m42 overheating during HPDE track sessions

[Asbradley21]

Probably m50TU, for the simplicity of the swap.

[u3b3rg33k]

Which 24V motor do you have your eye on?

[robgoesvroom]

24 valve swap time! :D

[FredK]

Ouch. Sorry to hear your engine blew up.

[Asbradley21]

Well it's all over for this HPDE. It didn't overheat with the new rad setup. It did however blow the bottom end up. I didn't see that one coming. I'm on my way home now riding in the flat bed truck. It seems to be 24 valve swap time.

[u3b3rg33k]

At first glance, it looks like the bmw rad has more orifice and less shroud, which is in theory better, but it probably makes little difference.

At idle, all it takes is a leaf blower to keep your engine cool. At least it seems to work for F1. As for ice racing, overheating at one of those events should be considered incontrovertible proof that something is wrong with your car. And it's probably the cheapest way to have fun sideways - one set of tires lasted me three seasons.

[TobyB]

For track use, a nice big radiator, NO fan, is best. At anything over 20 mph, the car moves
more air through the rad than any fan ever could.
I've tracked the E36 318 with a new stock rad (that pig is heavy) and didn't have a
temp problem with it.
So the MooshyMootoo should be fine. You might replace the t- stat just in case-
they CAN bind and not open completely. But usually not.

BMW designed their cars to run flat out for hours. The stock systems (except sometims brakes)
are good enough for most HDPE use. And even racing. Lookit Pro3...


t

[Asbradley21]

I run everything stock but with a Volvo electric fan with a two speed switch and I have no problems running autox here in FL. We run back to back runswhere we sit in line to run again and I don't have any issues, the only times the needle moves above half is if I have been running on the interstate and then come to a stop i.e. an exit and even then it is only a needle width over the half. I sometimes turn on the heater to dry my hands and then it will drop below half (an old trick to keep the car warm because the heater core acts as a second radiator). I would be sure to put the blue coolant in and make sure your thermostat is working correctly, do you know which degree is in there now?

I have the lower degree thermostat which was replaced not long ago and always use proper coolant. I've autocrossed for years without too much issue from the cooling system. However there is a big difference doing auto-x and being able to stop even for just a short minute and running the piss out of your car non-stop for 20 minutes on the track.

I think my radiator is in need of replacement, I don't want a junkyard radiator or even a new m42 radiator as they have crappy plastic bits that break apart and a non-circular seal on the expansion tank that is prone to failure. So my choice was the mishimoto. the zionsville shroud seems to take care of fan mounting and expansion tank at once while being top quality.

I can see the 1/2" or so of space, but if there's room for a fan on the back side, there's room for flaps - you would just need more, shorter flaps.

imagine the LOLtastic disaster it would be if it didn't have any clearance...



I solved all my heat related issues a few years ago with a new fan clutch. Only ever had a problem since when I had a broken hose - but it was in the winter before an ice race, so it was pretty easy to muddle through that event.

Do you think that the stock m20 fan shroud also is in need of these flaps?



I've replaced my clutch before already. Ice race sounds like fun.

[u3b3rg33k]

The one I posted :-P

It doesn't sit flat up against the fins. there's probably a cm or more of space. There's plenty of flow. There's also no room for goofy flaps like that.

I've already ordered all of the stuff to make the set up above. Got my fan today, 2360CFM 16in Spal, should do the trick nicely. Mishimoto radiator gets here tomorrow.

I can see the 1/2" or so of space, but if there's room for a fan on the back side, there's room for flaps - you would just need more, shorter flaps.

imagine the LOLtastic disaster it would be if it didn't have any clearance...

I run everything stock but with a Volvo electric fan with a two speed switch and I have no problems running autox here in FL. We run back to back runswhere we sit in line to run again and I don't have any issues, the only times the needle moves above half is if I have been running on the interstate and then come to a stop i.e. an exit and even then it is only a needle width over the half. I sometimes turn on the heater to dry my hands and then it will drop below half (an old trick to keep the car warm because the heater core acts as a second radiator). I would be sure to put the blue coolant in and make sure your thermostat is working correctly, do you know which degree is in there now?

I solved all my heat related issues a few years ago with a new fan clutch. Only ever had a problem since when I had a broken hose - but it was in the winter before an ice race, so it was pretty easy to muddle through that event.

[carguy101]

I also run 15-50 and have noticed it takes longer for it to warm up, I can notice when the oil is cold by the way it spins up and the power output. When it is warm it does run like a bat out of hell.

[carguy101]

I run everything stock but with a Volvo electric fan with a two speed switch and I have no problems running autox here in FL. We run back to back runswhere we sit in line to run again and I don't have any issues, the only times the needle moves above half is if I have been running on the interstate and then come to a stop i.e. an exit and even then it is only a needle width over the half. I sometimes turn on the heater to dry my hands and then it will drop below half (an old trick to keep the car warm because the heater core acts as a second radiator). I would be sure to put the blue coolant in and make sure your thermostat is working correctly, do you know which degree is in there now?

[Asbradley21]

The one I posted :-P

It doesn't sit flat up against the fins. there's probably a cm or more of space. There's plenty of flow. There's also no room for goofy flaps like that.

I've already ordered all of the stuff to make the set up above. Got my fan today, 2360CFM 16in Spal, should do the trick nicely. Mishimoto radiator gets here tomorrow.

[u3b3rg33k]

To illustrate my point, I have posted a picture of an old VW radiator and shroud.

Compare that, to this:


Monstrous radiator fan motor notwithstanding, which one do you think flows better?

[Ian Bowers]

How old is your radiator? When is the last time you flushed the system? I've taken my M42 out to multiple drift events on skidpad and fulltrack in 107* weather, and it never went past 1/2 way. Stock Radiator, distilled water only.

[Ryann]

Seems odd to me they'd block so much of it off in that manner. the way VW set up radiators on the old rabbits made more sense - electric puller, and some rubber one way check flaps. if you're driving, you get unencumbered flow, if the fan is on, then the flaps prevent wasteful recirculation.

I appreciate this post, agreed.

OP I see an m44 e-fan conversion in your future, possibly with a simple low-speed relay jumper from pin 30 to 87 while on the track.