Menu Sign In Contact FAQ
Banner
Welcome to our forums

Oil thermostat - why not universal?

It appears that a C150/152 has a “winterisation kit” which blocks off a part of the airflow.

It seems a weird way to do it, versus the cost of a thermostat which is just a small and highly reliable component.

Administrator
Shoreham EGKA, United Kingdom

Peter wrote:

It seems a weird way to do it, versus the cost of a thermostat which is just a small and highly reliable component.

What would the thermostat do in an air-cooled engine? Adjust the airflow? That would essentially be automatic cowl flaps.

ESKC (Uppsala/Sundbro), Sweden

An O-200 does not have an oil cooler as delivered in a standard C150. The C152 with its Lycoming engine has an oil cooler and this is equipped with a vernatherm. So I believe in either case an oil cooler thermostat would not be applicable.

To restrict the airflow over the engine’s cooling fins during winter times was not so uncommon when vehicles often had air cooled engines (and winters were colder). Maybe not so much with the engine in the back but a front mounted air cooled engine needs a long time to warm up in an ice cold airflow. The old Deutz powered fire engines had a winter cover for the grill as well even though they had a thermostat controlled fan.

An airplane engine without any temperature controlling element be it an oil cooler thermostat or cowl flaps will of course also have a hard time to keep the oil warm at minus 30°C when it’s cooling system needs to be able to keep the engine from overheating at plus 30°C. So it’s no surprise to me that in northern Canada one might want to have some kind of ground adjustable cowl flaps.

Google found a picture: Winterization Kit

EDQH, Germany

The O200 has provision for an oil cooler, but most use it to fit a cartridge oil filter mount.
My 1965 Skoda Octavia had a radiator blind, controlled from the cabin, as standard. Radiator blinds were usually an add-on item. The fan was belt driven, from the same pulley as the water pump and generator, on many cars, if my memory is correct.

Maoraigh
EGPE, United Kingdom

A thermostat is one additional item that will fail.

ENVA ENOP ENMO, Norway

Peter wrote:

It seems a weird way to do it, versus the cost of a thermostat which is just a small and highly reliable component.

Compared to blocking off part of the cooling airflow, a thermostat has only a quite limited control range.

Germany

Glad this subject has been raised and here is my engine oil temp graph for my PA28-181.

Oiltemp360_pdf

I was concerned some time ago that the Vernatherm might not be working so i asked maintenance to
fit a new one. It made no difference and all these figures relate to the new Vernatherm.

Sorry I am using centrigrade for OAT. I should have stated ALT 2000-3000 feet

The low oil temps might not be healthy so I have some more figures for winterization (3/4 blanking the oil
cooler) if you want to see them.

Oil temp and OAT records from EDM830

Archer2
EGKA, United Kingdom

Stanley wrote:

Glad this subject has been raised and here is my engine oil temp graph for my PA28-181.

What I read from these graphs is that the thermostat tries to regulate the oil temp at about 170F but above 18C OAT there is not enough cooling to do so and below about 8C OAT there is too much cooling to stay in range.

Germany

Thanks for your reply Malibuflyer, i appreciate your comment.

My aircraft is placarded with a message for the pilot “Oil Cooler winterization plate to be removed when ambient temperature exceeds 50F”
i have never been able to get one from Piper but obviously they had people there once who understood these things. Even in the UK we get temps below 50F in the winter!

Archer2
EGKA, United Kingdom
14 Posts
Sign in to add your message

Back to Top