m20 or m42?

[mikeedler]

The 318is is already a bit lighter and has better weight distribution due to the smaller motor. It would also be better do not do the 2.7i thing, it really doesn't make that much of a difference I don't think. Just boost the engine you already have rather than have the headache of swapping motors

there is a 50hp difference right from the beginning before you would even turbo the motor. of course you will get more power out of a 2.7l displacement. the sound of the M20 alone is reason enough to swap to it!

[jaye30]

The 318is is already a bit lighter and has better weight distribution due to the smaller motor. It would also be better do not do the 2.7i thing, it really doesn't make that much of a difference I don't think. Just boost the engine you already have rather than have the headache of swapping motors

you dont know what your talking about. clearly you have not ridden in a stroked m20

[Dj Buttchug]

m42 is also more expensive to boost.

[mr2peak]

m20 will take less boost to reach that goal, less boost usually equals better reliability.

[ApexGoblin]

sr20det swap?

lol nahh im too much of a bmw lover to do that... maybe if i had multiple e30's :P but i was thinking more rb26det though

[Dozyproductions]

sr20det swap?

[acolella76]

The 318is is already a bit lighter and has better weight distribution due to the smaller motor. It would also be better do not do the 2.7i thing, it really doesn't make that much of a difference I don't think. Just boost the engine you already have rather than have the headache of swapping motors

[ApexGoblin]

ok so i have a 91 318is with the 1.8l 4cyl m42 motor in it, i also have a m20b25 motor and trans that i bought. my goals for the car are around 300hp when its all said and done. this said i have read both m20's and m42's can achieve this hp range (if i was turboing a m20 i would do a Frankenstein with build with 2.7 lower and 'i' head). so with that in mind that I have both engine options, its really just which one should i invest the money into?

considering:
-money needed to achieve desired result
-power to weight ratio
-reliability (as it will be on the street with occasional canyon running and track days)
-etc.

any opinions would greatly help!