complete engine blow

[Richbot]

Can VANOS adjust valves far enough out of whack to cause interference problems? I thought the answer to that was no

[330ciprem]

Subbed - Interested in knowing more.

[Loki Motorsports]

Originally Posted by Richbot

Can VANOS adjust valves far enough out of whack to cause interference problems? I thought the answer to that was no

I don't believe so. I'm pretty sure it's been engineered to prevent that in case of failure, or excessive advance, etc. If not, I feel like that's a very silly mistake on BMW's part.

OP, how did the timing chain and tensioner look? It's possible the chain skipped a few teeth while over'revving and caused problems..

[reece146]

Been several decades since I've been into this stuff so maybe a current engineer in this thread can comment...

Relatively level and different colour dark regions seems to imply this was coming apart for a while and then the ridges are where it finally let go once it was apart enough to not be able to deal with the open/close stresses.

"Knurling" around the outside edge of the break is interesting but may be collateral.

Why did it come apart? Metallurgy/crack in the stem? That valve is shorter than the rest and was slamming against the seat? You over-rev / money shift it? I dunno. I'm guessing this is the area of root cause though.

2¢

[Solo_M_Tech]

1. Sorry for your loss.

2. Silver lining here is the VAC bearings look great!

3. I've seen valve failures like that before and in those cases ( not s65 based but LS1 based experience) That specific valve and spring either stuck open or floated enough to contact the piston. That bent/cracked the valve stem and the repeated bashing on the valve seat in the following few revolutions snapped the valve face off of the stem, causing engine failure. Somehow that valve touched the piston.

Keep us posted please.

[8k4]

Upgrade valve springs if you intend on increasing revs

[OneSickM]

Originally Posted by gordon@

What tune were you running on the car?

+1 Please disclose the tuner of the ecu

I have seen a lot of members who had their broken valve on their stock e9x M3 and yours is another one. Increasing rev is adding more stress on the valves and if one of them was weak/defect (in example like yours) then you would have engine damage at one point.

[GORDON.M3]

Originally Posted by OneSickM

+1 Please disclose the tuner of the ecu

I have seen a lot of members who had their broken valve on their stock e9x M3 and yours is another one. Increasing rev is adding more stress on the valves and if one of them was weak/defect (in example like yours) then you would have engine damage at one point.

There are some tunes safer than others that is for sure, with an engine with the S65 they are very high strung from the factory already.

That being said, increasing the revs by 200rpm I doubt it would cause that kind of catastrophic failure.

I've seen DME logs with 9600RPM over-revs from a mechanic downshift and still drive fine 30,000 miles later.

It's case by case and this one definitely needs more detail.

[maicol76]

My mention made some misunderstandings. sorry guys.

'raised the limit' means 'the recorded rpm data' on data logger. I didn't raise up stock rpm limit to 8600.
8400 is the limit on current ecu, 8300 was until last year. (I have pictures of mapping program from tuner)

recorded rpm was 8300~8500 last year, but 8400~8600 this year. difference is min 100~max over200 rpm nevertheless difference is only 100 rpm on the ecu map.
If you set the limit at any rpm, Normally +100~200 more rpm will be recorded in the real world(data logger), because engine is not a digital component like computer.

Anyway, my current rpm setting is '8400', and max recorded rpm is under 8600.

[maicol76]

Originally Posted by OneSickM

+1 Please disclose the tuner of the ecu

I have seen a lot of members who had their broken valve on their stock e9x M3 and yours is another one. Increasing rev is adding more stress on the valves and if one of them was weak/defect (in example like yours) then you would have engine damage at one point.

Thanks for information.
I don't think it is necessary to disclose the tuner, because we can't find certain things related in engine failure. If I find something, I'll disclose it. But, so far it is unlikely. No matter how I find, the condition of the engine is very good.

So next step, I'll test the injector of 1st cyl. asap.

[OneSickM]

Originally Posted by gordon@

There are some tunes safer than others that is for sure, with an engine with the S65 they are very high strung from the factory already.

That being said, increasing the revs by 200rpm I doubt it would cause that kind of catastrophic failure.

I've seen DME logs with 9600RPM over-revs from a mechanic downshift and still drive fine 30,000 miles later.

It's case by case and this one definitely needs more detail.

I am not saying that the extra 200 is causing the engine damage. I am saying that IF there is a problem (defect) in one of the valves (as the case with OP) then chances of seeing the valve broken at higher rpm is very high. It has been documented that many have seen broken/bent valves due to some defects

[maicol76]

For possibility of dumping fuel, I tested and checked injectors.
As a result, all injectors are normal condition.

valve itself or valve spring rate...These two might be the cause of 1st cylinder failure.

Why me again...why? ㅜ.,ㅜ

[OneSickM]

Originally Posted by maicol76

For possibility of dumping fuel, I tested and checked injectors.
As a result, all injectors are normal condition.

valve itself or valve spring rate...These two might be the cause of 1st cylinder failure.

Why me again...why? ㅜ.,ㅜ

wow..valve problems scare the hell out of me. Unfortunately it is not a very common problem yet a member or so report this issue every year

Please keep us posted once you know the exact root caue

[BPMSport]

Wow, that looks terrible! If you've been through two engines with the same tune - it might be advantageous to make sure that knock control was left in-tact on the tunes.

To answer a couple questions above - even with total Vanos failure, there wouldn't be any piston/valve contact. Also - the OP is correct that bone stock cars can see 8,600 RPM without any rev limit raise. We've looked at the freeze-frame data on thousands of of E9x M3's, and the majority of them have shown nearly 8,500 or higher. There are some that we've seen at only 6,500RPM, and even a few just shy of 10,000 RPM. On a number of occasions (less than 20), we've seen 9,100RPM, on engines that never exhibited any issues, even thousands of miles after this recorded maximum.

In all of these years, we have never seen one with broken or bent valves (without an over-rev), although we have seen quite a few of them with valve spring failure (mainly 11-13 models).

The added RPM limit (on cars with raised limiters) shouldn't exceed the mechanical capacity of the valves themselves, although it will stress the valve springs more. That said, our shop car has seen nearly 8,700 RPM 4,000+ times and never had a valvetrain issue. The valvetrain is strong on these cars and we chalk any failures there to external influence or a manufacturing defect.

Good luck OP in getting this resolved and please keep us updated!

[tdott]

Originally Posted by maicol76

For possibility of dumping fuel, I tested and checked injectors.
As a result, all injectors are normal condition.

valve itself or valve spring rate...These two might be the cause of 1st cylinder failure.

maicol76
Any updates on your engine tear down? So was it valve failure that caused it or was there signs of seized main bearings?

[Assimilator1]

Seized mains wouldn't cause piston to valve contact.
Jumped timing chain would've damaged valves on all cyls on that bank.
Detonation or duff injector wouldn't cause a valve head to come off.
I would think valve float + piston contact would bend the valve & cause a misfire instantly surely?

Personally I think reece146 is on the money, the only straight valve stem is the one with the head snapped off.
To me it looks like the head snapped off that stem, then it was pummelled around the cylinder bending the other valves, conrod & breaking the piston & cylinder wall.
The only thing I can think of that would cause the head to snap off like that is a manufacturing flaw, although I stand to be corrected .

So op, did you ever get to the bottom of it?

PS, yes I know the thread is 2+yrs old

[SYT_Shadow]

Originally Posted by BayE30

Looks like the old e36 m3 when the valves float and contact piston...curious to know the point of failure.

Speaking of which... steve dinan said anytime over 8500rpm the hydraulic lifters can fail

Based on that the redlines on both my S65s will be reduced to 8500rpm

[pbonsalb]

Don’t Dinan tunes set the limiter to 8600 rpm? Or did those tunes come out after Dinan sold the company? I forget when he sold it.

[SYT_Shadow]

Originally Posted by pbonsalb

Don’t Dinan tunes set the limiter to 8600 rpm? Or did those tunes come out after Dinan sold the company? I forget when he sold it.

I couldn't say. This information is a few weeks old

[pbonsalb]

I know that the Dinan tunes set the limiter at 8600 because I had a Dinan tune. Dinan has a reputation for tuning conservatively because it guarantees the factory warranty with its tunes. I am curious whether Steve Dinan is behind the S65 tune with 8600 limit and has now changed his limit to 8500, or whether he sold before the S65 tune was developed and never supported the 8600 limit.