Swapping in newer M42 and need a few pointers

[arrayxt]

I recently picked up a 1991 318i for dirt cheap that has definitely seen better days, and I'm now on the road to fixing it up to be my daily driver. The engine that's in it now is absolutely toast, timing was way off, nearly all valves bent, piston sent through the side of the block, etc. so obviously I opted to buy a better condition used M42 to swap in.

I picked up a new engine (plus a chipped ECU ) and it came from a euro car, so no a/c and single mass flywheel. My questions regarding swapping this motor in are:

- Are there any differences between the euro M42 and us/can M42 that I should be aware of? (besides single mass flywheel)
- The teeth on the timing gears are decently worn, down to a sharp point. Should I replace them soon, or will they be fine to use for a while?
- Is it easy to swap a/c from the old engine to the new one? (not even sure if it works)
- Would the Valeo 52161204 be an appropriate clutch kit to install with the single mass flywheel?
- The PO recently replaced the head gasket and timing cover gaskets. Is there anything else that should be checked or replaced while the motor isn't in the car?

Thanks for any help, it's very appreciated. Once I get this swapped in this coming summer I'm thinking of starting a build thread just for fun.

[roguetoaster]

1. O2 sensor single pin plug needs to be plugged in for most Euro DMEs
2. Pointy teeth do not necessarily indicate worn out gears, center scalloping does
3. Yes, bolt on
4. Not checking, but clutches are different single to dual mass
5. If PO actually replaced that stuff it should be okay, maybe vac hoses and VC gasket, but he should have done those too

[arrayxt]

1. O2 sensor single pin plug needs to be plugged in for most Euro DMEs
2. Pointy teeth do not necessarily indicate worn out gears, center scalloping does
3. Yes, bolt on
4. Not checking, but clutches are different single to dual mass
5. If PO actually replaced that stuff it should be okay, maybe vac hoses and VC gasket, but he should have done those too

1. Is that the black and white hot start cable I've read about on these forums?
2. Here's a picture of the timing gears:

3. Should I bother converting to r134a?
4. That clutch kit is meant for use with Valeo's own single mass flywheel, however upon inspection of their flywheel vs. the OEM flywheel they look pretty similar so I'm assuming it's good to go
5. Vacuum hoses look good but the VC gasket leaks, so I'll replace that, as far as I can tell everything else is good.

Is it worth changing any timing components before I even hear the motor running?

[roguetoaster]

1. Single pin connector, passenger side, under the cover mounted on the firewall
2. Those are beyond salvation, or at least the pic seems to show them that way, and I seriously doubt if any of the timing system on that car has been serviced
3. Yes, but do the entire system, not just refrigerant
4. Single mass is probably single mass, doubtful if it's proprietary
5. Spend nothing on an unknown quantity, especially if it's as neglected as the gears show. At least do a compression test before buying parts

[arrayxt]

The guy did a compression test for me before I bought it and the numbers were nice and high, so I knew it was good in that aspect, however if I had known that the timing system was in this rough of shape I probably would have reconsidered. I'm trying to learn more about this engine and E30's in general but I suppose I should have done more research before diving in haha, thanks for the help though

[downforce22]

there were two type of timing gears, that engine has the early, pointy style gears. the later squared style are different, but that doesn't mean the pointy ones are bad. As I read on a cycling forum the gear and chain wear together so I replaced the gears when I bought a new chain but there was no evidence that the original gears on mine were worn. The guides did show wear.







more info on my rebuild here https://www.r3vlimited.com/board/for...hful-track-car

[arrayxt]

Well, considering you're saying your old gears weren't really worn in comparison to the new ones, mine don't look much different than yours did so I definitely wouldn't doubt that my guides are worn and whatnot. I'm going to take the whole timing cover off and have a look at the condition of everything likely tomorrow.

[roguetoaster]

Both of your old gears seem to exhibit chipping, uneven base notch wear, and that seems to say that there was an issue with tension or link spacing at some point. However, even the loss of a full tooth probably wouldn't impact operation at all on a dual row chain, providing timing is centered on both gears.

[arrayxt]

Would it be worth checking the chain tensioner then? I know timing is off, I can kind of just tell the cams are off by a few degrees. I know there's supposed to be 15 links arrow-to-arrow (or so I read) and currently there's 16 links so I'll be sure to get that set properly before I even attempt to start the engine. AFAIK the bolts on the adjustable gears should be relatively centered in their slots.

[roguetoaster]

There's no checking the tensioner, either it's holding good tension when running or the timing system will be noisy. Always worth it to zero timing on an unknown engine, but approx one link one way or the other is probably okay. Centered is the ideal, and should be achievable even without cam locking tools.

[arrayxt]

Got it. Guess I'll figure most of it out once I hear the engine running, other than that I'll check timing components tomorrow and go from there Sent from my ASUS_X018D using Tapatalk

[roguetoaster]

Fair enough, if the remainder of the timing system passes a visual it's NBD to replace cam gears once the engine is installed. Also consider doing the upper oil pan gasket while out of the car if it shows any sign of leakage.

[arrayxt]

Right, is it worth taking off the oil pan anyways to check for loose bolts?

[roguetoaster]

50/50. I have never found any, but others routinely find them, so, if in doubt, do it.

[Andrew325is]

I believe that Valeo clutch kit is for their own single mass flywheel that’s meant to be a replacement for the DMF. I would get the correct Sachs clutch kit for the BMW flywheel.