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Wrenchgirl
10-28-2017, 06:47 PM
A friend has a 0-235 in his Citabria. Oddly enough, he is concerned his oil temp is too low. Does anyone have experience with a baffle covering plate on this engine to increase oil temp? Thanks for any input.

PerryB
10-28-2017, 07:07 PM
A swatch of duct tape on the cooler is the easiest solution. Either that or a bunch of money to convert it over to a Vernatherm. I did the Vernatherm swap several years ago and it rewarded me by failing in about 18 months. I'm back to using tape on the cooler, and it works just fine.

Wrenchgirl
10-28-2017, 09:00 PM
I have not had a chance to look under the cowling. He insists there is no oil cooler.

DENNY
10-28-2017, 09:13 PM
I would agree with PerryB. It is very easy to cover make a plate for the cooler in a o320 usually 1 inch of duct tape = 20 degree of oil temp increase. I would not want to cover in air inlet to the cylinders unless he had a 4 cylinder CHT/EGT.
DENNY

Wrenchgirl
10-28-2017, 09:16 PM
Thanks for this. Owner insists there is no oil cooler. Don't have any experience with this engine.

eskimo77
10-28-2017, 09:36 PM
There could be a box that goes over the oil screen housing and has a scat hose blowing air on the screen housing. I've seen this on a Piper Colt, doesn't drop oil temp, just cools the housing and temp probe to lie to the pilot. Worth looking.

Wrenchgirl
10-28-2017, 09:43 PM
Thanks for this great tip. I need to get to his airport and take a look at the whole set up. It's been airplane crazy around here so I am hoping to get there this week. Also need to investigate just what his oil temps have been. I have been reading here that temps 180-220 are acceptable. Comments?

BC12D-4-85
10-28-2017, 09:56 PM
My '69 7ECA w/O-235 didn't have one either. Never knew I needed one until I saw a plane that had one.

Gary

Wrenchgirl
10-28-2017, 10:04 PM
Well I don't have much time working on Citabrias but they sure are fun to fly. Looking forward to learning about this. Appreciate the feedback

BC12D-4-85
10-28-2017, 10:20 PM
Review TCDS A-759: http://www.hangar9aeroworks.com/AeroncaTechInfo/A-759.pdf

For the 7ECA note optional engines Items 122, 124, and 125 and required equipment. It appears to me (non-A&P) that the oil cooler Item 118-(e) is not. Might be a purchaser option during manufacture?

Gary

Wrenchgirl
10-28-2017, 10:31 PM
The TCDS is exactly where I was going to start. I just noticed this group's name came up when I began discussing the 0-235 so I started here instead. But I Ned to go to the TCDS and explore that. Thanks for your input.

mike mcs repair
10-28-2017, 10:40 PM
FIRST STEP!... is the gauge reading ACCURATE???? test it, cold(and dark, out of sun) = ambient air temp or in boiling water = 212F ... MANY ARE OFF....

Wrenchgirl
10-28-2017, 10:56 PM
Excellent point. I will do this first thing cowl is off.

hotrod180
10-29-2017, 10:06 AM
There could be a box that goes over the oil screen housing and has a scat hose blowing air on the screen housing. I've seen this on a Piper Colt, doesn't drop oil temp, just cools the housing and temp probe to lie to the pilot. Worth looking.

Pretty normal. In 1948, Cessna had high oil temps when certifying their new model 170 with the Continental C-145 engine. They added a blast tube blowing on the screen (where the temp probe is located) and everything was good.

Wrenchgirl
10-29-2017, 11:53 AM
Thanks for your input. When I get to the hangar I will look for this. Other folks have suggested a scat hose aimed at the screen housing might be the culprit. And just what we need....instruments lying to the pilot. Yikes! Really appreciate your response.

Steve Pierce
10-29-2017, 03:00 PM
Here is some good data on the blast tube on the temp probe.
http://www.shortwingpipers.org/forum/showthread.php?5524-Oil-Temperature-Probe-Blast-Tubes

Wrenchgirl
10-29-2017, 09:50 PM
Steve, many thanks for this extra lead. I will be sure to read it.

N86250
10-29-2017, 11:34 PM
Here is some good data on the blast tube on the temp probe.
http://www.shortwingpipers.org/forum/showthread.php?5524-Oil-Temperature-Probe-Blast-Tubes

Another place to put the bulb for the second temp gage is in the oil drain of the Continental oil tank. The drain plug thread is the same as the oil temp adapter thread in the back of the oil screen. Somebody did that, maybe Bill Pancake, and I thought that location confirmed the blast tube did lower the oil temperature a bit. I don't understand how the blast tube could cool the temp bulb in the center of all that hot oil without cooling the oil surrounding the bulb, too. Unless-- if the tube to the gauge is cooled or heated will that change the reading on the gauge?

Scouter
10-30-2017, 02:27 AM
Steve, many thanks for this extra lead. I will be sure to read it.


There is a ton of info on this on the Yahoo Citabria group. You have to sign up to read the archives

jim

Wrenchgirl
10-30-2017, 05:22 AM
This seems to be a logical place to go as well. Thanks for the tip.

Steve Pierce
10-30-2017, 06:03 AM
Another place to put the bulb for the second temp gage is in the oil drain of the Continental oil tank. The drain plug thread is the same as the oil temp adapter thread in the back of the oil screen. Somebody did that, maybe Bill Pancake, and I thought that location confirmed the blast tube did lower the oil temperature a bit. I don't understand how the blast tube could cool the temp bulb in the center of all that hot oil without cooling the oil surrounding the bulb, too. Unless-- if the tube to the gauge is cooled or heated will that change the reading on the gauge?

The data I posted came from Jerry Burr. If you knew Jerry you would take the results to the bank. Theory is one thing but when you take the time to build and test it you get real world results.

Wrenchgirl
10-30-2017, 06:14 AM
I must live in the wrong part of the country. (Well, I KNOW I do but that's another issue.) Good for you guys that you have/are these resources. It's just golden to have someone to go to with this. I had a guy like that for my WACO UPF. Practically had him on speed dial. I really appreciate all the hints and advice.

TcraftF21
10-30-2017, 02:46 PM
I have a TaylorcraftF21 with that engine and no oil cooler. Cold temps are a problem in the winter. Temp gets to 120 max. In the heat of summer and on floats the hottest it ever gets is 190. Try duct tape over a portion of the air intakes, a little at a time and you can get the temp up to 150.

Jim

Wrenchgirl
10-30-2017, 03:17 PM
Jim,
Thanks for that. This has been a recurring suggestion. Where is the tape most effective....front of the cowling on either side of the spinner? Taking care, of course, to keep it off the cooling fins. And yes, I would put some on, go fly, and repeat. I am concerned this engine is not getting hot enough to burn off all the condensation. Might just take the boroscope and peak into the cylinders. Do you think 150 is hot enough? Seems as tho the threshold ought to be in the 180 range. Maybe this just isn't possible in the winter.

DENNY
10-30-2017, 04:41 PM
Several factors involved with removing moisture from oil. How often and for how long comes into play. If he is doing long flights 150 degrees may be getting rid of a lot of the moisture. Lost of short flights won't help much. How often is he changing oil. Remember oil temp will trend with CHT however it is very easy to have a very high CHT in a single cylinder with normal oil temps.
DENNY

TcraftF21
10-30-2017, 07:13 PM
Duct tape either side of the spinner

Jim