R-1820 High Power Test Runs --- Oil Coolers and Cowlings

[DCarr]

We (B-17 Texas Raiders) are currently building a test stand to test run our five R-1820-97s. Our goal is to run about 55 gals of fuel through each one at 75% power.

I'm curious what other people have used to supply air to the oil coolers in this application. We will be using a test club, is there enough velocity from the prop blast to cool the oil? Or, do you have a separate electric blower that directs air through the cooler?

Secondly, do you cowl your engines during high power test runs? Most pictures I've seen show uncowled engines but I have the suspicion that many of these runs are short duration or low power "exhibition runs". Looking at the cooling baffles around the cylinders, it seems that I need the cowlings to direct the airflow through the cylinder fins.

Thanks for sharing your experience,
-DC

[Matt Gunsch]

From a prewar R-1820 overhaul manual

[maradamx3]

DC:

Maybe you can find out from Gary what set up they have on Testicles!

If not, try setting up a spray bar in front of the oil cooler.

Tommy

[DCarr]

Matt,

Thats a great page you have there. I only wish we had a couple of those special cowlings laying around. I bet they would be a real chore to build.

One question, can you read what it says about the propeller? I think it says "standard three blade .... modified?" or maybe mounted?

I like the water spray idea for the oil cooler, its one that several people have now suggested. Is there a problem with using water spray to help cool the engine itself too?

Thanks for all the help so far. This is turning into a team effort,
-DC

[SPANNERmkV]

If I cross my eyes just right I think I see a dash between the words Standard Propellor and Modified Cowl...

The modified cowl looks like one of those dog collars to keep your dog from scratching on the north end or chewing on the south end after something's been worked on at the Veterinarian's!

hmmmm

[Michel C-GNCJ]

I think I might have a picture of such an apparatus somewhere in my photo bank at home taken at one of the many museums I visited.

Will try to find if so and get back to you. May take a while though...

[Matt Gunsch]

Matt,

Thats a great page you have there. I only wish we had a couple of those special cowlings laying around. I bet they would be a real chore to build.

One question, can you read what it says about the propeller? I think it says "standard three blade .... modified?" or maybe mounted?

I like the water spray idea for the oil cooler, its one that several people have now suggested. Is there a problem with using water spray to help cool the engine itself too?

Thanks for all the help so far. This is turning into a team effort,
-DC

does this work for you

[bdk]

Is there a problem with using water spray to help cool the engine itself too?

Was done on the Super Corsair and Dreadnought at Reno.

[sdennison]

It really doesn't look like a difficult shroud to make. Appears to be a flat band around the rocker covers with a cone attached. There is a real simple formula for laying out any size cone if you know the desired ID and OD. It will allow you lay out the curve in flat stock and then when rolled, it will result in your cone. I'd have to dig but I have in my books somewhere if anyone is interested.

If you have a test stand built already, this shroud should be something easily built by a good sheet metal shop. I'd put a tubular ring around the major diameter as well as the rocker band. That way you can tie the two together for strength.

Heck, really, all you have to ask "prints available on request".