High oil temp

[a64pilot]

I’ve had oil temp problems since I’ve had this thing. In Summer it will get up real close to 200, I know that’s not hot oil wise but the problem is I’ll hold 40 PSI oil pressure until 175 or so, by the time I get close to 200, it’s down to 30.
This year I put 60W oil in it and to my astonishment it didn’t seem to help.
I know my timing is as perfect as I can get it, I believe carb isn’t running lean as she will accelerate well from idle with no stumble, but if I lean I don’t get any RPM increase, but while the Stromberg leaning works it’s overly sensitive and well, goofy compared to other aircraft.
Baffling is in decent shape, and I even have the deflector around the oil pan to help cooling.
I don’t know where to look, all I can come up with us maybe it’s too lean from float level being too low? But wouldn’t she lean stumble then?

In cold Florida weather, which isn’t even below freezing I have to block off the holes under the prop and block the blast tube to get decent oil temp

[6597]

Some tidbits to consider, from the Ercoupe bunch a few years ago. Sorry I don't have a proper answer yet...

https://www.ercoupe.org/index.php/forum ... re?start=0

[8342]

Some questions that come to my mind:

1. What does the average C-85 run for Oil temperature? What are the Limits?

2. What does the average C-85 run for Oil pressure? What are the Limits? Is the oil pressure adjustable?

3. Have the gauges been check for accuracy?

What you are seeing may be Normal for your engine.
If you have run it for a while and see what it normally runs and then see changes then I would be concerned.
Or if it is outside of Specified Operating limits, then be concerned.

Just my two cents.

Rick

[6643]

1. What does the average C-85 run for Oil temperature?

100*F above ambient temperature

What are the Limits?

225*F

2. What does the average C-85 run for Oil pressure?

30-40 psi

What are the Limits?

Min 30 Max 40
Continental specifies 10 psi minimum at idle, but this is not a limit.

Is the oil pressure adjustable?

Not really. Continental suggests replacing the spring in the relief valve. However, if the pressure is within limits at 180* "adjusting" it probably won't change much at 200*.

I'd check both gauges for accuracy.

Just my two cents.

[Edit] The most recent version of the maintenance manual lists 60 psi as the maximum allowable oil pressure and a minimum of 10 psi as a limit, but the most current version of the TCDS still says "oil pressure limits 30 to 40 p.s.i."

[a64pilot]

It’s been a few years, but both gauges were changed, easy to do and not expensive, read the same as the ones they replaced. It’s been this way forever, however if anything it’s gotten worse.
Only pressure adjustment is the relief valve, that’s the pressure you’ll see with cold oil, mine opens about 42 or so.
The concern is the pressure drop, it’s not normal for anything I’ve ever flown to drop from top of the green to bottom of the green with a 25F change in oil temp.
Climbs of course make it worse.

Anyone have a source for new baffles? Even if it’s not the problem mine probably ought to be replaced
Been years ago but I flew Cubs at Jack Browns, they if anything were just under 30 PSI and hot oil too, but they were over floated and speed was down because of it.

[2356]

Do you have the inner cylinder baffles installed? There is a company in Alaska that makes new baffles. They are quite expensive. But what isn’t now days.

[6277]

Do you have the spin on filter?

[a64pilot]

Do you have the spin on filter?

No, except for slick mags and now a Hartzell alternator she’s just like it was in 1946
I’ve considered an oil cooler but it’s a bunch of money and not a real fix, others don’t need them, making it seem something is wrong that I need to fix.

[6643]

You can try replacing the pressure relief spring. Shimming is not approved.

I don't think it's possible for Stromberg to run lean other than under sudden throttle movements...

What is your oil consumption? (Excess blow-by super-heats the oil.)

Do you have the inter-cylinder baffles from the "Summerization" kit? Also, items 41 and 44, and 56 and 57 in figure 37 of the parts catalog. How are the seals around the front, sides and across the top back?

Do you have the '46 cowl, or the '47-48 version? The early one has a larger opening across the bottom.

[a64pilot]

real sure it’s not the spring, cracking pressure is 42. It arguably could be the seat the ball seats on, have damage and leak, but I don’t think so.
Oil consumption is good probably leaks more than it burns, Millenium cylinders with a couple hundred hours on them, compressions above mid 70’s oil doesn’t turn black real fast
I need to find out about the intercylinder baffles , I’m not sure.
I have no idea which engine cowl I have, seals are OK, not perfect but not bad either, baffles could use replacing though, many repairs.
A concern is a worn accy case, when hot clearances open up and pressure in the pump is lost, but she doesn’t lose oil prime so maybe not?