Build up the m42? or go 24 Valve?

[fiftytakedowns]

Im thinking about doing a cam, and ITBs (maybe the rad dbilas setup)http://www.esatclear.ie/~bpurcell/m42wow.jpgI would like to go this route in the future. (stock bottom end, maybe port the top) and have a cam. but Also thinking about going to a 24 valve swap. But I am wondering if it would feel as fast, or fun as 24v, the car would be a lot lighter, and still as nimble as a 318, but not sure how the torque would compare, or how the car would pull. (top end pull is fun too :)

I think that it seems more realisitic than going 24v (hard to come by time as a student, and I'd like the 24v to be done RIGHT so it would cost more money to do so.

I dont want to rev my motor past 8, but would like to find a setup that would maximize or pull all the way up to about 7.5 cams itbs or whatnot.

opinions?

[Fast Frankie]

how much power would a stock bottom end, ported, ITB m42 make?

[fiftytakedowns]

200 with some good headwork.
My guess
anyone have that program that can do all that math stuff, and guestmate
desktop dyno

[johnwoo]

build the m42

[e30s52]

24v will be cheaper if its a m50 or m52...

[fiftytakedowns]

It's just tough, because I am not sure what I want, or which is better at what, I have been thinking so hard about them both that I have kinda merged all the thoughts

For now I would just go aluminum flywheel and cams for the m42. then later commit to a better build up. Not sure If I should just ignore that stuff, and just leave the motor as is, and wait for swap. etc... Im running in circles sort of.

then in the future go 24v swap (2 years or so)

I have done motor swaps (on 2002s) before and they really are a huge pain. that is why I am considering just builing up the motor. Also for the funds

[balooshinakus]

24v is going to be cheaper then building that motor with cams/ITBs I'd bet. 24v swap isn't that much of a pain. Biggest advantage to the m42 is the weight of it, so I guess it kind of depends on how much you want the lower weight. 24v will make more power in the long run though

[BUDNUNTA]

The x50/52 swaps are so gravy now.
Everyones doing them, the motors are getting dirt cheap, its imho cheaper for more power and one thing the m42 will never have is torque.
Being a 318 you would want to change the trans driveshaft and rear but its not necessary.
That does increase the cost but once again the parts are cheap and plentiful.

I love the m42 though. A built 1.8 m42 would be a blast. but your going to have $4-5K it that as well.
Dbilas- $2k? redone head $2k(cheap side) cams, vlaves, springs, it adds up quick. Then you'll need a clutch, dont forget tuning(stand alone? chip?)
You might make 200hp but no torque. Bolt in m50 numbers
It'll add up quick either way.

Id go with the m42. Way more unique and rewarding in my eyes. Plus a a screaming 4 banger is soo fun. What came in an e30 m3?
There was a Dbilas intake setup on m42club for sale a few months back

http://m42club.com/forums/showthread.php?t=9166&highlight=dbilas

Good deal. Theres a head start.




Hunter

[z31maniac]

If you build a 2.1L M42 with ITB's it would be cool.

Otherwise 24v.

[91 318is]

Kind of in the same boat as you. I've been thinking of going the 24v route, but the little M42 is such a fun engine, it would be neat to build one up.

I honestly never knew there was much of an aftermarket for M42 internal's, links?

[e30pq]

Stay with the M42 and build it. The 24v swap is becoming the norm. I've done a 24v swap and it was great but the swap that gets the most attention was when we pulled the M20 out of our 325i club race car and dropped in a built turbo M42.

Check these links for details on each build

http://www.m42club.com/forums/showthread.php?t=9663

http://www.r3vlimited.com/board/showthread.php?t=107147

[BUDNUNTA]

Kind of in the same boat as you. I've been thinking of going the 24v route, but the little M42 is such a fun engine, it would be neat to build one up.

I honestly never knew there was much of an aftermarket for M42 internal's, links?

they're out there but most of the 2.1 M42s around use mostly bmw parts.
m47 deisel crank and modified s52 pistons

Heres a good thread on it

http://m42club.com/forums/showthread.php?t=6866

Plus the pistons are super cheap.
I got 4 VAC forged s52 pistons of a guy on BFC for $200 shipped.
The e36 guys blow up motors, trash 2 pistons and we ge the leftovers.
Perfect





Hunter

[fiftytakedowns]

I am wondering if it would be worth it to put in cams, and a flywheel right now, then wait it out to see waht I really want..

If I were to build up the m42, I wouldnt do too much. I think literally I would just do the cams and the ITB's that dbilas offers (170 horsepower without headwork, according to their website.) right now I have Mark D, and supersprint.

[91 318is]

they're out there but most of the 2.1 M42s around use mostly bmw parts.
m47 deisel crank and modified s52 pistons

Heres a good thread on it

http://m42club.com/forums/showthread.php?t=6866

Plus the pistons are super cheap.
I got 4 VAC forged s52 pistons of a guy on BFC for $200 shipped.
The e36 guys blow up motors, trash 2 pistons and we ge the leftovers.
Perfect


Hunter

Oh ok, that's pretty sweet. Are the M44 and M42 crank the same? I know the engine my 318is was changed over and the guy told me it came out of a 95 E36. From what I heard, the E36 M42 (or is it an M44) had all forged internals?

Anywho, so the S52 pistons are 3mm larger then stock pistons, can youuse stock M42/M44 rods? I guess I need to go back and read some more, lol.

[Rob]

neither building up a M42 or doing a 24v swap will be "cheap" on a student budget.

I'd get the suspension sorted, hit some autocrosses and maybe some HPDEs, if the clutch needs replacing do the flywheel while the tranny is pulled, and enjoy the reliability and mpg of the M42. Save the builds/swaps for when you can afford to do either right. I'd rather have a stock E30 than an half assed project...

MHO of course.