High Oil Temp

SkyMaule · Post by **SkyMaule** » Wed Jul 23, 2008 4:22 am

my airplane had a towhook on it when I got it. It also has cowl flaps. I'm thinking they were added on when the tow hook was used.

a64pilot · Post by **a64pilot** » Wed Jul 23, 2008 5:02 am

Can you take pictures? I assume field approval? Interesting either way. I'd really like to see how they are put in. I've heard from a pretty reliable source that one reason you don't see many Maules pulling things is cooling (lack of)

aero101 · Post by **aero101** » Wed Jul 23, 2008 1:25 pm

Another option to help with cooling that I do when flying heavy loads on floats in HOT WX is to bolt on an extension at the bottom flap of cowl extending it an 1 1/2" to 2" increasing the angle about 20 to 30 degrees... (close the matching angle of tail pipe exit) .062" sheetmetal strip laps internally in cowl attached with about 6 ea structural screws and large area washers at cowl side, bent at back end of fiberglass to create more negative pressure in cowling. This also stiffens the bottom hole in cowl, which on mine, tends to collapse in the middle somewhat. Of course I would only do this after you have verified that your temp indication is correct. In the winter time I bend strip opposite direction covering the hole cowling provides which will bring up the engine cylinder head / oil temps in cold weather. With a little experimentation, I have found this to work very well?

a64pilot · Post by **a64pilot** » Wed Jul 23, 2008 3:36 pm

There is actually a factory part and drawing to do what you say. That way it's all legal like.

Duane · Post by **Duane** » Wed Jul 23, 2008 3:47 pm

Yes, there is a factory part to extend the lip on the cowling. Its for the earlier ones that dont have it already installed.. good for both TD and TG.

As far as reversing it.. ........... ?

a64pilot · Post by **a64pilot** » Wed Jul 23, 2008 4:57 pm

Duane wrote:Yes, there is a factory part to extend the lip on the cowling. Its for the earlier ones that dont have it already installed.. good for both TD and TG.

As far as reversing it.. ........... ?

I guess you could say you were looking at the drawing in a mirror?

aero101 · Post by **aero101** » Thu Jul 24, 2008 3:50 pm

I think if you read definition of Major / Minor Alteration you'll have to agree that extension is minor and all that's required is logbook entry... Of course depending upon your local Feds, everything is open to interpretation?

Major alteration means an alteration not listed in the aircraft, aircraft engine, or propeller specifications-
(1) That might appreciably affect weight, balance, structural strength, performance, powerplant operation, flight characteristics, or other qualities affecting airworthiness; or
(2) That is not done according to accepted practices or cannot be done by elementary operations.

Minor alteration means an alteration other than a major alteration.

mauleace · Post by **mauleace** » Thu Jul 24, 2008 4:43 pm

You gotta love definitions use definitions as prt of the definition.....

a64pilot · Post by **a64pilot** » Fri Jul 25, 2008 10:44 am

aero101 wrote:I think if you read definition of Major / Minor Alteration you'll have to agree that extension is minor and all that's required is logbook entry... Of course depending upon your local Feds, everything is open to interpretation?

Major alteration means an alteration not listed in the aircraft, aircraft engine, or propeller specifications-
(1) That might appreciably affect weight, balance, structural strength, performance, powerplant operation, flight characteristics, or other qualities affecting airworthiness; or
(2) That is not done according to accepted practices or cannot be done by elementary operations.

Minor alteration means an alteration other than a major alteration.

Not even a chance. Why did you install it? Why to pull more air through the cowling! Maybe that affects powerplant operation just a little bit?
Trust me, engine cooling is one of the holy grails. None of them are going to buy anything that affects engine cooling as a minor alteration.

AK Mauler · Post by **AK Mauler** » Fri Jul 25, 2008 12:41 pm

So much for our winterization mods. To my knowlege Maule does not have a special restrictor plate or other approved method for keeping the oil temp in the green arc in winter time. We all do something, maybe we need to get Maule to issue an approved method to keep us legal?

a64pilot · Post by **a64pilot** » Fri Jul 25, 2008 3:22 pm

AK Mauler wrote:So much for our winterization mods. To my knowlege Maule does not have a special restrictor plate or other approved method for keeping the oil temp in the green arc in winter time. We all do something, maybe we need to get Maule to issue an approved method to keep us legal?

I would continue the three monkey rule, you know, hear ,see or speak no evil. I wouldn't expect Maule to do anything unless they would have to, and if they did, then you would have to purchase the parts and drawings from them even if you didn't like their system. Or far more probably everbody would continue to do as they always have and Maule would be out the time, money and effort that say could be better spent elsewhere. Just an opinion of course, you could always ask.

Kirk · Post by **Kirk** » Sat Jul 26, 2008 4:08 am

So much for our winterization mods. To my knowlege Maule does not have a special restrictor plate or other approved method for keeping the oil temp in the green arc in winter time. We all do something, maybe we need to get Maule to issue an approved method to keep us legal?
_________________

While I had my airplane in Moultrie for an annual with David Wright, he installed a winterization baffle from Maule on my oil cooler. (1977 M5-235C O540J1A5D)

It helped bring my oil temps back up and interestingly enough, seems to be about the same width as a piece of duct tape.

Kirk

akloon · Post by **akloon** » Sat Jul 26, 2008 10:30 am

Gents,
I am in Alabama. Thank you all for the replies and discussion. Sorry it took me so long to get back online, I just got the internet hooked up at the house this morning. I'm in Prattville, AL until next June, then back up to Anchorage.
To answer a couple of questions, the annual had just been done, the timing was good. I didn't boil the indicator, or check it with IR, but that would be a next step. I just replaced the baffling at the front of the engine, because the previous owner had clipped it all out for some reason, I'm guessing they were incorrectly trying to solve this same issue. I will try pressing on the bottom cowl as directed and may try the extension to increase air flow. The baffling inside the engine is has a few small holes, but nothing abnormal.
My flights from Idaho to OK toal were good, got up high and at 18C the oil temp was fine, normal. As the temp went up the oil temp did the same drill, up to a needle width of the high mark, but no higher. Calibration or checking of the sensor with IR is my next step, but I feel confident that the engine is cooling as well as it can. A comment from the mechanic I spoke with that has some time with -540s on other aircraft is that the oil cooler itself seems small comparatively.
Dave

akloon · Post by **akloon** » Sat Jul 26, 2008 10:35 am

Jeremy,
Sorry, forgot to answer your other question. My takeoff power is at full RPM/pressure, not 23/20, that was what I pulled it back to at cruise climb. And yes, I removed the duct tape off the oil cooler intake in March. Alaska mod only...
Dave

UP-M5 · Post by **UP-M5** » Sat Jul 26, 2008 1:09 pm

akloon,

how big is your oil cooler? i noticed on a newer (2001) M7-235 that the oil cooler didn't fill the entire area above the air filter- there was a steel plate about 1.5 inches tall above it.
if you look in my cowling, the oil cooler goes from the top of the air filter to the "ceiling" of the air scoop box. it is roughly 6" tall. i can't recall how many rows it is.
if you have the small cooler, maybe the larger one is an option for you... ???

High Oil Temp

Definitions

thanks!

Who is online