Perry Pump and Four Stroke Question

LAST EDITED ON Jan-05-04 AT 08:07 AM (CDT)
 
Has anyone tried either of the two types of Perry Pumps to provide steady fuel delivery to the smaller four stroke motors? By smaller, I mean under .60 displacement.

Not sure the oscillating type will work due to the power pulse frequency. Would the pressure type work on muffler pressure. Perry calls for crankcase pressure which won't work on a four stroke.

Is this a waste of time and money and I should just continue to use muffler pressure? Your thoughts please.

I used the oscillating pump on a OS 40 Surpass on a RC plane. It seemed to work ok. The biggest trick is finding the space to mount it. Normally (as I recall, it has been >7 years ago), I mounted it to the bottom screws on the backplate (engine mounted upright). This might be difficult with the typical inverted stunt engine. Also as I recall, the orientation is important since it uses the normal engine vibration to vibrate the internal pumping piston.

Still have it, although I haven't used it for a long time. I love gadgets, but in the end, it wasn't really necessary for my application--muffler pressure worked fine.

>Has anyone tried either of the two types of Perry Pumps to
>provide steady fuel delivery to the smaller four stroke
>motors? By smaller, I mean under .60 displacement.
>
>Not sure the oscillating type will work due to the power
>pulse frequency. Would the pressure type work on muffler
>pressure. Perry calls for crankcase pressure which won't
>work on a four stroke.
>
>Is this a waste of time and money and I should just continue
>to use muffler pressure? Your thoughts please.

I have been running the pressure activated Perry pump for some time. Works good. Pretty much fixes all of the issues with the four stroke including eliminating the burn down, eliminating any changes in mixture during the flight, using special fuels, or just about any other issue you can think of.

I still have some test left to do, but I anticipate I will run pumps from now on. Period.

I was wondering if anyonme was going to catch my hints...

LAST EDITED ON Jan-05-04 AT 06:36 PM (CDT)
 
Thanks Mr G. I have a couple of questions.

Are you using muffler pressure or crankcase pressure on the pump?

Are you still using Powermaster YS 20/20 (lower viscosity fuel)?

See... I've been paying attention.

>Thanks Mr G. I have a couple of questions.
>
>Are you using muffler pressure or crankcase pressure on the
>pump?
>
>Are you still using Powermaster YS 20/20 (lower viscosity
>fuel)?
>
>See... I've been paying attention.

I use the "spooge tube" to power the pump. There is a T fitting to allow the excess spooge to exit. This is exactly how the instructions with the pump say to do it. Also, don't be afraid to call the guy at Perry pumps.

I ordered mine from www.perrypumps.com.

I have been using various fuels of late. I still recommend the YS 20/20.

(Little known fact) #1: Powermaster 15% "All Synthetic Heli" has the same oil package as YS 20/20. <this is my current fuel>

(Little known fact) #2: Powermaster 15% and 30% Heli "23% "Low Viscosity Synthetic" may actually work better than the YS 20/20 blend.

>I have been running the pressure activated Perry pump for
>some time. Works good. Pretty much fixes all of the issues
>with the four stroke including eliminating the burn down,
>eliminating any changes in mixture during the flight, using
>special fuels, or just about any other issue you can think
>of.
>
>I still have some test left to do, but I anticipate I will
>run pumps from now on. Period.

Hi Brad -

Are you using the perry pump on the Saito 72, or are you using the OS 70 Surpass that has an internal pump?

Also - if you're still using the Saito 72, how (& where) did you place the pump inside the fuselage?

>Are you using the perry pump on the Saito 72,

Yes.

>Also - if you're still using the Saito 72, how (& where) did
>you place the pump inside the fuselage?

Between the tank and the engine. I am working on some more mounting arrangements.