temps and pressures

[shogan50]

I've been out of the flying game for a while, but I previously did some work on a Reno racer glassair cooling system and am now starting to think about an RV-4 and possibly a 2.5L sub (also haven't ruled out wankel) of my own. In order to design an efficient cooling system, it would be helpful to know what temperatures and pressures pilots are seeing in the upper and lower cowl. You would have to be specifically instrumented to take these measurements, but I'm guessing with all of the problems I've read about with sub ffw's, a few have likely done it. I'll take any data, but prefer to know if cooling air temperature is influenced by exhaust heating or radiation and if pressures are taken using a picolo tube. Also would be interested in either lycosour, or water cooled in the typical 2 seat RV HP ranges. ( BTW, if memory serves, the cooling mods took the glassair from 360 to 375 (don't recall if he was indicating kts or miles) indicated all other things being equal.)

[pierre smith]

Scott, if you're even THINKING about a Subie, my buddy has one of Eggenfellner's on his hangar floor, complete with prop. Only 220 hours or so, Gen 3 gearbox for ONE TENTH of the original price!!

Call Ray at 478 232 9 five 6 oh.

Best,

[DanH]

Welcome aboard Scott.

A few of us have been gathering cowling pressure/temperature data and expect to publish here eventually.

The standardized test rig places a pair of piccolos in the upper plenum, another pair below the cylinders, and collects exit temperatures. We're also experimenting with exit velocity measurements.

My own efforts include exit, below cylinder, oil cooler air in and out, and a few other temperature points. I try to eliminate radiation from exhaust pipes using shields, but have not worried much about other radiant sources.

I'm not aware of any serious effort to instrument a water cooled installation in an RV, at least not mentioned here. We have one very bright fellow who was working on a belly mounted heat exchanger for his RV-10, which is not yet flying. My own view is that water cooling an RV is largely a packaging exercise with potential for lower cooling drag than the air-cooled install....but the packaging won't be easy.

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