CHT - Angle Valve vs Parallel Valve

[osxuser]

The angle valve does have more fin area. Cardinal owners have been aware of this since the RG has the angle valve, and the FG's have the parallel.

Also, remember that the power advantage of the angle drops off pretty quick below 2500 rpm, so if you are just loping around at 22" and 2300 RPM, the angle and parallel are probably making about the same power. The Angle will run MUCH cooler in that condition.

In the Cardinal RG, the temp limiting factor is oil temp, not CHT. Many people have installed 182RG oil coolers to solve that problem, so the piston squirters might have something to do with it too. Either way, the angle valves work better, which is why I prefer them... as long as I don't have to pay for the cylinders when overhaul time comes around.

[novipilot]

Just this morning watched the EAA webinar on EGT and CHT by Mike Busch. After that, I'd want a CHT no higher than 380, redlined at 400. I know Lycoming says 500, but in the webinar, Mike made a pretty convincing case for top of green arc at 380F

[Lars]

I really shouldn't be reading this. Now I'm wishing I had a Barrett IO-390. The extra horsepower would just be gravy.

[RV7Guy]

Originally Posted by novipilot

Just this morning watched the EAA webinar on EGT and CHT by Mike Busch. After that, I'd want a CHT no higher than 380, redlined at 400. I know Lycoming says 500, but in the webinar, Mike made a pretty convincing case for top of green arc at 380F

That may work for much of the Country, but I might as well park my plane from May to October in Arizona. In the Summer, I use 425 as my upper limit to determine climb rate. Other times of the year, 360-370 in cruise is common.

I have taken off with an OAT of 117 when leaving for work for the 15 minute flight. I only climb to 2900 ft because of the short distance and Phx Class Bravo. During the Summer, anything close to 400 is considered a victory.

FYI, 25 hour oil analysis shows no negative trends. TT now 640 hours on the ECI IO360 with Barrett magic work done.

[DanH]

It's going to be very interesting when we start collecting pressure data for the different cowls.

[F1Boss]

Originally Posted by RV7Guy

That may work for much of the Country, but I might as well park my plane from May to October in Arizona. In the Summer, I use 425 as my upper limit to determine climb rate. Other times of the year, 360-370 in cruise is common.

I have taken off with an OAT of 117 when leaving for work for the 15 minute flight. I only climb to 2900 ft because of the short distance and Phx Class Bravo. During the Summer, anything close to 400 is considered a victory.

FYI, 25 hour oil analysis shows no negative trends. TT now 640 hours on the ECI IO360 with Barrett magic work done.

Hey Darwin:

Your mention of 'magic' suggests that some sneaky person might have installed higher compression pistons in your engine. Might try pulling the mag timing back 2 deg or so to help with the CHTs. We moved mine (IO550) to 24 from the factory recommended 22 for the Reno activities, and dang sure I had CHT problems right away: installed a spray system to control the temps during the races. I sure like the extra power, but I'll be pulling the timing back when Texas summer comes around...

BTW I'd like to participate in this cowling measuring process.

Carry on!
Mark

[MOJO]

Love to read more of the details of 1Oldguys Angle Head 0-320. Currently
fly a 160hp Yankee and will start our -4 build in 15 months when I finish
A&P school. 32 year Tool & Die/Injection Mold Maker going back to try
the path not taken. Is this a great country or what?

David Mojonnier
Tucson