M20 Stroker Project/Questions

[Nathanp17]

Hey, I'm pretty new to the r3v forum but have been around e30s for a little bit and have a bit engine knowledge after some diesel engine rebuilds and done some research into m20 strokers. I have a euro 86 325e 4dr, no power steering or A/C. Ideally I have a power goal in mind of 175-200whp

My build plan was:
M52 crank
m20b25 motor or b27
885 head
130mm rods
B25 pistons with skirts machined off
+1mm oversize valves
mild port and polish
272 IE cam
NUKE cam gear
36lb injectors I have kicking around
Generic header with 2.5" exhaust

Getting a 525e m20b27 motor that was running for free and just have to pull it out and will probably start with that block, fitting the crank for clearance and such. Cleaning block, painting it getting crank spacer made up.

I wanted to use megasquirt for the tunning, was thinking of running coil on plug. I have a a set of m50 coils and could make a mounting plate, and have thought about running a cam sensor and try sequential injection. I have 2 m50 cam sensors I could use if they'd work for that, an could add them into the m20 harness with coil wiring. As far as running megasquirt would I be better off building a box and harness rather than pnp if I want to run coils and cam sensor. What megasquirt version should I run? Any input would be greatly appreciated an hoping to get going on this project and start posting a few pics up.

[digger]

id start with stock style injector stragety and dizzy setup when doing standalone. IMO there just isn't much to be gained going to COP/wasted spark and fancy injection strategies for the added complexity the most benfits are in emmisions, fuel economy etc which are not usually the primary concern. Id look for something as PNP as you can

[Reichart12]

This is fairly close to what I put together last year. M52 crank, 135mm rods, custom +1 pistons, 284 cam, stock valves, 30# injectors, and megasquirt standalone. I have a nuke adjustable gear but have yet to adjust and cant say I really ever plan to. My exhaust is bavauto headers to a 2.5 single with resonator and muffler.

My best dyno was 193hp I think. Ive been told it could do more with supporting intake mods too. It was a nice experience to build and so far I have 20k miles on it in just under a year. Its fun to drive around but I think it would be even more getting rid of the e 2.93 diff for something like a 3.64 or 3.73.

[Nathanp17]

This is fairly close to what I put together last year. M52 crank, 135mm rods, custom +1 pistons, 284 cam, stock valves, 30# injectors, and megasquirt standalone. I have a nuke adjustable gear but have yet to adjust and cant say I really ever plan to. My exhaust is bavauto headers to a 2.5 single with resonator and muffler.

My best dyno was 193hp I think. Ive been told it could do more with supporting intake mods too. It was a nice experience to build and so far I have 20k miles on it in just under a year. Its fun to drive around but I think it would be even more getting rid of the e 2.93 diff for something like a 3.64 or 3.73.

Cool atleast that show's that my goal is somewhat achievable, might pass on the nuke gear then. I'm also running a 2.93 lsd. How was megasquirt to use? Its all new to me but i've used some AEM piggybacks before and made patch harness for an e36

[digger]

i would always use a cam gear on a performance engine it can make some nice changes to the way it drives if you play around with it. Sometimes the cam doesnt go in the way it should due to different deck height, head machining or inconsistencies in the manufacture if aftermarket

[Nathanp17]

Alright I'll probably pick up a cam gear for the added tune ability, now I've been reading that the m52b28 crank needs the counterweights machined. Is that true? Or could I get away with machining the bottom of b25 pistons off and slight turn down intermediate shaft on the lathe? Don't want to machine crank if i dont have to, don't mind grinding the block castings tho.

[digger]

Alright I'll probably pick up a cam gear for the added tune ability, now I've been reading that the m52b28 crank needs the counterweights machined. Is that true? Or could I get away with machining the bottom of b25 pistons off and slight turn down intermediate shaft on the lathe? Don't want to machine crank if i dont have to, don't mind grinding the block castings tho.

some have just shaved the pistons but it gets pretty tight, its worth mocking it up if you can avoid machining the crank

[Nathanp17]

Acquired more parts towards building my stroker, got my crank and in the process of checking it for bents and journal sizes. Otherwise still on the hunt for a m20 to use as a base but I'm putting together all the small parts first.

I have injectors, m52 tps, coils, crank spacer ring on order.

Started make a tps adapter plate up out of 1/4" aluminum, I will be shortening the throttle body shaft by 5mm or so for my adapter to work. All I have left is it drill the two remaining mounting holes and trim off the excess aluminum.



If anyone is interested, I have another adapter made this far and could finish it. Miight slot the mounting holes aswell.

I'm also going to be making a distributor delete plate possibly or buy a blank from a forum member, I'd like to add a cam sensor for SFI. I'm trying to find info on where the sensor needs to be mounted. If I have the cam at TDC and turn it to where the intake valves start to open is that where the sensor should be mounted? Probably a degree wheel will help with this, I may make a single tooth ring to mount where the rotor does on the cam and the use a clear blank to figure out the sensor location. Any help with this would be great.