535i Radiator options

[Mr Project]

Well, it looks like I have the tiny nipple leak of death on my radiator. It's very slow, just white powder going down the side, and where I cleaned it off it hasn't leaked any more in the last 200 miles or so, but the fact remains that I'm radiator shopping.

My thinking is that I'd like to put together a light-pressure turbo system on this car in the next year or two, maybe to get in the 300-350 HP range. Would this require a radiator with greater cooling capacity? I'm thinking it would, and I'd rather buy the radiator I need now, then have to throw a good one away when the time comes.

Anybody been down this road? Any stock replacements from other models, or reasonably easy aftermarket solutions?

[winfred]

i have a e34 540 radiator in my 535ia, ill post some details when i get home

[Hector]

about how you had already installed a bigger radiator in your 535 but didn't want to put you on the spot for some reason or another. Anyway, as I we have swapped posts before, this is something I would like to do. Next time my rad goes south or better yet to the incorrect "correct" coast, I'll buy a 540 one. I'd be interested in details as well. Thanks.

[Mr Project]

Looks like BMA has the E34 M5 radiator for about the same price as the 540... anybody have experience with this? I would think it might be suitable for my future power levels since the M5 was around 310HP, but that's nothing more than a guess on my part...

[winfred]

i just happened to have a e34 540 radiator in stock when my stocker folded up on the way to work so i figured what the hell. i installed a e36 325 trans cooler because the 540 has it's cooler below the bellhousing on the tranny, and i wanted a better cooler anyway. to fit the radiator i used two right lower mounts and cut about a half inch off of each, but you could just buy 540 mounts i think they are real cheep it's a piece of plastic the size of your thumb, i used the 535 fan and shroud, i had to wire the shroud on because the radiator is about a inch wider, and the 540 shroud is offset differently for fan location, the hoses line up perfectly. so far in over two years i've gotten it hot once (about 3/4) sitting in line at the bank in 100* temp, ac on warp 9 after about 35 minutes (i had to get the shop deposit in and the asswipes locked up the lobby) i have no idea what temp the air was coming through the radiator off all the other cars but the obc pegged at about 125*, to cool it down a little i drove around in 2nd for a while the fan clutch was locked up all the way to 3k rpm, needless to say it was hot and i didn't want to park it like that and warp or crack something. at the moment i am running a behr thermostat from of all things a 80's 5 cylinder diesel mercedes (80*)

[Mr Project]

Thanks for the info, Winfred. Any knowledge of the M5 radiator? I would think it might be even stouter than the 540, but I don't want to buy both to find out.

[winfred]

never had my hands on one, it may be weird, i know the early ones had a air valve on the expansion tank and according to the book i saw that in to pressurize the cooling system to like 25 psi, but as i understand they did away with that

[Hector]

A couple of Qs:

(1) Is the 540 radiator just 1" wider than the 535 but has same height and thickness as the 535?
(2) What type of paint did you use for the intake manifold and valve cover? I like the looks.

never had my hands on one, it may be weird, i know the early ones had a air valve on the expansion tank and according to the book i saw that in to pressurize the cooling system to like 25 psi, but as i understand they did away with that

[winfred]

same height same thickness of the tanks and upper and lower caps, but the core is thicker, that's where the extra cooling capacity comes from.
i can't remember the brand, it was vht or duplicolor high heat engine block enamel, i did a little playing around with my m20, i sprayed clear lacquer over the enamel when it was a day old and got a cool light wrinkled effect, i plan something different for the m20 valve cover, now a days everybody does black

A couple of Qs:

(1) Is the 540 radiator just 1" wider than the 535 but has same height and thickness as the 535?
(2) What type of paint did you use for the intake manifold and valve cover? I like the looks.

[Hector]

I'll be painting mine after rebuilding the head. Can't wait. The chip I got from Mark is now in cobwebs... ****! Gotta give it some use...