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Stroker M50: 3.1lt Can it be done?

Posted: Wed Dec 09, 2009 1:42 pm
by Stevin
So i've been pondering this for a bit now.

I was thinking of using a 89.6mm throw crank from a M54 and 86mm pistons from a S50b30. That should give me 3.1lt.

I figure it should be possible but is it possible using all BMW parts? I'm not sure on the gudgeon pin heights, I know the M50 has a flat top piston while the S50 has a dished one. I also know these pistons can be machined down to a flat top (I did this in my m20 2.9lt stroker).

So this leaves me with the rods. I think that if I use the M52b28 or M20b25/ or S50b30 rods. The pistons will come out the bore by 1.5mm give or take.

Does any of this sound feasible?

Re: Stroker M50: 3.1lt Can it be done?

Posted: Wed Dec 09, 2009 3:18 pm
by DanThe
You wont be able to use S50 pistons on M52/M50/M20 rods as the gudgeon pins are different diameters.
Ive been considering a similar build myself, if I did I would be using custom rods to give maximum height

Re: Stroker M50: 3.1lt Can it be done?

Posted: Thu Dec 10, 2009 8:27 am
by Stevin
You can just by machining a new small end bush. If I remember correctly from my M20 build the S50 piston has a smaller diameter gudgeon pin than the regular BMW's.

Re: Stroker M50: 3.1lt Can it be done?

Posted: Sat Dec 19, 2009 1:17 am
by bss325i
A 3.2, 3.3 and 3.4 M50/M52 is possible.

Re: Stroker M50: 3.1lt Can it be done?

Posted: Sat Dec 19, 2009 8:14 am
by MarkT
What combination of pistons, rods and crank for 3.4?

Re: Stroker M50: 3.1lt Can it be done?

Posted: Sat Dec 19, 2009 9:58 am
by Gunni
custom, custom, custom as done by Hartge, AC Schnitzer or Racing Dynamcis,
I can´t remember who went the farthest.

Re: Stroker M50: 3.1lt Can it be done?

Posted: Sat Dec 19, 2009 12:17 pm
by MarkT
Ah so no OE route then!

Re: Stroker M50: 3.1lt Can it be done?

Posted: Sat Dec 19, 2009 6:06 pm
by bss325i
Gunni wrote:custom, custom, custom as done by Hartge, AC Schnitzer or Racing Dynamcis,
I can´t remember who went the farthest.
Alpina is the only one i know of to take an M52 to 3.4 with the engine used in the E46 B3S and Z4 roadster.

I have rebuilt one of these engines and yes custom crank, rods and pistons.

Even the head gasket is unique and that cost over £300!

Re: Stroker M50: 3.1lt Can it be done?

Posted: Sat Dec 19, 2009 10:19 pm
by DanThe
The rods in my B3 3.2 are custom, they have some German markings scratched into them :D

Re: Stroker M50: 3.1lt Can it be done?

Posted: Tue Dec 22, 2009 8:45 am
by jaistanley
You could go to 3.2 easy enough if you bought an S52B32us set of crank, rods and pistons from the US couldn't you? Shipping on the crank would probably hurt a bit so you'd want to trust the yank selling it!

Jai

Re: Stroker M50: 3.1lt Can it be done?

Posted: Fri Jan 15, 2010 4:28 am
by StuMc316is
Stevin wrote:So i've been pondering this for a bit now.

I was thinking of using a 89.6mm throw crank from a M54 and 86mm pistons from a S50b30. That should give me 3.1lt.

I figure it should be possible but is it possible using all BMW parts? I'm not sure on the gudgeon pin heights, I know the M50 has a flat top piston while the S50 has a dished one. I also know these pistons can be machined down to a flat top (I did this in my m20 2.9lt stroker).

So this leaves me with the rods. I think that if I use the M52b28 or M20b25/ or S50b30 rods. The pistons will come out the bore by 1.5mm give or take.

Does any of this sound feasible?
An 89.66 crank will work well with U.S. S50 pistons and 135 rods. The pistons will need machining, which gives you the ability to go ahead and set the c/r somewhere around 11:1 (maybe more, you might have better gas on your side of the pond.)

Re: Stroker M50: 3.1lt Can it be done?

Posted: Tue Mar 02, 2010 2:18 pm
by alexbaby88
jaistanley wrote:You could go to 3.2 easy enough if you bought an S52B32us set of crank, rods and pistons from the US couldn't you? Shipping on the crank would probably hurt a bit so you'd want to trust the yank selling it!

Jai
Given that the M54 crank and S52US crank are identical, you might be able to save on shipping just the S52US pistons over from the US.

Re: Stroker M50: 3.1lt Can it be done?

Posted: Tue Mar 02, 2010 5:01 pm
by jaistanley
alexbaby88 wrote:Given that the M54 crank and S52US crank are identical, you might be able to save on shipping just the S52US pistons over from the US.
That's a useful piece of info!

Re: Stroker M50: 3.1lt Can it be done?

Posted: Mon Mar 08, 2010 1:20 pm
by booomer
so if i wanted to make my e34 525i (m50) a 3 litre i'd definately need a crank from an m54/s52 but what other parts would i NEED for an OE conversion.

Re: Stroker M50: 3.1lt Can it be done?

Posted: Wed Mar 10, 2010 3:09 pm
by alexbaby88
booomer wrote:so if i wanted to make my e34 525i (m50) a 3 litre i'd definately need a crank from an m54/s52 but what other parts would i NEED for an OE conversion.
You would also need the pistons and 135mm conrods from the M54 to convert your b x s to 84 x 89.6 and 3.0L displacement. Basically an iron blocked M50B30. If you could get your hands on an M52 (say from an E36 328i) alloy block you would shave off some weight from the front improving f/r weight distribution.

BTDT Cheers

Posted: Wed Mar 10, 2010 7:39 pm
by N00b
Would the gains be worth the extra cost though, given that you can screw around 250bhp from an M52 2.8 fairly easily?

Re:

Posted: Wed Mar 10, 2010 9:44 pm
by booomer
So all the parts i need are obtainable from the M54B30 engine and its the crank, con rods and piston heads?

Posted: Thu Mar 11, 2010 1:32 am
by alexbaby88
N00b wrote:Would the gains be worth the extra cost though, given that you can screw around 250bhp from an M52 2.8 fairly easily?
If you think you can get 250 from a B28, what could you achieve with a B30?

For me the added torque was a significant improvement in daily driving environment.

Re:

Posted: Thu Mar 11, 2010 1:35 am
by alexbaby88
booomer wrote:So all the parts i need are obtainable from the M54B30 engine and its the crank, con rods and piston heads?
Yes, plug and play. How much you decide to refresh your engine given you have it open is up to you (and your wallet).

For software you could use the USm3 chip (assuming you have the S50us cams)

Posted: Fri Mar 12, 2010 6:33 pm
by N00b
alexbaby88 wrote:
N00b wrote:Would the gains be worth the extra cost though, given that you can screw around 250bhp from an M52 2.8 fairly easily?
If you think you can get 250 from a B28, what could you achieve with a B30?

For me the added torque was a significant improvement in daily driving environment.
That's not my point though.
Ok Stroking it would make more than 250, but at what cost? You only really need a few hundred quids worth of parts to get the M52 into the 240-250bhp ball park, possible even 260bhp with the right cams, but crank/piston/rods etc take the costs up quite a lot. It's a bang for your buck argument, really.

Re:

Posted: Fri Mar 12, 2010 7:03 pm
by DanThe
A pair of reasonable cams cost more than a few hundred quid

Re:

Posted: Fri Mar 12, 2010 7:14 pm
by Kos
you need more than a few hundered quids worth of parts to get 250bhp on an m52 2.8, and you almost certainly need cams to get 250bhp.

235bhp is about the ball park for a 2.8 m52 with every bolt on mod and a decent map, maybe on good day you may nudge 240bhp.

Re:

Posted: Fri Mar 12, 2010 7:30 pm
by N00b
DanThe wrote:A pair of reasonable cams cost more than a few hundred quid
Ok, but how much compared to the cost of a crank/rods/pistons.....plus if you've decided to stroke the motor you'd probably opt for changing the cams as well.

Re:

Posted: Fri Mar 12, 2010 7:43 pm
by DanThe
A pair of schrick cams is approx £800, second hand stuff is cheaper but very hard to find, S52 cams approx £400

M54B30 stuff rarely comes up for sale as it is more likely to be repaired, ive dropped on a few lucky buys but generally its going to be expensive as its not that common

Re:

Posted: Fri Mar 12, 2010 7:50 pm
by N00b
DanThe wrote:A pair of schrick cams is approx £800
Can you tell me why pretty much all of Schricks cams are so expensive?

Re:

Posted: Fri Mar 12, 2010 7:54 pm
by E30BeemerLad
I think they are cut from blanks rather than just being reprofiled, but that could be t'intenet guff

Re:

Posted: Fri Mar 12, 2010 7:56 pm
by N00b
E30BeemerLad wrote:I think they are cut from blanks rather than just being reprofiled, but that could be t'intenet guff
I suppose it the material they use is particularly exotic it could explain the price, but the profiles themselves could surely be copied as near as dammit by another company?

Re:

Posted: Fri Mar 12, 2010 10:12 pm
by DanThe
They use BMW blanks, BMW US S52 cams are over £500 per cam, so in comparison they are not expensive

I believe Catcams are around £100 cheaper per cam than Schrick

Re:

Posted: Fri May 28, 2010 7:21 am
by alexbaby88
US S50/S52 cams come up for sale all the time on Bimmerforums at about USD300 +/- per pair. For a M50/52 stroker, you need not go with $hricks.

Using OE parts I reckon holding out for M54 rotating parts, US S50/52 cams is the most straightforward route to get 3.0L (+).

Re:

Posted: Thu Mar 12, 2015 1:29 pm
by ryan_gwa
Sorry to dig up a relic thread, but I've had a M54B30 bottom end laying about for ages and want to do something with it.

Installing these into a M50 - is the only head option the M50?

Also want to clarify cams, Ive read rumours of being able to use the M54 inlet cam instead of forking out for Schrick?

Re:

Posted: Thu Mar 12, 2015 3:00 pm
by DanThe
The M54 cam is nothing like a Schrick, I will post some pics later but here are a pair of Schricks with an M52 2.8 cam in the centre
These are going into a 3.0 M52 I am building for somebody at the moment

Image

Re:

Posted: Thu Mar 12, 2015 7:48 pm
by ryan_gwa
Some difference there!

Everything just pops into a m50/m52 without modification or spacers?

Re:

Posted: Fri Mar 13, 2015 2:22 pm
by Automaton
N00b wrote:
E30BeemerLad wrote:I think they are cut from blanks rather than just being reprofiled, but that could be t'intenet guff
I suppose it the material they use is particularly exotic it could explain the price, but the profiles themselves could surely be copied as near as dammit by another company?

From www.bimmers.com:

"...The most well known aftermarket BMW cam manufacturer is Schrick. These are German cams made from new chill cast billets."