High Oil Temp on Hummel 1/2 VW 45hp

[slowflyer123]

Currently I have 4 hours on my new 1/2 VW 45hp Hummel engine. With the first 1.5 hours flight time during much climbing (touch-N-Go's) and some rpm’s around 3000, I got no indication of high oil temp (temp was in normal range of 210-220F). Today’s flight of 1.5 hours with virtually the same weather temp and cruising at only 2600 rpm, I suddenly got an oil temp of over 250F. The question is . . . What do you think might have caused my oil temp to suddenly climb to over 250F ? Possibly oil foaming ?  The oil level is maintained at 2 quarts.

My Hummel engine has a Zenith carb with oil tubing coiled around the intake manifold. If high oil temps persist, would you recommend a) simply adding an oil cooler (heat exchanger) or b) removing the oil tubing around the inlet and then adding an oil cooler ?


Also, Should I be using an oil with a non-foaming agent? I’ve heard that this is advantages. What oil is best for the 1/2 VW engine?

Also, I have the Zenith carb idle jet set at 1-1/2 turns open and the main jet set at 3 turns open (getting black spark plugs). What is the best jet setting for the 1/2 VW engine?

[leshoman]

I always ran 3 quarts oil in mine. never had any oil temp probs

[scott johnson]

I use Valvoline VR1 10w-30 it has the the zddp and zinc for flat tappets like the vw engine needs. It also has a anti foaming additive which our engines also need.

Scott J
Oshkosh Silver Slug

[slowflyer123]

Thanks for the information and suggestions. Scott Casler has also suggested that I may need an external cooler and that there's no need for a special oil.. I have a cooler on order and plan to install it and changes the oil to a zddp oil. Then I'll see if this improves the situation.  Thanks again.

[leshoman]

I have always used valvoline 15-40 HD diesel oil.