24V = smithereens after 50 hours of racing

[whodwho]

So here is something to lighten up the thread...

So we all know how they like BMW entries in lemons races... NOT! so we are going thru tech(bone stock high mileage stripped 87 325i 4dr sitting for 10 years)... judge Phil is checking out the car... he pushes down on the front fender... he says "Ohh Squishy... I like it!" with a big smile on his face!

We got teched, handed over our best refreshment stash got our bribed stencil 0 penalty laps and had a great time, placed 24th overall with switching out 5 drivers and 3 penalties(2 off track, 1 speeding on paddock) and that is what 24 hrs of Lemons is all about 8^)

NeoMaxiZoomDweebies - Rude Dog and the Dweebs theme - Button Turrible 2014

[Wanganstyle]

We have about 75+ race hours on our 320,000km junkyard M50 motor in our ChumpCar... and It still has 200 compression across the board.

I have about 20 hours on my s52 in my e30 that has also never been opened and hasn't skipped a beat.

Sounds like you had a bad experience, but let's not bash the reliability of these well built motors.

If you are not running in our conditions it's not apples to apples.

For here 50 hours is actually quite durable

Blowing Up Is Just part of racing; Don't Feel Butt Hurt About it.

[roguetoaster]

We have about 75+ race hours on our 320,000km junkyard M50 motor in our ChumpCar... and It still has 200 compression across the board.

I have about 20 hours on my s52 in my e30 that has also never been opened and hasn't skipped a beat.

Sounds like you had a bad experience, but let's not bash the reliability of these well built motors.

I think that should be the takeaway here.

Side note, what oil were you running prior to engine failure?

[Chris916]

We have about 75+ race hours on our 320,000km junkyard M50 motor in our ChumpCar... and It still has 200 compression across the board.

I have about 20 hours on my s52 in my e30 that has also never been opened and hasn't skipped a beat.

Sounds like you had a bad experience, but let's not bash the reliability of these well built motors.

[Wanganstyle]

Ain't the vanos valve springs to weak for 7k? Valve float?

No valve float; the retainer simply cracked from racing stress over time

Some vanos engines come from bmw with 7,000 rpm redline. I.e. my daily driver 1998 m3

A number of reputable tuners think 7k is safe on vanos engines although I doubt all vanos motors share the same springs.

Valve springs did not fail; a much worse problem happened - the retainer split and valve keepers pulled through.

Part # 11341432453 - failure point @ 50 hours racing - it split and dropped the valve; collets pulled through. All m50 family engines use this valve spring retainer; even the s52/s50 USA



m52 and m50 use valve spring part #: 11347504268

4 bangers and S52/s50 USA / s62 share a different valve spring Part#: 11341403709 (VALVE SPRING)
E36 M3 Coupe
E36 318i Convertible
E39 M5 Sedan


if the spring was a stronger unit I wonder if the failure would have happened earlier or later; we need a DIGGER to answer this question

[SmokeE30]

Ain't the vanos valve springs to weak for 7k? Valve float?

A number of reputable tuners think 7k is safe on vanos engines although I doubt all vanos motors share the same springs.

[Nisse Järnet]

Ain't the vanos valve springs to weak for 7k? Valve float?

[Wanganstyle]

I'm pretty sure that's because you were running it over 7k rpm. Not because bmw engines suck

Also running any sort of rebuilt anything motor in a lemons car is total BS.

People running 24v e30s with rebuilt heads are ruining lemons. At least karma caught up with you.

I'm pretty sure it blew up because racing; Also blew up because lemons.
Don't be too serious about lemons - keep your whistleblowing to yourself.


6,000 rpm rev limit would have killed it eventually; M52b28 and M50b25 and S52b32 all run the same valve spring retainer part number 11341432453;
the valve spring retainer is what failed and caused the valve to drop and have sex with piston #6.

S50b30 and s52b32 both have a 7,000 rpm factory rev limit with these spring retainers (pn 11341432453).

racing is all about cheating; my friends race a Porsche in lemons; they have a $7,000 engine in it. So what? I don't whine or even give a shit.
People spend money on lemons because they want to have a good racing weekend - not because they are trying to make you feel bad-


Our actual junkyard M52 with 0 new parts in the cylinder head and the block offends you?




- junk lifters, junk pistons and original mystery rings/bearings/mystery oil pump
- stock head surfaced and valves/seats ground with a basic valve job, original springs and retainers re-used. M52b28 parts
- original vanos never re-sealed has given us 0 problems; we do have a mystery junkyard spare as well.

engine swaps blow up just as much if not more than stock engines; they are NOT advantageous if one desires to win lemons; they are great for messing with people all over the track with.

This was a mystery junkyard M52 that anyone can go to PNP and buy on half off day for lemons money - nothing special under the sun. If you wish to buy me a set of VAC motorsports billet rocker arms I will happily put a M20 back into the car and murder the same cars I pass with the 24V engine.

We have held pole with engine output in the same car in the same races between 150-200rwhp; power doesn;t mean that much.

Vanos or non-vanos?

M52b28 stock longmotor with 0 mechanical modifications; vanos

Early S50 head?

no; s50 is the ultimate hater its even worse for head gasket/ valve issues - more than one friend has dropped a valve - S50 is worse than S52 for valve dropping

[pandaboo911]

I'm pretty sure that's because you were running it over 7k rpm. Not because bmw engines suck

Also running any sort of rebuilt anything motor in a lemons car is total BS.

People running 24v e30s with rebuilt heads are ruining lemons. At least karma caught up with you.

[mr2peak]

Early S50 head?

[Nisse Järnet]

Vanos or non-vanos?

[whodwho]

Hey now, it's old school!! and it passed tech inspection with a chuckle, they like seeing budget based solutions 8^)

[redsubdivisions]

nahh, got to go with hockey pucks - true Lemons style!!

LOL wow. Reminds me of some of the bozos I used to hang out with in my 240 days..

[Wanganstyle]

Really?? I'd not heard that before.

4 bangers and M cars unite:

Part 11341403709 (VALVE SPRING) was found on the following vehicles:
E36: Details on E36
E36 M3 Sedan
E36 M3 Coupe
E36 M3 Convertible
E36 318i Convertible
E36 318i Sedan
E36 318is Coupe
E36 318ti Compact
E39: Details on E39
E39 M5 Sedan
Z3: Details on Z3
Z3 Z3 M Roadster
Z3 Z3 M Coupe
Z3 Z3 1.9 Roadster

Not exactly the same, but our all stock, never rebuilt Chump raced M42 has had just over 70 hours on track (and has been crashed/reinstalled in a new shell) after being used on the street for ~130k miles. It made good enough power to get 4th at Daytona last year.

When you rebuilt it what did you do with the valves?

Considering how closely these two engines are related I simply wonder if was simply down to you run solid mounts, we run rubber?

Best of luck with the repairs.

I think our valvetrain failure has not so much to do with the solid mounts; approx 40hrs @6,000 + 10hrs @7,000 on a stock 6,000 engine is the cause.
a 4 cylinder has a much higher OEM rev limit so it's not a very fair comparison - the max OEM rev limit for a m52 family engine is 6430rpm in 3/4/5 gears (its 7000 in 1/2 gears but those are moot)

I would think the solid mounts prevented some mis-shifting that might have hurt the valvetrain more; BUT they contributed to destruction of the oil pickup tube

This would be best solved by a non cast AL material tube that is more vibration resistant; a braced steel pickup made from M52 e36 rear sump for front use might be the best solution.

[roguetoaster]

M42 has better parts for valves/springs/retainers iirc; they are shared with s52 and s62

Really?? I'd not heard that before.