radiator trans cooler for engine oil ?

[anrkii]

I just picked up a pair of radiators on ebay for my ITB crx, and they have auto trans coolers in them.

would it be a good idea to tie that into my engine oil? cheap oil cooler, or waste of time?

[charrbq]

I won't say it's a waste of time, but not a good investment of time. Fittings can be made to work, but the coolers actually hold a ton of oil. It would take forever to get it to operating temperature. I've got one for a spare, but I don't use the oil cooler portion of it.

[tom91ita]

doesn't your Si have an oil cooler at the oil filter? not sure what itb honda you have.

not sure if others can retrofit to these or not;

part 8 per: https://www.hondapartsdeals.com/honda_parts...component=E++08 (https://www.hondapartsdeals.com/honda_parts_list.php?hp_queried_components=0&hp_series_id=268&hp_series_model=CRX&hp_series_year=1986&hp_series_door_ext_grade=2DR+SI&hp_series_transmission=5MT&hp_series_slsareacd=KA&hp_system=A&hp_component=E++08)

[Eagle7]

Just make sure it's rated for the oil pressure you're running. Mixing the oil and water will kill an engine pretty quickly. Don't ask how I know.

[anrkii]

Yeah, on second thought, I think Ill skip it.
Its an SI, so it has a cooler already, probably wouldnt be worth messing with.

The automatic radiators are the only ones they had, and at $85 for TWO of them brand new shipped to my door, I couldnt say no.

[charrbq]

It's a good buy no matter what. My '86 Civic Si didn't have an oil cooler other than the little vent thingy at the oil filter. I had put on a remote oil filter and seperate cooler for Texas summers. Personally, I'd recommend a seperate oil cooler, though.

[joeg]

The inlets and outlets on those Rads are too small for purposes of an engine oil cooler.

[Zephyr]

I have heard differing opinions on coolers for Honda's. I am going to trust the engineer who created the cooler that comes on the Si even though the idea of putting in a larger cooler has crossed my mind. The factory cooler that came on the Si's can go on the DX block as well. You'll also need the crossover pipe that runs from the water pump across the back of the block for your coolant feed lines.

My new engine will be getting the same treatment this time as well.

Z

[charrbq]

No offense as I agree with your assessment of the Honda engineers. Except that they made a car that would be a little sporty, have crisp handling for the street, plenty of squirt from light to light or pylon to pylon, and get good fuel mileage. They never intended that street engine to be run as hard as we do in racing. My motor uses almost no oil, but slings it out of every possible hole it can find. It was never designed to go 7 grand on the street, but it goes there all the time on the race course. It frequently has its little nose stuck up behind the hatch of a VW or similar car where the air is thin for an extended amount of track time. Fortunately, even though the motor was never built to do the things we do to them, they were built strong enough so that we could make them better.

I run a small oil cooler up front, next to the radiator where it gets lots of cool air that I can control. I do on my C car, and I did on my Civic Si also.

[Greg Gauper]

Just about all of the aftermarket radiators come with the auto trans cooler connections. I run a Modine radiator on my G-prod Civic (11:1 compression, mild cam, close ratio box) and it cools just fine...in fact I sometimes have to add tape to my grill to get the water temps high enough.

I don't use the A/T connections. I did plug them to keep moist air out to minimize possible corrosion, and to prevent a potential leak source if the radiator decided to crack and leak internally into the A/T cooler section.

Regarding the factory oil cooler that sandwhiched between the block and the filter... You can upgrade DX blocks to the Si set up quite easily. I used to run this set up for many years on my ITC car. When I upgraded to Prod, I added an external cooler. I now run a cooler-less DX set up and just run with a big external cooler, since I needed a bigger cooler anyway (the small amount the factory cooler helped was much less effective with the prod setup, so I ditched it). My other reason for getting rid of the factory cooler is that it is a potential failure point. You have two coolant lines that can fail/leak, plus you have the cooler itself that can fail internally causing the oil & coolant to mix. So on the recommendation of the guys at King Motorsports, I got rid of it.

There is one area that the factory cooler is extremely helpful. Technically, it's not a cooler, but rather it is a heat exchanger. It will exchange heat from the hotter temp fluid to the colder fluid. Normally, we think of the oil as being hotter (my typical oil pan temps are around 220-230 so it's a reasonable assumption) with coolant temps in the 170-180 degree range. However, during cold start-up, the coolant heats up much, much faster than the oil. So the factory cooler does help to preheat the oil during warm-up. Now this probably doesn't help road racers, (typically after 1 lap, my temps are good to go) but I suspect it would help a Solo II car greatly, since their runs are so short, I would bet that their oil is just getting to a good temperature about the time that they have finished their runs.

I am also quite amazed at how good Honda engineering is. When I converted my engine to Prod, I looked at the old rod bearings when the new bottom end was being assembled. While the old engine ran for about 4 seasons and had a lot of race miles on it, the bottom end still looked like new. I also like the fact that Honda's for the most part, generally don't leak, provided you run the OEM gaskets in critical areas (pan and valve cover for example) and you don't screw up when you install them. Keep clean oil in them, keep the temperatures under control, and Honda's run forever!

[Bob Roth]

I am not sure what generation Si you are talking about, for what its worth I have a 88 si and its run for 12 years without a oil cooler, no problems on 5-30 mobile 1 oil, 10 years t 35 hours a year racing,inclusing a endurance race or so. I rebuilt the bottom end every 3 years with never a problem. I'd recommend no coolers on the D-16 for IT, save the weight, money and chance of leaks.

One thing to keep an eye on is keep your oil pan in good shape, a little denting on the bottom and oil pressure will start fluctuating in turns. there's only a 1/8 inch between the pickup and the bottom and a dent will close it up in a hurry. I had a dented pan, no problems with bearings but the pressure wa no longer roch steady in turns, new pan and the pressure went back to normal

[Greg Gauper]

I am not sure what generation Si you are talking about, for what its worth I have a 88 si and its run for 12 years without a oil cooler....
[/b]
85-87 Si.....totally different animal from the '88's and later motors, and not quite as stout as the later motors. While not required for longevity, you will see a drop off in HP if the oil gets to hot. There is an optimum oil temperature at which you will gain the most power (around 180 deg F). Honda racer and former GT5 national champ Kirk Olsen has dyno results to confirm this.

I agree that you won't hurt anything running as high as 250 with good oil, but you will lose some power.

[charrbq]

I make the most horsepower with the oil at 210-230 temp, and I run a small oil cooler, but then, I run in the south where it's pretty well mandatory. I run Mobil 1 5W-30 pure synthetic.