Is there a rule of thumb for radiator volume to horsepower? I've got a 150 hp Hisso that I'll be using in an O/T aircraft application but figured you guys would be a good place to start. Sent from my iPhone using The H.A.M.B. mobile app
I'm going to step out on a limb here cause no one has answered your question. There is not really a rule of thumb for hp. to radiator volume. It's more about quality and quantity of the heat exchange. This changes based on the material the engine is made from as well as the radiator. Optimum placement of the radiator to maximize air flow through it can also effect what size or volume is needed. What form of antifreeze or cooling liquid will affect the ability for the radiator to exchange heat. The average combustion chamber burns 600 degrees. The average cooling system manages heat between 160 and 210 degrees. If it was me, I would look at engines of the same cubic inches and same physical size to get an idea of coolant capacity and go slightly larger and adjust from there as far as placement and air flow. I hope I could help you. Thanks.
I don't remember when I first heard this but now seems like the perfect time to use it.~ "You got the right plane but the wrong airport!" I wish I could help but if it's involving aircraft and using the wrong radiator could result in less than a desirable outcome I doubt I would take the advise of a bunch of traditional hot rodding malcontents, HRP
HRP has got a good point. I'd think this through ALOT. I don't think there is any where to "pull over " in the sky! Nice looking engine!
Years ago I saw an experimental plane with a 215 buick and belt reduction prop drive, and I was surprised at the small size of the radiator. Possibly because of the airflow they were able to use a small one.
Maybe it's not a good comparison since planes generally operate at higher continuous outputs but it seems like there oughta be some some type of minimum cubic inches of radiator per horsepower formula. My set up will be similar to this. Sent from my iPhone using The H.A.M.B. mobile app
i really can't say for sure , every airplane i have ever flown or worked on had an air cooled motor. as you said , they normally run at higher power output.....75% at cruise.and 100% at takeoff do you know how much coolant the block holds? maybe you would want at least that amount in the radiator? would there be a thermostat?
That would look fantasy in a hotrod!! Call this guy Monday! http://www.autoradradiators.com/ There's no real Formula but there's some guidelines. 40 some odd Btu per hp then 1/3 of that goes into heat that cooling system needs to shed. Different engines need a different set of parameters. For instance a 80 hp flat head needs more radiator than a 300 hp LS engine.
That a good thought. I hadn't considered the amount of coolant in the engine itself. No thermostat, shutters. Sent from my iPhone using The H.A.M.B. mobile app
It's all based on fuel consumption. A lb of fuel produces X amount of power; depending on the efficiency of the engine, approximately 30% of that power will be used to power the plane, another 30% will be lost as heat out the exhaust, and the rest will need to be dissipated by the cooling system. A real crude guestimate of your system would be something like: Your engine produces 150 hp, it will need to dissipate ~ 200 hp equivalent of heat generated if operated at full power continuously, but since you don't operate continuously at full power, you can probably cut that to ~80%, or 160 hp, which = ~407k btu's per hour. That's obviously a real rough estimate, only meant to be an illustration. I'm not a mechanical engineer, and I've been drinking, haha! But that's basically it. First figure out the fuel consumption, determine the power potential of the fuel, the efficiency rating of the engine, and go from there. If we were just building a hot rod, we could guestimate this shit. But for a plane, guestimates aren't a wise way to go.
Fuel consumption is one way to look at it...but also, look at the temperature difference. The higher the difference, the more heat transfer you get. Since air planes usually operate at higher altitudes than cars, and also seem to have a much bigger fan, and move much faster, they should cool pretty well, even though the engine is running at a much higher % power output than cars most of the time. I agree that you probably need to find an aircraft engineer to help you figure it out.
Since this engine was used in the Curtiss Jenny in days of old, wouldn't the size of the Jenny radiator be an indicator of what you need? Looks like it would take some more creativity to preserve the nice look of what you have pictured.
Are your plans to have it up front like this ? http://www.theaerodrome.com/forum/showthread.php?t=48627
My wife say's that it's not the size of the radiator but what you put into it. And then she tells her friends something different.
In an airplane there is a constant flow of cold air so even a minimal radiator will work well. Sent from my iPhone using The H.A.M.B. mobile app
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