best m20 stroker combination.

[Chriskbmx]

so these are my goals for the m20 i want to build.
i want to make 200whp
i want to have a great power band with lots of torque.

i have been doing alot of reading latly and there seems to be a ton of different options for doing stroker motor. it seems the only way i can get to the horse power goals i want i have to do a stroker of some type. so this is what i know.

i was thinking the cheapest and easiest way for me to reach my power goals is this.

s50 crank
135 mm rods
10.5 to 1 compression pistons. could i run more on pump gas?
megasquirt.
21lbs injectors
a hotter cam, i was thinking a 284?
a good header. i have been doing alot of reading on m20 headers and it seems there are very few great options for it. supposidly if you wanna extrude the most horsepower out of your engine you need to tune the headers for the rpm range you plan on using it. any recommendations for a great header? or any place i can read up on so called exhaust tuning?

i wanna do something for the intake side of the engine because i feel like the intake would become a limiting factor with the extra air? any way to get better flow numbers without having to do a custom intake?

also want to do heavy duty rockers, probably ie.

i have been looking and its very tough to find good information on high performance m20's. if any one has a link let me know. so what do you guys think is the best m20 stroker?

[F34R]

I am glad someone has fucking read and researched instead of asking how to make one lol. Let's break this down, and try to follow to the end result goals you are after.
I have personally built two strokers: SETA turbo prepped monster(click my build thread link in my sig) and a 2.8 m52 knifed crank NA race motor for my brother.

I will explain it in a simple way: money invested for end result.

so these are my goals for the m20 i want to build.
i want to make 200whp
i want to have a great power band with lots of torque.

i have been doing alot of reading latly and there seems to be a ton of different options for doing stroker motor. it seems the only way i can get to the horse power goals i want i have to do a stroker of some type. so this is what i know.

i was thinking the cheapest and easiest way for me to reach my power goals is this.

People approach the m20 hp goal with the intent for cheap NA power. What they forget is the M20 is not cheap to get power out of NA verse M20 turbo or a simple m50 swap and cams and a chip. m20 turbo can be done dirt cheap or expensive, it would have helped if you posted a projected budget. m20, MLS, ARP, MS and a budget turbo can be done under 2,500 easy. It will nail down 250whp all day and be able to daily drive with ease.

s50 crank
135 mm rods
10.5 to 1 compression pistons. could i run more on pump gas?
megasquirt.
21lbs injectors
a hotter cam, i was thinking a 284?
a good header.

This was my long term goal with my m20 but with boost. NA you can get 200 hp but I would go with a 272 cam. It WILL NOT be cheap, 1,500-2,700ish for pistons, then you need rods(go for M3 rods if you cannot do Ross etc). I have close to 2,200 in JUST top end rebuild(best of the best).

(Mine)
Super ETA

b25(885) head upgrade/intake manifold
-Schrick 288 cam
-Schrick HP dual valve springs
-IE HD Rockers
-IE Adjustable cam gear
-Cometic .70 MLS
-ARP studs
-Guides, valves

There is no way around it, you will need MS if you want to manage this setup. The stock DME cannot handle all that change and run very well. I am sure you know that, just want to make it clear.

i have been doing alot of reading on m20 headers and it seems there are very few great options for it. supposidly if you wanna extrude the most horsepower out of your engine you need to tune the headers for the rpm range you plan on using it. any recommendations for a great header? or any place i can read up on so called exhaust tuning?

i wanna do something for the intake side of the engine because i feel like the intake would become a limiting factor with the extra air? any way to get better flow numbers without having to do a custom intake?

also want to do heavy duty rockers, probably ie.

Long tubes, and you are not going to be needing a tuned header on such low HP #s(no offence they are low). Equal/tuned headers and mostly used in HIGH hp dyno whore builds where extracting the last pony is a must/desire.

These fit GREAT and are priced even better.

http://www.ebay.com/itm/BMW-E30-325i-M20-Stainless-Steel-German-High-Quality-Long-tube-Headers-/160949405098?pt=Motors_Car_Truck_Parts_Accessories&hash=item25795505aa&vxp=mtr

i have been looking and its very tough to find good information on high performance m20's. if any one has a link let me know. so what do you guys think is the best m20 stroker?

Do a google search for 3.0 m20 builds, there are alot of them. I know because I have read pretty much all of them in prep/guidance for my last build.

Want my personal advice? do an m30, m50 or s50 swap. Each yields the #s you want as is, the power plant does not matter. The s50 has EVERYTHING you mentioned in spades at a fraction of a built m20 3.0. The cool factor of a m20 3.0 is SICK....but it does not compare to any of those mentioned above with simple bolt-ons.

Not trying to crush your dreams of a 3.0 NA m20, it is just not worth the money invested(trust me). Depending on what part of PA, I can get you an m50 or m30 easy and under 1k with transmission. Let me know, I have a few ;) If not google search around in the project section, use the 'Search' function for keywords: m20, 3.0

[Chriskbmx]

I am glad someone has fucking read and researched instead of asking how to make one lol. Let's break this down, and try to follow to the end result goals you are after.

I have personally built two strokers: SETA turbo prepped monster(click my build thread link in my sig) and a 2.8 m52 knifed crank NA race motor for my brother.

I will explain it in a simple way: money invested for end result.



People approach the m20 hp goal with the intent for cheap NA power. What they forget is the M20 is not cheap to get power out of NA verse M20 turbo or a simple m50 swap and cams and a chip. m20 turbo can be done dirt cheap or expensive, it would have helped if you posted a projected budget.



This was my long term goal with my m20 but with boost. NA you can get 200 hp but I would go with a 272 cam. It WILL NOT be cheap, 1,500-2,700ish for pistons, then you need rods(go for M3 rods if you cannot do Ross etc)

There is no way around it, you will need MS if you want to manage this setup. The stock DME cannot handle all that change and run very well. I am sure you know that, just want to make it clear.




Long tubes, and you are not going to be needing a tuned header on such low HP #s(no offence they are low). Equal/tuned headers and mostly used in HIGH hp dyno whore builds where extracting the last pony is a must/desire.




Do a google search for 3.0 m20 builds, there are alot of them. I know because I have read pretty much all of them in prep/guidance for my last build.

Want my personal advice? do an m30, m50 or s50 swap. Each yields the #s you want, the power plant does not matter. The s50 has EVERYTHING you mentioned in spades at a fraction of a built m20 3.0. The cool factor of a m20 3.0 is SICK....but it does not compare to any of those mentioned above with simple bolt-ons.

i get what your saying about doing the swap but that is not really my thing. i am into the m20. i like the idea of keeping the engine period correct. as far as build cost im not to worried about it. and i posted the 200HP number because i know that is very accessible. this is gonna be a very long term build. im just trying to gain the knowledge to do this. why m3 rods over i rods? and why not do a tuned exhaust if thats just better suited for the setup you are building?

[F34R]

i get what your saying about doing the swap but that is not really my thing. i am into the m20. i like the idea of keeping the engine period correct. as far as build cost im not to worried about it. and i posted the 200HP number because i know that is very accessible. this is gonna be a very long term build. im just trying to gain the knowledge to do this. why m3 rods over i rods? and why not do a tuned exhaust if thats just better suited for the setup you are building?

M30 is period correct ;)

M3 rods are 135mm and are a TON stronger(You cannot use b25 rods)(I would suggest s50 pistons too for an NA build). They are also alot stronger and cheaper. Granted custom pistons are stronger, but you will never hurt the S50 pistons that handle boost in the 400+ range easy.

You can snag an s50 bottom end all together for under 500. That is everything you need in the bottom end except for a crank spacer end cap.

Are you talking about the entire exhaust? You mentioned tuned headers or whatever. Do whatever you want, the long tubes I posted will be perfect and fit amazing for under 300.00.

I missed the intake upgrade question.

Now most think port and polish yields more power(I was one of them a few years ago), I know you did not mention that. I am explaining supported facts and #s in a thread below. The b25 head, intake flow more than an NA build can use. Now going turbo I can see a complete custom setup. This is all I can see you needing, it WILL gain more power and help the intake side.

https://www.millerperformancecars.com/catalogue.html?page=shop.browse&category_id=6

(Flow facts)

http://www.r3vlimited.com/board/showthread.php?t=261381

[deutschman]

You can also buy a stroker kit from some one like VAC or Ireland Engineering. They both sell good kits. The VAC kit is more expensive but I think might be of a bit higher quality. Cant say for sure though.
As fare as the tuned header. I think what F34R was saying is this. Tuned headers are not necessary for a 200hp m20.You only really "need" the tuned headers if you are trying to extract every last bit of performance possible from your m20, which you would not be doing at 200hp. A regular header would do the job just fine.
When choosing rods you need to take their length into account for two resins. First that the length of the rod will change compression numbers. Secondly that if your rods are to long your pistons and your valves will destroy each other. Of cores some rods are also better because they are lighter and/or stronger. Stronger is always good, and lighter is fun because you will have less rotating mass and there for an engine that revs up faster.
This PDF by Metric Mechanic may be of use to you. Read their section on the parts they use in their stroker m20 engines, and why they use those parts.

http://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=1&ved=0CDUQFjAA&url=http%3A%2F%2Fwww.metricmechanic.com%2Fpdf%2FM20-Engine-Booklet.pdf&ei=yA8GUcSTPM3MigKKjIDYBQ&usg=AFQjCNHq7UDnYEWy96K94y_ONSTU-Q5UqA&sig2=iRKQ12M13gP8yU1nmnKUbw&bvm=bv.41524429,d.cGE

[Chriskbmx]

haha i have thought about doing an m30 but i am not a fan of the extra weight. i wanna do some research on the tuned header thing though. even if i don't use it i would like to have the knoledge for future builds. i thought i rods and s52 rods were both 135mm? and what compression ratio would i get with the s50 pistons?

[Chriskbmx]

also i put the 200hp goal up as a starter. i feel like if i tuned everything together i could easily make 220. also what do you guys know about going to a bigger intake valve? i have heard that there is really no use for it. but in a na set up wouldn't you want it to flow as free as possible?

[tinkerputzer]

Headers are not something that should be overlooked when building a m20 of this level. I used "bav auto" headers made buy tubular design and have been happy with them. Bullet Ride will be organizing another group buy soon.

I rods and s52 rods are both 135mm. The s52 rods are lighter though.

I'm not sure on using s50 pistons. I think Ixer used some m54 pistons but it requires valve reliefs be machined into them.

Many who have built m20's including myself will tell you if you are building a stroker that requires custom pistons don't go any less than 3L because you'll kick yourself in the end for not going bigger. That metric mechanic catalog that was posted is a good reference for the different combinations.

Imo bigger intake valves aren't necessary but you definitely want a better cam. Schrick 284/272 is a good cam choice if it is to be daily driven.

If you are going through all the work of a building a motor go with an engine management system that will give you full authority like megasquirt. I'm running ms2 pnp from whodwho and am very happy with it.

Here is bullet ride's build which is an excellent resource:

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

My build:

http://www.r3vlimited.com/board/showthread.php?t=265471

Diggers:

http://forums.eurocca.net/showthread.php/20225-E30-331is

Some other good resources:

http://www.flickr.com/photos/peters-bmwmarlin/sets/72157625008707209/

http://www.msportster.co.uk/m20b28-engine-build/

[SkiFree]

Headers are not something that should be overlooked when building a m20 of this level. I used "bav auto" headers made buy tubular design and have been happy with them. Bullet Ride will be organizing another group buy soon.

If I'm not mistaken, those headers have a 1 3/8 primary, this is NOT ideal in the extreme. 1 3/8 is only ideal on a pretty much stock engine, the reason behind that size is that packaging into the E30 chassis can be pretty tight. You'd be much better off with an 1.5" or maybe 1 5/8".

[Chriskbmx]

Headers are not something that should be overlooked when building a m20 of this level. I used "bav auto" headers made buy tubular design and have been happy with them. Bullet Ride will be organizing another group buy soon.

I rods and s52 rods are both 135mm. The s52 rods are lighter though.

I'm not sure on using s50 pistons. I think Ixer used some m54 pistons but it requires valve reliefs be machined into them.

Many who have built m20's including myself will tell you if you are building a stroker that requires custom pistons don't go any less than 3L because you'll kick yourself in the end for not going bigger. That metric mechanic catalog that was posted is a good reference for the different combinations.

Imo bigger intake valves aren't necessary but you definitely want a better cam. Schrick 284/272 is a good cam choice if it is to be daily driven.

If you are going through all the work of a building a motor go with an engine management system that will give you full authority like megasquirt. I'm running ms2 pnp from whodwho and am very happy with it.

Here is bullet ride's build which is an excellent resource:

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

My build:

http://www.r3vlimited.com/board/showthread.php?t=265471

Diggers:

http://forums.eurocca.net/showthread.php/20225-E30-331is

Some other good resources:

http://www.flickr.com/photos/peters-bmwmarlin/sets/72157625008707209/

http://www.msportster.co.uk/m20b28-engine-build/

i just got done reading the metric mechanic link that was listed above and there was alot of good information.
so as far as im thinking looks like my best option for my power goal or even a little more would be this: listed below. now im only gonna use this car for sunday beating, track days, ect. not much dailying.

looks like i would want to go with an 85 or 86 mm piston in the 10.5 to 1 range
deffinitly go with s52 rods or custom rods? according to mm there is a huge benifit for going to longer rods.
89.6mm crank from an s52.
my question about the bottom end is what modifications need to be done to allow me to use the crank and piston combination? some say you need crank machineing ect? also have heard about crank spacers and machined intermediate shafts?
As far as top end goes its looking like this
ie hd rockers
bee hive dual valve springs
284 or 290 cam
obviously fully rebuilt with new guides and such.
anyone have any other options for good headwork?

[Mr. Burns]

(Mine)
Super ETA

b25(885) head upgrade/intake manifold
-Schrick 288 cam
-Schrick HP dual valve springs
-IE HD Rockers
-IE Adjustable cam gear
-Cometic .70 MLS
-ARP studs
-Guides, valves

There is no way around it, you will need MS if you want to manage this setup. The stock DME cannot handle all that change and run very well. I am sure you know that, just want to make it clear.

???

[RobertC]

Just did a nice stroker build for a customer.

2.7 Eta Crank
S50 135mm Rods
Metric Mechanic Pistons
Metric Mechanic Prepped cylinder head with Race/Rally Cam
Bav Auto style Headers
Stock Intake 19lb injectors
WAR Chip/MAF

With dyno tuning we pulled 197hp to the rear wheels.

[Chriskbmx]

what mm pistons did you use? sport or ralley?

[F34R]

???

Was talking about the 3.0 build he has planned. It really did come off as me saying my personal build needed MS. It does not, as I have already drove it on stock management with zero flaws. Could it use it? sure! any tuned MS management is an upgrade to 25+ year old outdated management.

[tinkerputzer]

what mm pistons did you use? sport or ralley?

They look like sport pistons.