M42 Oil Cooler

[gearheadE30]

I was at the track over the weekend and saw oil temperatures up around 280F. It was still climbing, but a fast lap followed by a cool down seemed to keep it in check. Any tips on where to find an oil cooler for the engine? I really like the idea of the adapter plate that sandwiches between the block and the oil filter housing, but it looks like those are out of production.

By the way, the M42 is a really tough little engine. Untouched 270k mile bottom end with 8 psi of boost for 200 track miles on 90 degree days and the only problem I had was high oil temp. Even with the turbo, it only lost 1/2qt of oil.

[Gerta]

Did you check with Metric Mechanic? Maybe JakeB?

[gearheadE30]

I haven't checked with either of them. I suppose I should check with VAC as well, since they have some support for the M42.

[ccsdo5]

If anything what you can do is drill two holes in the oil filter housing cap and have someone tig weld on AN fittings and run it to a oil cooler. Making the AN lines is pretty easy as too. A company called Victory used to make them I don't think they do anymore though.

[gearheadE30]

I'm really not a fan of bypassing the filter, even for a small portion of the oil... also, I don't think two holes in the cap would really get you anywhere, unless I'm missing something. I'm not sure what the flow direction is inside the filter housing, but I think the pump sends flow to the center of the filter, around the bolt that holds the cap on. The top of the filter seals against the center lug of the cap, forcing the oil to pass through the filter, and then flow back down into the engine. In order to use the pressure drop across the filter to push oil through a cooler, you would have to pull oil basically from the bolt that holds the cap on, send it to the cooler, and then plumb it to the other side of the filter with your welded bung idea. This is, of course, assuming that the pressure differential across the filter is enough to push flow through a cooler, and not so much that all the oil goes through the cooler instead of through the filter.

TLDR: two welded bungs on the cap would both be pulling from the outside of the filter, which has no pressure differential and no oil would flow through the cooler.

[TobyB]

It's been a while, but when I did the gasket on the E36's M42,
I remember looking at it and thinking there'd be a way to add fittings
to get oil to go through a cooler. But I forget how exactly that was...

Maybe get a spare housing and have a closer look at it?

If you run a full synthetic oil, 280's not going to hurt anything...

t

[gearheadE30]

I think I will end up getting a spare housing, since they are only ~$50. The idea would be to block a section of the internal feed to plumb a fitting, run an external thermostat and small cooler, and then pipe back into the engine.



Anyone know which direction the oil flows? I got the impression that it flows in the lower square ports and out the upper round one, since I think the upper has the head's anti-drainback valve in it. I don't really have a good idea as to what the small port that doesn't seal to the block is, but I have to assume it is something like a pressure relief should the filter get clogged.

Re:oil temps - I was hitting 280 about 15 minutes into a lapping session, consistently. That is oil PAN temperature - it is much hotter in other areas of the engine. At that point, to keep it from climbing I would have to run a lap or two a gear high, which is quite frustrating. I know it isn't theoretically a problem, and I still had good pressure at that temperature, but since I plan to keep developing this engine, at some point I will need to address the issue of heat. The sooner I do it, the less I wear things out.

[ccsdo5]

I'm really not a fan of bypassing the filter, even for a small portion of the oil... also, I don't think two holes in the cap would really get you anywhere, unless I'm missing something. I'm not sure what the flow direction is inside the filter housing, but I think the pump sends flow to the center of the filter, around the bolt that holds the cap on. The top of the filter seals against the center lug of the cap, forcing the oil to pass through the filter, and then flow back down into the engine. In order to use the pressure drop across the filter to push oil through a cooler, you would have to pull oil basically from the bolt that holds the cap on, send it to the cooler, and then plumb it to the other side of the filter with your welded bung idea. This is, of course, assuming that the pressure differential across the filter is enough to push flow through a cooler, and not so much that all the oil goes through the cooler instead of through the filter.

TLDR: two welded bungs on the cap would both be pulling from the outside of the filter, which has no pressure differential and no oil would flow through the cooler.

This is very true I didn't think about that, so now what if you got a slightly longer bolt and fitted a banjo fitting around the top of it on the center of the filter housing cap then ran that to the oil cooler and drilled and made the return into the side of the cap? So now you have pressure from the pump pushing to the oil cooler and the return going to the filter and back into the engine. What might also need to be done in this case is have a small piece machined and added as a spacer between the canister itself and the lid so the oil doesn't just go directly into the filter still.

But honestly I don't really know just trying to give ideas, because an oil cooler for an m42 would be awesome!

[varg]

Have a look at this:

http://www.r3vlimited.com/board/showthread.php?t=156425&page=2

http://www.r3vlimited.com/board/showthread.php?t=306947

[gearheadE30]

This is very true I didn't think about that, so now what if you got a slightly longer bolt and fitted a banjo fitting around the top of it on the center of the filter housing cap then ran that to the oil cooler and drilled and made the return into the side of the cap? So now you have pressure from the pump pushing to the oil cooler and the return going to the filter and back into the engine. What might also need to be done in this case is have a small piece machined and added as a spacer between the canister itself and the lid so the oil doesn't just go directly into the filter still.

But honestly I don't really know just trying to give ideas, because an oil cooler for an m42 would be awesome!

That might work, but drilling that long, small diameter bolt would be a challenge, plus the oil flow volume would be extremely low. I still struggle to see how the cap-style modifications would divert oil flow without either bypassing the filter or with enough pressure for there to really be any flow through the cooler.

Have a look at this:

http://www.r3vlimited.com/board/showthread.php?t=156425&page=2

http://www.r3vlimited.com/board/showthread.php?t=306947

I had found those threads when I was looking for ideas - I like that red takeoff plate, but it's not made anymore. E30guydownunder did a similar thing, and I actually saved all the pictures from his thread...I just really don't want to have a remote-mount oil filter, nor do I want to re-engineer oil flow and drainback. I guess if that's what it comes down to, though, then I can do it.

I think bmwman brought up the intermediate takeoff plate in one of those threads, which is a good idea. I need to look a little more closely at my engine and see how much space there is there, since the alternator would limit how far I can move the housing outwards. It is a complicated part to machine to maintain oil passages, though, especially since I would need to replicate the uppermost area that has an oring groove and sticks into the block. Not insurmountable, just expensive. Something like this would be ideal though, I think. It maintains the factory drainback valve, bypass valve, and filtering, so the system itself would still function as designed. I didn't get the part about getting an additional clean oil takeoff from the M44 housing, so I'll have to look around some online. That would make a great turbo oil pressure feed...

[varg]

There are better pictures of the plate here: http://www.visionracingdevelopments....roject-bmw.php
It looks like a pretty simple piece to replicate. The plastic piece shown in the pictures is an M44 oil filter housing bushing, 11421432228, which probably fits just fine in the M42's machined recess, and functions as an anti-drainback valve AFAIK. Of course, alternator bracket interference is a problem with either solution, though it would not be hard to space the alternator bracket out from the engine a bit, and probably wouldn't even require a longer belt.

The spacer plate sounds like the more complicated solution, IMO.

[gearheadE30]

Huh, interesting. I wonder what the reason for the note about that takeoff plate having been removed is....

Still haven't had a chance to look at my car since I'm also mid-chevy 350 build for my other car, and that is taking priority at the moment.