soulicious

My engine developed a tapping sound after a quick hard drive (with turns). BTW, my oil was topped off beforehand. I changed my TCT, timing chain, chain guides, LMAs, adjusted my valves, but the tapping sound was still present. I tore down the engine and found that the #3 wrist pin had cracked. It looks like a couple valves hit the top of the piston. Before the tear down, compression and leak down numbers were still good. I was thinking of just replacing the connecting rod, piston, wrist pin, and rings for #3, but I am sure that will be a band aid fix. I'm going to have my head checked out and have my short block rebuilt with lower compression. I'll probably drop the compression down to 9.5:1 so that I can run decent boost levels on 91 octane for a flex fuel setup. I don't have an oil cooler and baffled pan, but I am going to going to get those for sure now. I also plan on getting beefier wrist pins.

[attachment=98605:s2000_cracked_wrist_pin.jpg]

MARK AUS S2K

Hey mate, is an oil baffled pan that important?
Should I swap my stock pan for a baffled type to save future issues with my motor?

camuman

wow, that sucks. your car has held up well until this. as for rebuild, talk to some people, i am not sure i would go with that low of static compression. that means yuo will be in the 7's when on the high cam! most go for 10:1 when rebuilding with lower compression. good luck with the build!

staylor725

That suck sucks! What's the specs on the engine? looks like a stock piston, I'm the the middle of putting in a new short block do to a broken ring. Whatever you end up doing get ready to spend some money. I would also go with 10:1 cp Pistons.

06S2k07Si

Very sorry to hear that bud...now it's bigger better stronger faster time! It's unfortunate but I know you'll be back stronger! Best of luck Sir!

MorngWoodStewie

The static compression does not change on high cam, it's still 11 something static (stock)
However the dynamic compression will.
But with alot of boost... well its not gonna keep going down thats for sure.

Your still squeezing alot into no matter what (higher cr. Static) into a little area one wrong move and kaboom.
Hence the reason why running higher boost has its balance/weigh offs with boost and cr. And all that jazz.

joes sled 2000

This is somewhat surprising to me . After all the threads of people making much more power and no failures reported . Sucks big time ! Perhaps some knocking going on in that cylinder ? Just a thought . Good luck with the rebuild !

soulicious

Depends on your driving. It provides some insurance to prevent oil starvation during hard cornering with sticky tires.

soulicious

It's surprising to me too. If you search the site using Google, then you'll see some threads pop up about broken wrist pins. I drive my car pretty hard always taking it up to 8500rpms. I'm not just doing a couple straight line pulls here and there. Also, it's not a dyno/garage queen for bragging about online. It sees mostly canyon/mountain carving. I can go on 100+ mile runs in one sitting only seeing less than two handful of cars. The issue is probably related to rpms, oil starvation, and/or oil temp. I was on broken in RE-71 tires which are pretty sticky.

soulicious

I spoke with Mike at Laskey. I'm going to have him build my short block. He recommended going 9.5:1 for my setup (car will be on 91 sometimes). I want to have flex fuel capabilities utiliIng my whole rpm range. I don't want to have to mess with the rev limiter when running on lower ethanol content. I have flat faced valves which increases the compression a little. I'll take a slightly lower compression ratio for lower risk. I plan on overspinning my blower a little more to help make up for any power loss.