Looking for oil cooler with side inlet/outlet

[RussMcB]

I have in mind a certain oil cooler arrangement, but it doesn't seem to be common.

I'd like an oil cooler that is very similar to the layout of my Van Diemen water radiator. Ideally I'd like it to be about 7" tall. The length isn't critical (12"-20"). I'd like -8AN fittings.

More info: I'm plumbing it after the scavenge pump and before the oil tank. Since it will be a mixture of oil and air, it's important that I exit the oil cooler from the bottom. Otherwise, (if I exited the top), there may be oil sitting in the bottom of the cooler that never circulates.

While Googling for the cooler I want, I came across lots of coolers that would be great, except they are single-tube, multiple pass coolers. I've never seen that type plumbed into the oil system on a high quality race car. However, I'm wondering if it might be okay for my application (since it is low pressure, feeding into the oil tank). The type of cooler I'm referring to is usually used for automatic transmission coolers, like the attached picture. Bad idea? It would solve the problem of "puddling" oil never exiting the oil cooler.

Thanks for your thoughts.

[JEREMY HILL]

russ, i just installed a setrab cooler i my 99 vd, fits perfect in place of water rad on left side, part no is 172 8" x 22" , call marvin at setrab 740-625-6228, regards, jeremy hill

[Stan Clayton]

Russ, both my Ralt Atlantic and Zink CSR have oil coolers plumbed between the scavenge pump and the tank, but both of them feed oil at the bottom and exit at the top, to prevent air being trapped in the cooler. Stan

[Matt Conrad]

Stan makes a very good point as I know of one person that had the cooler plumbed the other way....and air doesn't seem to lubricate bearings very well.

We have always plumbed the cooler inline between the oil pump and the tank, but on the F1000 we are trying to run the cooler seperate from the dry sump system. At the first test the oil was warmer than I expected....but we are also measuring in the tank instead of exiting the cooler....where we used to measure. We also found that the AIM sensor unit has a metal spring that was against the engine block and could have been giving us a higher than normal reading. The temps are not high enough to really worry about, but we are paying attention to it.

For reference...our cooler size is currently 11" x 8" x 2" and we have a larger one in the trailer (11" x 10" x 2") just in case.

Matt Conrad
Phoenix Race Works, LLC

[RussMcB]

Russ, both my Ralt Atlantic and Zink CSR have oil coolers plumbed between the scavenge pump and the tank, but both of them feed oil at the bottom and exit at the top, to prevent air being trapped in the cooler. Stan

Y'know, I struggled with this in my mind for a while. The reason I think it should enter at top and exit at bottom is:
Since it is coming from the scavenge area, it will be oil potentially mixed with a LOT of air.
Since the oil is heavier than air, after entering at the top it will not have a problem finding it's way to the bottom exit (and will be cooled during it's trip).
If some air molecules happen to get trapped in the cooler temporarily, no big deal.

Matt, I'm not worried about air getting to bearings. That's a different part of the system. The main oil pump will always have a positive feed unless the oil tank is empty (or if oil is full of bubbles - a separate concern).

Conversely, if I ran oil/air into the bottom expecting it to exit at the top, I can see how some oil may decide to stay in the cooler while the air part of the mixture bypasses it to the exit of the cooler.

Now, if we were talking water radiators, I would agree that entering the bottom and exiting the top would be the way to go, but I think this is different.

I do appreciate your thoughts.

[RussMcB]

russ, i just installed a setrab cooler i my 99 vd, fits perfect in place of water rad on left side, part no is 172 8" x 22" , call marvin at setrab 740-625-6228, regards, jeremy hill

Thanks, Jeremy. Good info.

The second time I read your post, I noticed you said "replaced" the left radiator. I had not even thought of removing one of the two radiators. How has that worked out for you? You normally race in the north, right?

My gut feeling is that I want to retain two water radiators, especially since I am increasing HP compared to Pinto power and race in the hot southeast.

My rear subframe is 80% done, so I'm starting to thing about the other systems, contemplating where to put coolant lines, serial vs. parallel, etc.

Holy smokes, there is a lot more to this conversion than I anticipated. I still need to do axles, wiring, clutch, throttle, shift linkage, fuel system, body work, etc., etc. - but I don't regret starting it. I'm still excited.

[S Lathrop]

If you don't mind using brass radiators, you can make a radiator in any configuration you want. Before I started using oil/water heat exchangers instead of oil coolers, I would section a part of the water radiator and use it for oil cooling.

In aluminum cores it is hard to get a tight joint when you section part of the header on the radiator.

You can put the oil fittings on the radiator instead of the water fittings. The cooler is not under pressure so a water radiator will work fine. May be even better.

[JEREMY HILL]

based on my experience with the photon i think 1 water rad will be sufficient even in hot weather, the oil was a problem though, hence the slightly larger oil rad, cheers, jeremy

[Mike Devins]

Most of the DSR's run one rad for water and one for oil.

I run an 11 x 17 for the water and an 11 x 11 for oil with no cooling issues.

[RussMcB]

I talked with Sean last night. He reminded me that he tried a single radiator in his RF96 1000 and it didn't work well for him. Perhaps the mid 90's Van Diemens don't have the sidepod/cooling capacity for a single rad set up. At this point I'm leaning towards two rads, plumbed in series with an oil cooler mounted in front of one of them (or maybe behind the second radiator).

After a lot of Googling last night I may have found an oil cooler with the fittings arrangement I want - Earl's Temp-A-Cure "Narrow" 25 or 34 row cooler. I can get it with -8 fittings on one end. Seems perfect, but I need to get confirmation that it is what I think it is.

[formulasuper]

When I converted my 83 RT5 SuperVee to the Suzuki 1300 Hayabusa engine I stuck with the original left side radiator & right side oil cooler. Both water & oil temps are fine.

[RussMcB]

Very interesting.

I've heard from a few sources that a single water rad and single oil cooler set up is working fine for some people.

Of course, every car (model) and set up is different, so it's often not an apples to apples comparison.

If I could run a single water rad and single oil cooler, that would make my plumbing requirements MUCH easier.

At this risk of asking a dumb question in public: Could I use one of my current Van Diemen water radiators as an oil cooler? Any inherent bad ideas with running oil through a cooler made for water? As a reminder, my oil cooler will be plumbed into the scavenge side, so it will not see much internal pressure.

Another benefit would be more oil capacity. My oil tank isn't very big due to limited space.

[Eric Cruz]

Steve Lathrop thinks a radiator is a good idea (see above) and he should know!

Best regards,
Eric

[Joshua Held]

From my experience with my DSR the oil cooler needs to be relatively large when compared to what norally comes equipped on motor cycles; mine is probably 6x the size of the stock bike one. Your cars are somewhat different animals but the cooling capicity should be simular. We run a single radiator and oil cooler arrangement but we have a little more space. These little engines generate a good deal of oil temperature making the oil cooling configuration extremely critical. In your configurations there is going to be a huge benefit of perfectly ducting the air flow through the heat exchangers and providing a good exit path for the hot air.

I don't believe that regular water raditors are built for the sort of pressure (scavenge side or not) that an oil system would generate.

Josh

[S Lathrop]

The Dallara IPS cars use the same core for the oil cooler and the water radiator.

An alternative that I have used for years and prefer is to put a oil/water heat exchanger between the 2 radiators. I use over sized water radiators and a thermostat to control water temperature and the excess capacity is available to cool the oil.

On some cars I use hot engine water to cool the oil. In this type application I run some of the engine water to the exchanger and dump the water into the line between the 2 radiators. My water is controlled to run at 190 F max and the oil will settle in at 220 max. The advantage is that the oil is heated at the start of the race and the engine gets to operating temperature sooner.

My Zetec car is cooling very well with the exchanger between the 2 radiators. I got the exchanger from C & R in Indy. It is some kind of exchanger that is built into radiators. It is about 24 in long, 2.5 wide and 1.5 tall.

[RussMcB]

Thanks for the suggestions. It's tempting to devote one of my Van Diemen radiators to oil cooling, but I think my first iteration will be two water radiators and a decent sized oil cooler.

Follow up question:

I'm looking for thoughts regarding the thermostat - Keep, modify or remove it? I had planned on leaving it in place, but after reading some comments, wonder if it will restrict flow and affect cooling ability.

[sidney]

I read a post on the SportsRacer site, that said they left the thermostat in place, but drilled 3-4 3/16" holes in it for cold conditions. Apparently going from idle to 10k rpms when the thermostat is not open will do some damage.