Oil cooler plate for cold weather

[Don Ostergard]

Earlier in this thread I explained that I have flown my '59 -250 in OAT's as low as minus 35C on numerous occasions, have never restricted the airflow through my oil cooler, and never felt that the oil was running too cold. This was based on information from the original oil temp gauge which as we all know is an exceedingly crude instrument. I also mentioned that I have recently installed a JPI 830 analyzer in the interest of receiving better information as to what is happening inside my engine, and that I would report my findings. Since I live in Western Canada, I knew that it would be several months before encountering some high OAT's.

In the belief that no sacrifice is too great when it comes to adding to the knowledge base that exists within ICS, (and in the interest of geting it into the hands of our fellow members without undue delay) my wife and I decided to fly our Comanche down to central Mexico, knowing that we would encounter a wide range of OAT's along the way. So here is what we found:

OAT -20C........Oil temp 177F
OAT -17C........Oil temp 184F
OAT -14C........Oil temp 186F
OAT -01C........Oil temp 189F
OAT +07C........Oil temp 188F
OAT +19C .......Oil temp 184F

Based on the above, one can conclude that if the vernatherm valve is operating properly on a PA24-250, the oil temp tends to remain quite uniform throughout the OAT range of Minus 20C to Plus 19C. It should be evident that I have no intention of beginning to cover my oil cooler in winter. I will continue the course that I have followed for the past 31 years.

I am now facing a bit of a dilemma. I'd like to stay here in this pleasant little Mexican town awaiting some higher OAT's so that I can gain more knowledge about oil cooling at higher ambient temperatures, yet I know that the later I head back north the lower the likelihood of encountering REALLY cold OAT's once I get home. Which will of course means that we won't be able to learn as much as we might wish to regarding the oil temp/OAT relationship at extremely low OAT's. In the meantime, I think I'll have another beer while I think about what to do next.

Don Ostergard ICS 3263
c-flhv@magtech.ca

[Zach Grant L1011jock]

Don,
Thank you for your sacrifice in briging us this information. I'm sure I speak for the silent masses, in saying I hope you didn't put yourself out in finding this information on such a long flight. I commend you on your judicious use of beer, and hope that after a few more, and some time to think about it, you may considder the flight back north...or not...we probably have adiquate data from your arduous data aquisition flight down.

Zach

[9089P]

Hi Don,

I didn't want to hijack this thread but wanted to hear more about your trip so I started a thread under new destinations; "Mexico in Search of Truth". If you have a moment between beers you could fill us in?

Thanks, Don