M20 2.7 or M50 2.8?

[DADDG]

Hi i own a E30 325i convertible and i have a real dilemma 1st of all what i'm after is 200+ bhp 2nd Reliability! so here goes, what do you all think is the best conversion M20 2.7 or M50 2.8 ?. I'm swaying towards the M50 mainly because it seems to me more value for money?
Can anyone let me know also where i can find more info on the M50 transplant i.e. pro's & cons, parts needed,which exhaust manifold ? etc.....

[Karan]

defo more value for money... but if it wasnt an option id have a race spec m20 2.7 on throttle bodies etc

[m-dtech]

m50 2.8 will give better fuel consumption and similar performance.

m50 is lighter than m30

m30 has slightly more torque but heavier so not sure if it would make much of a difference.

[oze30]

m50 2.8 will give better fuel consumption and similar performance.

m50 is lighter than m30

m30 has slightly more torque but heavier so not sure if it would make much of a difference.

He ewants M20 not 30!

[Karan]

no one said anything bout m30???

[DADDG]

Thought about m30 3.5 conversion just for simple ease but as you said fuel consumption and similar performance would be on par with m20 2.7 and m50 2.8 edges it for me at moment

[Gunni]

M30 doesnԚ´t waste alot of fuel in a E30,
I did 10.8/100kmh the other day with one,

[DADDG]

has anyone bought the anything from zionsvilleautosport.com apparently they have full step by step conversion on cd called project orca?

[m-dtech]

there is this website, he used them i think

http://www.e30m50.com/E30/mym50swap.htm

[jonb]

if your prepared to convert to the m50 then forget the 2.7.

a 2.8 m50 will piss all over the funny money 2.7. so will a 2.5 m50 by the looks of it.

2.7 is a great motor when done properly, but doesnt give much gain for the Ԛ£Ã”šÃ‚£Ãƒ”šÃ‚£.

[bigdek]

2.8 is m52 is it not

[WillG]

i think it depends on if you want to do a conversion or rebuild

[Ant]

Good call Will !

the 2.7 is the only option to include a complete engine rebuild, might be worth bearing in mind when pricing those M50/52 engines, dont forget you'll need a matching gearbox for the 24V engines, and a taller(lower ratio ) final drive to get the best from them

Still not an M50 fan, they just luuuurve to pi$$ oil out all over the place

[DanThe]

they just luuuurve to pi$$ oil out all over the place

Are you pointing out similarities Ant?

[Ant]

But of course, just the leaks are easier and cheaper on the M20

seriously though, nothing leaks more oil than a tired M50, cam chain tensioner and profile gasket anyone ?

[DanThe]

Changed the sump gasket on mine after id fitted it in the E30,

Never again

The fibre gaskets used on the early engines are absolute crap, updated gaskets are steel

[m-dtech]

im going for the m50 conversion

sourcing parts as we speak

[Andyboy]

M50 is easier than you think. The way to go is a Ԛ£250 ebay 525i with a decent dry engine, M20 flywheel and clutch and bog standard M40 318i gearbox. This bolts straight onto an M50, costs about Ԛ£30 to buy and because it's an 0.81 overdrive means you don't need a different diff. You can also use a 320i prop, another worthless item. The 318i box is pretty strong and providing you don't kick the living shit out of it will tolerate an M50 okay. The E34 525i radiator also drops straight into an E30 with no mods. I'm sure the 525i downpipe can be mated to an E30 centre box with some deft modding.

The M50 is 192 bhp from the box, 200 bhp with a chip. If you get a J or K plate non vanos unit it's 2 hours max to lift the lid and drop a pair of Schrick cams in for 220 brake - never mind all this M20 drama of removing the head and punching old rocker shafts out. The M20 is just old, old news and when you can buy something so superior for peanuts - why bother? As for oil leaks, I beg to differ - the M20 is a shocking thing for oil leaks, the front cam oil seal being a prime suspect as well as the cam cover and the four rubber half moon seals.

Do it the above way and you could have it in the car running and driving for Ԛ£500. Then so sell all the remaining E34 bits on Ebay to get some of that back. Buy an H plate 525i and you might even be lucky enough to get the early one with the overdrive Getrag 260 box attatched.

A 2.7 has it's place but to get 200 bhp costs a lot of money.

[DADDG]

Not sure if i agree with oil leak scenario my daily drive is a 2.5 e36 with f/s/h to 96k then specialist for 20k no sign of a leak yet Maybe i,ve been lucky or who knows what the future holds will the m40 gearbox fit a M52 engine as easy as m50

[m-dtech]

i thought the vanos was the m52 units ??

[DADDG]

what are the differances between a M50 & M52 except for cc

[DanThe]

M50 - 2.5 - Non-Vanos or Vanos - Iron block

M52 - 2.5 or 2.8 - Vanos - Alloy block

If you drop an M50 into a RHD E30 you will need to fabricate a manifold/frontpipe to mate up to an E30 centre box

[DADDG]

Hi i own a E30 325i convertible and i have a real dilemma 1st of all what i'm after is 200+ bhp 2nd Reliability! so here goes, what do you all think is the best conversion M20 2.7 or M50 2.8 ?. I'm swaying towards the M50 mainly because it seems to me more value for money?
Can anyone let me know also where i can find more info on the M50 transplant i.e. pro's & cons, parts needed,which exhaust manifold ? etc.....

[DADDG]

thanks for that isn't btb making them saw something on site saying they could be around Ԛ£400+ depending on interest & if a proven fitment of M50/M52 is sorted ie; e36 rack or standard, engine mounts E28 M5 or 535 or aftermarket mounts, which engine s50 m50 etc

[jmc330i]

BTB is meant to making a 6 branch manifold for an M50 conversion, but that is also suitable for the S50 engine, but Im not sure how far its got.
TBH I cant see how it will work well for both M50 and S50 engines, but they are the experts.

As for 2.7 M20 or 2.8 M52 - its got to be the 24v conversion (either 2.5 M50 or 2.8 M52). As has been said, its a cheaper way of getting 200bhp and youre not getting involved in an engine rebuild.

[DADDG]

i've been looking through a few bmw sites at E30 conversions and apparently a E46 320d 6 speed gearbox will mate to M50/M52 using M54 clutch no problem is this possible

[m-dtech]

i have been looking at some power figures between vanos / non vanos 2.5 and 2.8 m50 engines.

id personaly go for an early non vanos 2.5 and consider turboing it at a later date if more power was desired.

take a look at

http://www.bmwworld.com/engines/m50.htm

difference between 2.5 and 2.8 is pitiful (in standard tune)

[Dan318-is]

i have been looking at some power figures between vanos / non vanos 2.5 and 2.8 m50 engines.

id personaly go for an early non vanos 2.5 and consider turboing it at a later date if more power was desired.

take a look at

http://www.bmwworld.com/engines/m50.htm

difference between 2.5 and 2.8 is pitiful (in standard tune)

The reason the m52 has such bad figures is because it was restricted from the factory so it had a lesser performance than more expensive models in the range. with a m50 throttle body and manifold an d remap they can see 225 brake in standard form; the alloy bock is also a lot lot lot lot lot lighter than cast iron anchor that comes with the m20/m50 imho; i think if i was going through any hastle whatsoever to install something like this in an e30 i would make sure i did it properly; put a light m52 in there, spend a couple of hundred tuning it and piss over most conversions out there

[m-dtech]

225bhp after the hassle of wiring up vanos etc, pissing about with re maps. for 35bhp more than standard 190bhp from 2.5 non vanos....

id rather spend on turboing 2.5 non vanos and get near on 300bhp

[DADDG]

while i tend to agree that its hassle for the extra bhp, once it s done properly thats it also if you go with the non vanos with new cams and the right exhaust mainifold your 200bhp+ which is still a big improvement on standard spec engine, compared this to a good 2.7 rebuild or turboing which is the most hassle

[Dan318-is]

225bhp after the hassle of wiring up vanos etc, pissing about with re maps. for 35bhp more than standard 190bhp from 2.5 non vanos....

id rather spend on turboing 2.5 non vanos and get near on 300bhp

yep then you've got the hastle of either a) paying around 800 quid to get standalone management and a re-map or b) the hastle or wiring and mapping megasquirt to deal with the turbo

[DanThe]

i've been looking through a few bmw sites at E30 conversions and apparently a E46 320d 6 speed gearbox will mate to M50/M52 using M54 clutch no problem is this possible

The bolt pattern is the same but there are some serious hurdles to get over.

Gear linkages needs shortening (wait till you see it in standard form), you will need a custom prop, spigot bearing needs a carrier machining to bring it out into the gearbox
Thats as far as ive got, the gearbox support needs modding to fit the E30 tunnel, clutch is a PITA, the new gearboxes use a different input shaft spline with about twice as many teeth, because the boxes are so recent there are no spurious clutches so its a dealer only part ATM.
Ԛ£150 just for the centre plate


Heres a couple of pics of the linkages just to put you off





Both need shortening by about 50mm

[m-dtech]

225bhp after the hassle of wiring up vanos etc, pissing about with re maps. for 35bhp more than standard 190bhp from 2.5 non vanos....

id rather spend on turboing 2.5 non vanos and get near on 300bhp

yep then you've got the hastle of either a) paying around 800 quid to get standalone management and a re-map or b) the hastle or wiring and mapping megasquirt to deal with the turbo

yep totaly

id go for option B its going to see more power

[oguz327]

I am still not convinced about the m50/m52 conversion, some of the options will still cost nearly 2.7 money unless you are very good with a spanner. What are the torque figures for these engines?

Personaly i will be going for the oldskool tryed and tested 2.7. Sounds awsome, easy to work on, you get a rebuilt engine and it will drop straight into any 6 cylinder e30 with hardly any mods.

[DADDG]

will rule out the 320d gearbox then just looked through a old total bm mag at a 3.2 evo conversion which was done by Zoom motorsport last year, tried web site & tel no. no joy Do they still exist