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M20b30
Posted: Sun Dec 13, 2015 7:41 pm
by 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
Re: M20b30
Posted: Sun Dec 13, 2015 7:47 pm
by steve_k
Marneus wrote: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
Re: M20b30
Posted: Sun Dec 13, 2015 8:24 pm
by 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! )
Re: M20b30
Posted: Sun Dec 13, 2015 8:27 pm
by 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.
Re: M20b30
Posted: Sun Dec 13, 2015 8:44 pm
by 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.
Re: M20b30
Posted: Sun Dec 13, 2015 9:09 pm
by Brianmoooore
Click on the 'search' function on here, and type M20B30 into the 'keyword' box. Will bring up plenty for you to read through.
Re: M20b30
Posted: Sun Dec 13, 2015 9:15 pm
by 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.
Re: M20b30
Posted: Sun Dec 13, 2015 10:35 pm
by 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.
Re: M20b30
Posted: Mon Dec 14, 2015 6:10 am
by 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
Re: M20b30
Posted: Mon Dec 14, 2015 7:25 am
by 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.
Re: M20b30
Posted: Mon Dec 14, 2015 8:10 am
by reggid
Marneus wrote: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.
Re: M20b30
Posted: Mon Dec 14, 2015 10:52 am
by jmc330i
I'm looking forward to seeing this take shape

Re: M20b30
Posted: Mon Dec 14, 2015 12:25 pm
by 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.