84-87 Civic Radiator options

[Motor City Hamilton]

What radiator options do I have for ITC racing? The radiator that came with my car looks to have been re-cored with more cores than stock. It has a couple of leaks and I'm trying to decide whether to repair or buy new. The radiator from my parts car looks to be about 1/3 more narrow than the one from my racecar. I got a quote for $60 to repair the two leaks. What other options do I have for racing radiators for this car?

Thanks.

[ITC Racer]

I had an oem style two core in my ITC CRX for several years. Car ran well and had some extra tubes to plug if one sprung a leak... I run in WI so temps are reasonable but is definitely nice for extra cooling reserve.

[Greg Gauper]

I run a bone-stock Modine OEM replacement radiator on my G-Prod with 11:1 compression and have no overheating problems. I actually had problems getting the car to run hot enough and I sometimes have to tape up part of the grill to get enough heat.

Car ran 170 all day long at the Indy national in 90+ degree heat.

[Motor City Hamilton]

Greg - that's pretty crazy that you can run a stock radiator on your G-Prod car. I'm guessing you also have an oil cooler or sump system? I am running the Honda oil cooler from the 86 Si that mounts between the oil filter and engine block. With the extra core radiator, I usually run between 170 and 180.

[ITC Racer]

It makes a big difference in cooling performance depending on how plugged the rad is from corrosion blocking the internal tubes or if it is clean internally.

[1stGenBoy]

I agree with Greg. I run a stock Modine also from a automatic Civic/CRX it is wider than the stock 5 speed unit and I have never had a problem with over heating on my ITB CRX.
Here's the kicker. We run the same radiator in a 225 hp GTL car and have no problems with that either.
Yes we run oil coolers on both cars but has Greg said half the time we end up taping the grill or the cooler up to get the temps where they should be.
Ask Greg about our GT car at the Sprints. 90 degrees out and we had over half the grill taped up.

Bob

[Greg Gauper]

I do run an big Mocal oil cooler and I removed the small stock Si oil cooler since it was a potential failure point. I found my oil temps were a bit high with a smaller 13-row cooler when I got my close ratio tranny (much smaller power band and more time spent in a smaller rev range) and upgraded to a pretty large unit. That said, I have it mounted in front of my radiator so there is a bit of heat coming off the cooler that also passes thru the radiator. I run a Moroso baffled 5.5 Qt pan with a stock wet sump pick-up and no accusump.

Both Bob & I ran into the same problem running 'old' radiators that were several years old and it seems like these plug up with corrosion over time which causes them to run hot. We both replaced our radiators with new stock units and they work fine. I found I did have to modify my T-stat in order to get decent temperature regulation. I originally tried an OEM Honda stat but it ran just a tad warm when I upgraded to GP (bumped CR to 11:1). I tried a plain restrictor but it ran too cold and was difficult to regulate. I modified a Stant T-stat by drilling out the air bleed pin and adding a bunch of holes around the perimeter and this seems to be the best compromise.

FWIW - I also run plain distilled water + water wetter.

And yes, I've seen how much tape Bob & Jim run on their GTL cars. These were originally designed for GT3 motors, but now that they are running in GTL trim with a 24mm inlet restrictor and won't rev past 7000 rpm, they have plenty of cooling capacity. When I run in the spring or fall in cooler temps, I have to add quite a bit of tape to the grill to get enough heat to run.

Last weekend at Road America I had no tape on the grill and it was in the mid-80 degree temps and I saw 170 water temp and 210-220 oil temp (measured at the pan).

Honda & Modine make really good cooling systems!