Adding a pump tp a glow engine

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Adding a pump tp a glow engine

Postby redappy » Sat Apr 23, 2005 7:05 am

Hi I have to pump a 61-90 size glow engine for a prop jet I am finishing ,what would be the best one to get and the best pump .I have allready looked into a Ys 61 besides the pricebeing a bit high they are out of stock .
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Postby Frank Klenk » Sun Apr 24, 2005 7:25 am

A pumped YS is an excellent choice in my opinion. They are pricey, but then you get what you pay for. I don't have one, but a few of my flying buddies do, and they are reliable and powerful. Another option may be to use a Dubb Jett. I have the BSE 50 and it is a strong running engine, and I don't use a pump on it. I have it on an r/c Nobler and it really moves. RPM on the ground is around 15000. AND, let's not forget the K&B engine. They sell several DF engines, right from a .21 up to a 1 cubic inch, now these will give you all out speed! Just my thoughts.

Frank :)
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Postby Chip Morrison » Wed May 04, 2005 5:23 am

Use any engine and get a Perry Pump. They bolt on to the back plate of the engine and use the engines dynamics to operate the pump. :lol:

Cheers,

Chip
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Postby William Robison » Tue Feb 21, 2006 6:40 pm

I have to go with Frank. A fan engine has to run a high rpm to work well, and that requires a specialized engine to get good life. Pipe pressure in the tank is all you should need, a pump is just extra complication.

Do check the K&B fan engines.

Bill.
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Postby Electric Tiger » Mon Nov 16, 2009 10:43 pm

i know this posting has been here a while but id add that you cannot just use ANY engine/carb. you must use a carb designed for pressure pump, otherwise it will go too rich in mid range. the high low will be ok but transition will suffer.
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Postby chiefss » Tue Nov 17, 2009 2:11 pm

Actually, a Perry micro oscillating pump will work just fine. It works off engine reaction, ie, the vibration of the engine. The faster the engine turns, the more the pump pumps. A special carb is not needed.
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pump carb

Postby Electric Tiger » Tue Nov 17, 2009 10:18 pm

according to the engine column by Clarence Lee ,April 1978 quote--"Any number of carburators will work on an engine in conjunction with the perry pump,but they will not work well. Because of the pump pressure, any carburator that works on a non-pumped engine is going to load badly through mid range if used with the perry pump, this due to the fact that few carbs have a mid-range mixture adjustment. the idle mixture you can set as well as the high speed. but without any means to adjust the mid range the engine is going to load up.this includes carbs with only air bleeds.the perry does not have a mid-range adjustment but has been calibrated to compensate for the mid-range richness....the tarno carb is like many, not calibrated through mid-range & like any other carb not intended for pump use, loads through mid-range.this can be helped by reducing pump pressure but by the time the pressure is low enough to lean the mid-range it is usually not high enough to supply sufficient fuel at high speed." end quote.
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Postby chiefss » Tue Nov 17, 2009 11:00 pm

The Perry oscillating pump did not exist in 1978. It works well with any carb and will not load up in the mid range. The pumping action rises and falls with the engine rpm.
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Postby Electric Tiger » Wed Nov 18, 2009 9:39 pm

i have the very magazine i quoted from right in front of me.You also DID NOT READ exactly what i wrote. ALL CARBURATORS LOAD UP IN MID RANGE to some extent. wether or not the rpm varies is of no consideration. it is the mixture that counts and without adjusting for that it will not work as well as it should in transition.how come perry made pump carbs & non pump carbs?- dont tell me they didnt.
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Postby chiefss » Thu Nov 19, 2009 2:38 pm

I didn't say perry didn't make pumps and pumped carbs and non pumped carbs. BUT... they didn't make the micro oscillating pump in 1978. THAT pump works well and doesn't load the engine at the mid range. I use that pump all the time. Especially on 4 cycles with a low mounted tank.

The perry pump that mounts in the back plate needs a regulated carb because of the pressure produced.
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Postby Electric Tiger » Thu Nov 19, 2009 10:40 pm

pressure is pressure regardless of WHAT pump produces it.If you want to believe it works without a pressure carb your entitled to your beliefs which obviously are at odds with known facts..
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Postby ron bennett » Fri Nov 20, 2009 12:54 pm

Oh, what the heck, I'll dive into this pool.

The only difference, for any given engine application, between a Perry non-pump carb and a Perry pump carb is that the pump version has a larger ID bore. With a pump on the engine, one does not need the venturi effect to draw a suction to pull fuel into the engine.

The bigger bore and higher fuel flow on a pump system with a pump carb gives an increase in torque across the power band and a very slight increase in HP from a slightly higer RPM.

It is all but impossible to have a smooth reliable idle, correct high speed needle setting AND a smooth mid-range transition with today's carbs with only a idle setting and a high speed needle setting. You could improve this with an in-flight mixture adjustment, but that would be a real pain to use.

The black slide barrel HP Gold Seal carb and the Webra Dynamix carbs are better than others at mid-range transition becasue they have assymetric barrel action, but are not ideal.

Ron Bennett
Hope this helps clearify.
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Postby propwobble » Sun Nov 22, 2009 11:12 am

The Perry website has info on both types of pumps. They don't give the max flow rate of the VP 30 but likely it is capable of pushing a fair amount of fuel at the claimed .25 psi. if it can fuel a 3.0. It sounds from their text that they are claiming constant pressure( .25psi) from the regulated pump does not adversely affect carburetor performance. They do not say that a larger venturi is required nor that there are induced midrange transition issues. (still implied is that if you start with a poor transitioning carb, no improvement will be seen) Note the use of term " any model carburetor". No doubt the presumption here is that if the pressure remains the same and pressure changes from changing pump speeds and its affects on high and low needle settings are negated. Since fuel pressure remains the same at all speeds, the fuel flow rate demands should be met at all speeds.



"VP-30 Regulating pump

The VP-30 regulating pump is capable of performing like no other fuel delivery system. It delivers an ideal .25 PSI to any model carburetor from a .15 to a 3.0 cu.in. engine. The pressure remains constant throughout the entire speed range, making the carburetor adjustment easy and simple. Once the needle valve is adjusted, the mixture will not vary regardless of how low the fuel or the attitude of the airplane, thus eliminating rich/lean runs altogether."
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Postby chiefss » Sun Nov 22, 2009 12:56 pm

Thanks PWobble. And that's how I found the Perry Micro oscillating pump to work. With the carb set properly there are no issues throughout the throttle range.
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