Engine Swap - M20b25 For S14 - BMW Forum

SynSyx · 08-30-2005, 11:46 PM

Hey, just playing around with the idea of doing an engine swap in my '89 325iC. Thinking mostly about putting in the S14 motor, since its the same chassis type and would probably be the easiest "S" motor to fit.

Some questions: are the engine bays in all E30's (including the M3s) the same size?
Are the motor mounts hard to change/deal with?
What else needs to be replaced for an engine swap besides tachometer (redline of 7000 or 7500 i forget instead of 6250 currently)?

Thanks!

german-speed-demon · 08-31-2005, 12:02 AM

I'm sure you have done your homework on this, but here is a little something i cooked up.

http://members.aol.com/ronchecca/faq.htm

And on top of that, didn't the s14 come in the nissan? WTF if your thinking of putting it in your BMW.

And the s14 revs to 7800, just to let u know.

Anyhoo, staying on subject, depending on width between mount brackets on the motor, you wouldn't really need to change much at all. If you're going auto to manual, thats a different story.

Dave

SynSyx · 08-31-2005, 10:10 PM

yeah i mean the S14 engine from the E30 M3

not sure about transmission swapping yet, i dont mind the auto except for its bad rep.

87 325iS · 08-31-2005, 10:18 PM

Do you have any idea how expensive an S14 is?

SynSyx · 08-31-2005, 10:27 PM

no, thats one of the things im trying to find out

DJProfessor · 09-01-2005, 08:20 AM

you already have an I motor, you ought to just think about hopping that up. those can be made to scoot for far less than the cost of a motor swap, esp. with an M motor......

Bmw1990 · 09-01-2005, 11:29 AM

Plus the S14 motor isn't exactly a monster of an engine. Yes it does have more hp, but it was meant to stay in the E30 M3. Also an S14 doesn't do well with modifications. Also they have to be rebuilt about every 100,000 miles. I would stick with the engine you have and rebuild that, and get new cams and bore it out maybe.

87 325iS · 09-01-2005, 12:32 PM

Quote:

Originally posted by Bmw1990@Sep 1 2005, 10:29 AM
I would stick with the engine you have and rebuild that, and get new cams and bore it out maybe.

[snapback]373845[/snapback]

M20 only has 1 cam. Get an S50 instead.

Bmw1990 · 09-01-2005, 01:00 PM

I meant to say one cam, my bad. Actually an s50 swap is very common in E30's. If money is not an option that would be a very nice upgrade.

DJProfessor · 09-01-2005, 02:29 PM

yes, but it is very damn heavy...........i would personally weigh the costs....

I motor with:
-M throttle body convo w/MAF conversion
-bigger injectors
-chip
-header with exhaust
-cam (and if you pulled the head to do it) decked head with mild port and polish
-lightened flywheel
-underdrive pulleys
-p/s delete (if you want to take it that far and get a couple of extra ponies)

and for big dollars

-don't deck the head, and rock two headgaskets and go turbo.
-or deck the head and do the diesel bottom end

VS>

doing the e30 M motor swap or the heavy s50 swap

personally i would hop up the I motor, it's a good base from which to start from......or you could always give to me to drop in my e21, she is only getting an e motor right now....and she asked me the other day if she could have an I motor for Christmas instead......

BMW Lover · 09-08-2005, 02:44 PM

there are some companies out there that mess around with the m20 and make it a 3ltr through a conversion of parts obviously, you might want to look into that instead, or just rebuild it and get a solid turbo kit for it, the m engine is outrageously expensive to upkeep and to upgrade, and you dont really get that much of a hp dif...seambmw.com is a company that does the m20 conversion i am sure there are others too. good luck

SynSyx · 09-15-2005, 08:52 PM

wow thanks guys, youre right, the s14 motor would be pretty expensive in the short and long run, but talk to me more about the s50 and turbo for the 2.5i motor

DJProfessor · 09-16-2005, 11:30 AM

Quote:

Originally Posted by BMW Lover

there are some companies out there that mess around with the m20 and make it a 3ltr through a conversion of parts obviously, you might want to look into that instead, or just rebuild it and get a solid turbo kit for it, the m engine is outrageously expensive to upkeep and to upgrade, and you dont really get that much of a hp dif...seambmw.com is a company that does the m20 conversion i am sure there are others too. good luck

yes i was reading about this......i have also heard the oldschooler trick of swapping in a diesel bottom end to make it stroker, great to build on too if you want to add boost at a later date.

and the more i think about this, the more i am thinking about doing it <_<

325eXTATIC · 09-16-2005, 01:05 PM

Haven't I read that you can do an Eta block and i head? Or am I mistaken? If so... you can get the torque of the longer throw pistons, and the HP of the i head/cam/valves. And of course there are handling issues that can make your car FEEL faster! M3 upper control arms, Bilstein Sport Struts, IE stage 2 springs, strut tower bars, sway bars and sway bar supports, camber plates... yadda yadda yadda! A good combo of all of these will give you a "seat of the pants" opinion that your car is faster... and on a track, it WOULD be!

Just throwing in my 2 cents!

Josh W.

DJProfessor · 09-16-2005, 04:09 PM

actually the only difference between the E and the I (if i am not mistaken) is the head. i heard you can swap heads, but i do believe the FI system is a bit different and you have to have the I goodies to make it work.