m42 into a 318i

[MrTom]

Well this thread bores me. I'm gonna pull my engine and tranny and see if the bellhousing mates up to the m42.

Then i'm not going to tell you if it does or not, just cause i'm mean.

[thejimlab]

Ill kill you! No, I'm just kidding. Let me know if it lines up, would save me a whole bunch of trouble.
Jim

[Febi Guibo]

Hey Jim, if you need more incentive to pull off his swap, check this out:

built-up M42 engine

I'm still working out the details, but it would make around 200hp at the crank.

[thejimlab]

I saw that, it's good reading.

[thejimlab]

bump...someone must have done this swap

[FredK]

Hey Jim, here's a blatant plug for myself:

I am doing a 24 valve swap on my 318is. Thus, my M42 becomes surplus to my needs.

The 178K M42 works great. No weird issues. Good power (we can do a compression test, and you can drive my car around the block so you can feel the POWA).

Anyway, I'm gonna sell my M42 uber complete, even including driveshaft for $600. You might be able to get a engine at a salvage yard for less, but mine has a whole bunch of cool shit included. :D Also, no wires will be cut, everything is still in the car! The problem with piecing parts together is that the costs will balloon out of control, making your swap eventually cost as much as a nuclear sub.

Here's what it'll include:

• Engine, includes wiring harness, ECU with both original and Dinan (currently installed) software. Excellent pull above 4500 rpm. Has an oil leak from some generic area on the front timing cover. Oil pan is miraculously dry as a bone. All accessories (ps pump, alt, AC comp).
• Engine mount arms and mounts (though the mounts are probably shot)
• Getrag 240 transmission; rebuilt because 2nd gear was hard to get into. It's still a little balky going into 2 when it's 35 degrees and below out. Once you drive a quarter mile, it loosens right up.
• Bav Auto short shifter (yes, it actually shortens the shift, so the only aspect of the car that reminds you of driving a truck is the gynormous steering wheel)
• Clutch. No idea how much mileage
• Driveshaft and center support bearing, and a cracked guibo. That's from all that MEGA torque that the M42 is capable of busting out.
• Radiator. You can have it, though I probably wouldn't recommend using it. No idea how old it is. Hoses. A timebomb waiting to strand you, but replacing them is easier if you replace them one at a time while the engine is on a stand.
• New transmission mounts, but no crossmember. Hey, I still need that! :D
• Intake components. Manifold, throttle body, elbow, HFM, stock air box
• Exhaust components. Manifold, downpipe / cat, rear section, O2 sensor

Let me know via PM! /End shameless plug.

[2002maniac]

The M10 shares the bellhousing with the M30 and S14. that's it. You need a 240 from a M42 car. Not hard to find for about $100.

Tranny from a M20 or M50 car would work too but they are heavier.

[thejimlab]

I bought an m42 parts car yesterday. I should have everything I need for swappage, and then some. Is there anything extremely important that I need to know?

[ZiMMie]

ull be a fool to boost the m42 instend of the m10. keep the m10. Very strong motors.

[thejimlab]

ull be a fool to boost the m42 instend of the m10. keep the m10. Very strong motors.

I have no plans for boosting. I just wanted to keep the handling characteristics of the 4 banger and get a little more power. All of the m42 owners really seem to love their cars, so I'm going to try this swap.

[moatilliatta]

hows the progress?

[thejimlab]

thread back from the dead. I have everything ready to come out. My biggest concern is fuel. Anyone have any idea if I will have to change fuel pumps? What about fuel lines? Is that charcoal cannister necessary? I don't think the m10 fuel system has a third line.

[FredK]

Yes, I think the M10 318i only had two fuel lines running to the front of the car, but they did have provisions for fuel expansion according to the ETK (realoem.com). I'm not sure where, but the car had a charcoal canister and expansion tank.

So, you shouldn't need to install the M42's charcoal canister. However, that leaves the issue of the electric valve that the DME will likely want to see, otherwise it will store an EVAP code. I believe the solution is to plug in the valve, let the hose dangle off the throttle body, but plug in some kind of small filter on the opposite side of the valve.

That leaves the issue of the pump. I don't think it'll matter too much. I mean, you're blowing 90 to 100 psi on two cylinders. You need to lean out the mixture anyway. HAHAHAHAHA.

HA.

HA.

HA.

No but seriously, I think the m10 fuel system is fine. It's the two pump system, right? There's an in-tank pre-pump and a main pump, the same system as the 325e. So, it should be fine.

[Hick]

i THINK theres no C101 plug on the chassis side of the 318i. Dont quote me, i have had an 83 and 84 318i and i dont think either has the plug.

This doesnt mean its impossible to swap motors, just that it may be pain as far as wiring the motor is concerned. You may be able to get away wit removing the old engine harness and simply powering the M42 ECU to run the motor, but again thats just a guess.

I swapped an m42 into an m20 chassis with very little problems. The only issues i had were that of the C101 plug [chassis side had a ground, motor side had a power wire] and removing and welding in the mounts for the m42 coil pack and air box. Aside from that it was rather painless.

[FredK]

I believe early cars had a different, rectangular (as opposed to round) C101, so he'd have to make a wiring adapter. It shouldn't be too hard to figure out.