Breakin Temperatures

[chrisb]

After 5 years, I finally got my RV-7A in the air this last week. I have a TMX-0360 engine with VAN's firewall forward kit for baffles, seals etc..

During this first flight, my CHTs creeped a bit over 400 in climb with oil temp reaching about 225. I was able to get the CHTs below 400 in cruise and oil temp below 220.

Flight was from a 4500 ft elevation strip - used 120-125 mph climb speed with full rich mixture. I stayed below 6500 ft altitude.

Are these temperatures normal? I assume that break-in temps will be a bit high? Any Advice.

[L.Adamson]

I've seen slightly over 400 on the CHT in climb, but cruise settles at just over 325. I have the CHT probe only on cylinder #3, which is the hottest cylinder on every RV I've seen around here.

My oil temp runs between 185 & 190. The cooler is from Van's and mounted on the rear baffle.

I've been in a 9A, with an 0320 that would generally see higher temps than mine on it's breakin.

RV6A, Lycoming 0360. 9.3 hrs. Airport altitude 4603', initial cruise at 6500-7500.

L.Adamson

[carguy614]

Temps in my 9A 0-320 were over 400 in climb when engine was fresh. Temps dropped 30 degrees or more as engine break in occured. I installed louvers in the bottom cowl as well, and I now see cruise temps at 320 to 340 and oil temps 190 at cruise with 20 hours. My advice would be to wait until break in is over to address the temps, as long as they are not dangerously high. At first, I was unable to apply more than 2300 rpm to keep them in check. Now full power cruise is ok with temps well below 400.

My 2,
Chris

[Ironflight]

Chris - those numbers look to be in the ballpark for the first few hours of operation of a new engine. If you are really worried about it, give Mahlon a call at Mattituck - they built the engine, and can he'll talk straight!

Paul

[Kyle Boatright]

One question - are your wheel pants, gear leg fairings, and intersection fairings installed? If not, you'll see a temperature reduction when you do install them.

Either way, I'd be OK with slightly above 400f CHT's in climb. That's fairly typical of most RV's (except the -4 which runs cooler). On oil temperature, 220 -225 is on the high side for the long term. Again, it will probably come down some as your engine breaks in. Anywhere between 180F and 200F is a good place for oil temperature.

The thing you have to be concerned about is if your steady state oil temperatures remain in the 210-220 range, that leaves little cooling margin for a hot day or a quick turnaround on a hot day. In those conditions (particularly the fast landing, shut-down, followed quickly by a restart/departure), you'll be hard pressed to keep the oil temperatures in the green.