Going glass but need to retain vacuum pump.

Chip Sylverne

Chip Sylverne

Final Approach
Joined
Jun 17, 2006
Messages
6,133
Display Name
Quit with the negative waves, man.
Home Airfield
DMW
Old girl is getting new glass instruments, but because I have a LoPresti cowl without provision for a crankcase vent tube, I need to retain the Rapco pump to utilize the exhaust for the Airwolf oil/air separator. I had only one vacuum instrument, the AI. Does anyone have any guidance on running the pump unloaded through a loop, or does an orifice of some size need to be installed to restrict flow? Not been able to find much.
 
Is it still going to be feeding the separator?
 
Airwolf separators are also fully certified and applicable for aircraft with dry vacuum pumps or no vacuum pumps at all. Without a Vacuum Pump: The system can be installed on aircraft lacking a vacuum pump by using an alternate warm air source, such as upper cylinder deck air or a baffle kit connected to pressurized ram air. [1, 2]
 
Mikey52 said:
Is it still going to be feeding the separator?
Click to expand...

That's the current thinking. The LoPresti cowl is so tight that keeping cylinders cool, especially #5 and #6 can be a challenge. I'd rather not start messing with changing the baffling and possible altering the differential pressure above and below the cylinders.
 
Clip4 said:
Airwolf separators are also fully certified and applicable for aircraft with dry vacuum pumps or no vacuum pumps at all. Without a Vacuum Pump: The system can be installed on aircraft lacking a vacuum pump by using an alternate warm air source, such as upper cylinder deck air or a baffle kit connected to pressurized ram air. [1, 2]
Click to expand...

Looked at it this morning. I'm over thinking it. Your suggestion is the way to go.
Thanks.
 
We had an Airwolf separator on a 172 that made no difference to the airplane's belly. It still got oily. Besides that, there were two other hassles that went along with the Airwolf: The ICAs for that item demand that it be opened and cleaned every 100 hours or annually and is a legal requirement set out in the STC. It's a messy job. The other problem is that not only oil being returned to the case, but water is, too, much more than the oil. That is definitely a problem and can cause serious internal engine corrosion.

I took it off the airplane and we never missed it.
 
Last edited:
Dan Thomas said:
We had an Airwolf separator on a 172 that made no difference to the airplane's belly. It still got oily. Besides that, there were two other hassles that went along with the Airwolf: The ICAs for that item demand that it be opened and cleaned every 100 hours or annually and is a legal requirement set out in the STC. It's a messy job. The other problem is that not only oil being returned to the case, but water is, too, much more than the oil. That is definitely a problem and can cause serious internal engine corrosion.

I took it off the airplane and we never missed it.
Click to expand...

I may end up getting there eventually. The lower cowling was installed without a hole for the breather to pass through. Whether it was a matter of the PO not wanting to poke through this ridiculously expensive piece of carbon fiber, an STC requirement or some other reason, I'm just not up for dealing with it now. Installing a nipple in the baffle and being done with it sounds pretty for now.

Just data point, I've disassembled the canister a few times now, and it's always been clean as a whistle.
 
Find a spot for the AI right side.
Never have too many AI’s.
 
You must log in or register to reply here.
Back
Top