Engine build turned nightmare :( update

[maniacmatt]

Wow! I went passed on the sherwood park freeway while your car was sitting there!

I remember thinking man what's that clean e30 doing with the hood up, wonder if it is anyone I know.

[nrubenstein]

Yeah, if the clearance is really close, the motor will often run for a little while with the valve just tapping. Until it gets to be too much, and then he valve will break.

[immajackuup]

dang that suck donkey dick.

[RedDefiance]

Holy damage, sorry to hear about that. Hope round two will be successful.

[2quikmotorwerks]

Im going to assume you ran better than stock valves springs, perhaps there was a lil valve float causin valves and pistons to kiss

[2quikmotorwerks]

Now that i look at the pics better it seems as if it dropped a valve seat causing valve to break

[nando]

did you check and double check valve to piston clearance?

this is most likely the fatal error.

aftermarket cam + big valves + stock bottom end = carnage. even if it rotates by hand, and doesn't touch - things expand when they heat up. the piston to valve clearance decreases.

you can't trust "it rotated by hand just fine " because it's meaningless. you have to measure the clearance, and you have to measure it a few degrees before and after TDC as well. minimum is 1.5mm and that's living on the hairy edge. anything less and BOOM. :(

anyway, I hope you get it sorted. at least it was just a head casting and some valves, not a spendy bottom end too. a tough lesson learned the hard way..

[mikeedler]

I have the EXACT same set-up in my M tech II car.

My oversized valves were from IE. kinda has me worried now. I drove mine the whole last summer with no problems and redlined in MANY times.
To me it looks like that was a faulty valve- it just snapped the head right off with no bending.


If it would have been valve clearance, there would be signs on the other cylinders too????.... plus mine has been just fine for over 5000 miles so far.

motor looks great.

[nando]

I have the EXACT same set-up in my M tech II car.

My oversized valves were from IE. kinda has me worried now. I drove mine the whole last summer with no problems and redlined in MANY times.
To me it looks like that was a faulty valve- it just snapped the head right off with no bending.


If it would have been valve clearance, there would be signs on the other cylinders too????.... plus mine has been just fine for over 5000 miles so far.

motor looks great.

it depends on if the head/block have been shaved, and how much. the simple way to know is to measure your VTP clearance. if it's 1.5mm or greater, you're fine.

also, from the pics it does look like the valve seat possibly came off which would certainly be bad. I can't say I've ever seen that before but I suppose it's possible. if that's the case, then it was just bad luck (or the machine shop screwed it up).

it doesn't have to be full on contact to break stuff. it's definitely possible that only one would break - it just depends on how close the clearance is. also it's possible the head wasn't decked square and one end was thinner than the other.

[FredK]

Gutted for you man. I hope you can get it back on the road quickly.

[CorvallisBMW]

Fuck... that sucks man! I hope you can get her back up and running. Good luck.

[LJ851]

The valve seat coming loose is certainly the cause of this failure. Sorry about your loss, get that 3.1 on the road!

[Raxe]

Found the valve seat in the throttle body... yikes. Thanks for all of the encouragement guys, it's really motivating. The head is stripped now - practically none of the valves are reusable. One of the techs noted the strange wear pattern on the intake valves, it appears as if they were all touching and rotating.



I think this is a case of a hasty valve adjustment, poor parts combination and not enough double checking. Lesson learned, the second rebuild will be done much more carefully. Picked up all of the new gaskets and hardware today. :)

[Massimo]

Sucks bro. I would recommend Xworks method of valve checking, saves having to remove the head on and off.
Valve to piston clearance

Never mind that wont work with M20 heads

[Pac1373]

Wow, I feel bad man. that is some nasty luck and total valve carnage, so unfortunate.
Good to hear your jumping right back into it, Can't wait for the reports on teh Successful new build.