Rocket, hot oil, low oil press

[Austintatious]

Hey everyone, Have a newb Rocket question.

Today, while flying around making multiple stops, I noticed after landing that at 1000 RPm the oil pressure was down where the yellow and the green arc meet.  Oil temp was a little past mid way on the gauge (still in the green).   For takeoff RPM it was in the green so I went and in flight everything seemed to return to normal.  Is this typical for a hot engine? 

I took some pictures if they would help I will post them.

Thanks for any help!

Austin

[carusoam]

Important to know oilt and what type of oil you are using...

What was the OAT while this was going on...?

It might be possible to select a better oil for your summer environment...

Viscosity and oilT are very much tied together at the hip...

The higher viscosity will generate more pressure...

realistically we are more interested in the lubricating principles of the oil... but if it gets too thin... it may not be lubricating well enough...

PP thoughts only, not a mechanic...

Best regards,

-a-

[kortopates]

Actually the answer is spelled out in section 2 of your POH. The supplement for the Rocket doesn't really change anything. If you don't see it, let me know.


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[Austintatious]

Acft just had a fresh annual and oil chang at Dmax.  15w50 iirc

It was HAWT today

 

I will do some more reading

[aaronk25]

Shouldn’t really matter what oil as long as it’s the common aviation oil, 15w-50, 20w-50 or straight 50w, at 212f there all the same viscosity as a straight 50w and if he got the oil slightly hot say 230f or more, the multi-weight oil would have a thicker viscosity than the straight weight oil due to the viscosity modifiers still continuing to “uncoil” meaning that as the multiweight oil continues to rise it in temp it will thin at a slower rate than the straight weight oil. Until it’s gets really hot300-400f???? Where the viscosity modifiers shear back, well then your stuck with a 15w or a 20w oil viscosity at 350f. Not good......

Target temp for 50w correct viscosity is 100c/212f. After that the multiweight oil is better......and way better for cold starts.

I wouldn’t worry about it to much unless your deep in yellow. Low rpm and hot oil doesn’t make normal pressure.


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[Austintatious]

As a follow up to this issue... Upon reading the Manual for the engine, it appears I am well within the limits.  No less than 30 for flight (where green arc begins) and no less that 10 for idle ops (the red line).

 

When all else fails, read the destructions

[M016576]

17 minutes ago, Austintatious said:

As a follow up to this issue... Upon reading the Manual for the engine, it appears I am well within the limits.  No less than 30 for flight (where green arc begins) and no less that 10 for idle ops (the red line).

 

When all else fails, read the destructions

Yes.  That is normal.  My IO-550 has significantly lower idle oil pressure after a flight, than before.  But still well within limits.