M20 B3x Naturally Aspirated Stroker build past, present and future

[digger]

I love seeing what can be pulled out of the m20, I really want to build my m30 up like these m20s.

m30 has lots of potential probably 20% more than the M20 as far as peak hp just due to the bigger bore, valves and headflow. i also like the fact that you get to 4L pretty easy and even 4.2L M30 these days. An engine like that would be a monster if built right

[2mAn]

:popcorn:

[digger]

i laid some thin plastic on the main airbox and put the carbon fiber on top to get a perfect fit. the plastic was there to stop it sticking. i put about 7 layers of 200g/m2 plain weave carbon fiber cloth which ended up 2mm thick and plenty stiff.

the rest of the box is 2x2 twill cloth which drapes better and looks more vibrant in a way. i deliberately chose plain for the lid to contrast plus it is more structural which is important since the lid only has slight curvature so could be too flexible otherwise

this is the lid.

[eb224]

Nice build. I have a Dbilas setup at the moment but it really kills the mid range of the engine, if you build a enclosed plenum and intake system I would be interested. Cheers Leigh

[Bearmw]

Incredible work. I too am interested in maxxed out m30 motors but question the feasibility of anything over 3.7L or so due to the bore spacing. How important is longevity?

[ThatOneEuroE30]

Incredible work I like seeing work put into m20's. One day i'll do the m30 one day.....

[LJ851]

Incredible work. I too am interested in maxxed out m30 motors but question the feasibility of anything over 3.7L or so due to the bore spacing. How important is longevity?

Cant really take the m30 bore much past 95mm, the rest of the capacity gains are in the crank (obviously).

http://www.pureperformancemotorsport.com/bmw-e12-e24-e28-e32-e34-m30-4-2l-stroker-kit.html

[ThatOneEuroE30]

Cant really take the m30 bore much past 95mm, the rest of the capacity gains are in the crank (obviously).


http://www.pureperformancemotorsport...roker-kit.html

Holy crap! What a price tag I'd just turbo it if i wanted more power.

[digger]

Nice build. I have a Dbilas setup at the moment but it really kills the mid range of the engine, if you build a enclosed plenum and intake system I would be interested. Cheers Leigh

i wont be building more than 1 it is too time consuming and it wont fit a dbilas setup anyway. RHD may offer something though. ive seen a prototype but not sure if it will be available or just a one off

[digger]

Holy crap! What a price tag I'd just turbo it if i wanted more power.

S38 crank is a cheaper alternative and will net about 3.7-3.8L tbh properly sorting the rest of engine will make a huge difference.

IMO the two piston design is poor with PPM stroker kit. i would buy the crank alone and get my own shorter rods and pistons.....when you target fictitious rod ratios and subsequently compromise the piston its a big no no. design the best piston you can, choose the engine size and fill the gap with a rod.

Everyone loves strokers these days, VAC now sell a 97mm crank for M5x engines. wont fit in an M20 unless you were talking about a short life drag motor ;) youd need a 2 ring piston, ultra small piston pin size and a custom aux shaft from quality steel. you could extend the block deck height with a spacer and sleeve it to run a longer rod and normal piston though but the timing belt and other issues would arise

[Dj Buttchug]

more on intake plenum design and molding pls op!

[Bimmer_man]

one of the greatest M20 builds ive ever seen

[JinormusJ]

[Bimmerman325i]

Wow. Subscribed for more!

I always wanted to do an all-out build on an M20.

[digger]

more on intake plenum design and molding pls op!

the idea is to run open trumpets but seal off the hot air and provide a means to filter the air, that is all its doing sealing off the trumpets. so i made it as big as i can within confines of hood, booster etc. .

mould is just foam shaped with a saw, files, rasps and sanded smooth. apply a thick coat of epoxy let it dry. sand it roughly so subsequent layers will bond effectively and apply coat of epoxy and sheets of glass or CF cloth then a thin layer ontop to make sure its fully wetted. trick is to cut pieces to size that drapes well and conforms to the mould. i did each layer in 4 pieces with overlap. radii can tricky same with corners to avoid pockets. then get a roller to squeeze out excess and remove air bubbles of each layer. it takes alot of time