Oil Cooler Mod - non RV

Janekom · #1 08-16-2007, 01:36 AM

I apologize for posting non RV stuff but as a RV7A owner and bulider (yes again) I would like to get advise on this one. I have a C150 in the experimental category. There is a fairly large oil cooler mounted on the firewall connected with a 4' scat hose to an inlet in the front lower cowl. Looking at the picture attached - this is a mock-up of what I want to do. Will the 2" scat hose be big enough? The oil cooler box does have an outlet at the bottom. Thanking you in advance.

Shot at 2007-08-16

rleffler · #2 08-16-2007, 04:50 AM

I have a STC from Paul Romanos to do something similiar for my Cherokee. The Cherokee has a winterization plate that is suppose to be put on in the winter to keep temps up. This tends to be a royal pain when the temperature is borderline or if you are going cross country.

The solution was to install something that looked like a flue damper that is controlled via what looks like a throttle cable in the cockpit. The damper is 3.8".

This doesn't give you an answer to your question, just another reference that has been signed off by multiple FSDOs for a certified aircraft.

mahlon_r · #3 08-16-2007, 05:22 AM

2 inch is pretty small...have never seen an oil cooler ducted with that small of a scat tube that I can remember.
Good Luck,
Mahlon
"The opinions and information provided in this and all of my posts are hopefully helpful to you. Please use the information provided responsibly and at your own risk."

Stephen Lindberg · #4 08-17-2007, 01:12 AM

Resistance to the flow of liquid in a tube is inversely proportional to the fourth power of the radius, meaning that halving the diameter would increase the resistance to flow by a factor of 16!. At least this works for blood, not sure about air (a compressible fluid), but I'll bet is is close. Two inches is way too small.

Mel · #5 08-17-2007, 07:24 AM

I originally had a 2" hose to the oil cooler on my -6. It was not enough. I added another 2" and it works fine. Actually a 3" hose would have more area than 2 2" but I had lots of 2" hose laying around. I would recommend at least 3" and probably 4" just to be sure.

Janekom · #6 08-18-2007, 09:23 AM

Thanks for all the advise. I wil see what I can fit a 4" hose into the baffle.
Another thought - the oil cooler box sits very close to the side of cowl. Maybe I can open up a slot/grid/duct on the side and feed straight into the oil cooler box?

flyeyes · #7 08-18-2007, 09:35 AM

Quote:

Originally Posted by Janekom

Thanks for all the advise. I wil see what I can fit a 4" hose into the baffle.
Another thought - the oil cooler box sits very close to the side of cowl. Maybe I can open up a slot/grid/duct on the side and feed straight into the oil cooler box?

I've seen this done with reportedly good results.

One example is the red turbocharged RV-8 "Grezdlightnin" from ?Oklahoma maybe.

There was a sport aviation article, and I have a few photos of his oil cooler if they would help you.

Janekom · #8 08-19-2007, 10:43 AM

Thanks Flyeyes. If possible please send some of the mentioned pics to jan"AT"tilt-tech.co.za