24V = smithereens after 50 hours of racing

[kronus]

i bet the rabbit pilot is real happy he doesn't have a face full of tire also

[M-technik-3]

I betcha he pissed his pants. That must have been the talk of the pits

[Wanganstyle]

so, you rebuilt the head, did you refresh the bottom end? replace the oil pump? any kind of longevity maintenance?

not being accusatory, just playing devils advocate. can you say for certain that the engine was never mechanically overrun beyond its rpm limits?

IF going beyond stock 6,000 rev limit = over run then yes, it was ran with a turner motorsports chip to 7,000rpm for about 10 hours; I am 100% sure the raised rev limit contributed to the valve spring retainer failing.


We leaked down the short block cylinders individually before installing the built head; each cylinder was within 1.5% with MAC leak down tester.
It is easy to build a fixture to test for this; you can use it on each cylinder on head or block



Oil pumps on these engines rarely fail unless the nut backs off; ours was welded on.

The pickup falling apart due to vibration was something new to me


A dropped valve from broken retainer caused the carnage; it simply wore out.

All the bottom end bearings were still alive amazingly even with the destroyed oil pickup

lemons car = Looks like ASS, goes like stink

We run plain jane HD ones. Cheaper is better, hell we have run used ones. Cooked our last motor as well. Three races on it. Slapped together another 2.8 out spares that we cannibalized from previous engines. We expect to to get three races out of it.

any good carnage photos ;) I love to look at aftermath of kabooms!

[M-technik-3]

man who can piss the furtherest up the rope without it burning. too much whining going on in this thread.

it's lemons, i expect it to blow up or get destroyed now. It happens nearly every race for the team I'm on. My one guy will end up into the chevette no matter where it on the track. Three incidents with them it's like the cars are meant to be together.

[camshaftgsxr]

so, you rebuilt the head, did you refresh the bottom end? replace the oil pump? any kind of longevity maintenance?

not being accusatory, just playing devils advocate. can you say for certain that the engine was never mechanically overrun beyond its rpm limits?

[Wanganstyle]

We can all totally disregard your posted failure results. Why? You took a 20 year old engine, and rebuilted it in indy shop, resurfaced the head, this increased the compression ratio higher, changed the dynamics of timing chain, valvetrain, then you increased the rev limit into red zone. Solid engine mounts plus that kind of RPM created some nasty harmonics inside the engine.

Proper test would be brand new 24v from BMW factory with stock engine management and stock mounts, then do your racing.

This is a race car; things are yes full raze.


have you ever read the Tis for a Bmw 24v engine?

Do you even know what detonation looks like? This engine has 0 detonation damage; I hope you have working eyeballs if you hold a drivers license.

Compression is easily adjusted with the proper Bmw head gasket; there is more than one thickness avail.

you probably have never asked at the bmw dealership.

M50 and m52 heads are designed to be resurfaced by bmw.

S52 is not; go read the Tis if you don't believe me

[DesertBMW]

Head was rebuilt stock; before it was swapped into our e30 racecar it had about 70k street miles attached to an automatic.

we learned the hard way that valve spring retainers are not strong enough for over 7,000 rpm redline + endurance racing

We can all totally disregard your posted failure results. Why? You took a 20 year old engine, and rebuilted it in indy shop, resurfaced the head, this increased the compression ratio higher, changed the dynamics of timing chain, valvetrain, then you increased the rev limit into red zone. Solid engine mounts plus that kind of RPM created some nasty harmonics inside the engine.

Proper test would be brand new 24v from BMW factory with stock engine management and stock mounts, then do your racing.

[Liquidity]

Title of thread applies to actual racing cars

No. The body of your post applies to you trying to form this thread into you becoming the be-all end-all of 24v reliability. If you want to share your experience, fine. But don't go preaching this like you've uncovered some truth and you must get the word out to the people before chaos strikes. You blew up a motor. Yeah, it sucks, but in the grand scheme of things - whoopty fucking do.

[e30_302]

$500 car my ass.

[M-technik-3]

We run plain jane HD ones. Cheaper is better, hell we have run used ones. Cooked our last motor as well. Three races on it. Slapped together another 2.8 out spares that we cannibalized from previous engines. We expect to to get three races out of it.

[Wanganstyle]

That's really your argument? Seriously? That logging your hours somehow makes your engine failure more relevant?



Listen up everybody! Wangan logs his hours! He's the expert of all BMW racing now! All of the time you've been reliably racing your BMW engine, it doesn't matter anymore, Wangan is here to tell you your engine is unreliable!

Title of thread applies to actual racing cars; please don't spout r3vtarded data if you are not actually racing. i.e. your Suit, cage, HANS actually all passes tech.

Street car + hpde does NOT = actually racing.


everyone else seems to have no problem understanding the context of this post; solid mounts is = not good for your engine

Well, S50s are known to drop valves, and S52s have terrible crank harmonics. They are both well known to be prone to blowing up on track.

This was a M52b28; Dropped a valve (cracked retainer on #6 intake)
We were hoping its more durable in regards to harmonics BUT solid mounts did not help it at all.

[mooseheadm5]

the vorshlag style through-bolt mount with poly sandwiched between metal cups is probably the best approach I've seen.

So far...

[nrubenstein]

That's really your argument? Seriously? That logging your hours somehow makes your engine failure more relevant?



Listen up everybody! Wangan logs his hours! He's the expert of all BMW racing now! All of the time you've been reliably racing your BMW engine, it doesn't matter anymore, Wangan is here to tell you your engine is unreliable!

Well, S50s are known to drop valves, and S52s have terrible crank harmonics. They are both well known to be prone to blowing up on track.

[Liquidity]

how many millions of miles has yours been racing? Do you log the hours?

That's really your argument? Seriously? That logging your hours somehow makes your engine failure more relevant?



Listen up everybody! Wangan logs his hours! He's the expert of all BMW racing now! All of the time you've been reliably racing your BMW engine, it doesn't matter anymore, Wangan is here to tell you your engine is unreliable!

[2mAn]

S52?