It's basic auto tech. The Valves won't hit the pistons unless the valve springs "float" or are operated at a RPM where the spring can not close the valve, (a mechanical over rev does this) Or the valves hit the pistons if the engine is turning while the cams are out of time, and the valves are help open when they are not supposed to be, such as a broken timing chain or assembling the engine with the cams out of time.

Since a S2000 will not run with either cam off 1 tooth it's safe to say the engine wasn't assembled out of time.

A mechanical overev can bend the valves enough where they do not break anything immediately. It's been seen multiple times on overrev'd cars where the engine runs fine for many miles after the over rev, until a valve retainer that was cracked during the overrev breaks.

 

if it makes your feel any better normally when they send out someone that normally is good. just hold the "well you said the computer didnt show" and since its used you can blame it on other drivers. i think his statement of "it will not work immediatley" is to cover his butt and make you believe you did something wrong. either way good luck

 

suggestions............worst case scenario i get to rebuild the engine slightly. if that would be the case new pistons and maybe cams wound be in store. any suggestions on good pistons and cams to replace the stock ap1's? if it needs to get done...might as well have some work done to it.

 

Depends what you want to do. OEM parts are very good, even if you are going for lots of NA bolt ons. If you are going FI then you need to ask how far you are going to go, and build accordingly.

 

*******update********

Just talked to the shop manager. They took apart the engine down to the heads and valves. They FOUND NOTHING.... The pistons look fine (no notching), the valves look perfect, the heads look like normal. Accentually there was no over-rev and they don't know what caused the valves to stay open and why there was a loss in compression. In the mean time, I am driving a 2006 Toyota Camry, and because I have been without a car for almost 2 weeks, they are now going to give me a 2007 Infiniti G35.



edit

they found the valves in the 4th piston stuck open b.c they were elongated and the 1st piston was showing signs of this to happen. they said that this is something that happens, snow balls until we have the problem occurs, which is what i have. everything will be taken to the machine shop tonight and should have everything back by Thursday or Friday. they also said that everything will be covered under my warranty. we are hoping by next week my car will be back in my possession.

 

got word once again***** machine shop, plaza and warranty company are all on the same page. they are over nighting all of the parts. they are replacing the retainers, intake valves, exhaust valves and pretty much rebuilding/replacing the head so it is brand new. all of this SHOULD be completed by next week, and all I have to pay is 100.00 for the deductable.

 

Good news.