G/J-body radiators

What are you guys running for a radiator? Particularly you guys that road race or time attack. The rad in my Lebaron is only a few years old, but it won't cool enough on mountain runs. Twisties and light grades it's not bad, but long 3rd and 4th gear pulls up steep grades causes the temp to jump up quick, even on only 9-10 psi. Are there any dual core factory rads that might work, like from a Dynasty or something? Or am I just gonna have to get an aluminum rad? T-stat doesn't seem to matter either, does it with either a 180 or a 192. In fact with a 180 it would normally run 175 on the temp. Maybe there's too much bypass through the heater core?

Are you running a T1 radiator or a TII radiator?
Have you blocked all paths that would allow air to flow through the rad support and around the radiator?
Is your head gasket sound?
Is your timing correct?

I'm running a T1 radiator in mine. It just so happens that the inlet/outlet on an SRT-4 intercooler are spaced perfectly to go right around it! I'm also running this fan: http://www.summitracing.com/parts/hfm-zfb16s . I'm running a 2.4 with a DOHC Neon intake, and I needed a little narrower fan with some good pull. This works great. I've taken this exact setup through some beautiful mountain roads up in Vermont and New Hampshire in the middle of August with no issues.

One more question to add to Mike's list: do you have the black plastic air dam underneath the radiator installed? It's the piece that's only a few inches high that attaches directly below the radiator. I will say that not all G/J bodies I've seen have it, but my 89 did. It may have been a piece put on just the turbo cars. It does make a difference. Plus, I'm lowered on Mopar springs and I've never scraped it, so no worries there.

I think it's a T1 radiator, or a V6 rad maybe. It's a full size radiator. Running a air-to-water intercooler system. The black plastic airdam is missing. Also, my 2.5 is bored .040" over, might have something to do with it also. Car does weigh 3300# with me in it and a half-tank of fuel.

Other thing I just thought of is I have a aftermarket fan which only covers about half the radiator, no shroud.

Can you send pictures of your setup? Might be easier for us to get an idea if we see pix. Where is the a/w intercooler located? How about the heat exchanger for the intercooler?

The fan lack of a fan shroud would be more of a detriment at low speed/idling conditions. Once your above ~40mph, you shouldn't need a fan at all.

Attachment 52430

The heat exchanger is mounted to the front bumper support behind the lower grille.

Put the airdam on and it should improve. And again make sure all pathways for air through the rad support but not through the radiator are blocked.

I will try that. I do need to do some air channeling, there isn't any blocking done at all currently.

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Originally Posted by Force Fed Mopar

I will try that. I do need to do some air channeling, there isn't any blocking done at all currently.

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That's probably most of your issue then, barring any engine/tuning problems. Good luck!