E30 2.7i build

I have an 86 325es, and a parts 89 325ix, I'm wanting to build a 2.7i out of the two motors. Does anyone have any good information about this build? I'd like to use my bottom end, and the IX's complete top end. Thanks...

Sean

I've been wondering the same thing. I've heard of it before, but couldn't find any info.

I can find a lot of different info on it, but that's just it, it's different from place to place. I found a nice write up on it in a European print mag, but it has all UK CR ratios, I wish I could find a write up on the US motors. i just thought I'd try here and see if anyone knew anything. Hopefully I can find out something.

Basically, put the i head on the e block. Go over to http://www.e30tech.com/ and look in the engine forums. This was a pretty common setup before a world where newer/better M50 could be had for $800. IMO you are better off grabbing an M50 out of an E34 and dropping it in there. It will be cheap to buy and make about the same or more than the 2.7L M20 with some potential left over for when you happen upon that set of S50 cams for $300 on ebay.

IIRC, the distributor rotates counter to the other M20 engines--maybe oil pump as well.

Will Bates

http://www.r3vlimited.com/board/showthread.php?t=125429&highlight=stroker

http://www.r3vlimited.com/board/showthread.php?t=100939&highlight=stroker

Two good threads from r3vlimited on the subject.

I second walterj's sentiments, unless you're doing the stroker to maintain an original looking bay go for an m50/m52 swap instead, newer/better engine design with much better management.

e30tech and r3vlimited have excellent information on the m50 swap as well.

umm, dosent it kill your compression ratio?

edit reading the links, it can take you down to like a 8.4:1 comp ratio.. i thought i remembered someone mentioning it was lower then that. would be good for a turbo app though.

Yeah, I've read that it drops the CR to 8.1:1 - 8.4:1, I'm thinking about doing the swap because I have all the parts laying around the garage. It'll make the car a little more entertaining to drive, and it also uses a better engine magament system, until I can get a v8 together for it An LS1/T56 setup would be nice, but I may go with an old school iron block aluminum head setup, it will just depend on money.

You can always deck the head before it goes on to raise it back up. Might be worth doing even just to correct warpage from 20 years of use.

The lower compression could make it a good candidate for a supercharger down the road!

an "E" block with an "i" head has less than 8:1 compression. If you boost it that's okay. N/a? no thanks.

A 325i has 8.8:1 compression stock. A SuperETA has 8.5:1 compression stock.

I've done the SuperETA/325i hybrid before. Loved it. Couldn't tell you about the M50 in an e30.

Here you go

http://www.r3vlimited.com/board/showthread.php?t=97872&highlight=stroker

actual dyno sheets of the low comp "stroker" setup

Yeah, I've seen this post before, but I'm pretty sure that he's running the UK spec stuff which had a much higher CR than our stuff here....so even when they lose a bunch of compression they are still above 9:1. I wish I could find some good info on a US spec build to see what it produces. Thanks though...

Build a stroker using 24v parts and your current block/head, or just save the money and 24v.

I have an S52 waiting to go OBD-I at my dad's warehouse.

my superETA with 325i head made 155 hp and 162lbs of torque at the tires on a dynojet.

The S52 would be nice, but how much?

If mine were a SETA I would have already done the swap, it would be alot easier that way, no wiring to deal with, just swap the top end and the dme.

I think when it's all said and done I'll have spent 4000-4500 on the swap. But I'm also doing a new radiator, e36 rack, obd-I etc. Glad my girlfriend isn't on here to see that number!

Yeah, she'd have a cow....but for that much I could probably have an ls1 in it. I've seen ls1/t56 combos with an ecu and wiring harness for around 3k, and I've got a buddy who can fab up the mounts and do the install. That's the dream anyway, it's going to be a while though

Maybe I am having a senior moment - didn't this magazine do a feature on a modified (for track duty) 325 with an upgraded 2.7 eta engine as described here. Would have been years ago, but I could of sworn this is where I learned that the "fuel efficient" version of the 325 really had a 2.7 litre engine, to recover low end torque and make-up for the lack of RPM capability that resulted from the weak valve springs (for lower valvetrain friction?), if memory serves me.

Mark

SEdgell wrote: Yeah, she'd have a cow....but for that much I could probably have an ls1 in it. I've seen ls1/t56 combos with an ecu and wiring harness for around 3k, and I've got a buddy who can fab up the mounts and do the install. That's the dream anyway, it's going to be a while though

In my opinion that's way more power than the rear suspensions of these cars han adequately handle. Having a bunch of power isn't any fun if you can't get it to the ground.

z31maniac wrote: In my opinion that's way more power than the rear suspensions of these cars han adequately handle. Having a bunch of power isn't any fun if you can't get it to the ground.

The rear of these cars can handle a lot of power, but you need to bolster the diff mounts and make sure you use axles from one of the more powerful (Z3 MCoupe, etc) . Stiffer springs and dampers to manage the exta-sudden weight xfer and your gold. I've seen a good number of 400HP+ E30s at the track and they get out of corners pretty well when setup right.

One of my best friends runs 11's in his boosted e30. he replaces guibos regularly, but the rear end has never failed in any way.

Yeah, there's a nice video on youtube of an e30 m3 with a twin turbo 3.5L in it, chasing down a Carerra GT at the Nurburging, and he doesn't seem to have any traction issues.

SEdgell wrote: Yeah, there's a nice video on youtube of an e30 m3 with a twin turbo 3.5L in it, chasing down a Carerra GT at the Nurburging, and he doesn't seem to have any traction issues.

Isn't there a video of that car trying to run the quarter mile, and spinning through the 8th? Or is that the guy that did the huge single turbo 3.5 litre?

I haven't seen that one, could be the same guy, but in the video I saw it seemed to hook and go.