best crank/rod/piston combo for m20 stroker ?

[jrabbit]

currently have 2.7i motor in my e30 [super e lower end, i cam, intake, 1.3 motronic, big six afm, 415 injectors ] i would like to upgrade, have access to s50 3.0 crank and rods, m52 2.8 crank and rods. don't know what combo works best for the street, pistons ? [need to run pump gas and pass tailpipe emissions] also how do you mod the crank to fit the timing cover seal. is the stock i cam best for street use, need torque for stop and go.

thanks for your input,
jj

[jrabbit]

have decided to go with m52b28 crank and s50 135mm rods, stock cam or 272 [have not decided] 85mm pistons,9.5:1 or less. has anybody built anything similar, trying for good street setup, engine will not see high rpm's on a regular basis. thinking that more displacement with less rotating mass [piston and rod] combined with mild or stock cam will make an awesome e30 commuter.

any input would be helpful,

jack

[nando]

that would probably be a good combo for what you are looking for. I just question spending that much on a motor that you admit won't be pushed very hard.. and it will cost the same amount regardless of your plans for it's use.

realistically for a commuter car, you should look into an M50/S50 swap. you aren't going to get good fuel economy with an M20 stroker (I'm betting I'll see around 17-18mpg when I'm done), but an M50 can make 200hp+ with minor mods, all while getting ~30mpg.

[jrabbit]

i have m52, m20 cores and one blown s50 engine at my shop, the only cost will be pistons, possibly a cam, gaskets, etc, and machine work. i have looked into s50 conversion, a good engine may be three grand, i don't know. it is a good thought to consider, i like the idea that the m20 is matched to the suspension, brakes, etc. i really like e30's, but always looking to upgrade. will definately think about it more before diving in.

thanks

[nando]

you are still easily looking at over $2k ($850-1000 for pistons, $500 for a cam, and then all the other misc. shit + machine work). I'm not saying don't do a stroker (I have my own reasons for going that route), but consider what you are looking for (a daily cruiser with more oomph), and consider what a stroker will get you vs. a swap. an M52 would provide everything the stroker does, with a better power band (dual vanos FTW), more upgrade potential and better economy. the only real drawback is the added weight, but it's not all that significant.

my stroker budget is currently $2200, but I've already done all the headwork (which actually cost me about the same amount, hah!). I also still need to get a new oil pump and other misc. bullshit like bearings and freeze plugs. I found a set of S50 rods for a good price, and I'm trading some parts for a low-mile block and crank, so my bottom end build costs should be similar to yours.