b18 gsr motor stock bore, stock crank, Eagle rods CP 9:1 piston acl race bearings.
Head has supertech nitrade valves, springs, retainers and keepers and running on stock GSR cams.

Driving at about 15-20MPH boost set at 7 psi car bogs and shuts off. Tried to crank nada, kept cranking slower and slower and then nothing. Took the head off to find 3 valves in the number two cylinder and a hole in the piston all other valves and pistons perfect. Cylinder walls in number 2 fine also.

Any Idea as to what the heck went wrong here??

 

interesting.......valve heads broke off? how do the retainers look?

 

Right at the tip. Retainers look perfect, all of them.

 

can you get a closer picture of cyl #3. around the intake valve relief. looks burnt off/chipped/missing?

possible piece of the piston broke off and cause the damage? how was it tuned? how many miles on the engine?

 

hmmm might have been a bad head

 

Will try to for you.

Got the head pressure tested and looked at and it was said to be perfectly fine. That's the only reason I installed it.


motor has unknown mileage to be honest and it was un-tuned running at a said 7psi.

 

Most likely detonation killed your engine because it was not tuned. You live and learn, YOU MUST HAVE A TUNE, even if you are running 1psi or no psi, even NA engines will fail when not tuned.

 

Caution: Don't eat popcorn while reading this topic. Danger's include: Spitting popcorn all over your keyboard, laughing so hard you fall off your chair and choking on the popcorn.

 

Untuned.....what did you expect to happen?

 

tune had nothing to do w/this... you bent a valve, it broke, it took out everything else w/it

 

Ouch........

 

Thank you! Tune had nothing to do with it. One of you valves broke or one of your valve cotters mysteriously popped out some how. This is assuming something weird didn't go on with your timing belt of cam gears causing your valves and piston to collide.

 

X2

could have floated a valve?


but do get a tune next time

 

motor had 400 TUNED miles by previous owner. ;-)

 

you are not the only one. hehe

it does happen once in a blue moon.

and i agree. Tune has nothing to do with this. this can happen even while cruising speed.

 

Wrong. Potential mechanical failures + untuned = havoc.

You can have a perfectly running motor, excellent compression, great pressure test results, but an untuned/bad tune will ultimately fail your motor. The ecu compensates for timing, air/fuel accordingly to rpm, and if the timing is off at any rpm it could lead to bending/breaking valve(s) and/or worse.

 

How can you say its not the tune when your running 7psi without one?

 

^^^Look at the other cylinders, do you see any sign of detonation? I think Jason is correct: broken valve.

 

the motor would have failed eventually b/c of the lack of a tune... however THIS particular failure had NOTHING to do with tune or not, it was plain and simple a mechanical failure. judging by the look of the pistons and other chambers i'd say the "tune" wasnt too bad either way.

 

X2 again

 

def looks like it bent/dropped a valve and thats what happens...

the tune would have nothing to do with a dropped/bent valve

 

that looks like what happen to my cousins N/A type r motor. I think it bent a valve also..

 

Are you sure those are CP Pistons? I was unaware they engraved their part numbers on the piston top, they look like Wiseco's to me.

Either way there are some serious carnage pics in here.

 

The motor timing was said to be fine. Owner was a little worried about the timing belt being too tight but he said it was on timing.

I would have expected to see carnage in atleast two cylinders. Not just 1 and the rest in perfect condition.


The turbo setup was just put on. Car was only being moved. The tuning of the motor was to take place last weekend but due to the motor saying bye bye that never happened.

why in only 1 cylinder though??

you have 3 screwed cylinders I have 1 and all of the cylinder wals are perfect. Seems weird to me.


I was told they are CP pistons by the owner.

 

its hit or miss which valve will fail first when you have bent valves.

my last motor had all 8 exhaust valves bent, it dropped 2... who knows why only those 2.

those look like older cp pistons... it would probably have blown up anyway.. lol

if the valve was bent due to floating the valve it very well could have only floated one or 2 if it was a minor overrev..

with out having the motor in my hands i cant really give any more insight other than bent valve.