PERRY REGULATOR, WILL IT WORK ON MY OS 70 SURPASS
06-17-2012, 10:36 AM
#26
Senior Member
RE: PERRY REGULATOR, WILL IT WORK ON MY OS 70 SURPASS
ORIGINAL: 1QwkSport2.5r
One of my buddies is a Saito fan, and I prefer to be an Enya fan.. I'm simply making mental notes and comparisons between the Saito's and Enya's.
One of my buddies is a Saito fan, and I prefer to be an Enya fan.. I'm simply making mental notes and comparisons between the Saito's and Enya's.
Saito has one of the highest power to weight ratio for N/A 4-strokes. The YS "pumped" engines are not really natuarally aspirated (N/A)
The high HP output of the Saitos is due mainly to the one peice cylinder/Hemi head design coupled W/aggressive valve timing that takes full advantage of the Hemi head design. Not having head bolts to design port runners around makes for optimal port runner shape/size & optimal breathing.
The cylinder head is the heart of 4-stroke HP potential. Even the best cam timing can't make up for poor cylinder head breathing.
I've made over 500 crank HP (426 RWHP) from a stock rotating assembly Gen III Dodge 5.7 Hemi pulling a 4259# 2006 Charger through the 1/4 mile in 12.06 @ 114 MPH. And the car still got 26 MPG on the hi-way.
06-17-2012, 12:25 PM
#28
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RE: PERRY REGULATOR, WILL IT WORK ON MY OS 70 SURPASS
You are definitely wrong about that, a Perry pump solves a low tank/ long, distance tank problem and a Cline or IronBay regulator solves any kind of fuel delivery problem bar none..
06-17-2012, 03:18 PM
#32
Senior Member
RE: PERRY REGULATOR, WILL IT WORK ON MY OS 70 SURPASS
Some say the same thing about electronic ignition. The Perry ocilating pump is simplicity personified. It is merely 2 check valves, in & out W/an ocilating plunger that has an adjustable end plug sealed W/an "O" ring. All you have to do is adjust the lenght of the plunger stroke via that adjustable end & forget it once it is dialed in. Mount yout tank back over the CG so you [lanes handling doesn't vhange W/fuel load.
Electronic ignition is the same, set it & forget it. On any (roomy) plane over say 7# that is running a .91 or larger 4-stroke, EI is another no brainer. 5-8% more HP on 25% less fuel. If the plane has the room, run both.
This is especially true if you need "ballast" in the nose. Just mount an ignition module & battery pack right behind or over/under the engine for the proper CG & enjoy the added HP & fuel economy.
06-18-2012, 06:09 AM
#33
RE: PERRY REGULATOR, WILL IT WORK ON MY OS 70 SURPASS
ORIGINAL: earlwb
Well you cannot use the crankcase vent on a four stroke engine to operate a two stroke pressure pulse pump. There are no crankcase pressure pulses inside a 4 stroke engine crankcase. The engine quickly develops a mild vaccum inside of the crankcase, without a vaccum inside the engine would lose a lot of power and blow out gaskets and seals from the pressure. What full size scooters do that have a pressure pulse pump, is they run a tube off the intake manifold to use the pressure pulses inside the intake manifold to operate the pump, unfortunately these pressure pulses all but disappear at full throttle or high load conditions. But with a scooter people don't normally go WOT all the time like they do with model airplane.
But what you do on the model airplane 4 stroke engine is use the Perry oscillating fuel pump. What it does is use the engine vibration to operate the fuel pump.
Well you cannot use the crankcase vent on a four stroke engine to operate a two stroke pressure pulse pump. There are no crankcase pressure pulses inside a 4 stroke engine crankcase. The engine quickly develops a mild vaccum inside of the crankcase, without a vaccum inside the engine would lose a lot of power and blow out gaskets and seals from the pressure. What full size scooters do that have a pressure pulse pump, is they run a tube off the intake manifold to use the pressure pulses inside the intake manifold to operate the pump, unfortunately these pressure pulses all but disappear at full throttle or high load conditions. But with a scooter people don't normally go WOT all the time like they do with model airplane.
But what you do on the model airplane 4 stroke engine is use the Perry oscillating fuel pump. What it does is use the engine vibration to operate the fuel pump.
The fours stokes indeed do have pressure pluses and just as strong if not stronger than a two stroke. However the two stroke has positive pressure pulses, it may go negitive briefly but mostly positive as the intake port is open when the piston is traveling up. The four stroke has a strong negitive pulse followed by a strong positive pulse. This positive and negitave pulse can indeed drive a diaphram pump. However you have to vent the oil or enough oil could collect to cause damage from hydraulic lock..
06-18-2012, 06:48 AM
#34
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RE: PERRY REGULATOR, WILL IT WORK ON MY OS 70 SURPASS
Thanks Hugh, yes the blowby isn't enough to offset the entire swept volume of the crankcase so indeed there are positive and negative pulses.
