best m20 stroker combination.

[cavpilot]

If you are looking close to 200 you will need atleast a 2.8l or a 2.7 with ITBS.

Im running 524td crank, CP pistons, 86mm bore, 135mm Eagle H-BeamRods, BimmerHeads cam and racesprings and 19lb injectors with stock intake, stock AFM, no head porting and ebay headers.

So, these numbers are with a stock ECU?

[CamE30]

yep stock ECU, stock AFM, no head porting, stock throttle body.

[cornchip]

Just starting to research this for my own build. My eta came with the “i” head, header, and a few other bits to do the swap. I thought I read you could get pretty close to 200hp just putting the head/header on without tearing the motor apart. Realistically how much hp am I looking at without racing pistons & rods & all that?

[2mAn]

maybe 155whp....

all of those setups above have much higher compression than yours.

[digger]

Closer to 140

[ForcedFirebird]

If you are looking close to 200 you will need atleast a 2.8l or a 2.7 with ITBS.

Im running 524td crank, CP pistons, 86mm bore, 135mm Eagle H-BeamRods, BimmerHeads cam and racesprings and 19lb injectors with stock intake, stock AFM, no head porting and ebay headers.

[IMG][/IMG]

This a little before and after for kicks and giggles. This was a few days after the build was done. I had it re-dynoed at it makes closer to 198hp and 215ftlbs. You can see where the intake definitely limits the power in the upper RPMS.

How much compression? We just did a budget stroker using eta crank/rods stock b25 pistons (~9.7:1), block shaved 2mm, stock cam and it made 180/178 at the wheels. Also no porting, just a good valve job...

[ForcedFirebird]

Just starting to research this for my own build. My eta came with the “i” head, header, and a few other bits to do the swap. I thought I read you could get pretty close to 200hp just putting the head/header on without tearing the motor apart. Realistically how much hp am I looking at without racing pistons & rods & all that?

maybe 155whp....

all of those setups above have much higher compression than yours.

Closer to 140

I did this years ago and hit the dyno (ignore the 200tq number, that was a fluke with the ignition pick up)...





Since then we played around with various combinations, most ever made was 145whp/170tq, stock eta bottom end with 885 head/cam, open headers, eta intake manifold and 325i throttle. Great for TQ, but a stock m20b25 is still more powerful.

[cornchip]

Since then we played around with various combinations, most ever made was 145whp/170tq, stock eta bottom end with 885 head/cam, open headers, eta intake manifold and 325i throttle. Great for TQ, but a stock m20b25 is still more powerful.

Oh. Well that’s disappointing. So basically not worth it at all. What like 20hp give or take? Geez.

Edit: so that’s with the eta intake.. I have the “i” intake too tho.. that’s worth what... another 5hp? hahah!

[cornchip]

block shaved 2mm

So still an engine out job. Hmm.

[2mAn]

The stock eta block CR drops when you put the 885 head on it. If you are happy with the block and dont want to pull it, you could search for a 731 head and go wild porting and adding larger valves. This will avoid the engine out and just be a head swap and you retain the stock CR, but it wont really be cheap

[cornchip]

The stock eta block CR drops when you put the 885 head on it. If you are happy with the block and dont want to pull it, you could search for a 731 head and go wild porting and adding larger valves. This will avoid the engine out and just be a head swap and you retain the stock CR, but it wont really be cheap

Interesting. Good to know. I already have the 885 tho so might as well just stick with what I’ve got.. assuming I ever go for it. Is it not possible to take the difference off the head rather than the block?

[2mAn]

Not from the head no, might be able to get away with a thinner headgasket... I would buy a new cam, rockers just enjoy that.

What header is it, because a good one can help make a difference with the cam

[cornchip]

I have the intake, head, & header from an “i” car.

[ForcedFirebird]

Oh. Well that’s disappointing. So basically not worth it at all. What like 20hp give or take? Geez.

Edit: so that’s with the eta intake.. I have the “i” intake too tho.. that’s worth what... another 5hp? hahah!

Bone stock eta is less than 100whp...

http://strictlyeta.net/pictures/dynoday/dynoday1/dyno_sheet.jpg

It's a nice upgrade for a stock eta if you don't want to pull the engine.



You can find eta engines for cheap. Just buy a spare to build while driving your car as is. Find some good used 325i pistons, shave the block 2mm and use the 885 head/parts on it, then you can swap it fairly quickly with no down time.

[cornchip]

Bone stock eta is less than 100whp...

http://strictlyeta.net/pictures/dynoday/dynoday1/dyno_sheet.jpg

It's a nice upgrade for a stock eta if you don't want to pull the engine.



You can find eta engines for cheap. Just buy a spare to build while driving your car as is. Find some good used 325i pistons, shave the block 2mm and use the 885 head/parts on it, then you can swap it fairly quickly with no down time.

Well… that’s a good idea!