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Perry pump?

Old 09-13-2008, 11:02 AM
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FAST-J
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Default Perry pump?

I have a phoenix extra 330s and the engine is sitting at 270 degrees, when i roll over inverted it wants to load up real bad, i know i can mount the engine at 90 degrees but don't want to buy a pitts style muffler or new cowl. Will a perry pump solve this problem? motor is a JBA 91.

Thanks, Jay
Old 09-14-2008, 01:33 AM
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Default RE: Perry pump?

It may as it will offer a regulated fuel flow. I don’t know that engine so I can say much more. I’d try it, the Perry pumps are cheap.
Old 09-14-2008, 07:32 AM
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Default RE: Perry pump?

and they work well

david
Old 09-14-2008, 08:09 AM
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Default RE: Perry pump?

Jay, I agree with John & David. Without knowing anything about your engine or tank set-up, I'd say install the Perry Pump, adjust it, then your low end and high end needles on your carb (in that order). With the pump, you do not have to be concerned with the tank location. Just make sure you tap into the crankcase of your engine, close off the pressure nozzle on your muffler, and use the pressure directly from the crankcase to power the pump. Also, make sure your tank vent is left open.

And above all remember; "Experience is a hard a hard teacher. She always gives the test first, and the lesson some time later!"

Phillip
Old 09-14-2008, 10:38 AM
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Jetdesign
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Default RE: Perry pump?

If you use a Perry Pump, make sure it is not a silver 'can' with a plastic red top. I bought one of these 'new' from a store and it didn't work; I called Perry and they said it was old and to throw it away. The new ones are blue. Also, you can use a one way/check valve on the exhaust line into the tank, which will allow air to go in but fuel won't come out.
Old 09-14-2008, 12:07 PM
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Default RE: Perry pump?

I have seen the valves in tower, which would be the best way to go? pump or valve. how much does the pump weigh?
Old 09-14-2008, 08:11 PM
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greyfoxx
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Default RE: Perry pump?

Jay - I think that garRCfield is saying that you can use a one way valve in the tank vent line to prevent fuel from leaking out and still allow air to fill the tank as the fuel is used when using a Perry Pump. If the tank does not carry a neutral pressure, the pump will create a vacuum, and possibly collapse the tank walls due to the vacuum, and you will have will not get fuel to the engine. I use a one-way valve on mine as well.

I really should not answer for gar, and if that isn't what he's talking about, I hope he will respond and correct me as I would like to know how he uses it if it's not used this way.

As for the weight of the pump, not more than an ounce or two - they are very light. Just make sure that if your using a 2-stroke that you get the pump made for 2-strokes as those for 4-strokes are different, and make sure that the pump has a blue case as well as the older ones had red cases.

Phillip
Old 09-15-2008, 09:56 AM
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Default RE: Perry pump?

Why would you bother with a check valve? Just route the vent line from the top of the tank through the bottom of the cowling, That way when upside down the vent opening is at the top. When right side up the fuel goes to the bottom of the tank. You don't use muffler pressure with a Perry Pump.
Old 09-15-2008, 10:03 AM
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Default RE: Perry pump?

To late, it's all on the way, pump and valve.
Old 09-17-2008, 07:04 AM
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Default RE: Perry pump?

The one way valve will only restrict vent air, better to route the fuel line to the bottom of the cowl. In fact I wouldn't use a pump at all. I would simply set up the system with a uniflow setup and set the tank centerline slightly higher than the carb. To load up bad inverted means the tank is too low.
Old 09-17-2008, 07:47 AM
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Default RE: Perry pump?

Tank is just behind firewall and is centered, alot of guy's with this plane have had problems with the motor being mounted at the 270 degree, having same problems as mine. pump and and valve will be here thursday, i will try it all and see what happens.
Old 09-17-2008, 03:53 PM
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Default RE: Perry pump?

Tank is just behind firewall and is centered,
That is the problem, a normal tank setup should be somewhat below the center of the carb. If you look at most ARFS that is the norm, the engine is higher than the centerline. However a uniflow setup will work centered.
Old 09-17-2008, 05:45 PM
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Default RE: Perry pump?

You know your right, the way the engine is mounted the carb is way below center, never thought about that, well do you think since the perry is on the way this will solve the problem once installed? It's bought now so i need to use it. perry says no matter what the tank height, it cure the problem.
Old 09-17-2008, 06:06 PM
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Default RE: Perry pump?


ORIGINAL: greyfoxx

Jay - I think that garRCfield is saying that you can use a one way valve in the tank vent line to prevent fuel from leaking out and still allow air to fill the tank as the fuel is used when using a Perry Pump. If the tank does not carry a neutral pressure, the pump will create a vacuum, and possibly collapse the tank walls due to the vacuum, and you will have will not get fuel to the engine. I use a one-way valve on mine as well.

I really should not answer for gar, and if that isn't what he's talking about, I hope he will respond and correct me as I would like to know how he uses it if it's not used this way.

As for the weight of the pump, not more than an ounce or two - they are very light. Just make sure that if your using a 2-stroke that you get the pump made for 2-strokes as those for 4-strokes are different, and make sure that the pump has a blue case as well as the older ones had red cases.

Phillip
Yup, that's what I meant. The pump will allow you to mount the tank in any location/position, as per the Perry directions - no need to pay attention to tank height/location.
Old 09-17-2008, 11:45 PM
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Default RE: Perry pump?

Yeah, it will probably help due to the pump/regulator combination. I'd probably bail on the 1 way valve on the vent. Really no need for it in my opinion and just one more thing to deal with.
Old 09-18-2008, 11:44 AM
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Default RE: Perry pump?

well do you think since the perry is on the way this will solve the problem once installed?
Yes.
Old 09-18-2008, 12:15 PM
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Default RE: Perry pump?

Thanks guy's, I'll try the valve since i got it and try without and see what happens.
Old 09-19-2008, 08:28 PM
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Default RE: Perry pump?

Well, pump is in and cranked her up in the back yard, got the low and high end set pretty well but can't figure out what's going on in the mid range, wants to load up real bad, now i did order an APC 15X4W (someone suggested) and this is the prop i was trying to tune it with, it will only turn 9800 rpm, could this prop be to much and making the mid range act up? did not try my zinger 14x6 (prop i been running, will turn 10500rpm) and ran fine at mid without pump, will try it saturday sometime just to see if the APC is to much.
Old 09-20-2008, 01:47 PM
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Default RE: Perry pump?

Took her out to the field this morning and found out what happens on the ground and what happens in the air are two different things, finally got it adjusted and she runs better in the air and on the ground, tried the apc 15x4w and it seems to not run as well, put the zinger 14x6 back on and was more tuneable, think i will try a 13x6 later today and see what happens. Inverted is running a heck of a lot better (no problems), the pump does make a very good change in running quality, (once you get it set right)..

Thanks Guy's for all the input, if it wasn't for rcuniverse i don't know what i would have done..

Jay

P.S. Valve was not needed.
Old 09-20-2008, 11:58 PM
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Default RE: Perry pump?

If you're still having mid-range trouble, it's probably due to the pump setting. With a pump, the low needle affects the low end, the high speed affects the high end, and if you're bogged down in transition the pump is probably too rich. Turning the adjustment counter clockwise decreases fuel flow (counter-intuitive - you're releasing tension from a spring, not opening a valve).
Old 09-28-2008, 07:55 PM
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Default RE: Perry pump?

Well guy's here it is, The pump did cure inverted fight problem but meanwhile the perry fooled me thinking it was too rich and so i kept leaning, guess what happen? She don't run like she did before she got to hotttttt!! So, I have a new piston, sleeve and ring coming, the same day i decided to go all out and get a good motor (o.s. 91fx), I wll run the o.s. without the pump first and see if it needs it or not, I talked to perry pumps and they said the v-30 would work just fine with the 91 fx. will post updates as they happen.

Thanks, Jay
Old 09-28-2008, 08:02 PM
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Default RE: Perry pump?

Next time you can try doing a pinch test. With a pump, you want to hear just a very, very slight increase in RPM when you pinch the line - like just enough so you know it's not lean. The pump will prohibit the engine from leaning out in flight and in verticals, so no need to richen your needle a few hundred RPM below peak as if you didn't have a pump - maybe 100rpm lower is all you need.

I like my tachometer, and find the pinch test works very well for me.

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