M20b30

[Marneus]

Evening all,

I'm still thinking of ideas for a stroker motor in my 4dr & keep coming back to a b30....

Any ideas on what parts I'd need? As in which crank & Pistons to use? Would I need custom or are there any late engine parts I could use?

Cheers

Jamie

[steve_k]

Evening all,

I'm still thinking of ideas for a stroker motor in my 4dr & keep coming back to a b30....

Any ideas on what parts I'd need? As in which crank & Pistons to use? Would I need custom or are there any late engine parts I could use?

Cheers

Jamie

have a look at ireland engineering. not cheap though.

http://www.iemotorsport.com/bmw/E30-engine/m20-30.html

http://www.iemotorsport.com/bmw/E30-engine/m20-32.html

[Marneus]

Yeah, I've got their site bookmarked on my phone. I was just wondering if there was another way.... I don't fancy paying the shipping, insurance & import tax on their stroker kit (although a 3.1 would be fun! )

[steve_k]

all i can suggest is have a dig online, as far as i know i'm sure they used an S5x crank but as for pistons & rods i'm stumped.

[Marneus]

I'm sure I read somewhere that I could use an M54b30 crank with custom pistons but would like some clarification before I make my shopping list.

[Brianmoooore]

Click on the 'search' function on here, and type M20B30 into the 'keyword' box. Will bring up plenty for you to read through.

[jmc330i]

I remember reading on here that you would need some serious (expensive) head work for an M20B30 build to be worthwhile. There's also an issue with rod length... too short causes issues and longer rods (140mm??) will need custom pistons... The advice iirc was to stick to a B28 build for an M20 and if you wanted a B30, build an M50B30.

[Marneus]

I've been looking at bimmerheads race heads with 1mm over sized valves for it (with 284 cam) that should flow enough with some sort of ported intake manifold.

Eventually I'd like ITB's but that will be a few years down the line.

[reggid]

most economical way to achieve decent results is to get a m54b30 crank, m50 style 135 mm rods locally and a set of custom 85/86 mm slugs via the USA (be sure to get correct crown to match combustion chamber IE and topend can both do this others may not)

i would get a head ported by a local reputable mob with flow bench, that US mob dont use a flow bench so who knows if they do anything beneficial, chucking in a set of oversized valves needs to be done properly to see anything worthwhile. the shipping on a complete head is also not for the faint hearted

[Marneus]

I was hoping you'd catch this thread Reggid, your engine is a great inspiration to me.
I'll try source as many parts in the UK as I can. Most parts I should be able to get & sourcing the odd bit from the US shouldn't be too much hassle.

[reggid]

I was hoping you'd catch this thread Reggid, your engine is a great inspiration to me.
I'll try source as many parts in the UK as I can. Most parts I should be able to get & sourcing the odd bit from the US shouldn't be too much hassle.

dont copy what i did otherwise you wont do any better, and you can do better for less outlay. what i did was good for 2005 but these days its meh.......here are some tips

the key to hp is the head and cam combo. find a good head guy it will make the world of difference. the stock cast intake will become hindrance at around 240bhp no matter what you do with head and cam you start to get little gain so there is a point you just need to bin it (some might even say bin it from the start). you dont need as much duration as you think you need.

the key to torque is displacement, dynamic compression, squish / combustion dynamics.

you need a good way to do a custom tune especially with ITBs so dont neglect this.

[jmc330i]

I'm looking forward to seeing this take shape

[Marneus]

I've sorted the ECU out (not vems or megasquirt) and I'll get the manufacturer to tune the car once it's built. I'll get it running on the 2.5 the put in the 3.0.