I havent seen it yet but the mechanic told me one of the pistons, i think #6, has a hole in it. What i dont understand is, the car never ran funny until I flooded the engine. Can a hot engine taking in some water put a hole through the piston? Could the cold water have done something to the piston so that it was more prone to damage when under stress from FI? What makes things more complicated is that i had the dealer change my engine oil and coolant, a day after the flood, but the dealer didnt bleed the system and the car overheated. The tech drove it after he added more antifreeze and i have no idea what happend during those 5 mins. I do know that the car's temp spiked a few more times on the drive home, prob due to more bubbles in the system.

I'll try and get some pics and post them Monday night.

 

Usually water into the combustion chamber means a bent rod or a hole in the piston. Water does not compress so well

 

#6 is dead.

 

 

 

 

you posted the same image twice.

Hey you broke your engine with the supercharger. Come on this is ridicoulous. I think 350z guys need to cool it on the timing. Even if you have to pull lots of timing you car will be much safier.

 

This forum's server was taking a dump yesterday so yea i somehow posted the last pic twice.

 

I just pulled my motor apart this weekend as well. I can't get over how small the rods are. They are about the same size as the rods I pulled out of a 90 1.6 liter Honda Civic years ago. I can truly understand why these rods are going south even with a perfect tune. I was very impressed with the block quality however.....super thick sleeves.

 

Classic detonation damage. If I had FI on mine with stock compression it would have water injection. Water injection will surpress detonation at much higher cylinder pressures and after the initial investment water is pretty cheap insurance.

 

100% agree.....

 

That hole was made during the last 20 miles i drove the car. Notice there was almost no sign of cylinder wall scare. I could rub the surface of the cylinder where it looks like there might be a scratch but i couldnt feel it there. The flood damage was done 5k miles ago. Whe they get the rods out, i'll take some more pics. For those 5 k miles, the car would idle a little ruff with a slight ticking sound.

 

Enron Exec....Did you have an ATI blower ? I would like to know what pistons you are going with ? 9.5 .....9.0 to 1 .

 

Yea I have the ATI procharger and I went with the standard 8.6:1 and 0.20 overbore.

 

Yeah, that's detonation damage alright. Cracked the ringland right off! I bet once you pull the other pistions you will find the rings are stuck in the pistons from the ring lands bending.

 

How would that broken piston do in a compression test? Sub 100, or around 160? I need to find out when that thing broke because i had a compression test done just 3 weeks prior to these pics.

 

I had a turbo Fiat that was a little down on power. I did a compression check, and measured about 30 psi. on three cylinders.

Found broken ring lands when I took it apart.

 

You will be able to tell when you crack a land like that. It's either det damage or weak piston design. If it didn't kill your block, count yourself lucky and throw some low comp internals in there and turn the boost up.

 

Well in addtion ot the high 10.3 CR, the OEM pistons as do all newer NA engines place the top ring as close to the top as possible , which makes the top land very vulnerable to cracking under detonation. The reason fro OEMs to do this is to reduce the squish volume as much as possible and to improve emissions , especially during cold operation. A Turbo piston will thicken this top land by moveing the top ring down.

 

A turbo piston with a thicker top ring land is better as it may buy you a nanosecond but if the engine experiences detonation it will eat any piston forged or otherwise and the weakness part will fail first. You are not going to build an engine that will survive with detonation. Detonation must be avoided.