cooling lip

[yarddart]

Do you think a cooling lip on the bottom of coul would help temps?

[gmcjetpilot]

Originally Posted by yarddart

Do you think a cooling lip on the bottom of coul would help temps?

A larger lower lip at higher angles of attack (climb or high G turns) may help cooling but in cruise, no. Van's stock cowl as fairly generous radius around the inlet. Have you seen vans inlet? They have very round edges for that reason and a upper inner cowl guide ramp.

In general RV's are designed to have adequate cooling if built per plans. Are you having problems or just anticipating a problem?

The only exception is the IO360 (200HP) which is a challenge for some. This seems to be the hottest running engine. It actually is an oil cooled engine and requires careful selection of oil cooler and installation, more so than other engines. I have some ideas on that.

Do you having cooling problems, plane? engine? High CHT? which ones and what is the temp? Oil temp high? Oil cooler brand model? Method of mounting? What RV?


Hope that helps. G

[yarddart]

RV8 io360 in climb 98 deg temp saw 230 oil temp. My pa18 has a 2inch lip bottom of cowl dropped oil temp 8deg .Just wondering.

[rvbuilder2002]

Originally Posted by yarddart

RV8 io360 in climb 98 deg temp saw 230 oil temp. My pa18 has a 2inch lip bottom of cowl dropped oil temp 8deg .Just wondering.

Your PA18 has a hole in the bottom of the cowl which the air has to exit down out of the bottom into relative wind that is flowing aft. The added lip produces a hole in the horzontal airflow making it easier for the cooling air to exit the cowl (extreemly simplified explanation).

RVs all have cowls that by design have the cooling air exiting aft mostly parallel to the airstreem, into a hole already made by the cowl.

The lip has no noticable effect on RV's.

[gmcjetpilot]

Originally Posted by yarddart

RV8 io360 in climb 98 deg temp saw 230 oil temp. My pa18 has a 2inch lip bottom of cowl dropped oil temp 8deg .Just wondering.

Try the Lip and let us know how it works.

This is oil temp's OK and it was a hot day. To be realistic 98 deg is HOT and 230 oil temp acceptable (below red line), but higher than desired.


Great, a lip may help in climb as I said, may be you should get some foam and tape it on and test it? You did not mention what airspeed, but of course there always is the time honored method of lowering the nose.


However, if you really want it lower I would attack the oil cooler and or installation first. You can expect up to 30 degree drop if you are NOT using a Stewart Warner oil cooler. A SW cooler is more efficient. Not sure is you have a 180 or 200 HP.

IF you have 180HP IO360, SW part # 8406R (see web site link below)

IF you have 200HP IO360, SW Part # 10611R (see link to thread below, you may get away with a 8406R)


If you have a firewall mounted cooler using the Van's oil cooler kit, than that is a problem. The kit works OK for a 150/160HP 320, but not so well for 360's, an IO360 (200HP) forget it. The Van kit has a small 3" duct and a poor transition to the cooler (a very flat square metal pan).

Here is a builder's post with the ultimate cooler set up. Notice the size of the duct (4") and the tapered duct attachments at each end.

http://www.rvproject.com/20040519.html (8406R)
http://www.vansairforce.com/communit...ead.php?t=9223 (10611R)
http://www.vansairforce.com/communit...ead.php?t=9146 another thread

Good Luck, but if you have a 200HP and getting 230F OT in an aggressive climb at 98F day you are doing OK. There may be room for improvement.

[yarddart]

Thanks guys