Been Thinking.... Cooling system upgrade for M10

[midlifebmw]

After having my latest E21 go redline on me New Year's Eve (no damage thank goodness but it was a panic!) I've been looking at doing some mods that may help either reduce or eliminate some issues with cooling.

My thoughts are: Replace the rad with an E30 type with expansion tank like on the M20 engines, with no rad cap on the rad but on the expansion tank. I have the parts for this in the shop.

The goal would be to increase cooling capacity for summer, have a way to recover fluid instead of dumping out the overflow hose as the M10 rad does it now and upgrade to a higher capacity and newer rad.

I'll have the room with the battery relocation and airbox upgrade so the engine bay will be close to what I had in the 323i.

Anyone done this or thought about it?

[bassboy3313]

I am using a chevy sb aluminum radiator that has a thicker core than stock. I havent found a clean way of doing the recovery tank, so right now I am just using a beer bottle, lol. works great surprisingly. The best way would be going the m42 radiator swap since it has an integrated recovery tank built in, but it has a third hose outlet that would need to be figured out. Currently I havent found any info on this being done with an m10 tho.

[Imolarot2]

I bought a radiator from a 77 that is being re-cored with a 2 row high flow system, it should be more than adequate even on the hot summer days here. Now I just need to figure out a pusher fan to replace my stock supplemental one

[pommeree]

I bought a radiator from a 77 that is being re-cored with a 2 row high flow system, it should be more than adequate even on the hot summer days here. Now I just need to figure out a pusher fan to replace my stock supplemental one

There is little-to-no figuring necessary.
I bought a generic fan from Summit which came with the push-through zip-ties and rubber pads for mounting.
Even the plug matched where the OEM Aux fan connected.
Mount it. Plug it in. Done.



This shows the old fan but the new one had the identical plug.

[gsumzzz]

New stock radiator and mechanical fan are very hard to beat.

- - - Updated - - -

Shroud is key as well.

[midlifebmw]

I've got the evap for the a/c that BCalis greatfully had worked on and should be working.That sticks right in front of the stock rad so a fan in front may not work. The main concern is recovery and reintro of fluid just blown out. I drove today in the blizzard (whahoo! Limited Slip!) and when a reved the engine some fluid blew out.

There's not any evidence of leaks or things like that, just the overflow allowing fluids out and then I run low. This is freaking January so I can only imagine what July will be like with A/c on and such.

[amarino]

You can go with an E30 M10 water pump/fan clutch, its a simple bolt on upgrade. Might need to double check clearance, at the same time I did that upgrade I also installed an aftermarket E30 M3 dual core stainless steel radiator. I had to get the fill neck welded on by a radiator shop, but after doing all they its been running at about 1/4 on the temp gauge. The host from the top of the radiator to the engine was a lucky find at AutoZone, since the stock one was too short.

http://www.ebay.com/itm/88-91-BMW-E3...81271391942%26

[jtbgonesailing]

As gsumzzz stated, install a new OEM radiator. I put a new alunimun core/plastic tank Hella in couple of years back from RMeuropean, with a plastic overflow bottle and havenot gone above midline on temp guage here in Florida. RMeuropean now appears to sell a all metal unit. Throw on a fan shrould and you should be good to go.

[Imolarot2]

There is little-to-no figuring necessary.
I bought a generic fan from Summit which came with the push-through zip-ties and rubber pads for mounting.
Even the plug matched where the OEM Aux fan connected.
Mount it. Plug it in. Done.

I agree, my thinking was more of down the road if I was to do a 6 cylinder swap and delete the puller fan as to how much CFM would be necessary so I don't have to buy another one later

Edit: this would only really be a concern for me in the hot summer months as even with my stock plastic tank I rarely get past 1/4 this time of year. Last summer I climbed past 1/2 anytime I was not in motion

[midlifebmw]

Thanks for the pics on the install for that one amarino! I guess my comfort level with the M20 would have led me to just install an overflow bottle with the cap on it instead of having someone mod the radiator for the cap. I have 2 clutch fans in the shop and I didn't even think of that!

Do I spot alpina front bars under that radiator?

[amarino]

You can also use the same radiator with an M20 expansion take and not have to worry about the neck. Check out Ski's M20 Build thread, I believe that is what he did. Also that radiator is a bit more involved for swapping over because you need to drill out the spot welds on the top plate that the stock M10 radiator mounts to and you also need to take off the bottom support mounts and make tabs that bend up to hold the bottom of the radiator in place.

Also yes that is an Alpina front lower strut bar, I picked it up from Ireland Engineering.

[gusm325]

There is little-to-no figuring necessary.
I bought a generic fan from Summit which came with the push-through zip-ties and rubber pads for mounting.
Even the plug matched where the OEM Aux fan connected.
Mount it. Plug it in. Done.



This shows the old fan but the new one had the identical plug.

+1 same thing here, have a 71 degree stat, well over 100 degrees in the summer with A/C on not passing middle, unless prolonged over 80mph...

[bcalis]

I think that the overflow tank is your answer.

The car already has a 71 degree thermostat and a shroud installed. I used to run it with AC in DC summers with no major overheating issues. Make sure the AC fan is running correctly though as it used to not kick on sometimes.

Also so check the AC fuse as someone had done a hack job on it.

[Imolarot2]

+1 same thing here, have a 71 degree stat, well over 100 degrees in the summer with A/C on not passing middle, unless prolonged over 80mph...

Yeah, I think my radiator might have just been clogged up. When I pulled it I saw the stamped date in the plastic so it apparently was the original radiator. I should be fine now with a new radiator


I was also wondering, has anybody gone to an E30 style M10 puller fan with a clutch? Do you just need the E30 water pump, pulley, fan w/clutch? Can you re-use the E21 pulley? Does the fan fit within the shroud?

[amarino]

I was also wondering, has anybody gone to an E30 style M10 puller fan with a clutch? Do you just need the E30 water pump, pulley, fan w/clutch? Can you re-use the E21 pulley? Does the fan fit within the shroud?

I don't remember which pulley I used, if it was the E21 or the E30 one. But I don't think there would be enough clearance with the stock radiator location and the E30 M10 water pump/fan clutch upgrade. The only reason it works for me is because the radiator is forward of the stock location.

[Imolarot2]

I don't remember which pulley I used, if it was the E21 or the E30 one. But I don't think there would be enough clearance with the stock radiator location and the E30 M10 water pump/fan clutch upgrade. The only reason it works for me is because the radiator is forward of the stock location.

Interesting... could I ask you to measure how thick your radiator is as it looks larger than the one I will be using? I guess I can cutout that plate and mount mine forward if necessary so it doesn't damage my radiator.

This is the re-cored early radiator I will be using:

[amarino]

I got these measurements from the eBay ad. Also you might want to verify how the mounts would line up.

Overall Size: 17.75" x 19.25" x 2.25"
Core Size: 17" x 14.5" x 2"

[dups]

Yeah, I think my radiator might have just been clogged up. When I pulled it I saw the stamped date in the plastic so it apparently was the original radiator. I should be fine now with a new radiator

How much did it cost to recore?

[Imolarot2]

I got these measurements from the eBay ad. Also you might want to verify how the mounts would line up.

Overall Size: 17.75" x 19.25" x 2.25"
Core Size: 17" x 14.5" x 2"

Cool, thanks!

How much did it cost to recore?

$300 at my discount (I've taken a bunch of stuff to him in the past), 2 row high efficiency core

[Allenwilson33]

I am using a chevy sb aluminum radiator that has a thicker core than stock. I havent found a clean way of doing the recovery tank, so right now I am just using a beer bottle, lol. works great surprisingly. The best way would be going the m42 radiator swap since it has an integrated recovery tank built in, but it has a third hose outlet that would need to be figured out. Currently I havent found any info on this being done with an m10 tho.

I installed an m42 radiator on my m10b18 but surrendered to the return pipe--or lack thereof problem. I shouldn't have given up so easily though, for all that is needed for that to work involves:

>Route a return hose from the bottom of the overflow reservoir to the return pipe
>The return pipe needs to become a junction now, by using a T-junction

Still yet, I'm not sure that water flowing back to the overflow tank would work through a variety of outside temps...Forum members?

[ole guy]

Being a new E21 owner, I am keeping an eye out on these temperature/radiator posts.
I have a 79 with A/C. having the extra electric pusher fan up front.
I noticed one cool day while stopped in a parking lot that the pusher fan turned on.
Temp gauge was 1/2 way on the gauge.
So I'm thinking to myself that if the pusher fan is having to run on a 50 degree day that I may have to worry about the summer days when it is over 100 degree outside temp.
I'm sure that the original radiator could use a good cleaning.
I have no idea how well the water pump is or is not working.
I'll keep an eye on things and keep up on what you guys do.

[duuder]

how is your engine running so hot? mine doesnt past the middle while stuck in traffic in the middle of a humid summer?

[John Adkins]

how is your engine running so hot? mine doesnt past the middle while stuck in traffic in the middle of a humid summer?

Cooling systems have never been a strong point for BMW. In later models, E-36's on up, reliabiliy was engineered out in favor of weight and cost reduction. I had never heard of so many cooling system horror stories until I bought my first BMW and started following the mark on the internet.

[duuder]

i dont have ac either so i guess ive been pretty lucky

Cooling systems have never been a strong point for BMW. In later models, E-36's on up, reliabiliy was engineered out in favor of weight and cost reduction. I had never heard of so many cooling system horror stories until I bought my first BMW and started following the mark on the internet.

[Thecatmilton]

If I am idling (200-800rpm surges) the car's temp will creep up slowly, but if I hold the rpms at 1500 it goes back down to half quickly. I shouldn't be too worried about this right? I probably should flush my coolant though.