ITC CRX radiator

[CDS]

Is there a preferred aftermarket radiator for the 1st gen 1500 CRX? Mine runs a little hot at slower speeds with the stock unit. Also, is an oil cooler recommended? I run in the southeast where the ambient temps can be pretty high. I will be installing an oil temp guage soon to get an idea how hot things are running. I'm still learning this car so any advice would be appreciated. Thanks

[bamfp]

When I had my CRX I ran the stock rad. with an 175 thermostat. It still ran alittle hot on caution laps. I would definately install an oil cooler. My oil temps were in the 220 range with it.

Blake

[Greg Gauper]

The stock radiator does work ok if it is good shape...as well as the rest of the cooling system.

However, the stock radiators do tend to plug up over time with corrosion and deposits. This will effect the cooling system. Make sure your water pump is in good shape, as well as the cap, and T-stat, and also that you have bled the cooling system properly. I had an issue with hot temps my last year of IT with an 8-year old radiator. Car would run 190+ in cool weather. A new Modine OEM replacement dropped the temps right back to normal and it has run fine ever since.

I run a bone stock radiator on my G-Prod (limited prep motor but higher compression and more revs than IT) and ironically I have been fighting a problem getting the car to run hot enough!! I had issues with 150 degree water on a 95 degree day down at IRP two years ago. I tried substituting the T-stat with a simple plate with 5/8" hole but it ran too cold. I now carry two modified Stant brand T-stats that I switch between depending on the ambient temps i.e. run the 'hot' T-stat in cooler spring/fall weather and the 'cold' T-stat in the summer and use races tape to block off part of the grill to fine tune my temps. If you drill a series of small 1/8" holes in the outer perimeter and a 3/16" hole in place of the dribble pin, it will help drop your temps and make it easier to bleed as well. It will also take a little longer to warm up so you do need to plan ahead when you pull up to the false grid.

Make sure you shroud off the left side of the radiator to help keep the air from spilling off the side and forcing it thru the radiator. I use a scrp of air dam material about 2-3 inches wide cut to shape and bolted to the side if the radiator.

Removing the cooling fan is a compromise. The car will run cooler on the track since the stock fan actually blocks the airflow at speed, but you have to be careful idling the car or running in the paddock, and time when you start the engine relative to the 5-minute and 1-minute warning on the grid. I have been thinking about adding a small, light-weight aftermarket fan to help with this problem but presently I run without a fan.

Running plain water with Red Line Water Wetter will help with temps as well. Plain water is more efficient than anti-freeze. Use 'Steam' distilled water to minimize the deposits from minerals.

As Blake indicated, an oil cooler really helps these motors. Pegasus (and others) carry a real nice billet aluminum oil cooler adapter that sandwhiches between the block and the stock oil filter. This will allow you to plumb an aftermarket cooler. Use a good synthetic oil like redline/mobil1/amsoil etc.

[iambhooper]

I use a stock radiator in my C car, with an oil cooler, the thermostat has been gutted. My car runs cold in cold temps. At VIR last month, we had about 75% of the grill taped over to block air to the radiator. Usually anywhere between 25-75%. At Lowes last summer, and VIR test day in August (Oak Tree Nationals date) we ran normal temps with out tape.

My car is using regular coolant, per the builder. I do not have a temp gauge on the oil, but don't see any need for it. As for buying an oil cooler, you own an ITC car.... no need to go overboard. Search ebay, and "used" race car parts. I think my oil cooler came from a NASTYCAR truck, as did the seat.

[tom91ita]

i'm guessing that the fins between the tubes have corroded and are not really doing anything.

i had this on a street honda and it was running hot at 70 mph whenever the a/c would be on. i thought the bugs and leaves were plugging off the air flow.

i tried to hose it off with a garden hose (just a very slow stream, no pinched nozzle, just an open hose) and the first thing i got wet, stuff just fell out of the radiator. i then touched/pushed with my finger on places where i had not touched it with the water and stuff fell out there too.

if your honda had seen any road miles in the rust belt in its first life, you might have the same thing.

take a very close look at this and see if anything falls off yours. i am thinking if you go after thermostat, etc., you might be chasing the wrong issue.

tom

[CDS]

Thanks for all the replies! I have no idea how old the radiator is; I think I will try a stock replacement. I am also using antifreeze and no cooling fan. No fan has its drawbacks as I've learned I can't idle very long on the grid before I have to shut down. With the header I have there is not much room for a fan. I've also been meaning to switch to plain water with water wetter, and I will try to block off the space to the left of the rad and see what that does.

Greg, are you talking about drilling out the t-stat? I'm not sure I follow you. Also, where is the best place to locate the oil cooler? Thanks for the help. :)

[Greg Gauper]

Yes, I was talking about the T-stat.

The first hole to add is where the air bleed dribble pin is located. Cut off the pin and open the hole to about 3/16ths inch. Next, take a 1/8th inch bit and drill 3-4 holes in the offset part of the T-stat flange. This will cause the T-stat to operate about 10 degrees cooler, but still provide some control over the warm-up. This also makes it much easier to bleed the air out of the system BTW.

As far as age of the radiator goes, the corrosion and deposits form inside and inhibit the cooling. The outside can look perfectly fine. Both myself and fellow Honda racer Bob Clark went through this exact same problem with old radiators.

I used to see oil temps in the 240-250 degree range without an oil cooler, and adding a cooler dropped the temps to 200-210 degree range. This was measured at the pan.

Most people mount the cooler in front of the radiator.

BTW - A stock Si oil-to-water heat exchanger can be installed and this will help your oil temps slightly, especially if you can get your water temps down to 165-170, but a traditional oil-to-air cooler will help the most.

Jegs carries a large selection of aftermarket racing cooling fans. Perhaps you can find a smaller or thinner fan that will fit. Also consider mounting it in front of the radiator instead of behind.

[1stGenBoy]

What Greg said is true!! I have a brand new non-AC radiator for sale if you need it. This is the small radiator not the larger AC/Auto trans unit.

Bob