Rebuilt S52 lasted 289 miles :/

[e30forlife]

I'm really having a hard time on how I would be to blame on this. Maybe I'm missing something. This is my first engine to be built. Should i have asked certain questions? Should I have expected the builder to just bolt stuff together without care of measurements? All I know is I have a blown motor and the builder has left me stranded saying it's the machine shops fault...really? They didn't bolt it together. The builder was the last to touch it. End of story. Still loss for words.

[rkettner]

What did this sound like when running? I can't imagine it sounding good.

[ForcedFirebird]

Why are the valves not damaged in that picture? If the pistons were contacting the head, you would think the valves would have some marks.

Valve to piston clearance is usually .080"-.100", piston to head clearance is usually .040" to .060". As the rods stretch with RPM, the pistons get closer to the head than when it's static. Ideally you want as little space in there as possible at your max RPM. This keeps the head gasket from having to hold compression, the chamber will.

I'm really having a hard time on how I would be to blame on this. Maybe I'm missing something. This is my first engine to be built. Should i have asked certain questions? Should I have expected the builder to just bolt stuff together without care of measurements? All I know is I have a blown motor and the builder has left me stranded saying it's the machine shops fault...really? They didn't bolt it together. The builder was the last to touch it. End of story. Still loss for words.

It's whoever assembled the engine's fault. Shaving the head on a 24v doesn't cause valve to piston issues, shaving the block does. They would have had to shave a lot off the block, or used too thin a head gasket. We have a sacrificial head gasket to check clearances before the final assembly. Only takes a few minutes to bolt the head down and rotate it with clay (or solder) on the pistons.

What did this sound like when running? I can't imagine it sounding good.

It would only be at high RPM and not overly audible. Seen it before in one of our race cars (rushing to swap heads, didn't check it), but not as bad as the OP's. It just lost oil pressure as the rod bearings were beat up from the contact.

[frankenbeemer]

This is an example of having accurate documentation whenever you are having expensive custom work done. Get it in writing and have the the shop lay out a work order that details what they are doing.

[Matt-B]

Had a friend get head work at a shop in Virginia, somehow they didnt install valves correctly, or time it right, destroyed head, he was able to file in small claims and received i think 3800$ the cost of another used motor plus $ lost in work to shop, small claims cap I believe is 5000$. Definelty avenues of attack when this happens, get some quotes from other shops, like 4 or 5, and print out motors for sale, used etc. It was a clean cut case for him. Best of luck