Roadster radiator placement.

2.3Turbo_T · Aug 5, 2014

I'm asking this question on a couple of forums 'cause I need some input.

The roadster's been on hold for awhile while I get other projects outta the way but I'm about ready to get back into it. One of my big concerns is radiator placement. Right now I have a Geo Metro rad mounted and after much pondering, I came to the conclusion.........no way is it gonna work! It's a 2-row and it's tiny! Granted, I'm not running a hemi but the turbo 4 does produce it's fair share of heat. There's no room in front of the rad 'cause the space in the nose is taken up by the intercooler and a massive spring perch. Can't really move the motor back due to firewall clearance and motor mounts are already welded in. As the Geo rad sits, there's just enough room to mount a small puller fan. Definitely, not enough girth!

Then I got to thinkin'. I've seen guys run rear mounted rads. It always seemed kinda hokey to me but now it's making some sense! I've got a ton of room under the gas tank where I could fit a monster rad and elec fan in that space. Maybe form some sort of air dam underneath to scoop air directly to it? Or, I could drop the tank down lower and run the rad and fan up top. The car will have a decklid. Do I need to worry about venting hot air? What does everyone think? I'm looking for input. Is it feasible or am I way off the mark here?

choppinczech · Aug 5, 2014

I say go for it!

This builder has a radiator in the rear and runs the lines through the frame rails. https://tbucketeers.com/threads/big-redo-of-the-old-bucket.13677/

IAM-LDS-2 · Aug 5, 2014

You are assuming the radiator is not big enough . As long as the fan will fit it can be used . Not much work or expense to hook up the fan and plumb the radiator up , it might do the job and you will not really know until you try it . Are you going to run a hood and side panels ? If not you could fab two new top pieces to extend your frame out what ever distance you needed for the new larger radiator . Yes there are some guys who say they make a rear mounted radiator work , but there are a lot who seem to be fighting it . My radiator is small and it has no trouble cooling a 2.8 V6 engine . It is 1 9/16 deep , 23 1/2 wide and 17 tall .
it .

Track-T · Aug 6, 2014

Mine has a track nose also, I'm running a 3 row '65 mustang.
It's tight but fits well.

choppinczech · Aug 6, 2014

Can you extend your track nose back?

I'm using this 20x16 Northern radiator.
http://www.circletracksupply.com/product.php?productid=4359&page=1

It's a kit. So it can be set up vertically or horizontal. I'll fill it at the manifold.

2.3Turbo_T · Aug 7, 2014

All good ideas! I'm out of town right now so I can't really measure. If memory serves, the track nose is 18" or 19" wide. A Mustang rad might possibly work although I'd have to extend the nose back and out a little with some sort of flaps. My main concern is adequate air flow. The nose opening is very small and, as mentioned the nose is filled with intercooler, piping and spring perch. There's a complete blockage of airflow to the rad.

When I ran my motor in the Mustang, I had to run the electric fan constantly. Even at freeway speeds the temp gauge climbed to unacceptable temps and yet it had great frontal airflow! When running the fan temps stayed right at 180*-200*. I was using a Volvo crossflow rad and a giant T-Bird SuperCoupe fan. Of course, I did have a full size Isuzu NPR I/C blocking frontal airflow.............hmmm. I just might have to take IAM-LDS' suggestion and try it 'as is' to see if it works!