Which radiator do you prefer?

[Regnar75]

^ damn thats pretty good

[BenjaminButtton]

Wow, great info guys.

There are a lot of overheating/head gasket threads on these engines.
Go with the biggest newest radiator, it will save you a lot of aggravation.

I'm using a new M42 radiator but the behavior of the cooling system makes me nervous and will be going larger ASAP.
I'm in Iowa. During the summer, the Aux fan is VERY active.
m

Good to know, I'm in about the same climate. What aux fan are you running...?

That's what I have, with the 16" SPAL, no issues whatsoever, even in the middle of summer.

I used to deny it a little more, but it's true that the M42 radiator *CAN* be a bitch to bleed properly.

Hmm. Food for thought for sure, any coolant system related maintinence is a bitch in my book, it's so messy.

For Street use the smaller I6 radiator (usa 325/e36M) would seem the smarter choice as clearance is also a concern with street rubber mounts potentially failing. Unless a S54 is installed :)

Thank you sir! Very helpful post man.


I'm in southern MN, it does get quite hot in mid-summer here (90+ and a bajillion percent humidity in July occasionally) so just based on size alone the e36 325 may be the way to go.

And my car is an '88, so late model.

I was also curious which fan is more efficient, stock mechanical or an electric pusher? I've been hearing over and over that keeping the 24v's as cool as possible is very important. I was going to run the mechanical fan if I have the room, but maybe I shouldn't even bother and just get a pusher e-fan?

[evandael]

run a slim puller fan, it'll be the most efficient.

it's tough to get clearance (and maintain it under hard braking with solid mounts) between the crank pulley and the radiator.

[BenjaminButtton]

Gotcha. So puller > pusher?

I guess I figured the pusher was the way to go since that seems to be what most people run. Now that I think about it, the puller setup seems a lot better. Especially since it doesn't cover up the font of the radiator.

[Wanganstyle]

Oem mechanical is honestly the best option if it fits; our car has a pusher in front of the massive PWR.

The body: m20 e30 was designed for mechanical fan

The engine: m52/s52/s54 was designed for use with mechanical fan but some cars have an oem electric puller:

E46 328i
E46m smg

If the engine was shifted rear wards enough to fit the oem 24v mechanical fan it would be the best of all options (although unlikely to happen for most)

Aux electric fan would ideally be retained as secondary cooling if sitting in traffic/in pits etc.


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[BenjaminButtton]

That makes sense.

I think I'll use the e36 rad, and -if I have enough clearance- run the mech. fan for now. If she's running too hot I'll add an e-fan.

[NickL]

I'm running an m42 rad with my s52. I like the integrated expansion tank because it keeps the bay clean. I have a 16" pusher wired to the stock wiring with a lower temp thermo and fan switch and the car stays cool.

[MR E30 325is]

I am running an S52 and I had the M42 radiator, but had constant issues with it not being able to keep the car cool.

I run the E36 Mishimoto now. I have a 16" Spal pusher, but I rarely have to use it. Keeps the S52 calm and cool even when it is being pushed very very hard.

I am a fan of the "Get the biggest and most efficient radiator" mentality. Driving around Phoenix in the middle of the summer (~115 degrees) is something that my E30 does often, and I never wanted it to be an issue.

[BenjaminButtton]

I'm running an m42 rad with my s52. I like the integrated expansion tank because it keeps the bay clean. I have a 16" pusher wired to the stock wiring with a lower temp thermo and fan switch and the car stays cool.

I like the built in expansion tank as well. And I've already cut off the external expansion tank mounting stud... hehe

I am running an S52 and I had the M42 radiator, but had constant issues with it not being able to keep the car cool.

I run the E36 Mishimoto now. I have a 16" Spal pusher, but I rarely have to use it. Keeps the S52 calm and cool even when it is being pushed very very hard.

I am a fan of the "Get the biggest and most efficient radiator" mentality. Driving around Phoenix in the middle of the summer (~115 degrees) is something that my E30 does often, and I never wanted it to be an issue.

That's a good mentality to have sir, I completely agree. The more bulletproof I can make my car the better.

I've actually read you build thread too, I really dig your e30 man.

[Spitfi-r]

If the engine was shifted rear wards enough to fit the oem 24v mechanical fan it would be the best of all options (although unlikely to happen for most)

In my chassis, there is simply not enough room to shift the motor back any further witout modifying the firewall.
My head is ~1/2 from the firewall and there is still nowhere near enough clearance for the OEM mech fan (unless you run without a radiator :nice:)

[yahh]

I have the thicker 2 row z3m mishimoto radiator and it fits tight, but it fits. I have condor speed shop swap mounts which shouldn't flex much so I'm not to worried about it hitting as well as a 16" spal pusher fan in the front with no a/c.

[turbo325i]

This is a great discussion! I am swapping my m52 turbo (600whp) into a new e30 chassis. previously I had the a/c condensor in the middle between the radiator and intercooler, and was running the standard e30 late model radiator with the lower thermostat. I had no issues Except for the 60-160 pulls in the 85+degree heat it would move from where it was normally to between middle and 3/4 but that is to be expected. It ran 3 years this way.

I am now installing it into my stripped out clean e30 with no ac condensor between the two, but I moved to a 4" core intercooler. I shaved the bay to keep it clean looking so now I want to run the best radiator I can that keeps the expansion tank on the side.

I am all about keeping it simple and have LOVED my standard e36 mechanical fan with my e30 radiator, it fit by an RCH, but it fit and worked well.

I currently have a m42 radiator but am not thinking its going to be up to the task...

Please give me suggestions that will work with keeping the mechanical fan. I guess I am limited, because I dont have much space.... thanks guys!

[7pilot]

Wow, great info guys.



Good to know, I'm in about the same climate. What aux fan are you running...?



Hmm. Food for thought for sure, any coolant system related maintinence is a bitch in my book, it's so messy.



Thank you sir! Very helpful post man.


I'm in southern MN, it does get quite hot in mid-summer here (90+ and a bajillion percent humidity in July occasionally) so just based on size alone the e36 325 may be the way to go.

And my car is an '88, so late model.

I was also curious which fan is more efficient, stock mechanical or an electric pusher? I've been hearing over and over that keeping the 24v's as cool as possible is very important. I was going to run the mechanical fan if I have the room, but maybe I shouldn't even bother and just get a pusher e-fan?

I'm currently running a noisy cheap fan from my local Advance Auto/O'Reillys.
I have it wired so that it is directly controlled by the fan switch and not by the 2 fan relays.
This way it can be activated independently of the ign switch...Like a water cooled VW.

m

[Cyrix2k]

I don't like the M42 radiator - it seems too small. Go with the e36 radiator. I have an e36 325i radiator in the '85 and an e30 M42 radiator in the '91. The e36 radiator does ok, but struggles with the heat load of my turbo motor. It probably doesn't help that I'm running a 195* thermostat.

[turbo325i]

I know I can search, but i dont have time right now. So I have the motor in the car now, and the only problem with the m42 rad. is the mech fan contacts the plastic side tank on the driver side. It wont work. Is the e36 going to give me the same issue? I hopefully will have an e36 rad later but was wondering if someone could tell me sooner?

Thanks guys.