Aftermarket Alloy Radiator

[Boost Junky 1]

Hey guys, im going to purchase an aftermarket 40mm thick radiator for my turbo setup. Im looking at using the S14/15 ones that are available because they are roughly the size that will fit in my car with the upper & lower outlest roughly in the right spot.

Now these radiators have the the filler cap on the radiator itself so I will have to do away with my remote reservoir and the hose that runs from the bottom of the reservoir to the back of the waterpump housing.

Will this work without that hose? Pretty sure it will as the cooling system will just fill via the upper and more so lower radiator hose correct?

[Silver Fox 43]

I think you need a return hose to the reservoir from the engine, other than the one from the thermostat? AFAIK water needs to be able to circulate thru the tank, and then thru the radiator when the thermo's open. Stand to be corrected tho.

[User Name 19]

Im not to sure about that - i throurt it was part of the pressure system for the radiator although ive plugged it up before and held it up to bleed some air

its a good question cause i was going to get a a custom radiator made and would hate for it not to work cause they use some weird pressure system to keep them working - instead of just pushing the water round.

hopefully someone has the answer

[kerry 10]

Im not to sure about that - i throurt it was part of the pressure system for the radiator although ive plugged it up before and held it up to bleed some air

its a good question cause i was going to get a a custom radiator made and would hate for it not to work cause they use some weird pressure system to keep them working - instead of just pushing the water round.

hopefully someone has the answer

why dont you use a e36 radiator

[Boost Junky 1]

I used to have the m50 hooked up without the reservoir im pretty sure it was working but went back to the reservoir for a reason i now forget why. Pretty sure the E36's with the m50s have the filler tank as a part of the radiator so cant think of any reason why that hose from the reservoir on the e30's to the back of the thermostat housing is needed?

why dont you use a e36 radiator

Kerry, I think because I was under the impression they wouldnt fit? Is that what you are using? I want to go thicker again because my system already runs at like 90-98deg and thats just under light throttle around town and i want to have a descent one when im getting things a tad hotter.

[RyanG 0]

Yes, the e36 one fits fine. And has a built in / clip on expansion tank.

You can get a thermostat that opens at a lower temperature that might help.

Alot of people run turbo setups with standard radiators.

[kerry 10]

I used to have the m50 hooked up without the reservoir im pretty sure it was working but went back to the reservoir for a reason i now forget why. Pretty sure the E36's with the m50s have the filler tank as a part of the radiator so cant think of any reason why that hose from the reservoir on the e30's to the back of the thermostat housing is needed?

Kerry, I think because I was under the impression they wouldnt fit? Is that what you are using? I want to go thicker again because my system already runs at like 90-98deg and thats just under light throttle around town and i want to have a descent one when im getting things a tad hotter.

yep it fits mint . use e36 320-328 with external bottle . thats what i have . with a good pull fan youl have no hassle at all

[Boost Junky 1]

My mate has a thicker 40-50mm thick radiator for $160 cant really go wrong there? Problem is guys I have no room for factory viscous fan or even room to put the fan on the motor side of the radiator, the fan is on the front of the radiator.

[Forrest 35]

^ Go electric fan ?

[kerry 10]

^ Go electric fan ?

yea get a e34 electric fan for the front side they are a 15" pull fan and you wont have any probs, there nice and thin in the blades so fit good

[Boost Junky 1]

haha it is an electric hence why i have it on the front of the radiator as in behind the bumper and its a 16" so shes pretty big already

So im better to stick with an E36 fan or a much thicker aftermarket one? I just thought it would be much more of a benefit and only $160 so long as it will work with the BMW cooling system..

[kerry 10]

haha it is an electric hence why i have it on the front of the radiator as in behind the bumper and its a 16" so shes pretty big already

So im better to stick with an E36 fan or a much thicker aftermarket one? I just thought it would be much more of a benefit and only $160 so long as it will work with the BMW cooling system..

i should learn to read better haha , i would still go with e36 rad . no mucking around and factory

[Boost Junky 1]

i should learn to read better haha , i would still go with e36 rad . no mucking around and factory

Damn I really wanted to run with a thicker core, so the E36 radiator is fine for the track? Even if i did get this aftermarket one, I could easily seal off where the cap is on the top of the radiator and keep running the remote reservoir and retain the hose between the reservoir and the back of the water pump/thermostat housing. If it is possible guys let me know because I would like to go with something thicker that will deal with a good thrashing on the track.

Like BimmerBeast said I hope someone has the answer haha!

Thanks heaps Kerry for the info I could end up going E36 radiator...

Edited September 1, 2009 by Boost Junky

[kerry 10]

Damn I really wanted to run with a thicker core, so the E36 radiator is fine for the track? Even if i did get this aftermarket one, I could easily seal off where the cap is on the top of the radiator and keep running the remote reservoir and retain the hose between the reservoir and the back of the water pump/thermostat housing. If it is possible guys let me know because I would like to go with something thicker that will deal with a good thrashing on the track.

Like BimmerBeast said I hope someone has the answer haha!

Thanks heaps Kerry for the info I could end up going E36 radiator...

at the end of the day $160 is cheap for a radiator, you can only but try

[*Glenn* 854]

I'd personally go with the E36 radiator with the seperate expansion tank on the drivers side of the radiator. The hose from the bottom of the expansion tank goes to the hose behind the thermostat under the manifold. So long as you have no external leaks the thermostat will control temperature. Use a 88' or 92' thermostat. Go with the electric fan as Kerry suggested. This can be thermaly switched if you fit an adaptor into the top hose, switching at 5' above the thermostat running temperature. Use a relay to operate the fan. If you go to a dismantler you might be able to get the top hose adaptor (made of alloy) from a E30 that had the switches in them when they retro fitted AC into the cars.

Edited September 1, 2009 by *Glenn*

[Boost Junky 1]

Hey Glenn cheers for that! What is the reasoning for the E36 radiator?

Glenn my thermostat at the moment is an 82deg one i think and i already have a thermo fan switch running from the factory hole in the top drivers side of the tankless E30 radiator which switchs on at 90deg i believe.

Glenn I was talking to Rod Gilbert who is the local BMW specialist down here he used to own what was called Continental Auto i think. He explained the cooling system as this:

The remote expansion tank is obviously your point of filling the cooling system. Then you have your big hose that goes to the backside of the thermostat under the intake like you say and a smaller hose that that runs from the top of the radiator to just under the cap on the reservoir.

He explained it as the system is fully self contained thus meaning like typically on all vehicles when your cooling system gets hot the water expands and has to have somewhere to go (in this case the remote expansion tank) and the way BMW has designed it is that there is no need for maintanance on keeping the cooling system topped up. Which is typical of a quality vehicle manufaturer like BMW.

Anyone who pays money for such a car from factory does not want to spend anytime under the hood and this type of system prevents one of those maintanance requirements. Now please feel free to make any correction to this.

So we concluded that I could run a much thicker race radiator and make rid of the hose going to the back of the thermostat and just have a typical overflow bottle running from the radiator. Please remember guys this is going to be on the track alot guys so its not meant to be practical as to the standards of BMW.

[*Glenn* 854]

Your running a M50 motor. An E36 radiator is more than adequate and you just use all the OEM parts. If clearance wont allow you to use a viscous fan...go electric and use the largest fan you can get in there. I would switch from the top radiator hose though as I suggested rather than from the opposite side of the heat source. If your thermostat is the 82" degree one switch the fan at 90'. If you use a hotter running thermostat, switch at 5' above the thermostat temperature. E36's use three different thermostats. 82' 88' & 92'. The E36 radiators have a large surface area and so long as there are no airflow restrictions it should be more than adequate, so long as the system is sealed and there are no leaks. Kerry should be able to provide one of the fittings I described. It has 2 switch fittings so you can run a low speed switch & a high speed switch, so that you can run a 2 speed fan through 2 relays. I definately would do all my temperature switching at the top hose though. Run a 90' low speed and a 100' high speed.

BTW: Are you running a water cooled Turbo ?

Edited September 2, 2009 by *Glenn*

[Boost Junky 1]

Your running a M50 motor. An E36 radiator is more than adequate and you just use all the OEM parts. If clearance wont allow you to use a viscous fan...go electric and use the largest fan you can get in there. I would switch from the top radiator hose though as I suggested rather than from the opposite side of the heat source. If your thermostat is the 82" degree one switch the fan at 90'. If you use a hotter running thermostat, switch at 5' above the thermostat temperature. E36's use three different thermostats. 82' 88' & 92'. The E36 radiators have a large surface area and so long as there are no airflow restrictions it should be more than adequate, so long as the system is sealed and there are no leaks. Kerry should be able to provide one of the fittings I described. It has 2 switch fittings so you can run a low speed switch & a high speed switch, so that you can run a 2 speed fan through 2 relays. I definately would do all my temperature switching at the top hose though. Run a 90' low speed and a 100' high speed.

BTW: Are you running a water cooled Turbo ?

So adequate for the track also? Could be alot cheaper going E36 radiator. So much thicker aftermarket ones are for cars that get really hot? Oh I am using a electric fan already Glenn haha its a massive 16" mate. Oh right so how come the factory E30 radiators have the switch in the drivers side top location of the radiator? Might have to change that then. The radiator isnt exactly well exposed so when you mention restrictions I do have a intercooler blocking the bottom half of the radiator and there will be an oil cooler blocking the top half very soon...

Studid thing is Glenn, the car takes forever to heat up (cooling system capacity the reason?) but it seems to run at 95' once warmed up which is more than it used to and that maybe because of the water cooled turbo? Which answers your last question mate. When you speak of the twin speed setup for the fan.. at the moment the fan is just either I/O so when its on it will be at full speed correct?

Probably not a bad idea because then when the system gets hot even with the fan on low (in race condition) it will switch to a better faster speed correct?

Thanks heaps mate