hypothetical build.

[kiwi535 538]

Just say you can get your hands on a e28 or e24 or e34 .You like big sizes,esp bmw big sixes.What modern big six wouldyou/could you build to put in one.How big can you build a m54?What else could you build.?could you build an efficient m30?I was always disapointed in how hungry my 535 was,but loved how the 535 actually drove/felt/sounded.

[_ethrty-Andy_ 2122]

just fit two sixes in there

[Ahmedsinc 414]

M54B30 would be a great place to start. Light, good power (230ish hp with vanos delete and DME remap) and easy to get parts for.

N53 would be nice too as they didn't get the valvetronic so would be easier to use an aftermarket ECU. Twin turbos and 3.0l displacement is attractive too.

Dunno about stroking the 3 litre to any bigger without a custom crank / rods / pistons. $$$$$$$$!!!!!!

My pick would be an M50B30 stroker with around 10 - 14psi in an E28. Iron block reliability with boost. Win!

Or just go mental and throw an S54B32 at any of the above

[BM WORLD 1258]

3.8L or 4l m30 m88 s38 etc

but don't expect ecnomy

[Rubix 434]

just fit two sixes in there

In a V shape

[eliongater 718]

E24 v12 (its just 2 m20s right?)

[_ethrty-Andy_ 2122]

E24 v12 (its just 2 m20s right?)

yes it is just two M20s

[BM WORLD 1258]

yes sort of with m40 heads

[kiwi535 538]

3.8L or 4l m30 m88 s38 etc

but don't expect ecnomy

economy is relative.I am ussually quite economical driver,but my average consumption in the 535 was prolly 21 mpg(13 l 100 k) .On the open road it was almost impossible to get less than 10 l 100k.My bloody automatic pajero is more economical than that.The only thing that saved the car was it had a decent sized tank so you could go a long way between fills and was such a nice drive.

[kiwi535 538]

M54B30 would be a great place to start. Light, good power (230ish hp with vanos delete and DME remap) and easy to get parts for.

N53 would be nice too as they didn't get the valvetronic so would be easier to use an aftermarket ECU. Twin turbos and 3.0l displacement is attractive too.

Dunno about stroking the 3 litre to any bigger without a custom crank / rods / pistons. $$$$$$$$!!!!!!

My pick would be an M50B30 stroker with around 10 - 14psi in an E28. Iron block reliability with boost. Win!

Or just go mental and throw an S54B32 at any of the above

so whats a stroked m50 b 30 come in at ?(cc i mean} iron block,alloy head....not so keen on that combo!

[Allanw 1051]

yes it is just two M20s

yes sort of with m40 heads

So it's (mathematically) two M20's with 3 M40 heads on?

Is that metric?

M54 is a nice engine - all alloy, so not too nose heavy. Probably going to use less fuel than an M30, with similar demands, but probably a better performer in full Vanos giuse - the M54's have an impressive torque curve, and are REALLY happy to rev. They're like an M20, but with some nice low down grunt. Plenty around too.

[Ahmedsinc 414]

so whats a stroked m50 b 30 come in at ?(cc i mean} iron block,alloy head....not so keen on that combo!

Within a whisker of the M54B30, so 3l. M50 has a slightly taller deck height than M54 but I don't think it makes much more than a couple cc difference. Drops the static compression from 10.5:1 to somewhere in the 9s. Personally I'd only go down that path if you like the idea of a turbo, otherwise just stick with the M54 - alloy block is around 30kg lighter than its ferrous cousin. More power and less weight = much Keeping the dual Vanos requires a suitable aftermarket ECU as the stock DME will only work if you transplant the fly by wire throttle, ABS brakes, dash cluster, key receiver and a bunch of other headache inducing gadgetry across from the donor car.

M54 is a nice engine - all alloy, so not too nose heavy. Probably going to use less fuel than an M30, with similar demands, but probably a better performer in full Vanos giuse - the M54's have an impressive torque curve, and are REALLY happy to rev. They're like an M20, but with some nice low down grunt. Plenty around too.

Agreed, but it does make it expensive to find a suitable ECU and a major pain to tune. Better to set it up as a single vanos engine and run it off a 413 DME remapped for the new fuel curve. Recently learned the M43 uses a block mounted crank sensor that sends a VR signal as opposed to the hall type M54 one, so it should be a case of swapping the crank & cam sensors for other ones to provide the 413 with a signal it can understand. I understand the oil pressure keeps the exhaust cam at 0˚ retard, from what I've read the exhaust side is more for emissions than torque / power gains so it might as well be ignored.

Neat little engines though, as you say they rev very happily and still produce enough grunt to launch our 2 tonne wagon about with ease. Probably quite economical mated to a manual gearbox too.

[_ethrty-Andy_ 2122]

So it's (mathematically) two M20's with 3 M40 heads on?

Is that metric?

yep its a 5L not a 305 lol