M42 to M20 Swap

Author Topic: M42 to M20 Swap  (Read 9989 times)

Romrog318is

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M42 to M20 Swap
« Reply #15 on: April 19, 2010, 01:34:32 PM »
^^^ well kinda wat he said... BUT no the M20s are probably one of BMWs most reliable motors..... my friend was trying to blow his up and it had 270k on it and it wouldnt go...
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no more M42

Sarstan

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M42 to M20 Swap
« Reply #16 on: May 02, 2010, 02:55:10 PM »
If I can hijack the thread since it's going the direction of my question.  What sort of parts would you guys start from a stock 318is to get it (more) track worthy?  I know my shocks are out, but I'm curious what others move through first.

deekay

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M42 to M20 Swap
« Reply #17 on: May 02, 2010, 04:41:07 PM »
Quote from: Romrog318is;91100
^^^ well kinda wat he said... BUT no the M20s are probably one of BMWs most reliable motors..... my friend was trying to blow his up and it had 270k on it and it wouldnt go...


all you have to do is wait long enough on the timing belt :P

anyway that is kinda less the point of what i was saying. it's more work to swap in an older engine that makes less power. you'd probably spend less money and have less headaches putting an m50 in. if a swap is what you're after, i don't see why you wouldn't go that route.
5-lug'd big-braked torsen'd hardtop'd ITB'd m42 vert
"the e30 colin chapman would have built" ;)

B318M42W

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M42 to M20 Swap
« Reply #18 on: May 30, 2010, 05:47:38 AM »
our m42's are much lighter than the m20, and smaller too, giving us the possibility of doing pretty much what we want with it (mod-wise) Maybe your engine isn't running right and don't have all the 134 horsies working for ya.

+1 with chipping it
might be interested in a lightweight flywheel too
replace fuel filter if it isn't already done, might help free up a few hp's up high
check your spark plug condition - worn?
drivetrain resistance?

just a few places to poke around if some maintance was negleted...
« Last Edit: May 30, 2010, 05:55:55 AM by B318M42W »
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M90 Blown M42 :cool:

NisseJärnet

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M42 to M20 Swap
« Reply #19 on: May 30, 2010, 04:14:21 PM »
M20 is a great engine :)
-88 E30 325i M50 6spd turbo, 764whp
-89 E30 318i M42, 140hp COP conv. (E36 engine + gearbox, 3.73 188 diff)
-90 E30 318is M42 turbo, 240whp (sold)
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DesktopDave

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M42 to M20 Swap
« Reply #20 on: May 31, 2010, 09:59:08 AM »
I like them both.  The torque of the M20 and the peakiness of the M42.  It's Bavarian Motor Works after all...they're really serious about good engines.

On the M20 side the the valve adjustments and timing belt changes are a PITA.  But, no worries about cam chain/tensioners/guides, profile gaskets and leaky radiators.  And the baby six is so deliciously smooth.

On the M42 side you get less weight and it's all further back, better flow through the head, far better fuel economy and even some cam timing magic on the later models.  On the downside...oil leaks like nobody's business, ridiculous prices for motor mounts, buzzier car, transmission is less durable, the diff is undersized.  I'd like an oil cooler too, but that's quite a bit more difficult than the bolt-on M20 version.

Speaking of swaps, who's going to be the first to put a newer (like post-1993) BMW engine in an e30?  The N52, N54 & N55 look very promising, don't they?

Six of one, half-dozen of another...
« Last Edit: May 31, 2010, 10:03:00 AM by DesktopDave »
'08 Karmesinrot 128i 6MT
'86 Zinnoberrot 635CSi (M30B32/G265/3.46 torsen LSD)

Sold: '97 Montrealblau 318iS, '91 Brilliantrot 318i, '91 Brilliantrot 318iS

Romrog318is

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M42 to M20 Swap
« Reply #21 on: May 31, 2010, 12:42:42 PM »
Quote from: DesktopDave;93080
I like them both.  The torque of the M20 and the peakiness of the M42.  It's Bavarian Motor Works after all...they're really serious about good engines.

On the M20 side the the valve adjustments and timing belt changes are a PITA.  But, no worries about cam chain/tensioners/guides, profile gaskets and leaky radiators.  And the baby six is so deliciously smooth.

On the M42 side you get less weight and it's all further back, better flow through the head, far better fuel economy and even some cam timing magic on the later models.  On the downside...oil leaks like nobody's business, ridiculous prices for motor mounts, buzzier car, transmission is less durable, the diff is undersized.  I'd like an oil cooler too, but that's quite a bit more difficult than the bolt-on M20 version.

Speaking of swaps, who's going to be the first to put a newer (like post-1993) BMW engine in an e30?  The N52, N54 & N55 look very promising, don't they?

Six of one, half-dozen of another...



ive already seen some N5X swaps done...
but still the OBDII in those is kind of a bitch... but still i cant believe this thread is still up... the M20 is a great motor but performance stuff is not cheap! lol
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