I think this is very good question about the two cars.

What is the biggest difference between the E30 318i drivetrane and the E21 320i drivetrane?

From looking at pictures the engines seem to be the same so then what about the transmission.

I have an M roadster SSK and was thinking couldnt i install that into an E21 because it does sure look they share the same engine and tranny.

I could be wrong if not then thats awsome because i could find a low mileage 318i motor and swap it into the bay of an E21. Or maybe go m42 if i still want good gas mileage and a 4 cylinder.

I kinda like the styles of an E21 i just found one for 1k with new paint and seems legit and its 45 minutes away. 203k however but as well know they are tanks and this car has 103k to go before it starts to putter.

Ask nic,

He has a m42 in his e21 and he is bulding a 300 hp monster turbo.

There is very little difference between the e30 m10 and e21 m10 drivetrains but there is no perfromance to be gained by swapping them.

The M42 swap is a good one for some increase in perfromance and is not too difficult. Serious performance gains call for boost or larger engine swap. Any BMW engine can be made to fit the e21, from the m20 to the V8....

ken

There is very little difference between the e30 m10 and e21 m10 drivetrains but there is no perfromance to be gained by swapping them.

The M42 swap is a good one for some increase in perfromance and is not too difficult. Serious performance gains call for boost or larger engine swap. Any BMW engine can be made to fit the e21, from the m20 to the V8....

ken


How about an S70 engine? :)

http://b.im.craigslist.org/6O/h1/sbERsDXt48BvEV8BiRBYKa6qiQY7.jpg

http://a.im.craigslist.org/xQ/SG/wVHmErYgwGFKUN0MJqBwMqN3WyAQ.jpg

Its a 1980 5 spd with 203k miles. it has a fresh coat of paint.


Is 1k a good price for it?

Is the s70 the v12? That one is a little long...

If the car is rust free, runs and shifts well $1000 is a decent price.

ken

I'd do an M50 swap with M3 cams. ;)

I figured this out a long time ago:

"Don't do what others want or would do. Do what YOU want". The engine in my car has been called a "boat anchor". So be it. They can all kiss my posterior, I didn't do it for 'them', I did it for me. I think these posts are a little hard to read for me. I really think that deciding on a project is a personal choice.

http://e21.tricord.be/members/M42powered/DSC03290.jpg

Nic,
Don't take that stuff so personal. I have always admired your car and still seriously consider doing a m42 swap into one of my cars. The m42 does pretty darn well for it's displacement and it looks WAY better than the m10.

Bang for the buck it's hard to beat the m42. There are bigger engines with more power but you won't get them in there as easily and they will cost a bunch more. Heck, you can't even do a decent stock rebuild of a m10 for the cost of a low mileage m42 and trans!

ken

What car does an M42 come from, just curious... Is it an e36 1.8 by chance?

^^
If I'm not mistaken the m42 is from the e36 and later model e30 318's. Please correct me if im wrong.

Kool, that's the swap I am going to do in the future in my car with a DASC (Downing Atlanta Supercharger) and I will most likely build the motor up before I do it.

Nic,
Don't take that stuff so personal. I have always admired your car and still seriously consider doing a m42 swap into one of my cars. The m42 does pretty darn well for it's displacement and it looks WAY better than the m10.

Bang for the buck it's hard to beat the m42. There are bigger engines with more power but you won't get them in there as easily and they will cost a bunch more. Heck, you can't even do a decent stock rebuild of a m10 for the cost of a low mileage m42 and trans!

ken

No one on this board is guilty of shooting down my swap. And everyones oppinion is their own. I am just sharing my experiences with others. I'm not saying I regret it, I'm saying the opposite. Everyone here knows I could give two $#!ts about what other people 'think'.

^^
If I'm not mistaken the m42 is from the e36 and later model e30 318's. Please correct me if im wrong.

This is correct, E30 318is only. I believe the M42 stopped in 95 in the E36 models. Dead give away is the intake manifold.

Kool, that's the swap I am going to do in the future in my car with a DASC (Downing Atlanta Supercharger) and I will most likely build the motor up before I do it.

DASC says their kit does not fit on 1991 motors (which came out of E30's). Most kits I have seen are installed on M44's which are post 95 (not 100% sure on that year though). E36 M42's I BELIEVE can work. You'd have to contact them with the year of production. DASC is a good choice and can make BIG power (seen dyno sheets for 250 with a massaged M44).

Oooh! That's a promising proposition! Yeah, I didn't plan on using an e30 motor, but thanks for the heads up! The M44 is a better motor then? I was just going to use an early e36 318 motor.

Oooh! That's a promising proposition! Yeah, I didn't plan on using an e30 motor, but thanks for the heads up! The M44 is a better motor then? I was just going to use an early e36 318 motor.

This is NOT neccesarily true. Pro's below (con's are a moot point):

Pro's of each:
M42 has an 8 counterweight crank, M44 = 4 counterweights (read better balanced, high REV)
M42 has oil squirters (atleast my E30 motor does, not sure about M44)
M42 has forged crank and rods (M44 does not)
M44 is 1.9 liters as opposed to M42 1.8 liters
M44 has DASC bolt on capabillities
M44 has knock detection and suppression, M42 does not (one of my concerns)

All of these are based on research I have done for an E30 motor. I can't speak for E36 M42's.

Thank You very much for that! I was thinking about doing a gut replacement as well, so what motor do you think would be better for this? I saw how the early motor has forged crank and rods, and those seem like one less thing I would have to change if I were to rebuild the whole motor. I plan on port/polishing the head, hard springs, and stainless oversize valves and obviously the stock cam. Is there any improvement to be had in forged pistons in this case? I would assume that there would be no increased compression ones. What you say about there being e36 m42s and e30 m42s makes me think that they are most likely the same. I shall do some research before I do this and I want to make sure it is done 100% properly so that the car is reliable.

You will be hard pressed to find "off the shelf" pistons for an M4x motor. Trust me, I tried. Mine are custom CP units in an 8.5:1 compression ratio. Stock is 10:1. The ultimate setup would the be a mix of all of the above pros. I have no idea if this has been done or is even possible. Using an M42 crank and rods means 1.8 liters. Therefore the ECU would be weirded out for use with knock detection (as this ECU is only available on 1.9 liter motors). It's a tough call which is "best". I obviously made my choice.

Yep, I am going to make sure I look into all possibilities because atm I am building a fresh head for the car to last another good amount of miles because the current head is leaking a little oil and I want to put on my mikuni 44s and have a hairier cam. I am going to make sure that this is done correctly if I do it at all, I could always buy a 318ti! Also, I have to say that m42 looks extremely at home in your e21!