M50 stroker or M20 stroker

[PeteD]

can you give me details about your build ? what parts did you use and what are the HP numbers ?

s50 bottom end, m50 top end, 325is non vanos intake cams.

200hp to the wheels. There is more room for power but the size of the injectors halted any more progress. To be fixed!

[Ryann]

..there are twice as many parts..

Shall we count up the parts in both heads? The cost of a head refurb varies directly with what actually needs to be done. That an m50 head will cost 2 or 3 times an m20 head at the machine shop is a presumptuous and thus bullshit statement.

..if you're building a stroker and using stock cams, you've just wasted your time.

Disagree with this 100%.

[BMW B3 2.5]

I have a 3.0 non vanos motor. I love it.

can you give me details about your build ? what parts did you use and what are the HP numbers ?

[5Toes]

that 2.8 can make 260hp with good tuning

[PeteD]

I have a 3.0 non vanos motor. I love it.

[BMW B3 2.5]

Since a few guys said m30, I'm going to go ahead a say m54. With zhp cams it makes as much power as the s50, but is all aluminum.

that is actually not a bad idea with headers and a gd remap it will make more power than a US S52 or S50

[BMW B3 2.5]

if i had access to us S50 i would bought it and called it a day :) and about the search well i just don't want to read a 30 page or more threads and most of the comments are suggestions of members to put an M30 S50 S52 ........ i owned an E21 with an M30B35 i sold it know i want to have a nice engine in my E30 but not for too much $$$ if i had the money and wanted an track car i would have bought an euro S50B32 with a 6MT so if anyone can and wants to help by giving me info or even links of builds those are really useful thank you in advance

[CrusherCurtis]

Since a few guys said m30, I'm going to go ahead a say m54. With zhp cams it makes as much power as the s50, but is all aluminum.

[F34R]

if i change the connecting rods an keep the crank and pistons ? for example can i use M50B25 rods ?

Go to the engine tech section and please for the long of all that is good SEARCH. It has been covered ten fold on anything you have been asking. You are not even asking hard questions, I am sure there is 1k+ threads started by people just like you in there.

How about you just put an s50 in there? It is just a bored out m50 with s50 cams. You WILL spend more building an m20 or m50 stroker than swapping in an s50.

Search my builds...built an m20 and it was a lot more than a s50 with transmission.

[BMW B3 2.5]

Unfortunately no, eta pistons, eta rods, and B27 crank will still lower your compression. You will be around stock m20b25 hp. You will probably get more out of your B25 bottom end with that head work.

Here is an excerpt from another thread: http://www.r3vlimited.com/board/show...&postcount=308

This was using a Myster-e head which sounds like similar to the head work you have planned.

if i change the connecting rods an keep the crank and pistons ? for example can i use M50B25 rods ?

[bimma360]

so for the M20 if i port and polish the head keep the M20B27 pistons and just throw in a 282 ro camshaft with larger injectors will the engine have 200 HP ow more ?

Unfortunately no, eta pistons, eta rods, and B27 crank will still lower your compression. You will be around stock m20b25 hp. You will probably get more out of your B25 bottom end with that head work.

Here is an excerpt from another thread: http://www.r3vlimited.com/board/show...&postcount=308

This was using a Myster-e head which sounds like similar to the head work you have planned.

[Bullet Ride]

what is your M20 build ? can you give me a link or more details ?

There is this nice tool at the top called "search" you know

http://www.r3vlimited.com/board/showthread.php?t=243359

[BMW B3 2.5]

M20 stroker all the way. My 2.8L stroker made 183whp/194wtq (running rich because of a bad O2 sensor) with a schrick 284 and Bavauto headers. However the shape of the curve lead me to believe that my cam was too advanced. I'll be going back to the dyno in 2 weeks with some retarded timing and a better fuel map hoping for something like 190whp/190wtq.

The only head work done was gasket matching the exhaust ports. Combustion chamber and intake side was stock except that I have no AFM because I'm running MS.

There's a number of good build threads out there (one of them is mine ;), just google M20 stroker.

what is your M20 build ? can you give me a link or more details ?

[BMW B3 2.5]

one problem with a full out build of an M50 is the cost of the head.

Take the cost of building up an M20 head, and multiply it by 2 or 3. there are twice as many parts and things such as cams are significantly more expensive. if you're building a stroker and using stock cams, you've just wasted your time.

also, if you're going to build a full out stroker on the basis of you can get a block for $600 your head is in the wrong place.

also for an M20 stroker you don't really need or want a TD crank. it weighs more and costs more for no real benefit. if you're going to bother you would be better off fitting the biggest stroke you can get to have the most potential torque output.

focus on the head. the cost of the bottom end is going to be nothing in comparison to a properly built head, and that is where you will see the difference between a motor that makes 170bhp and one that makes 240+.

if i go withe M50 build i will Regrind the standard cams to 254°/244 and if the stock internals are in a good shape i may reuse them
and do you have any idea what is the maximum HP that can be reached by an M20 engine if i keep the bottom as it is or maybe use other connecting rods with the eta block ,crank, pistons ,282 cam with headers and larger injectors ?

[Bullet Ride]

M20 stroker all the way. My 2.8L stroker made 183whp/194wtq (running rich because of a bad O2 sensor) with a schrick 284 and Bavauto headers. However the shape of the curve lead me to believe that my cam was too advanced. I'll be going back to the dyno in 2 weeks with some retarded timing and a better fuel map hoping for something like 190whp/190wtq.

The only head work done was gasket matching the exhaust ports. Combustion chamber and intake side was stock except that I have no AFM because I'm running MS.

There's a number of good build threads out there (one of them is mine ;)), just google M20 stroker.