What are the odds of this happening... smh

[Kozworth]

Took my "boosted" car for a rip down the road. <1 mile on the full engine refresh and whatnot, head gasket blows on an oringed block with arp studs. This was with zero boost, as my turbo adapter is of poor fitment (got it money now) and had a huge exhaust leak preventing boost.

Went to pull the head today, and noticed this.




So right now I have a 7v m20b25. I had oil pressure ~50psi. This car does not want to drive and be enjoyed :(

On another note, any other rocker arm ideas besides IE? Billet must be nuts, 2k for arms.. Thats the price of the car and the engine rebuild of my car. I would assume replace all 12 rocker arms but is there any reason not to replace only the intake? I find it funny that 5 arms broke all intake, and my buddy has a spare 885 head with a broken intake arm aswell..

At this rate, I do not even want to see how the head gasket and bottom end look.

[CarsSuck]

That isn't the way I've seen most rockers break from fatigue. Looks like piston to valve contact, what pistons and cam are you running? Did you verify cam timing when you put it all back together?

Sorry for your loss, must be hella frustrating.

[mikeedler]

I think your going to have a HUGE surprise when you take the head back off.......

i will bet you were having contact with pistons to break 5 rockers.

New valve springs- that is 90% of he problem, and you won't have any broken rockers anymore.

[Kozworth]

Basically the head and block internals were from my good running 325i. Its funny because that setup was in my first 325i that I beat the piss out of. I had it bav chipped and I pretty much redlined 1st and 2nd everywhere for the first few months I owned it. I oringed an eta block and was going to 2.7 stroke it, but went to b25 to keep it simplier.

Timing was all spot on, i rotated it 4-5 times afterwards. If it was piston contact, wouldnt that affect all intake valves?

Also, timing belt seems to be fine, I doubt it skipped a tooth but at this point in the game anything could really happen. I let the car idle a lot (to bleed coolant) and never had any issues, the car pulled really well for NA.

So odds are, if the piston hit the valves somehow even though the car was timed on the money and whatnot, I am probably looking on the easiest route new valves? If I got to take the bottom end appart I am just going NA swap.

[flyboyx]

I know that you don't want to hear this but........


It pretty much goes without saying by the looks of it that you did something wrong when you put it back together. Those rockers did NOT break from fatigue.

As far as remedy, you might want to find someone who knows what they are doing to help you or just pay them to do it right the second time?

At least you can chaulk this up to a somewhat costly learning experience.

[jlevie]

Rockers can break from fatigue, but seldom will you see more than one fail at time. For five to fail at the same time valve to piston contact is almost always the cause.

I've seen enough rocker failures on engines that were never stressed by trips to the redline to have a theory as to the cause. In my opinion a history of poor maintenance, namely a lack of valve adjustments every 15k, is the primary cause of rocker failure. The repetitive impacts from excessive valve clearance fatigue the rockers.

[AlphaE]

Re the comment about valve springs, I REALLY doubt usin old valve springs caused it. I tested some from a head that'd been dead for years and all were spot on I'm spec.

OP, like stated its likely piston contact. However I say figure it out and do it again yourself. Don't pay someone else for something u CAN do yourself.

RIP THAT HEAD OFF AND FIX IT UR YOURSELF BUDDY :)

[ak-]

Brand new OEM ones are fine.
I'm going to guess lack of adjustment.

[Vtec?lol]

If it was timed on the money then you didn't adjust them properly.

[Kozworth]

Well heres the update. This head was on a daily driver and no issues, and had a recent valve adjustment. I know what a bad valve adjustment sounds like, because the first valve adjustment I did on it was off, and sounded really loud. I readjusted it and it was great sounding, and daily drove the car like that for probably another year or so. I am pretty darn sure that the lash was good and def not excessive.

The part that I do not get is this. Since I had the car idle a few times to bleed coolant and such, why did the arms not break then? If the piston hit it, that means that the belt would have had to be off on the timing. This, I know for a fact, was spot on. I had rechecked it a ton because I had to prime the engine and did not want to do it again.

Since the car idled fine, and did a couple of short movings around my driveway, why did they happen to break during the rip? What would have caused the pistons to make contact if the timing has been proven good? Only thing I could think of would be the belt slipping, but even that during the head gasket popping seems far from reality.

And yes, this whole car is my build. Its the best way for me to learn (I am an auto tech grad) so I would rather be doing the mistakes and learning on my own rather then at work.

[Raxe]

Well heres the update. This head was on a daily driver and no issues, and had a recent valve adjustment. I know what a bad valve adjustment sounds like, because the first valve adjustment I did on it was off, and sounded really loud. I readjusted it and it was great sounding, and daily drove the car like that for probably another year or so. I am pretty darn sure that the lash was good and def not excessive.

The part that I do not get is this. Since I had the car idle a few times to bleed coolant and such, why did the arms not break then? If the piston hit it, that means that the belt would have had to be off on the timing. This, I know for a fact, was spot on. I had rechecked it a ton because I had to prime the engine and did not want to do it again.

Since the car idled fine, and did a couple of short movings around my driveway, why did they happen to break during the rip? What would have caused the pistons to make contact if the timing has been proven good? Only thing I could think of would be the belt slipping, but even that during the head gasket popping seems far from reality.

And yes, this whole car is my build. Its the best way for me to learn (I am an auto tech grad) so I would rather be doing the mistakes and learning on my own rather then at work.

Did you manually check the clearance using clay? Things can move/settle after running for a bit and heating up, it might also be possible the timing belt (assuming it was brand new) stretched just enough to allow contact. I had an M20 run strong for 100km before failing due to contact.

[Vtec?lol]

If it was timed on the money then you didn't adjust them properly.

[redlightpete]

Check that your cam timing is still correct.

[PeteD]

Did you check the specs on the endline for the rotary...girder...?

[nando]

Why not IE HD rockers?

also, I agree that you have more than just a broken rocker issue, that looks like piston/valve contact. but regardless, I don't get building a motor and using old rockers.

as far as why now and not before - metal expands and contracts as it heats and cools. if you were on the razor's edge when it was cold, well.. now you know. :(