I have a Saito 120 that has a !QUOT!Pump System!QUOT! as stated by Saito. It consists of 2 ports in the crankcase with one way check valves. One allow air in the other out. You hook a hose to the tap that blows out. This hose goes to what I would call a remote needle valve. From there the hose goes to the tank. You use the needle valve to adjust the pressure on the tank. I have a situation with an FS OS engine that I need a pump. I was thinking of adding another port and using the one way check valves made by one of the suppliers. I would put one in to allow air in and one to allow air out. I would get a remote needle valve to adjust the pressure. Does anyone have any experience with this setup?

Thanks

I can only say I still have 2 old Varsane fuel pumps that are 10 to 15 years old now. They still pump in any position at any G force and they are ajustable for # of psi.
-
-The bad thing about a good pump, is the boring constant engine speed in most maneauvers.

Your pump system idea sounds good. We may never know until you try it? Use the fourmost check valves, tees, and a Tower remote needle?

Enjoy,

Jim

Click on --www.perrypumps.com----Save yourself a lot of juryrigging. They are great. Watch out for your fuel type.

I don't plan on running any muffler pressure. Do these perry pumps accomadate this and if so how do they prime the engine for starting?

I don't plan on running any muffler pressure. Do these perry pumps accomadate this and if so how do they prime the engine for starting?

Go to the www.perrypumps.com ---Look at the different pumps then post back or call them.
NONE use exhaust.
most are 1 hole crankcase fitting types.
Piece of cake.--------carefull on type of fuel you use!!!!!!!!!!!!![sm=thumbup.gif]

While on their site read the NEWS and NITRO NEWS sections.

The Perry VP30 will require a jury rig set up to work with a four stroke.

The Perry VP20 works with vibration. It will not need any connection to the engine other than the fuel line from the pump to the carb.

Enjoy,

Jim

The only pump recommended for a FS is the type 20 pump. Again, how do you prime the engine with this pump?

By flipping the prop through compression by hand or with a starter will create enough shaking to create enough pressure.

A lot of people use them

The 40 year old ST .90 has one and idles perfectly upside down in a 48" Spitfire.
Set the screws 1 time and fly.
Normal finger choke.

Your ST 90 has the VP 30 with a line run to the crankcase of the engine?

Enjoy,

Jim

Yes.

I can scan my old original instruction sheet and PM to you for reference?

The crankcase on a four stroke engine has to breath, You cannot connect a VP30 directly to the crankcase vent. You have to put a tee in the vent line with a restrictor in it.

Enjoy,

Jim

Then you know I am a 2 stroker.
That is why I sent him to the company site for the 4 stroke versions.

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Paul McIntyre (I hope I remember his last name correctly!), from rec.models.rc.air, posted his experiences with using a Perry/Varsane/Conley VP-30 with an OS FS-91 Surpass. He puts a tee in the crankcase vent tubing and powers the VP-30 from that. He used his while racing in California and says that the impulse from the Tee is more than adequate to drive the VP-30. He also says that the oil drains out of the other side of the tee as is needed for this engine.

Paul is a very experienced modeler and has even designed glow engines with his own brand name on them - Raptor.

Yes, I know it seems unlikely to work, but work it does, according to Paul. I believe Paul without reservation on this matter. Anyone wanting more information on this topic should look up Paul's posts on rec.models.rc.air. They are a couple of years old by now, but are still very relevant.

Ed,

Thanks for the input.

Jim

Jim,

If I could get an orifice with the correct diameter hole I could do away with the Remote needle valve and simplify this setup.

I did a diagram in case anyone is interested.