Thorp Air Command - T18.net

Local temp was 36 degrees this afternoon. I took the Thorp up for a little test hop to see if I got a massive air leak blowing on the back of my neck plugged. I did but the engine was running a little cool for my liking. Tomorrow’s forecast is a high of 30 and I have an appointment 103 sm away (more than a 2 hour drive). I intend to fly. Blocking off the oil cooler is pretty common but has anyone in the colder climates installed baffles at the front of the cowl similar to the Cessna cold weather kits to restrict air entering the cowl?

_________________
Thorp T18
O-320-B3B (160 HP)
68x74 Sterba Propeller

"The joke in aviation is, 'If you want to make a million, you'd better start with £10m.' " -Bruce Dickinson

I did something a little different...go figure ? Ran SCATT tube thru a shut off valve that allows me to control the air flow to the oil cooler from the cockpit via a push/pull control . No duct tape or removing/replacing gizmos . I think I got the idea from a Vans site ? Instead of paying $75.00 for the valve made one from left overs for about $5.00 . Smoother than a new jar of Skippy...ZAZAM !

RB

Mine had a slotted sliding gate assembly on it when I bought it but I had to remove it because the oil was getting too hot when the air temps were above 50. I have been meaning to do something with that but tape works and I really haven’t had time. However, my CHT topped out about 325 yesterday. Just checked weather for my flight today and the temp is forecast to be 25. It has been a lot of years since I’ve flown below freezing and that was in a rental so I don’t have personal experience setting up the aircraft for cold weather. When I get figured out I will do more winter flying.

_________________
Thorp T18
O-320-B3B (160 HP)
68x74 Sterba Propeller

"The joke in aviation is, 'If you want to make a million, you'd better start with £10m.' " -Bruce Dickinson

They sell these over on the VAF website. Not exactly what you were asking for.

https://antisplataero.com/products/oil- ... ir-shutter

That is what was installed on the cooler when I bought the aircraft. When it is wide open it still cuts airflow in half. I thought about reinstalling it for winter flying but I used that control cable for the fuel shutoff valve I installed last winter. Cutting the airflow in half to the cooler may be enough during the colder months. Even if I had to wire the gate in place I think it would be better than tape.

_________________
Thorp T18
O-320-B3B (160 HP)
68x74 Sterba Propeller

"The joke in aviation is, 'If you want to make a million, you'd better start with £10m.' " -Bruce Dickinson

What is Winter flying ? 75 here in San Diego .

RB

74 in Hawaii.

_________________
Bob Highley
N711SH
SN 835
KLAL

24 where I took off. 16 at my destination. With some tape on the oil cooler I was able to get 164 degrees but couldn’t hardly get the CHT above 310 on the hot cylinder. Thankfully it doesn’t get that cold here very often.

_________________
Thorp T18
O-320-B3B (160 HP)
68x74 Sterba Propeller

"The joke in aviation is, 'If you want to make a million, you'd better start with £10m.' " -Bruce Dickinson

It's always 74 somewhere in HI .

RB

We use aluminum tape.
Cubes

When I went to pull the aluminum tape off the cooler this past spring, there was a birds nest contributing to air blockage - who knows how long it had been there. My engine runs cool on the colder days, and I get the temps wanting to be up to burn the condensate off, but I gotta think that running 160 degrees for a few hours worth of flying each winter isn't hurting it either. It beats 234 degrees F. Metals seem to like being cool - it keeps their molecules calm and static. I change the oil every 30 hours, even with a remote filter....I gotta think that does alot of good for the corrosion protection. I also live in the 2nd driest state in the union.......It's 74 in front of my fireplace.....

_________________
Fraser MacPhee
N926WM
Serial #279-1
Angel Fire, NM (KAXX)

Aluminum tape ? Are you sure you're not using used aluminum foil peanut packages after those airline flights !!

RB

Maybe but the O-320 manual says the desired oil temp is 170° F for this air temperature range. 160° F is desired when air temp is below 10° F. A little more tape and that will be good. I was a little concerned about CHT but the same manual gives a range starting at 150° F so I won't be restricting any airflow up front.

I am glad I dressed like the Michelin Man today. I've ridden in colder aircraft but not many and none of those had heat! It's time to plumb some heat to the pilot's side and find a way to cover the big holes at the flaps. I think we will be back into the 50's this weekend.

_________________
Thorp T18
O-320-B3B (160 HP)
68x74 Sterba Propeller

"The joke in aviation is, 'If you want to make a million, you'd better start with £10m.' " -Bruce Dickinson

I think you’re right, Frase. Living in a semi-arid environment also, here in Colorado, definitely reduces some corrosion issues. I built a neat little snap-on air restricting cover for my oil cooler, but found I don’t need to use it... I admit that I also don’t usually fly too much when it gets real cold. I’ve used 15w50 AeroShell for 27 years, and I think the semi-synthetic multi-vis oil mitigates some of the potential issues with oil temp sometimes being a little lower than “optimum”, including moisture formed as a product of combustion. I think that frequent running and keeping everything, especially that camshaft on our Lyc’s, bathed in fresh oil is the very most important factor. Frequent oil changes also are good, like you said - I do mine every 25 hrs. My oil temp gauge is accurate, and I’ve flown a lot with temperatures in the 160 - 170 deg. range. FWIW, I’ve put a little over 1300 hours on my O-320, and it still uses very close to 1 quart of oil in 25 hrs. & is strong with good compression. Maybe I’m just lucky. I wouldn’t stress over temps a little low... like you also said, it’s much better than too high.

_________________
John Evens
Arvada, Colorado
T-18 N71JE (sold)
Kitfox 7 SS N27JE

What happens if you sit on the ice too long ? You get Polaroids !

RB