View Full Version : 3.5 conversion in E30

02-12-2002, 02:42 PM
Ok I know that everyone is gonna tell me the M50 2.5 is the best conversion to do but for some reason the 3.5 intrests me more. I want to keep my E30 low tech so I can work on it.

The absence of torque in my 4 banger is driving me insane. also I like the fact that the Big Six block has been built for a long time. I don't have much experience with this engine and would like some info from you guys. I know Korman has a lot of performance parts for the 3.5 as well as a turbo kit I think.. but I want N/A power and lots of it! Does anyone know of a write up on this conversion?

Also i'm a little worried about weight.. I can lighten the front of the car a little but i'm still a concerned about turning my e30 into a "mustang" I would like to track the car still so i'm not 100% sure at this point if i'll go through with any conversion.

I'm having a lot of problems with my M42! otherwise I think I would keep it.

Thanks guys


'88 325e
02-12-2002, 06:31 PM
...his name is Dave and he is a really cool guy.

I will guarantee that anyone will say that is it a pain in the butt to do the 3.5L because you have to relocate the rad support. Unless you are daddy war bucks then go for it.

The torque would be so insaine that you would never use first gear.

02-12-2002, 06:56 PM
I have someone to do the welding to get everything in there and I have someone to wire it all up.. I just need the parts to do the job..

Were can I buy a good 3.5? Are heads interchangeable can I gain some hp numbers by swapping heads or plaining down the existing head. Whats the difference between the 535 motor and the M5? maybe i'll do the 3.8 stroker kit??? Now there would be some real torque!

I have a 4.10 limited slip so i might need to change tranny gears or the tranny itself i'm not sure about that!


02-12-2002, 10:14 PM
also the tranny tunnel has to be made larger and some relocation of other parts too that is a pain to do alot of people in germany have done it check out www.e30.de

02-13-2002, 12:20 AM
Ryan... don't bother. The car will be in the shop more than on the road. I don't even think Motronix will even do another conversion (not worth the time and $$$). Just get an M50 with a blower. I'll be just as fast.... the 3.5L only has 211HP.... a blown M50 has 300+ with way more torque!

GR8 Ride
02-13-2002, 12:44 AM
Depends if he wants to drive it on the street or the track.

Street reliability, yeah, I'd suggest going for forced air. It's relatively cheap, and on the street, it's reliable enough for ordinary use. You could probably get 100,000 on a supercharged motor if properly maintained.

If the car is to be a dedicated track beast, then forced air gets into some reliabilty issues, heat soak etc.

Not impossible to manage, but forced air on a track motor will significantly reduce it's life expectancy. This is primarily due to being on the gas flat out, 80% of the time. Head gaskets tend to suffer, et al.

The "big six" does fit into the E30, but it SEVERELY changes the balance of the car. I'd doubt anybody in Toronto has the proper knowledge to balance the car out, even if they were able to do the conversion. It might be bloody quick in a straight line, but it would be a pig to corner, and won't have anywhere near the precision it has currently.

A 3.2L M3 motor is a better bet in that sense.


02-13-2002, 12:59 AM
the weight of the 3.2 is almost the same as e30 motors with the aluminum block 2.8 being lighter then the s14 i belive. honestly if your gonna do the 3.5 y not the m5 engine or even better do a v12. i wass soo tempted to buy a v12 and squeze it on in but the thought of my brake boster being in my glove box detered me greatly. the 3.5 swap is nice but if your gonna be on the track then just invest in a m50 or 2.5l s14. if you realy want n/a hp then think euro m3 engine but that 2 needs some relocations

02-13-2002, 02:24 AM
Randy I hear ya.. but i don't wanna spend $15,000 on a blown 2.5 when I could do this conversion for about $6,000.. Keep in mind my car is olny worth $6,000 in the black book.. well so is yours :D :D but you know what I mean.. I don't have an unlimited budget.. so I might not even do the conversion! i'm still in the possibility/planning stage Nothings gonna happen till the fall if i do go through with it.

Right now i'm saving up for my Rims.. BTW Randy how did you fit 8 inch wide rims on your car.. I would love to find a set of 17x8's but I'm not having any luck. I don't want chrome or polished.

Thanks guys for the help!! vodomagoo too bad I can't read german that site has it all


02-13-2002, 08:10 AM
No problem Ryan. I see your dilema now... mostly price. Well, It sure would be cool to see a big six E30 bootin' around the GTA and I know you haven't been to the track yet (didn't you sign up this year??) so maybe the 3.5L might be an alright choice.. you just need someone to install it for you. If I'm not mistaken, I think it bolts up to your M42 tranny. The first people that come to mind for that conversion are www.pjcautoworks.com (site currently down) on the Danforth... they race a 460HP Supercharged V8 E30 beast (and actually win!) and can probably do the conversion you ask for a reasonable price... call them up and inquire.

PJC Autoworks Ltd Phone: (416)694-7242

3290 Danforth Av, Scarborough, ON M1L 1C3

GR8 Ride
02-13-2002, 10:17 AM
Bill is also running a 3.8L S38 motor in an E30 chassis as well.

It's a pretty quick car also.

The biggest issue, however, remains the balance of the car.

Bimmer (I've got the issue somewhere) had an article on a 3.5L powered E30, and it was quite a driveability nightmare until Frank Fahey tuned the whole car up and had it working right.

The Big six is called that, simply because it's a much larger block than the *small* six that makes up the 2.5/2.8/3.0/3.2L E30 and E36 motors.


02-13-2002, 04:17 PM
The article in Bimmer was about a s38 not a m30 in the e30 chassis. I have no idea what the weight difference betweent the two is, although the s38 is probably heavier due to the 24 valves, complicated intake, stronger block, etc.

02-13-2002, 04:42 PM
go to altavista.com and use babble fish(there translator) on e30.de it helps alot still confusing