Potential overheating issue

marco454v8 · #1 (**permalink**) 04-14-2011, 03:04 PM

Hi guys,
I'm still doing my initial running in at the moment. I went for a short (15 mile) drive earlier this evening, temp steady at about 80degC- got stuck in traffic for about 10 mins, and temp rose to 120! I have twin fans behind the rad, dash controlled, they go on as soon as I stop moving. As it's still quite cool here at the moment, I want to make sure I don't have a problem when the air temp is 30degC
I have a bleed valve in the intake manifold, so I'm sure I don't have an airlock. My only concern is my expansion tank- it an original style FE, but without the small pipe outlet that goes back to the rad- could this make a difference?
Cheers, Mark

strictlypersonl · #2 (**permalink**) 04-14-2011, 04:45 PM

What kind of fans? What configuration?
A picture of your setup would help.

marco454v8 · #3 (**permalink**) 04-14-2011, 11:33 PM

I have a 28" alloy radiator from a Mitsubishi 3000gt, and two 12" fans pulling.
Mark

marco454v8 · #4 (**permalink**) 04-14-2011, 11:36 PM

I have a 28" alloy radiator from a Mitsubishi 3000gt, and two 12" fans pulling.

Mark

marco454v8 · #5 (**permalink**) 04-15-2011, 12:21 AM

Sorry about that- computer malfunction!

Mark

Rick Parker · #6 (**permalink**) 04-15-2011, 12:22 AM

In that radiator you may not have enough coolant volume, generally a radiator for these is 3" thick and has multiple horizontal tubes IE: 2x1.25". OEM application for Mitsu was a little over 300HP (??) it may not be able to handle the heat put off by your BBC. If the fans come on as soon as you stop, it's running on the verge of overheating or your fan temp sensors are set too low.

marco454v8 · #7 (**permalink**) 04-15-2011, 12:29 AM

Hi Rick,
I remember when I was looking for a Radiator, hunting for the biggest that would fit, with outlets in the right places. I also read that these rads were as efficient as the old three cores, but maybe not

Rick Parker · #8 (**permalink**) 04-15-2011, 01:02 AM

In an OEM installation much of the cooling air is brought from below, with chin spilers and the like. A Cobra has to get all the air through the body/grill/radiator opening. Combine that with the closed quarters of a Big Block and you have the potential of a warm engine.

undy · #9 (**permalink**) 04-15-2011, 04:42 AM

Dump the OEM radiator garbage. You're going to fry your motor if you don't!

There's B-Cool, Griffin, Durodyne and a multitude of other custom performance radiator manufacturers who makes a radiator that'll keep your BBC cool. You'll need dual 1" or 1 1/4" tubes as Rick said. I'm running a Griffin in mine and it has dual 1 1/2" tubes. Griffin also has a geat website. You can choose radiator sizes and inlet/outlet locations to match your configuration. For a minimal fee they'll even custom make one EXACTLY like you need.

marco454v8 · #10 (**permalink**) 04-15-2011, 05:01 AM

Thanks guys I'll have a look at the griffin site. You don't think not having the small pipe from expansion tank to radiator makes any difference?
Mark

marco454v8 · #11 (**permalink**) 04-15-2011, 10:06 AM

Heres a picture of my set up-maybe another potential problem is that my pipes should be switched i.e. upper outlet should go to rad, and lower should go to stat (it would bolt directly onto the head of an FE)