Hot or Not?

[Anticept]

Gerotor pump (used in rotax):

 

Pumping action: https://engineering.purdue.edu/Maha_AVteam/research%20projects/Gerotor%202011%20sept%2017/01_New_gerotorpumpsformahawebsite/Gerotor_Pump_25percent.gif

 

How the lines are hooked up to the entrance and exit: http://www.scherzinger.de/typo3temp/pics/Funktionsprinzip_Gerotor_01_8c0e99abaa.jpg

 

Rotary vane pump:

 

http://www.pumpschool.com/images/vanePumpLarge4.gif

 

I'm not going to fault roger, principles are similar but the gerotor is vastly more reliable and used in a huge, HUGE number of applications. You'll even find them in your little backup house generator. I think more than anything he was just making a point of what they kind of act like rather than aiming for accuracy.

[Roger Lee]

Hi Tom,

 

Sorry you're right about the pump and vane. I changed it.

 

It isn't restricting it and causing a flow issue, only slowing it. It's still within its flow specs and engine needs. A slight slowing causes temp change. Oil is not staying in the crankcase longer. It has been slowed not stopped. It is still within flow specs. Just slower.

 

You keep thinking in large flow changes or restrictions. It isn't that at all. Just a little slowing. That tiny bit of slowing that is within flow specs for the engine and pump has an effect on temps.

[Roger Lee]

Hi Ed,

 

There are different kinds of radiators and coolers used in the Rotax 912 engine. Look at many different builders and you will see some. It isn't a one cooler engine. The one we have is what Rotax does use and FD chose.

[Ed Cesnalis]

Hi Ed,

 

There are different kinds of radiators and coolers used in the Rotax 912 engine. Look at many different builders and you will see some. It isn't a one cooler engine. The one we have is what Rotax does use and FD chose.

 

Yes but when FD chose an upgrade they chose the Seatrab series 6 19 row cooler.  The Canadian float plane has one.

[Tom Baker]

Hi Tom,

 

Sorry you're right about the pump and vane. I changed it.

 

It isn't restricting it and causing a flow issue, only slowing it. It's still within its flow specs and engine needs. A slight slowing causes temp change. Oil is not staying in the crankcase longer. It has been slowed not stopped. It is still within flow specs. Just slower.

 

You keep thinking in large flow changes or restrictions. It isn't that at all. Just a little slowing. That tiny bit of slowing that is within flow specs for the engine and pump has an effect on temps.

 

Roger,

I'm not talking big changes either. Because of the design of the pump the hose can't simply slow the flow of oil to the pump, without starving the pump and engine. Either the pump has all the oil it needs controlling the rate of flow, or it doesn't. Starving the engine in the process.

 

If the oil is not staying in the crankcase longer, then it hasn't been slowed at all. If the oil is still being pushed out as fast as it can, the return line is not slowing the flow of oil at all.