Lazer

My Feedback: (27)

Is anyone familiar with this Perry Pump? What suggestions do Y'all have on using this with an O S 91 Surpass and how it is best attached to the engine. Thanks in advance.[8D]

grotto2

My Feedback: (2)

Whatcha got there is a P30 pressure pump. Use it with a 2-stroke only. Whatcha want for your Surpass is a Perry micro-oscillating or 'shaker' pump.

piroflip2

I have used the oscillating (V20) perry pump with mixed success on OS 120 and 160 two strokes.
It will allow you to mount the fuel tank over the c of g but I have still suffered from fuel starvation during 3d.
After wrecking a UCD60 in a low prop hang due to an engine cut I stopped using them.

Lazer

My Feedback: (27)

P30, V20? Guys I thank all of you for your help, but now I'm not sure what I have. One question that does not seem to get answered is how does this pump operate? How does it connect to the engine? The plane that is going to be used with this pump or a different one are to be used for patten flying and not hovering. Thanks to all.

AllTheGoodNamesAreTaken

My Feedback: (180)

Lazer,
The single line in you photo that isn't attached to anything is the "pulse" line. It is connected to the back-plate of a two stroke. The pressure and vaccum of the two stroke piston moving up and down actuate the pump diaphram. The other two lines (connected to each other in the photo) are "In" and "Out" fuel connections. There should be an arrow indicating flow. Mounting is up to the installer. The pumps come with a strap to mount to the engine mount, fire wall etc.
Because the four stroke doesn't have the pressure/vacuum/pressure/vacuum cycle like a two stroke has, the pump you have wont work (well). Perry makes the "shaker" version which uses engine vibration to actuate the pump.

http://www.perrypumps.com/prod02.htm

piroflip2

A search here will come up with plenty of info on how to instal and setup these pumps.
The instructions with mine were basic and bordering on useless.

AllTheGoodNamesAreTaken

My Feedback: (180)

Shaker (4 stroke) VP-20 pump instructions: http://www.perrypumps.com/VP-20%20and%20VP-22.pdf

Two stroke VP-30 pump instructions: http://www.perrypumps.com/VP-30%20and%20VP-40.pdf

jetmech43

My Feedback: (9)

the vp30 uses crank case pressure to operate I have one on mu OS160 works like a champ

Taurus Flyer

Gents,

I did find some interesting pictures on Internet, with and without a header tank
This is for a two stroke!

1 Lay out principle
1A Flow scheme
2 Lay out principle with header tank
2A Flow scheme of lay-out with header tsnk

Cees

Edit: Don't use tank pressure!

KLXMASTER14

I do not recommend using muffler pressure to the tank vent when using the Perry pump. It can/will cause the regulator to shut off the pump, and your engine will quit. Usually at a bad time.

-Robert

Sport_Pilot

You can use it with a four stroke. Check it out on their web site. www.perrypumps.com

Sport_Pilot

The vent should not be connected to exhause when using the pressure pump. The tank should be vented to atmosphere. They will work that way but it is hard on the pump.

No it works fine that way, but when I did this the pump lasted a year and ruptured the diaphram.

Taurus Flyer

KLXMASTER14/Robert.

I understand your post and I did find these pictures but do not use them myself.
I do use a constant tank pressure and a second pressure controller near the carb (like Cline) and that's oké for me.

When I see the pictures I would change the system as I show on the scheme of this post. So without tank pressure of the exhaust
The double vent line to the unpressurized tank probably gives a barometric pressure near the checkvalve outlet, one of the two lines has to be filled with air, the other is for retour of fuel. It does not matter which for what
The checkvalve does have a nearly constant pressure on the inlet side and that's also the fuel pressure on the carb inlet side, and that seems to be alright.
It has to be a checkvalve with little spring force to close the valve. The surface of the valve (A) and force of the spring (F) does make the constant fuel pressure (P).
The checkvalve mounted near the carburator!

It still is a study picture, so not prooved by me.

Cees


Edit : added some text details after second post (A) (F) (P).

AllTheGoodNamesAreTaken

My Feedback: (180)

Agreed. It says not to in the instructions as well.

AllTheGoodNamesAreTaken

My Feedback: (180)

Perry recommends only using a T inline between the output of the pump and the carburator IF the engine is rich at midrange. If it is decided that a T is needed, no checkvalve should be used. The pump will provide enough pressure/flow to eliminate any possibility of the carb sucking air from the vent.

Taurus Flyer

Jeff,

In my scheme the checkvalve is used for constant pressure, not to prevent the carb sucks fuel from the ventline!
The flow of the pump always has to be more than the engine needs, the checkvalve reduces the pressure a little above barometric pressure.
The principle is the as the threshold voltage of a diode!.

Cees

AllTheGoodNamesAreTaken

My Feedback: (180)

Items 10 and 11 are optional. The plus side of using the T is easy access to fill the tank.

AllTheGoodNamesAreTaken

My Feedback: (180)

I agree in theory of using the diaphram type check valve, but in speaking with Conley Precision (Perry Pumps), they recommend not using one.

Taurus Flyer

Gents,

Maybe my scheme of post 13 is a solution for bleed air, single needle valve carburators! (This is Classic Pattern Flying)
These carburators normally do not work with fuel (pump) pressure.
When I have time I will give it a try on my Orion with ENYA 60 4C engine!
Cees

Edit, Jeff I did not read your post when posting this one, you are also right, w'll see!

Sport_Pilot

You could use a small fuel line. Acutally this bypass line should not be required. I have never used it the pump regulates the pressure well enough for the engine to run well even if the needle is peaked out to max, not even a bit rich.

KLXMASTER14

Most people could not figure out how to set the pump pressure "back in the day". Mostly, this was a result of not reading the directions.

Here's how you do it: Set you high end needle, and idle. (If the high end needle is way off, adjust the pump accordingly.)

Then- the "magic" part- bring the throttle to mid range, and adjust the pump to the correct mixture. The pump is largely responsible for the mid-range mixture. Give the high and low speed needles a final tweak, you are done. Go fly!

You may need to go through more than one iteration of the above procedure to get it perfect. Once it is dialed, it is set-and-forget. It was (and probably still is) a great fuel system.

-Robert

NM2K

My Feedback: (14)

I really like Perry carbs, especially when replacing a basic, non metered type of air bleed carb.

The original Perry Pumps were built into backplates for each specific make and model of engine. The instructions were very specific about having to use a Perry Pump Carburetor. I never had great luck with that combo and eventually returned to using suction for fuel feed and the stock carb. You can't use the Perry Pump Carburetor without the Perry Pump, or something else that boosts the pressure way up there.

To add insult to injury, what is probably a great product when properly handled and setup was ruined many times by the owner inadvertently using a petroleum based after run oil, which promptly destroyed the pump diaphragm.

If you need a pressurized fuel system, buy a YS, or other brand, pumped/regulated engine right from the start. You'll save money, airplanes and a whole lot of prayers begging for forgiveness at having lost it and cursed at the flying field. BTDT.

The Cline Pressure Regulator and the Iron Bay Pressure Regulators do work well, but both, the last time I heard, are out of production and can be difficult to find. Good luck.


Ed Cregger

Sport_Pilot

The use of a Perry Pump carb was only for those engines matched for it. The VP 20 was always compatable with two needle carbs, most of them anyway.

NM2K

My Feedback: (14)

Did I state otherwise? If some folks think so, thanks to Sport_Pilot for straightening out the matter. We do not need more confusion concerning these carbs.


Ed Cregger

Taurus Flyer

Gents,

My way of thinking because the name of the thread is
"Perry pumps and regulators."

The (Perry) pump
(Perry) pumps do not give you fuel injection, so you always need a metering system to get the right fuel air ratio and the carburetor ventury and sucking inlet of the engine will do that for you.

Using a (Perry) pump, you normally need less fuel sucking pressure, so to have more power you can use a greater bore, with the result less resistance of the carburetor but it still is a metering system.

Using a pump can give a better, more stabile fuel air ratio, more independent of the position of the plane and level of fuel in the tank in full power situation than without having one.

Because of the higher carburetor inlet fuel pressure when using a pump, you need a two needle carburetor to prevent the engine gets too much fuel in low power rate.

Adjustment of the pressure in midrange and optimal fuel air ratio at max does not guaranty me the optimal fuel air ratio in the mid range but only one fact, the engine does get (more than) enough.

When you cannot optimize the midrange with a Perry pump you can try to modify the characteristic of the (“low”) needle. I did it in the past for my Webra Speed 10 cc (0,60) with pipe and “standard” carburetor. Maybe this is done by Perry with their carbs.

The regulator

There were more than 2 brands (Iron Bay / Cline) of fuel pressure regulators in the past and I built them even myself for more than 30 years.

A fuel pressure regulator gives you a more optimal fuel air ratio for your engine, less or even not depending of position of the plane or level of the fuel in the tank.

When using a fuel pressure regulator you also can use a greater bore carburetor so less resistance and more power, just as with the pump.

When using a pressure regulator the inlet fuel pressure of the carburetor normally is lower than when using a pump so you have often a better fuel air ratio in the midrange and even on a lower power level than that.

You have to check if the exhaust pressure is enough to get enough inlet pressure for the pressure regulator in “nose up” position, if not, you can generate more tank pressure by using a check valve between exhaust and tank., When you use one, you have to dé-pressurize the tank after the flight or have to make a very little tiny air outlet hole between check valve and tank.

You can use crankcase pressure by using a tap on the crankshaft housing or back plate (with check valve) for the tank but you will have a lot of pressure, about 7 PSI on your tank, so be careful and think about not forget the dé pressurizing after the flight. (with a fuel tank leakage you have to drain the plane!)

My Conclusions, to make my story complete

All my points are independent of two stroke or four and even a brand, it’s important to look at fuel consumption because with a pump on a four stroke the engine maybe is as thirsty as a 2 stroke!
Last point and not technical, I think using a fuel pressure regulator is typical Dutch, because we want power for money and not a wet airplane. I use them on all my planes, see the picture.
Two regulators, one "experimental" pump/regulator like Walbro.
Walbro a brand of carburators, does show us, making a fuel air ratio is something else than making horsepowers!

Just my two cents for any drop of fuel.


Cees


Edit: Walbro description