m20 and m30 engines??

[Blackie_No1]

What are the differences?? are there any identifying marks to tell the two apart??

My car has been fitted with a 2.5 engine from a 5 series, i aint sure what age and want to know if it is the M20, with 170bhp or the M30 with the measly 150bhp.

It feels loads faster than the 318iS so i fink its the m20, but how can you tell them apart??

[Fushion_Julz]

M30 is bigger, chain driven and the cam cover has the oil filler nearest the bulkhead...

M20 physically smaller (and lighter), belt driven and the oil filler nearest the rad.

[Blackie_No1]

Thats the news i wanted to hear big fella!! Mine has the oil filter near the rad!! that means the 170bhp lump then??

[Ziggy]

I personally would be hoping for the m30... Makes it an easy job to swap a 3.5 in then! Realistically, it's going to be the m20 though - why would anyone go to all the bother of getting custom engine mounts etc for less power?!

Just look in the photo gallery for pictures of other peoples cars...

[Fushion_Julz]

Thats the news i wanted to hear big fella!! Mine has the oil filter near the rad!! that means the 170bhp lump then??

yep...sounds like it...except most standard M20 2.5s don't make the claimed 171bhp...
It isn't too hard to get 200-215bhp from an M20, but an M30...bearing in mind the same block can be up to 3.5litres as standard....can give 260bhp without too much cost/headaches...

As ziggy said, an M30 would be a choice for more power at the cost of (considerably) more weight!

The M20, though, is a standard fitment to E30s...320i and 325i both use the M20...whereas the only E30 factory fitted with an M30 block was the SA 330i

The fact it came from a 520/525i (presumably an E28 or early E34) means little...IIRC, there are a few detail differences, mainly to do with cooling hose routing/connections, but nothing to stop an almost direct swap onto existing engine mounts.
Slotting in an M30 means custom/fabricated mounts and uprating the front suspension to deal with the extra weight...Then you have the issue of the bigger gearbox/bellhousing fitting the transmission tunnel, the propshaft needing shortening, etc, etc...

Plenty of people here seem to have done it, so loads of experience to draw on if you fancy a go!

[Jimbob]

Er

It's nigh on impossible to get 210bhp from an M20 without Ԛ£Ã”šÃ‚£Ãƒ”šÃ‚£Ãƒ”šÃ‚£Ãƒ”šÃ‚£
Especially leaving it as a 2.5!

[Blackie_No1]

[quote="Fushion_Julz
The M20, though, is a standard fitment to E30s...320i and 325i both use the M20...whereas the only E30 factory fitted with an M30 block was the SA 330i

The fact it came from a 520/525i (presumably an E28 or early E34) means little...IIRC, there are a few detail differences, mainly to do with cooling hose routing/connections, but nothing to stop an almost direct swap onto existing engine mounts.
Slotting in an M30 means custom/fabricated mounts and uprating the front suspension to deal with the extra weight...Then you have the issue of the bigger gearbox/bellhousing fitting the transmission tunnel, the propshaft needing shortening, etc, etc...

Plenty of people here seem to have done it, so loads of experience to draw on if you fancy a go![/quote]

[Blackie_No1]

[quote="Fushion_Julz
The M20, though, is a standard fitment to E30s...320i and 325i both use the M20...whereas the only E30 factory fitted with an M30 block was the SA 330i

The fact it came from a 520/525i (presumably an E28 or early E34) means little...IIRC, there are a few detail differences, mainly to do with cooling hose routing/connections, but nothing to stop an almost direct swap onto existing engine mounts.
Slotting in an M30 means custom/fabricated mounts and uprating the front suspension to deal with the extra weight...Then you have the issue of the bigger gearbox/bellhousing fitting the transmission tunnel, the propshaft needing shortening, etc, etc...

Plenty of people here seem to have done it, so loads of experience to draw on if you fancy a go![/quote]

Nah i dont fancy that man!! LOL!! i have to get used to the power she has as is yet!! LOL!! she loves throwing the tail out without much provocation!!!

What does IIRC mean?? she doesnt have an airbox in her at the mo as the guy said the 525 airbox was too big to fit into the engine bay, it looks like the pipe between the AFM and the manifold is too long to accomodate the airbox, any suggestions??

[Fushion_Julz]

IIRC=If I Recall Correctly

The air box on a 325 is before the AFM...AFM has a pipe to Plenum

@ Jimbob....A tubular manifold should give you +10bhp a decent exhaust +3-4bhp
Blueprint the motor..another 10bhp (or even a decent rebuild with a good bore hone, balance and lighten)
Port the head and match to inlets...5-10bhp

Reckon you're there already....cost <Ԛ£1k

but if you need more, then you can always invest in a cam, vernier timing wheel and bigger valves

If you need even more, then improving the injection (slide throttles, for example) will get you there...

still on a 2.5 block, although a decent 2.7 crank and appropriate pistons will make it a little cheaper to get the power...

I raced a 2002 with an M10 motor...standard displacement...on 50DCO carbs with 198bhp at the flywheel and it was very reliable! Still exists and is going in a road car!

That cost about Ԛ£4k....OK not cheap, but it was built professionally and revved to past 8000rpm easily (peak power at 7200, though).

Bearing in mind the standard 2002Ti (on carbs) only made 115bhp, I think that was pretty good...
I also know of M10s, normally aspirated, on Kugelfischer with slides producing over 210bhp!