HELP! found the reason for my motor shutting down.

[fastzcars]

Thanks for all your help guys. I finally got a call from the engine builder he said that 3 pistons top and second lands had failed? Not the piston skirts thrust face , but the top lands. How could that it be? If the shop didn't machine the bores large enough, woul'nt the skirts be scored. They are saying the that motor was probably running lean. Could you guys figure this out. The builder said he's never seen anything like that before? The motor didn't smoke. didn't overheat. It would just shut down after about 10 to 20 minutes of warmup. #6 and #7 pistons were the ones that were damaged. One more thing, do you guys think should I be paying for the damaged parts? I want to be fair about it. Grumpy. Kevin. Thanks again.

[jap tin]

what type of pistons and what was the ring end gaps on the top and second rings? Hypereutetic pistons need a larger gap to prevent the ends from butting and poping the ring lands.

[fastzcars]

Jap tin. The pistons are Speed Pro. aka TRW. forged -12 cc , 383 stroker SBC PN# LW2605. The whole top and second lands are scorind around the circumfrance of the piston. It's my understanding that if the rings where to but up against each other, the top land would be pulled and or yanked away from the piston. Maybe someone may have a link to some pictures of different damages that are possable to a piston's and there causes? Thanks Jan tin.

[Kevin Shasteen]

.., One more thing, do you guys think should I be paying for the damaged parts? I want to be fair about it. Grumpy. Kevin. Thanks again..,

 

Product Liability is definately a legitmate concern. You need to pose this question to your engine builder.

 

Prior to posing this question you need to realize that:

 

1) You need to understand that the product in the "Product Liability" has a possible three way split as far as liability goes. The parts are products of the mfg's, while the built engine is a product of the engine builder, and you as the end user fall under the principle of "an Assumption of Risk". Assumption of Risk can be translated to mean you are asking your engine builder to build a performance engine with the sole purpose of some form of racing in mind...AKA: Excessive Engine RPMs.

 

2) the "Evidence" has already been compromised as it has been torn down by the engine builder w/out representatives from Speed Pro...hence your possible Product Liability Claim has also been "Spoliated" if the failure was a defective piston...(Spoliated is $20 word for meaning that some item's defect is compromised to the point a legal complaint's investigation could not proove that those two pistons came from your engine).

 

I understand from your point of view that you would argue, "Why would that be a concern..I NEVER LIE" Granted your intentions are good - yet for a legal Product Liability claim to be made...and if the pistons were defective, you would have to proove that those two pistons came from your engine. You have to proove this because there were no Speed Pro reps on the scene when that engine was being torn down. Speed Pro's posturing, and the court's posturing, would be from the stand point that "People do Lie and Peopld do file fraudulent claims". So, the burden of proof is currently in your court. If the pistons were defective, then Speed Pro would be on the hook. Because spoliation is a question at this point: you would have to get sworn affidavits from your engine builder stating that he removed those pistons from that engine. The affidavit would have deeper teeth if your engine builder also had witnesses that saw him remove those pistons from your engines...and they too would need to sign sworn affidavits.

 

3) In the event the engine builder is at fault you would still need to prove this. Many issues are in question such as how much time has expired from the time the engine was built to the moment you began driving as well as the obvious - what was actually the cause & origin of the failure. This requires an unbias expert to confirm the "Cause & Origin". Tests such as a mettalurgist would not be out of question either.

 

4) What is the relationship between you and your engine builder? Any claim you make against that shop would in no doubt prejudice your relationship.

 

5) Involving a Specialist usually means some sort of Mechanical Engineer, Metallurgist, and the expensive test that a Metallurgist would perform. All this involves time and money. From the cheapest "less profesional" C&A reports would be in the range of $400-$1200.00 not to mention 30 days to 90 days.

 

6) If you are comtemplating a Product Liability claim against his shop's insurance then you need to protect the damaged parts ASAP. You need to get your engine and its parts in an area whereby no more spoliation will take place. If the damaged engine has already been rebuilt then your claim is pretty much ZERO.

 

The best thing to do is to present your engine builder with your concerns. Obviously, as one of his customers - you expect your engine, for which you paid hard earned money, to have a long and lasting life...keepgin in mind the "Assumption of Risk" that comes w/a performance engine.

 

Attempting to handle disputes amongst yourselves is what the courts call "Exhausting your Administrative Abilities" and will insist you do this prior to taking this to court.

 

As youre engine builder for a discount on the rebuilt engine - due to the fact he and you have never seen anything like this before. Tell him you would like for his and your relationship to continue and that you dont feel you should pay for the said damamges w/out some kind of consideration.

 

Negotiations are only limited to your imagination. A good settlement is where both parties feel they had to give up something (this is equity) and is fair.

 

After saying all that I would also say that I have seen a piston's top ring land fail. In my teen & early twenties - I and my dad had a few Internationals. I rebuilt three of them and found out something interesting. Intern'l altered their coolant passages in 1973 due to overheating problems which brought about cracked cyl.heads and egg shaped pistons.

 

The interesting thing about the overheating prob's, besides the cracked cyl.heads, is that the piston's whose ring lands would fail would always be the pistons at the front or rear of the block...never the inner pistons. Intern'l increased the length of the coolant passage on the ends of the block and heads to solve the problem.

 

Two of the Intern'l engines I rebuilt had pistons whose top ring lands that were damaged. One engine was the improved block while the other enigne was the old style block. I remember driving the P/Up w/a broken ring land...it caused a hyper-static lock to the airflow of the engine as it pushed air and oil up to the air breather through the egr system. Once the air filter saturated w/oil it would cause the carb to stumble...eventually causing the engine to stall. This also usuall occurred after the choke opened up and the air-fuel ratio leaned out.

 

Kevin,

[fastzcars]

Thanks for your response kevin. as always you brought some insight to this subject that I haven't even thought about. You know I may have found the reason for the piston's failures. In the discussion with the machine shop, they said they bored the block for 0.0035 clearance. They said they like to make them on the tight side to reduce piston slap noise when the engine is cold. But when I went to Federal Mogal's and summit racing web site's, They both said 0.0050 clearence. Could it be that the 0.0015 make the difference? It could explain why the motor ran fine when cold, until it warmed up. I'm going to have to take this information to the machine shop to see what they say. By the way the part number on Federal Mugal's website is LW2605F30. The piston's made of 2618 aluminum. Thanks for your input guys.

[jap tin]

I would say your machine shop put it to ya. a thou and a half can do it. Time for a new machine shop.