T-28Man

My Feedback: (5)

Is there any big difference with either one ? I have read good things about both. I want to use it on a OS 160FX. Perry seems alittle cheaper- both need a crank tap. Help Thanks

JimTrainor

I have a Perry pump (v30) that I plan to test with a smaller engine.

My understanding, based only on anecdotal reports found on the net, is that the Cline regular depends on carb suction to open the regulator and draw fuel from the pressurized tank. I'd like to hear more about the Cline as well.

The Perry is an actual pump (no pressurized tank), but the output pressure is regulated. Perry claims it delivers "an ideal .25 psi" (http://www.perrypumps.com/prod02.htm). I think it would be an interesting excercise to actually verify that, and hope to do so over the winter.

I can't recommend one over the other... since I have yet to use either! My only conclusion is that it is hard to find concrete information about them.

Here is one person's experience with the Cline:
http://www.maac.ca/committees/report...o_2000-10.html

Here's a guy that couldn't get either to work well:
http://webpages.charter.net/rcfu/Kit...WGiles202.html

... you've probably seen these if you've been searching.

Hobbsy

My Feedback: (102)

I've had total success with the Cline Regulator, three of them and only marginal luck with the Perry's one Perry for gas came with no guts in it. The Clines need no adjustment and the engine needle settings stay nearly the same, the engine runs exactlly the same from full tank to empty, nose up or nose down. Just like a YS but without the supercharging. Also you can run the engine closer to peak because it won't lean out near the end of the tank. And for Jim above, the Cline is a demand regulator and only passes fuel when the carb demands it.

bob_nj

My Feedback: (62)

Since Morris initially came out with their line of profiles in 1995 or so, I've built, flown, tinkered and fiddled with several of their kits (Gee Whiz Bee_Knife_TopCap) and also the wasp. My pet peeves have been less weight, proper cg, fuel, plugs, props and throttle transition. I've tried both systems and for the kind of flying I like to do, that is hoverbatics, 3D, tailtouching and overall fun flying, I prefer and use the Cline. With the Perry/Varsanne/Conley my experience has always been to change the carb for best performance because of the pressures involved, especially in the midrange. When you need the engine to be there, you need it to be there-NOW! The Perry is a PUMP. The Cline is a demand system. It gives the carb what it needs. You can pull the fuel line off the Cline at idle for instance, and no fuel comes out. So let's talk about what engine you are using, and what type of flying you like to do and go from there_bob

GoNavy

My Feedback: (15)

I bought and used two cline regulators when they first came out. They worked as advertised on a Webra 120 and a Rossi 35R60*.

Last year I bought two and neither could be used on a Laser 120 and Saito 100. Cline sent a third unit which he assured me was fine. It suffered the same problem: Air bubbles entered the fuel on the outlet of the Cline. The Laser 120 would run, but unevenly. The Saito could not run over 1/2 throttle.

I took one of the old Clines and put it on one of the 4 strokes and it worked fine.

I have discussed the problem with Jim Cline to no avail

*Oh, just to make things more interesting: When I got the Rossi 60, it came with an integral backplate pump which could not meet the needs of the engine...air bubbles at the very high end (14,000+). The pump was replaced...same problem. (I don't know who made those pumps. Sig handled Rossi at that time). I removed the pump and the engine ran fine with one of those old Cline regulators. The tank was a full 20 inches from the engine.

w8ye

My Feedback: (16)

Heed what Bob says:

"The Perry is a PUMP . The Cline is a demand system . It gives the carb what it needs. You can pull the fuel line off the Cline at idle for instance, and no fuel comes out."

The Cline has no pump in it. You need some reliable way to get fuel up to it. Then it will supply fuel to the engine as demanded but it needs to be as close to the carb as possible . Like Bob says, If you jerk the outlet fuel line off the Cline, no fuel will come out. The Cline is only a demand regulator. There's no pump in it. You can get fuel to the Cline with crankcase pressure and a check valve, or a Perry pump, or you can use muffler pressure and a check valve.

The Perry is a pump. You can adjust the outlet pressure to a certain extent but it will always try to maintain that pressure. Your engine does not need 2.5 psi all the time (or whatever pressure you set it to). Sometimes, the Perry will cause a lot of transition problems with an engine. You end up having to adjust the pressure to get around this problem. Typically a rich midrange means too much pump pressure and a lean midrange means not enough pressure. Sometimes, with a stock carb you cannot get them to perform very well period.

The engines, like the K&B's, that came with Perry pumps on them, also had special Perry carbs that accommodated this relatively constant pressure.

Jim

rajul

My Feedback: (58)

How does air bubbles get into the outlet ? Something inside the regulator is not sealing well ? Did you verify if any air bubbles are getting into the Cline unit to begin with ?..........

GoNavy

My Feedback: (15)

Rajul: The answers to the three questions are:
1. No one knows: That's the $64,000 question;
2. Not sure; No if you trustthe Neil Tidley underwater test.
3. Yes, no bubbles going in.
See the thread started by jrtmaser, "cline regulator", last post 11/13/02, a two page saga.
I remain open to new suggestions.

ml3456

I love the Cline. I have 3 tanks buried in a GP F-14. No mixture change ever,never leans out, and runs great. It is a demand system, and the tanks do get a little pressure in them. Remember when installing the regulator, put it at carb level, just like a fuel tank, and as close as you can to the carb. Mine is mounted right behing the engine back plate

rajul

My Feedback: (58)

Thanks GoNavy. Was planning to shift my tank to the cg with a cline regulator. Seems like safer to go with a perry regulator and perry carb ? Hope to get some good advice or recommendation here........

Volfy

My Feedback: (23)

Just got done installing a Perry regulating pump on a 1.20 4stroke. It works great with the stock carb with no lean or rich spots. I have the tank right behind the firewall at the correct height and am using the carb strickly to rid the dependence on muffler pressure. Very happy with it and just ordered two more to try on my other engines.

bob_nj

My Feedback: (62)

Good point Volfy. I was talking from a two stroke point of view only. I've never used them on a four? How did you arrive at your method?

Volfy

My Feedback: (23)

bob_nj, check out this thread:

http://www.rcuniverse.com/showthread...82&forumid=145

I too thought the Perry pump was 2stroke only. Thankfully, I was wrong..

Iflyglow

My Feedback: (79)

I have used the cline system on everything from an osfp40(crank case pressure) in a powered parachute, to a saito100 twin. They work awesome with four strokes, just use muffler pressure. Spin them with a starter to build pressure or fill the tank untill the pump boggs with an electric fuel pump and clamp the line with a hemostat then install the plug in the line. My saito 100twin would start with one hand flip when I did this. These systems work just like the ys system but it is external. This system is a demand system, and the harder the engine sucks the more the diaphram moves to allow more fuel. Unlike a pump which is allways trying to push fuel through the needle valve. You do not need a special carb with these. The throttle responce is awesome when these regulators are used. Like I mentioned earlier I used one with my saito 100Twin, right behind the T fitting,(DUAL CARBS), This system worked so well, I adjusted the needle valves 2 times in a whole summer of flying (5 gallons of fuel). People would ask me all the time what kind of onboard glow do you have, and they never believed me when I said it does not have any. The only thing I do not like about them is you have no warning when you are running out of fuel, because the engine does not go lean untill the last drop of fuel hits the carb.

Hobbsy

My Feedback: (102)

Volfly, the Abitar 120 came with a Perry oscillating pump on it because the carb is mounted high on the head above the intake valves. The Conley 120 had the carb mounted down beside the crank and needed no pump.

GoNavy

My Feedback: (15)

Ok, re Hobbsy and Volfy last posts, a related question: If you are not using a pump or regulator, where should the fuel tank centerline be in the vertical plane? aligned with the spraybar? Aligned with the intake ports or valve? Aligned to a point half way between TDC and BDC of the piston? Wherever the engine instruction book suggested? Or?
I presume there is an "ideal" location, to ensure engine performance in all regimes, and I wonder what factors determine that. In my experience, most aircraft designs will not allow the tank to be located properly. Frequently the limited range of tank location drives the position of the engine: ie, install the engine at whatever angle best aligns the spraybar to the tank centerline.

One followup question please: If we use a small hopper tank in the "ideal" position, and the main tank is high or low, have we solved the problem?

Hobbsy

My Feedback: (102)

Go, I think the normal recommendation is to have the centerline of the tank 1/4 inch below the spray bar.

Volfy

My Feedback: (23)

Yes, I believe the conventional wisdom is to mount the tank centered slight below the carb.

Now, I have recently read in some engine manufacturer documentation (forgot which one) that says to use the needle valve as the reference point instead of the carb. This would supposedly be applicable to those engines equipped with a remote needle valve. I don't have any independent verification of this. Can anybody shed some light on this?

JimTrainor

Nobody has replied the hopper question so I'll try.

If the main tank and hopper form a closed system, then the addition of the hopper won't affect the fuel pressure. In case it is not clear, by "close system", I mean a single input (exhaust pressure) at the main tank, and a single output at the hopper (to the needle valve).

I have read that the main advantage is to prevent foaming.

GoNavy

My Feedback: (15)

I'm curious about the tank position question because I've had at least two situations where significant engine problems were solved by moving the tank, again I'm talking about situations where there is no pump or regulator. I had an ST 91 mounted upright in a rehabbed Stinger. With the tank in the normal position, you could not adjust the needle so the engine would run both upright and inverted. It went rich inverted and died.
The Laser engines have the carb at the height of the intake valve. That makes it unlikely you can align the carb and tank if the engine is either upright or inverted: you must mount the engine sideways. This can be solved by a Cline which works, but not one that feeds air bubbles to the engine.

Hobbsy

My Feedback: (102)

Go, I have a Laser 180 vee-twin on my Ultra Stick and the carbs are above the fuse but it is not a problem, I run two clunks one for each carb as they suggest and it works well.

JimTrainor

Curtis Youngblood uses a Perry pump with an OS91 on a heli:
http://www.curtisyoungblood.com/os_engines.html

Here's a picture with and without a header:
http://www.curtisyoungblood.com/OS91-Diagram2.jpg

He uses muffler pressure, *and* the pump, along with some extra plumbing to return excess fuel back to the tank.

Look at the check valve numbered "11" in the jpeg diagram above. On one side of the check valve is exhaust pressure, on the other side is the pump pressure. If the pump always lifts the fuel pressure slight above exhaust pressure, then it looks like the net effect would be to regulate the fuel pressure to match the exhaust pressure.

Regulating the fuel pressure to match the exhaust pressure seems ideal. That is the exact condition that engine manufactures expect when the design their carbs.

Essentially, the check valve acts as the regulator in this case. You could probably get by with a simpler pump (if one existed) using this arrangement. As long as the pump is pushing more fuel than the engine needs, your good.

GoNavy

My Feedback: (15)

Oh my oh my, what hath God wrought! (Stretch the spring in the perry to twice its normal length.)
I don't have the kind of time and patience all this appears to need. I just want the dumb thing to run reliably.
Oh, in the for what it's worth category, Laser says muffler pressure may be used but is not necessary. Maybe carb design affects sensitivity to tank location. I know that having the tank c/l an inch below the spray bar on the ST 90K resulted in it dying inverted every time. Lining them up solved the problem. There was no problem when the Stinger was new because the engine was mounted on its side, hence the spray bar was closer to tank c/l than with the engine upright.

JimTrainor

Yeah, I agree... in general, it's too complicated to be taking apart a pump that was intended for another purpose. The take home message, I would say, is that another approach to the whole problem is worth examining. That is, to regulate the pressure to match the exhaust pressure. You match generic carb designs if you do that (exotica such as YS excluded). The carb mismatch seems to be half the problem with these setups. I'm diverging here. I'll stop now )

GoNavy

My Feedback: (15)

Jim: I'm always interested in something new.
Just too much for my skills.