Oil to coolant heat exchanger

[EcoCivic]

Hey everyone, I recently installed a dual temp gauge in my 2005 Civic to monitor engine and trans oil temps, and I am somewhat surprised to see how long the oil takes to warm up and how cool it stays, at least in cooler weather. But the oil temp in 30 degree weather sometimes won’t get above the low 150’s in cool weather driving down the highway and it takes forever to get there.

So I am looking to install an oil to coolant heat exchanger to warm the oil up quicker and keep it warm in the winter, while also keeping the oil cool in the summer and when under a heavy load. I have a highway about 2-3 miles from my house, and the oil temp is sometimes barely to 100 degrees by the time I get there. I guess I shouldn’t have been flooring it getting onto that highway for the last year with cold oil. Oops!

So I am wondering how big of a heat exchanger I need to warm the oil up with the coolant and to keep the 2 temps similar at all times, say within 10 degrees of eachother. I could either install an OEM style oil cooler between the oil filter and the block, or I could build a custom setup with a larger heat exchanger like this one https://www.amazon.com/Brazed-Exchan...s%2C163&sr=8-1

So I am wondering which you would choose if your goal was to keep the oil and coolant temp within maybe about 10 degrees of eachother the majority of the time. I would prefer to simply install an OEM style oil cooler between the oil filter and block because it’s simpler and much cheaper, but if it is too small to do what I need it to do then I will go with a custom setup.

Thank you very much in advance, I appreciate your help

[Daox]

I would go for a Honda OEM unit and see how it works. Bigger is probably better, but how much is hard to say without testing.

[EcoCivic]

Originally Posted by Daox

I would go for a Honda OEM unit and see how it works. Bigger is probably better, but how much is hard tonsay. Without testing.

Thanks. Do you have a suggestion on which Honda I should get a cooler from? An RSX cooler won’t work because of where the coolant lines come out, but an S2000 cooler looks like it might. However, an S2000 oil cooler is pretty expensive and I am wondering if it would be worth a minimum of about $70 for an OEM cooler when that’s probably almost half of what a custom setup would cost and there’s a chance it won’t do what I need it to do. Thanks

[Gasoline Fumes]

I'd get one from a junkyard. There are other Hondas besides the RSX and S2000 that have them. Just make sure the threads and o-rings are the same size.

[Daox]

The Insights had them as well as the Civic VX.

[EcoCivic]

Originally Posted by Daox

The Insights had them as well as the Civic VX.

Thanks, I didn’t know that. I will look into that and see if it may work in my application

[Daox]

There are lots of them out there actually. Typically they are labeled as oil coolers, not warmers or heat exchangers. The harder part is finding a way to mount them properly if it wasn't designed for your engine. If you stick with the Honda stuff it'll hopefully simplify that.

[EcoCivic]

Originally Posted by Daox

There are lots of them out there actually. Typically they are labeled as oil coolers, not warmers or heat exchangers. The harder part is finding a way to mount them properly if it wasn't designed for your engine. If you stick with the Honda stuff it'll hopefully simplify that.

Thanks. I’m hoping if I get a Honda one it will screw right in. I have an extra engine in the garage to test fit it on though, so that's helpful. I know it’s hard to say, but do you think adding an OEM Honda heat exchanger would significantly improve the oil’s warmup time, or do you think the difference would be negligible?

[oil pan 4]

The Honda one is supposed to be a big improvement if you don't have one.

[EcoCivic]

Thanks everyone for your help, I really appreciate it. Another question- Would you expect a significant difference in the performance of the oil cooler if it is fed by 5/16 or 5/8 hoses? Some Honda coolers have 5/16 hose connections instead of 5/8 inch, which I would prefer if there isn't much difference in performance so I don't have to install it inline with the heater core. I bypassed the coolant running through my throttle body when I installed my Y8 intake manifold, so being able to just connect those hoses to the cooler would be nice. Thanks