kit removes the tensioner and includes a new chain guide, like the early LS2, the dog bone looking guide that goes between the chain.

taken19

My setup is an early 2005 and had the dog bone tensioner - still didn't save me...

I'll try to get into the motor soon so I can get to the bottom of this. I'm working 13 hour days 6 days a week so finding spare time is tough.