Matt Kirsch

My Feedback: (21)

I have an OS 1.60FX on a 1/4 Scale Hangar 9 CAP 232 that rattles and pings in the midrange. It's done this ever since it was new, but it got worse once I went to the Bisson Pitts muffler.

From my research, it sounds like I need a pump. Now, which one? Looking at the Perry pumps website, both the VP20 Oscillating pump and the VP30 pressure-actuated pump have the same statistics. I like the idea of not having to disassemble my engine to cut holes in it, but it seems very few, if any, people are using the oscillating pump.

Can I simply tap out the backplate of my engine for the VP30 pump, or do I have to drill a hole in the crankcase?

visioneer_one

My Feedback: (506)

I'm putting together a GP Giles / OS 1.60 / Bisson muffler combo. After reading about the fuel-related problems this engine has when run with a pitts muffler I did the same research and decided to use a VP-30.

If you don't want to drill holes in your backplate you can use the OS 1.40 RX trick which was posted here a while back.

The pressure tap from this engine replaces the upper-left backplate bolt. You remove the bolt, drill the rest of the way into the case with a 1/16" bit, clean out all the debris then screw in the pressure fitting.

I've just set this up on my Giles over the weekend. I can post pictures, if you'd like.

Shogun

My Feedback: (2)

VO is correct about the VP-30 and the OS tap fitting for the 1.40. But don't drill the crankcase pressure port out with tthe fitting out of the engine! Simply remove the backplate, screw in the fitting loose and insert a bit that matches the Id. of the fitting itself, using the fitting as a guide for your drill bit. Voila' no buggered up threads! Be sure to clean any aluminum chips out of the engine before buttoning it back up.

The Perry pump works so good it should be included in the box with the 1.60 FX.

Matt Kirsch

My Feedback: (21)

Must be a pretty common modification. The 1.40RX Pressure fitting description on Tower Hobbies listed the Perry VP30 pump as "People Who Purchased This Product Were Also Interested In..."

Thanks for the recommendation!

MHawker

My Feedback: (16)

Ditto on the VP30.

rightflyer

Any pictures of the finished product?

RonC

Ditto with VP30. One other idea I heard and used =>
Use small piece of fuel tank copper tubing in hole (upper left hand screw removed) and use 1/16 bot size when drilling through. The copper tubing prevents buggering up the thrreads. After you;re done; remove copper tubing, clean out drilling residrue and insert OS 140 fitting from Tower

visioneer_one

My Feedback: (506)

Mounted as per the instructions - they recommend that you install the pump oriented horizontally, with the vent hole pointing down.

I wrapped a bit of sticky-backed felt around the pump to keep it from sliding fore and aft. The mounting strap is a strip of plastic cut from an old fuel jug.

I'm using a three-line, two-clunk system. Fill/drain line to the tank (clunk), feed line to the pump (clunk), and a vent/overflow line out the bottom of the engine box. Pressure line goes directly to the pump. Medium fuel line is used throughout, except for the vent line - I used large tubing here. I'll be using a single fuel dot for filling and draining the tank.

The lines are longer than I'd like right now. I'll shorten them once I'm ready to mount the cowl.

The pressure tap is visible in the last picture.

m.gramling

My Feedback: (8)

How come some 1.60's run great with pitts muffler with no regulator, and then some need the regulator. Doesn't make since to me.

I have seen 3 OS 1.60's run and their midrange was perfect. And all three didn't have a regulator.

MHawker

My Feedback: (16)

The VP 30 is a regulator and pump in one unit. You adjust the pressure with a small allen head screw on the top of the pump.

You could also get a cline regulator instead of the pump which also acts alone.

Mike

PlaneKrazee

My Feedback: (14)

If you have pinging in the midrange the low end needle is too lean. The Bisson muffler has less back pressure than the stock muffler, that is why it pings after it's installation. The BGX muffler is larger and quieter with the same bolt pattern. My engine does not need a pump, the tank is behind the firewall and I use the Hobbico large exhaust deverters.

Brian

Matt Kirsch

My Feedback: (21)

Got the pump over the weekend and plumbed it up last night.

It should be okay to use standard fuel tubing now, right? The nipples on the pump are for regular tubing, and the large tubing I was using just didn't seem like it would fit tight enough to make a good seal.

MHawker

My Feedback: (16)

Yup, with the pump, you'll be fine with regular fuel tubing.

Mike

Matt Kirsch

My Feedback: (21)

Thanks!

I put a few ounces of fuel in the tank, ran the output of the Perry pump through a line back to my fuel jug, "primed" the system and cranked the engine over by hand. The little Perry happily started pumping fuel back into the jug. Looks like it's working.

arniebarn

vissioneer-one,looking at your installation of the v30 it looks like you are using reg fuel line to the pump from the engine,should you not be using the harder red line that comes with the pump,it is a harder material then the reg fuel line so the engine pulse will operate the diafram of the pump fully,the regular fuel line if used will expand and contract a lot taking away the full action of the pump,just my thoughts,arnie.

Sport_Pilot

visioneer_one's installation also has the pump a bit further from the needle than I like. It will have a lower pressure to the carb when inverted than when upright. Also could be a little more foward the carb, though that will not be critical unless hovering a lot.

visioneer_one

My Feedback: (506)

You're right - I didn't think about that. The supplied red line was too short for my install, so I used the med. fuel line.

I have some 'Easyflex' tubing on hand from Aerotrend. This stuff is pretty stiff - you can't pinch it shut with your fingers. I'll give it a try on the pressure line.



The lines are cut 'long' right now pending the arrival of a new cowl - the one included with the kit was *warped*. I'll be shortening the line which runs from the needle to the carb, for certain.

Isn't there a regulator built into the Perry? I'd think that the only time that the pressure to the carb would vary would be if the feed clunk sucked air. Explain please?

Sport_Pilot

Isn't there a regulator built into the Perry? I'd think that the only time that the pressure to the carb would vary would be if the feed clunk sucked air. Explain please?

If you read the instructions you will find that they say to install the pump as close to the carb as possible, and at the same level or near as possible to the spraybar. The pump only regulates the fuel at its outlet. So mounting the pump below, above, or behind the spray bar will now vary the fuel as much as moving a tank above, below, or behind the spraybar. If you mount a tank 2" below the spraybar you will have 2" of glow fuel negative head flying upright and 2" positive head inverted. That would have a considerable effect on how the engine runs. Moving the regulator 2" below the engine will have the same effect, the only difference is that it will stay the same through the entire run VS the tank further leaning out during the run.

chris100

If you should not run regular fuel line for pressure to the pump, what is a good replacment? I had the stock red line split on me causing a lean run. I was thinking of using the black neoprene tubing as it is pretty stiff.

visioneer_one

My Feedback: (506)

I've read this a couple of times, and must be missing something. If the fuel pressure is regulated at the pump's outlet what difference does the pump's height relative to the carb make? If its regulated it should be delivering consistent fuel pressure to the needle, regardless of its attitude.

I'm not real happy with the length of the run from the needle to the carb. I don't see any way to remedy that without changing the carb for a standard type... and I'm not changing the carb. Since I placed my pressure tap through one of the backplate bolts I had to move the rear-mounted needle valve to the firewall. I didn't think that it was a good idea to use the pressure tap to hold the needle valve bracket in place - I was concerned that it wouldn't seal properly.

Sport_Pilot

The difference is the weight of the fuel. The same principle that regulates the water pressure in our pipes, the height of the water column or tower maintains the water pressure in our water systems. The pressure is measured in feet of water or head, if I recall correctly 2.3 feet of water is 1 PSI. Except we are using fuel. If you tee off a piece of tubing open one one end from the pump and run it straight up a rule you can measure the fuel height from the regulator in inches of fuel I think the height will be about 8"or so. If the pump is 2" above then the pressure to the carb will be 10" of fuel. If you turn the plane upside down the pressure will be 6" at the carb. That is almost half!

arniebarn

vissioneer-one,in my sig extra 300 arf i installed my v30 pump on the fire wall,there is about 3 inches of tubing from the pump to the os remote needle valve, my needle valve is mounted on the engine back plate,my fuel tank is right at the fire wall,the v30 pump instructions says not to use longer line from the engine to the pressure pump fitting than whut comes with the pump [aprox 4"s],i tryed this set up yesterday for the first time,the engine runs purfect.i did mount my pump at the same level as the carb which i dont think matters much.anyways try your set up and see if it works ok,in my os engine instructions it did make a comment on using the fuel line that came with the motor from the carb to the needle valve ,that size and that length,which i dont know whut diff this would make,i read somwhere that the pump can have a max out pressure of .25lb.as i did not use the stock muffler [ went to a 4500 st bisson]i know i was not getting the fuel pressure to the carb that was needed as on the ground i could set the engine to run but in the air with gravity force these settings would not work,there are so many diff factors when the plane is air born that test bench and ground run up and testing dose not tell the whole story,after 30 years in this hobbie i am still learning,its a bit like a black art,i had two v30 pumps for some thim but did not want to try this set up as i tryed a pump on my webra 120 last year and all it did was pour fuel out of the carb, i did not think the pump would then work on my os160.was i wrong.also the tubing to use on the pump pressure is [aerq2005]tower hobbies,arnie.

visioneer_one

My Feedback: (506)

Gotcha. Sounds like I need to mount the pump lower. Since the engine is mounted sideways I'll try getting it closer to the centerline of the engine.

The only way I'll be able to accomplish this is if I hang the pump off the back-bottom-inside of the motor mount, oriented vertically. This will also get the pump a little closer to the main needle - another win.

(I've added a green dot in the original picture #1 showing the (potential) new mount point for the pump)

Does anyone know if the pump's orientation makes a major difference in how well it works? The manual recommends that the pump be oriented horizontally, not vertically.

This is the first externally-pumped engine I've set up. My YS engines have spoiled me

Azcat59

The pump location in relation to the carb does make a difference, believe it! (Been there, done that)

I have been mounting the pump on the firewall directly behind the engine head. Nice short shot to the backplate, which I tap, and not far to the carb. Do not worry about the small hole in the pump being upright. I have several mounted this way and there is no problem. My mount has the pump laying horizontal, with the pressure line aimed at the center of the firewall, the inlet nipple pointed at the firewall, and the carb nipple pointing forward. Hope this is clear. And I do think the hard red tubing is important.

Clair

Matt Kirsch

My Feedback: (21)

Nooooo! Why do my threads always get hijacked???