How effective is the engine oil cooler on our C4's? I have a 1988 with the L98 and the oil cooler that the oil filter screws into. The coolant line for it T's off of one of the heater lines and mine has started leaking after 35 years. I'm just trying to decide whether or not its worth sourcing a new one and keeping the T or just simplifying and cleaning up the appearance of the engine bay a little.

 

When I removed that on the one car I had that was becoming just a track car the oil temps dropped. It's more of an oil warmer! I think on the street you may not notice a big difference but it might be best to test it in your area first.

 

I've heard as much as 10-20F difference, but I don't believe it, maybe in certain situations. Its more of an oil warmer.

If the cooling system on the car is working well I wouldnt hesitate to remove.

 

And as further evidence, GM removed the cooler entirely on the '92^ LTx cars...which rev higher and make ~20% more hp. GM "compensated" by specifying M1 oil but the oil temps don't run high even w/o the cooler/heater.

 

The 84s had a different type of cooler, it's actually like the systems found on newer trucks and vans. It has lines that pump oil up to the hot side of the radiator.

 

Kind of like an auto trans fluid cooler/heater

Which do you want; coolant leaks? Or oil leaks? 'Cause they BOTH leak!

 

If it didn't do anything then GM wouldn't of put it on. Any time they can save 5 bucks building a car for something thats not needed they will. When they switched to Mobile 1 Oil they saved the cost of the cooler and passed the cost of exspensive oil (1992 it was) to the consumer. GMPP sold a Kit with all the parts back in the day I have had it on my C3 ever since. The Lower Hose is still avalable the others not so easy.

 

I have one on my bracket car for an oil warmer before a run.

 

I thought 84s had an actual air to oil cooler?

 

I removed it from my '90. Less hoses to leak. Made no difference that I can tell.

 

Yeah, you might be right. I saw a picture of one. It's a rare option that came along later in the 84s model year.

 

Fair enough. Ive seen 1 in my life and most all the factory components were missing so I can't even say that it was truly delivered that way. There isn't a ton of documentation floating around on it either so I'm really not sure. I don't recall if it was into the radiator or not but I do seem to think it wasn't. I might be equally as wrong.

 

I might have gotten bad info from that book 101 C4 Corvette projects.

 

That's funny. Kind of like the TB heater? The louvered lid on the air cleaner?

 

I have an early 84Z51 and it did not come with an oil cooler. I added the sandwich adapter and cooler from an 85.

 

My opinion on this, is that the only time you will need the KC4 is when you are on truck, running very hard.

All that KC4 can, and does, do, is *regulate* the temperature within 7-9degrees celsius of the coolant temps. And it absolutely does work.

This is no different than the auto's that send a line to the side tanks on the radiator and the coolant is used to regulate the trans temps.

For people on the street, its not going to make any difference i don't think. But don't kid yourself, anyone racing, pushing their car hard for 2hr sessions, NEEDS an oil cooler.

I can say that for myself, on my 1986 track car, that I drove very hard for 45 minute sessions, i was very happy to be regulating the engine oil within 7-9deg c of the coolant temps.

I see mention of a track car above that removed the KC4 heat exchanger and found his oil temps went down on track? I find that very hard to believe if it was done in isolation. Now if you also installed a bigger radiator i could see that. You can do a better job cooling the engine (and its oil) by installing a much bigger radiator! I mean thats the job of the coolant flowing through the system after all. The KC4 is nothing more than a bit of extra heat transfer out of the oil into the coolant, which is then transferred into air at the radiator. I am myself a huge fan of the KC4. Another think about the LT1 is that there were a couple changes right? Like the reverse of the coolant flow, and the leaned back orientation of the rad (good or bad, i don't know) the addition of a second fan rather than a single fan, and the addition of the expansion tank which increased capacity and would likely help with a tad bit of cooling.

IMO, so its not as simply as KC4 good or not. I am a huge supporter of the KC4 for use on the track, in the early cars.

Id be very interested in learning if anyone running very hard on track with an LT1 for 30 minute to 1hr long sessions.....have you modified your cooling system?

Cheers and just my opinion!

 

I can take a guess here that the second fan, and the expansion tank, and possibly the orientation of the rad, have something to do with it. Then the LT1 comes along and also goes to reverse cooling. Im sure the answer is nuanced beyond what we can postulate here.

In the early cars the addition of the KC4 100% affects the temps. Just my experience.

 

To be fair, the TB cooler was admitted to only have any effect whatsoever at "northern climates" meaning who the heck drives their vette in Canada when its -30c. haha. In a similar way, perhaps the KC4 only made any difference when running very very hard, on a hot arsed tarmac, in the early cars only.

I just want to point out to anyone who has the KC4 on an early car, and is going to start tracking the car, leave it on. It does help regulate the oil temps.

 

I did the same with my base 86. It did not have a KC4, I took it to the track, it was very hot, so I added the KC4 cooler from an 85. Ran my own lines using blue silicone hose and brass fittings into the heater return line. Dropped my track oil temps to within 7 C of the coolant temps.

 

I HEAR you....and agree that in theory, those are the times/places you'd need a TB warmer or a oil to water oil cooler. But in practice, I don't see it. Never froze a TB -even in northern Maine winters and high Colorado blizzards....and never seen oil temps hit 300 in the LT1...so it's hard for me to figure how even on the track, a 4500 RPM'n L98 would need an oil cooler.