Radiators and oil coolers

Time to start planning out some mods for the upcoming season.

My '91 Firebird has finally seen some open track and needs help in the cooling dept. Starts to run hot after about 15 minutes of lapping. Still has the 2 core 305 rad, a 3 core 350 seems like the easy button, but finding one is the issue. The stores all have "one size fits most" 2 cores and a used unit would be 25 years old at this point. Its aluminum and plastic, not sure if it can be recored larger. After market aluminum is pretty expensive.

Oil cooler also seems like a wise addition. My '88 Corvette had a small factory cooler that ran water back to the filter housing were a small cooler lived. The TPI F-body used the same thing. The Vette would run oil at nearly 300 degrees with this system on a 100 degree day. That seems high to me. A remote air to oil cooler seems like a better bet.

Questions on that front are: Do I have enough capacity in my oil pump to push the oil that much further and still maintain enough flow and pressure to the engine? I have increased the pressure relief spring in the pump but it is not high volume. It maxes out the 60 psi gauge until fully warm. Then its 30 at idle and 50-60 when cruising.

Are barbed fittings going to be enough? I did this on another project for a remote filter and it worked fine, but it never got over 40psi.

dont worry about the oil pump not being strong enough, don't think thats ever been a problem, heck I slapped a cooler on my 200k mile original motor and pump and never gave it a thought cause it's a non issue. It's said that oil is responsible for 20% or so of engine cooling so it's always a wise choice if your tracking the vehicle but I believe you should upgrade your radiator as well. There's some thick all aluminum ones on eBay for around $200 and many people across many different chassis have proven them to be completely fine.

Edit: about barb fittings, I'd shy away. Personally I would have a hydraulic shop make some hoses, that's what came factory on most cars with oil coolers if it wasn't hard lined and it's suitable for over 300* and tons of pressure. Not going to find that kind of ratings with normal hose like you could put on a barb. You said 30psi at idle, 60-70 at cruise, what's it at at wide open? Max pressure would worry me with normal hose and barbs

As far as the oil cooler goes, if you can get a big enough radiator in there to handle the extra heat, there's nothing wrong with using an oil/water heat exchanger (as long as it's big enough). It'll also let you skip the thermostat for the oil cooler, as the oil won't get below coolant temp (and it'll come up to temp faster when warming the car up from cold).

In reply to rslifkin:

I'm sure the 3 core radiator can handle the heat load, I'm just not sure if the oil/water heat exchanger will be effective enough. It's tiny.

Speedway Motors sells very nice all aluminum "universal" radiators, take a look. Tracked SBC's need an oil cooler- turn to ebay here for used NASCAR hoses and a cooler. -10 would be an appropriate size.

Also, use a thermostat, and box in the radiator as best as you can. Those cars are big time bottom feeders (I assume, if it's like other 3rd gen's), and if you don't have the chin spoiler in place below the radiator, you're gonna have trouble.

size your radiator then look to ebay for an aluminum one. when i was dealing with the stupid V8 swapped WRX i measured the space i had, then went to ebay and found one with the proper dimensions and correct gm sided inlet/outlet

a quick search on thirdgen netted me with the biggest core size on a stock radiator of 26x17. usually that's plus tanks. a jump over to ebay with those dimensions gave me this:

http://www.ebay.com/itm/1973-1980-CHEVY-GMC-C-K-PICKUP-4-1L-4-8L-L6-Aluminum-Radiator-17x26-CORE-AT-MT-/321900781583?hash=item4af2c8200f:g:CsMAAMXQWlFRvblj&vxp=mtr

given the fact that i put a radiator and upper hose from an 85 z28 into my 76 c30 pickup years ago because my buddy parted out the camaro, i'd guess it'll fit pretty well. wouldn't order anything without measuring for yourself though.

I have used about a dozen champion eBay all aluminum radiators across multiple platforms. Never had a bad experience. Cheap and effective. Usually about $200.

I would also stay away from the Barb fittings. Seen multiple failures in hpde of these, to the point I will no longer allow them to pass tech inspection due to safety hazard. Hydraulic shop hoses, plate and fin cooler, and sandwich adapter for the win there.

Also, make a stiffer air dam than the factory part. Seen a lot of them fold up at speed.

A buddy put a 70-72 Chevelle Big Block 4-core radiator into an 88 Firebird, fit almost like it was meant to go there. He had a 400 small block in it and it stayed cool on track days.

The Speedway universal radiators work well and are reasonably priced, I have one in my 81 Camaro autox car. I also run an Earls external oil cooler with a thermostat bypass (opens at 185 degrees), with AN-10 SS lines. I would use either AN lines or get the hydraulic lines made like chiodos said.

Oil pressure shouldn't be an issue, it may drop a little, but your pump will be good.

81cpcamaro wrote: A buddy put a 70-72 Chevelle Big Block 4-core radiator into an 88 Firebird, fit almost like it was meant to go there. He had a 400 small block in it and it stayed cool on track days.

Oddly enough, I put a plastic 3rd-gen radiator in a '69 Chevelle and it fit

And they work just fine in G-bodies too. Work great as a substitute for the unobtanium Grand National radiator if you redo the trans lines and eliminate the oil cooler.

Gearheadotaku wrote: In reply to rslifkin: I'm sure the 3 core radiator can handle the heat load, I'm just not sure if the oil/water heat exchanger will be effective enough. It's tiny.

Yeah, the OEM heat exchanger is probably too small for hard use. But you might be able to find a bigger one from some other OEM application, otherwise Mocal (and probably a few others) sell bigger ones.

Dusterbd13 wrote: I have used about a dozen champion eBay all aluminum radiators across multiple platforms. Never had a bad experience. Cheap and effective. Usually about $200. I would also stay away from the Barb fittings. Seen multiple failures in hpde of these, to the point I will no longer allow them to pass tech inspection due to safety hazard. Hydraulic shop hoses, plate and fin cooler, and sandwich adapter for the win there. Also, make a stiffer air dam than the factory part. Seen a lot of them fold up at speed.

I've heard of Champion rads, glad to hear a positive veiw on them before purchase.