Vanos M50 to 3.0L (Stu?)

[Holland]

I thought the M50 2.9 strokers were the high comp beasts?

[Pudmunkie]

I thought the M50 2.9 strokers were the high comp beasts?

That's a different combination Frankenstein. M54 internals in an m50 nets 3.0 liters

Sent from tablet in ('rooted','nook','cm7')

[FreedS4]

That's a different combination Frankenstein. M54 internals in an m50 nets 3.0 liters

Any idea on the compression ratio for this Frankstein?

[Pudmunkie]

The 3 liter Frankenstein should be 10.5:1 from everything I have read. I'm still in the middle of building mine though.

[FreedS4]

The 3 liter Frankenstein should be 10.5:1 from everything I have read. I'm still in the middle of building mine though.

Me too, ready to have it installed and driving. Any idea what kind of power we should expect with this combo? Not stock M54B30 numbers, but definitely more than a stock M50 and a lot more torquey.

[lifeiskaos]

An m50 with m54b30 internals and a stock headgasket will be about 9.5:1 compression. m54's use thinner headgaskets.

[Pudmunkie]

An m50 with m54b30 internals and a stock headgasket will be about 9.5:1 compression. m54's use thinner headgaskets.

Interesting. Everything I've read says 10.5:1, have you measured the compression and/or the two headgaskets? Or are you juts postulating.

*Edit, found some more threads that say around 10:1. Still should make some decent power.

[trackjunkie21]

I was debating doing something similar aswell, but I would need a custom chip for the extra boring/stroking correct? Since I wouldn't be able to use a 413DME. Will be on the lookout for some m54 internals ;)

[FreedS4]

An m50 with m54b30 internals and a stock headgasket will be about 9.5:1 compression. m54's use thinner headgaskets.

Why not just run a factory M50 head gasket? Would that not put the compression back towards the original 10.5:1?

I was debating doing something similar aswell, but I would need a custom chip for the extra boring/stroking correct? Since I wouldn't be able to use a 413DME. Will be on the lookout for some m54 internals ;)

Should run off a stock DME just fine. No boring is needed, both are 84mm, just an increased stroke.

Chris

[lifeiskaos]

Interesting. Everything I've read says 10.5:1, have you measured the compression and/or the two headgaskets? Or are you juts postulating.

*Edit, found some more threads that say around 10:1. Still should make some decent power.

Hi Pudmunkie.

I've dealt with both engines several times and have built the exact stroker you're talking about. I'm not "postulating".

I crunched some numbers for you. There are several ways of finding these, some more precise than others. I decided to use BMW's advertised values. I started by going to realoem.com and finding out that m50's use 1.75mm headgaskets and m54's use .7mm headgaskets. So there is a 1.05mm difference.

Use the bore (84mm) and stroke (86.9mm) to find the displacement. Now some math:

42*42*3.14159=5541.77*86.9mm=481579.76

So that's about half a liter per cylinder. So far so good. Now, BMW claims 10.2:1 compression ratio for an m54b30. Use that to figure out combustion chamber volume.

x=combustion chamber volume
(481579.76 + x)/x = 10.2
x = 52345.6

So ~52cc's. Now add the extra thickness of the headgasket to find new volume of the combustion chamber.

52345.6+5541.77*1.05mm=58164.48

Now to calculate new compression ratio:

(58164.48+481579.76)/58164.48= 9.3:1 compression ratio



So there you have it. Like I said there are many ways to calculate it. If you go by this guy's numbers, the compression is even lower. http://www.e46fanatics.com/forum/sho...d.php?t=730757. Also, the headgasket might compress slightly more or less than the spec. Also, your compression would be higher if you resurface the head or block, etc.

You can order custom thin gaskets from MLS, but make sure your valve clearances are adequate.

[devon.818]

might be doing the s52 crank and m54 rotating assembly stroker.
few ?'s

1. what computer do you run? i read you use a normal m52 DME with a good chip along with s50 cams to get best power...that right?

2. any dangers to stroking the motor?

3. anything that should be replaced while in there?

4. POWER TO BE EXPECTED? some say you get a 9.5.1 comp, others say 11.5.1 comp, which is right? i read 250whp, that right?, how much tq to expect?

reason i ask is i am weighing cost/power gains right now. my mechanic said he could do all the labor for under 800 and quoted about 15-20hrs.

appreciate info.

[nando]

S52 crank = M54B30 crank

it makes more sense to just buy an S52. same stroke, bigger bore, built as a "stroker" out of the box..

[Pudmunkie]

Hi Pudmunkie.

I've dealt with both engines several times and have built the exact stroker you're talking about. I'm not "postulating".

I crunched some numbers for you. There are several ways of finding these, some more precise than others. I decided to use BMW's advertised values. I started by going to realoem.com and finding out that m50's use 1.75mm headgaskets and m54's use .7mm headgaskets. So there is a 1.05mm difference.

Use the bore (84mm) and stroke (86.9mm) to find the displacement. Now some math:

42*42*3.14159=5541.77*86.9mm=481579.76

So that's about half a liter per cylinder. So far so good. Now, BMW claims 10.2:1 compression ratio for an m54b30. Use that to figure out combustion chamber volume.

x=combustion chamber volume
(481579.76 + x)/x = 10.2
x = 52345.6

So ~52cc's. Now add the extra thickness of the headgasket to find new volume of the combustion chamber.

52345.6+5541.77*1.05mm=58164.48

Now to calculate new compression ratio:

(58164.48+481579.76)/58164.48= 9.3:1 compression ratio



So there you have it. Like I said there are many ways to calculate it. If you go by this guy's numbers, the compression is even lower. http://www.e46fanatics.com/forum/sho...d.php?t=730757. Also, the headgasket might compress slightly more or less than the spec. Also, your compression would be higher if you resurface the head or block, etc.

You can order custom thin gaskets from MLS, but make sure your valve clearances are adequate.

Thanks, I appreciate it! The postulating comment wasn't meant to be inflammatory, I was just trying to goad some numbers out of you :D

How did you like the one you built? Did you get any power numbers? I don't necessarily think the lower (relative) compression is going to be the end of the world. I spoke with TRM and they've seen quite a few of these , so something must work.

S52 crank = M54B30 crank

it makes more sense to just buy an S52. same stroke, bigger bore, built as a "stroker" out of the box..

I think the point is that this has the potential to be quite a bit cheaper than purchasing a full S52, especially for anyone who may have originally swapped in an M50, or M52! Sure, I'll be leaving a bit out over an S52... but this should do until some forced induction comes my way!

might be doing the s52 crank and m54 rotating assembly stroker.
few ?'s

1. what computer do you run? i read you use a normal m52 DME with a good chip along with s50 cams to get best power...that right?

2. any dangers to stroking the motor?

3. anything that should be replaced while in there?

4. POWER TO BE EXPECTED? some say you get a 9.5.1 comp, others say 11.5.1 comp, which is right? i read 250whp, that right?, how much tq to expect?

reason i ask is i am weighing cost/power gains right now. my mechanic said he could do all the labor for under 800 and quoted about 15-20hrs.

appreciate info.

1. OBD1 PCM w/ custom tune would be best. an S50 stock PCM would probably work as well.
2. Aside from the dangers any motor build would have, probably not.
3. Anything you can afford to swap out. I've got a severe case of WhileImInThere, so chains & tensioners, bearings, stems & seals, etc.
4. according to the Intelligent gentleman I quote earlier; 9.3:1 compression. The 11.5:1 you've seen was from the 2.9liter stroker variant.
Most people seem to think near stock S50 power numbers (with S50 or S52 cams), allowing for the same improvements that S50/2's can install.

I wish I could track someone down who'd dyno'd the swap with M3 cams!

[devon.818]

Awesome! No replacement for displacement!

So basically I'd be turning my m50 into an S motor. Up side is for under 2k it will be rebuilt fresh and I will know everything is up to par and reliable.

Yeah I could buy s52 for around 1700-2300, but would still want to spend a few hundi on maintenance


Stroker the way to go, for me.
And I know I can lessen the hrs I pay for by pulling motor myself.

I will likely run a MS unit on it, plan boost far down road, so it will be dyno'd.

Time to start saving. Build thread when it starts.

Thanks guys, I will come back with more ?'s closer to my build.


P.s if anyone has s52 crank or m54 rotating assembly hit me up.

[lifeiskaos]

Thanks, I appreciate it! The postulating comment wasn't meant to be inflammatory, I was just trying to goad some numbers out of you :D

How did you like the one you built? Did you get any power numbers? I don't necessarily think the lower (relative) compression is going to be the end of the world. I spoke with TRM and they've seen quite a few of these , so something must work.

E36 FI guys love that combo because it keeps some gasket thickness between the cylinders, though most of them get custom 8.5:1 pistons at ~84.5mm. The one I built was turbocharged. It made some power :D

It sounds like you guys plan on using used pistons. Obviously not ideal, but it should last a while with a hone and new rings. By the time you buy the internals and new rings, bearings, seals/gaskets, and machine work, you'll be pretty close to the price of an s52...