Front Oil Cooler for Racing 2.8 Liter Six, How Big Do I Need to Go? Options

[motorvated]

Working on my Vintage racer to upgrade to a 2.8 liter six race engine and was looking for recommendations for sizing my front oil cooler. This race motor has an oil filter installed in place of the stock oil cooler on the engine, so my front oil cooler has to do the full job of cooling the oil up front. I have been looking at the Setrab coolers and specifically their model number 50-150-7612, which is 16" X 8.25" with 50 rows. Smaller option is their Series 9, 20 row model number 920F22 which is 16" X 6", which might be undersized. I'm curious to learn what you racers out there have found to work best.

Also I'm trying to size a differential cooler for the Wevo 915 transaxle. It had a Tilton pump and cooler on it when it ran in the prior race car, but unfortunately they stayed with that car. So any recommendations for sizing that, with or without fan also would be helpful.

Thanks Mike S.

[wndsrfr]

Go as big as you can...especially without the engine mounted cooler....I favor the fluidyne....installed their OGEN.DB-30417 which is 6.5x15 inches and 2.75 inches thick....-12AN fittings. COst at Summit Racing was $425 couple of years ago but really worth it....

[Krieger]

I run this setrab from Patrick Motorsport on my carbed 3.0. My engine also has a new factory engine oil cooler. On a 108* day at the track the oil temp was 230* the smaller one might be ok with it's 96 sq inches. Mines a little more than 75 sq inches. Put a thermostatically controlled fan on either cooler you choose for driving in traffic.

[motorvated]

Thanks for the input guys. I'm leaning towards the Setrab Series 9 Dual Pass Dual Fan cooler with 20 rows and 84 square inches of cooling area. Hoping that with the fans it will be enough for race conditions on a hot track. It's a little narrower than the 911RSR one so it might be a better fit.

[JmuRiz]

I think I have that setup, I can get some photos and specs if you'd like. I was going to run it under my rear trunk with the fans for street use.

SETRAB 20 Row Cooler NEW, 2 6" SPAL Puller fans NEW, M22 to 12AN fittings, 16 x 6 x 2.25 bare, 16 x 7.25 x 6 with fans

Let me know if you'd like more info and I'll send what I have.

[Krieger]

Thanks for the input guys. I'm leaning towards the Setrab Series 9 Dual Pass Dual Fan cooler with 20 rows and 84 square inches of cooling area. Hoping that with the fans it will be enough for race conditions on a hot track. It's a little narrower than the 911RSR one so it might be a better fit.

You'll need the fans if your driving in stop and go traffic. On the race track you'll need really good airflow to keep the oil cool.

[JmuRiz]

Looks like mine is the setrab 50-920-7612 (920M221) measuring 16”w 6”h

With the matching fans/shroud.

[brant]

Fans are a bad idea on the track
Become a resistance to air flow at speed
Fans are for street use
No fans on my double front fluidyne mounted coolers

[technicalninja]

(IMG:style_emoticons/default/agree.gif) (IMG:style_emoticons/default/agree.gif) (IMG:style_emoticons/default/agree.gif)

Above 30 mph the fans are a restriction.

Below 30mph the fans are needed.

Stopped in traffic an absolute requirement.

I don't think I've ever seen fans for anything on a dedicated track car.

[stownsen914]

Think big when it comes to oil coolers for a tracked car with some hp.

For a data point, for my 2.7L 6 I have B&B's biggest cooler (I think the core is 24x6x3). That has kept temps below 200 degrees where I wanted them.

In fitting the cooler, make sure to properly duct air to and from the cooler. In front of the cooler, make sure the incoming air has nowhere else to go except into the cooler. Or else it'll just flow around the cooler and you'll lose a lot of efficiency. I once sealed up gaps of 1/4-1/2" in ducting on a front mounted cooler and the oil temp dropped 20 degrees on track. (Sealing was done with weatherstripping foam tape.)

Just as important, make sure the air is exhausted efficiently without restriction into a free airstream. If you're exhausting it GT style through the trunk, put a downward facing lip at the leading edge to trip the air.

[stownsen914]

And agreed on no fan for a track car. As mentioned above, a fan's value is only for a street car in stop and go traffic.

[technicalninja]

No-one has mentioned it...

There is ABSOLUTELY no good reason to intentionally run the oil over the boiling point of water on a track car in my book.

It's HUGELY important on a street-based vehicle but you should be changing your race oil far before moisture contamination is a concern.

Now if it does run over 212 during a session it's a plus...

I'd shoot for a minimum temp over 170 but I'd try hard to build a system that did not require a thermostat.

"Fewer parts" is more dependable, lighter, and less expensive...

[stownsen914]

I agree with the above. A few thoughts below.
Water evaporates increasingly as the temp goes up. There's lots of evaporation happening by the time it gets to 200 degrees. There isn't anything magic about hitting 212 degrees to get good evaporation.
If your oil temp gauge says 200 degrees, remember that's post-cooler. In the bottom of your engine, post bearings and exposed to all the heat the oil is probably 25-50 degrees hotter, so condensation has a chance to evaporate off more aggressively.

[technicalninja]

I'd have a sump temp sender as my "normal" sender to the gauge and the post cooler as a secondary...

Might just have a momentary switch below the gauge to check the efficiency of the cooler but the temp I would want to know is sump.

If I only had one, it would be sump.

Now, I don't race 911 engines...

The above info is GENERIC!

911 stuff may be different, and others might come in a say, "The Ninja is a fool"! (IMG:style_emoticons/default/clown2.gif)

I'd put more weight in Brant's and Stownsen914's comments.

They are "hands on" where I am not! (IMG:style_emoticons/default/ninja.gif)

[Justinp71]

I talked to a race engine builder a couple years ago, for a race 2.5L they elected a pretty healthy sized Fluidyne, said the Setrabs don't offer enough cooling. If you go too large you can always add some tape on the front. The factory had those circular holes for that reason, so you can adjust oil cooler temps with a larger cooler.

I have a healthy 3.2 (warmed over with headers, cams, carbs, etc.) with the factory GT Setrab cooler it only lasts on track with cooler days about 10-15 mins then I pull off as it approaches 215f. It's been on my list to upgrade the cooler size but its more of a street car so it's not a big issue for me.

[technicalninja]

I talked to a race engine builder a couple years ago, for a race 2.5L they elected a pretty healthy sized Fluidyne, said the Setrabs don't offer enough cooling. If you go too large you can always add some tape on the front. The factory had those circular holes for that reason, so you can adjust oil cooler temps with a larger cooler.

I have a healthy 3.2 (warmed over with headers, cams, carbs, etc.) with the factory GT Setrab cooler it only lasts on track with cooler days about 10-15 mins then I pull off as it approaches 215f. It's been on my list to upgrade the cooler size but its more of a street car so it's not a big issue for me.

Are you shutting down because of 215f?

My limits would be MUCH higher. Another 50 degrees +.

If I could sustain 215, I'd be fine with it.

On a mostly streetcar 215 would be my LOWER limit!