rlmcnii

My Feedback: (3)

KHodges,
Thanks for the reply. My son-in-law is assembling a plane that is going to be powered by a Saito 1.00. We will be breaking that engine in sometime in the next few weeks. Your information is appreciated.

Hobbsy

My Feedback: (102)

rl, the LS needle being set too lean can also cause the HS needle to be ineffective creating a lean condition at high throttle settings.

rlmcnii

My Feedback: (3)

torque wrench,
Thanks for the reply. I think this is why it is best to adjust the HS first. With it set correctly, if you inadvertently get the LS too lean, the engine probably will not transition out of idle. At least, it probably won't do it well.

Is this not correct? rlmcnii

Hobbsy

My Feedback: (102)

Thanks r, I find I get the best transition and idle by deliberately getting the LS needle just lean enough that the engine hesitates when the throttle is opened a tiny bit suddenly. A quick open and closed (to idle) will make it hesitate but not quit, then an 1/8th turn rich usually does it. I'm sure there are other methods that work equally well. I've found that when a Saito is set this way all the plug hoopla is now a moot point.

khodges

My Feedback: (1)

Speaking of plugs--I have a problem with the pin on the Saito plug. I can't seem to keep a remote starter cap on a Saito plug, it vibrates off after I start the engine, so I have to remove the cowl and re-seat the cap each time. I finally got tired of it and replaced the plug with an OS-F, no more problems since. Otherwise, I like the Saito plug fine.

Old glow plugs make great sling-shot ammo, BTW[X(]

Kmot

My Feedback: (24)

A slight diversion here.

When I wanted to convert my FA-40 to marine use I searched high and low for info on ANY marine versions of the Saito engines. Specifically looking for a cooling jacket and if any flywheels had been availble. I found nothing.

Now just recently someone sold a supposed Saito FA-40 MARINE version that is NIB. I am suspect of this engine. I believe it was a conversion done by an individual and not a factory Saito production item.

What do you all say? Anyone else EVER seen a factory production Saito marine four stroke? I would love to know if this is indeed a FACTORY production engine.

loughbd

I've been using Saitos since 1980 and I worked for Hobby Shack the importer and I never saw or hear of a marine saito except for their 2 Cycle ignition engine.

lrr

One would assume those are castor beans, right?

[drum roll please ...]

loughbd

Constant bearing and decreasing range?? You best turn as you are on a classic collision course

khodges

My Feedback: (1)

[/quote]

One would assume those are castor beans, right?

[drum roll please ...]
[/quote]

Considering what castor oil is good for (it lubricates parts OTHER than our glow engines), I'd be worried about "particulate matter" after eating castor beans.

FFOURU

I have been looking at a couple of twin engine aircraft. It is normal for full size aircraft to have counter rotating engines. Is there such a thing for RC aircraft?

William Robison

My Feedback: (3)

Eff-Fore-You:

Since we are in the “Club Saito� thread I’ll start by saying that any Saito mid block or big block engine can be reversed easily.

Quote:

It is normal for full size aircraft to have counter rotating engines.

Sorry, sir, I have to differ with you on that one. I have never heard of a "Transport" aircraft with CR engines, one of the very few military AC that had CR was the P-38.

Some of the Piper twins could be bought with CR as an extra cost option, not too many were sold.

Counter rotating engines on twins are really more rare than you might think. Stocking parts for the reversed engine, completely different props from one side to the other, not to mention having to be very careful to assemble the right engine "Backwards" at overhaul time.

Back to the military side. Grumman considered CR on the XF5F Skyrocket and XF7 Tigercat, The idea was dropped mainly due to the logistics problems, props, engines, and spare parts stocking would all be much simpler having both engines turn the same way.

On a model plane, where we aren’t going into volume production, there are definite advantages, but there are still problems. Among them, the selection of reverse pitch props is much smaller than normal pitches. You first have to be sure you can get the right size props in a matched reverse pair for your engine size and power, matched to the airplane.

Staying with the right brands of engine, reversed rotation is no problem.

Any two stroke engine that uses a separate bearing housing for the crank can be reversed by turning the front cover 90 degrees in the direction of normal rotation. Some K&B and some Enya engines, for two examples, can be done this way. Also, for K&B reverse ported cranks can be gotten. OS, in the past, has supplied reverse cranks but I don’t know if they are still available from OS.

Going to four stroke engines, any Enya 4s engine can be reversed by retiming the cams. Reverse rotation cams are easily available for all Saito single cylinder engines, all the Saito twins that use separate cams for the two cylinders can be reversed simply by switching the camshafts side to side.

The Saito FA-120 is the best of all possible worlds for a CR twin. Just by switching the intake and exhaust from one side to the other not only is the rotation reversed, but the engines are then symmetric and can be installed with both cylinders pointing to the fuselage, but you still have both exhaust pipes coming out the lower side of the nacelles.

All this is to say it can be done, and if you want to bother have at it. At the same time it’s not necessary, and increases the complexity of building, maintenance, and parts supply. There are other ways to tame the “Flameout Monster� without going to counter rotation. And remember also that CR does not guarantee survival after flame out.

A much better way is selecting a plane that is known to fly well on one engine. The Northeast Aerodynamics “Twin-Air 45� and the “Duellist 2/40� are two examples that can be flown easily on one engine, I’m sure there are others as well. Another method is out thrust. Ed Moorman has done some experiments, he’s found that seven or eight degrees out on each engine allows him to ignore any flameout, other than just having a bit less available power.

A long dissertation sir, but you DID ask.

Bill.

loughbd

The only airplane in WWII with counter rotating props was theP-38. Even today all of the Douglas airliners (DC-4, DC-5 6 and 7 ) super connie etc had engines that all turned the same way. P-3, S-2 etc same.

khodges

My Feedback: (1)

When you say "right" are you saying "correct" or do you mean "opposite of left"? On the P-38 the right-hand engine turns right, or clockwise (as seen from the cockpit) and the left turns left, or counter-clockwise. During the P-38's development prototypes were set up with both engines turning right, as well as trying the right engine counter-clockwise and the left clockwise, and also the configuration that production models have. Considerations to set them up like they ended up included turning performance, and one-engine-out performance.

William Robison

My Feedback: (3)

KH:

For purposes of this discussion “Conventional rotation� is taken to mean the propellor turning clockwise when viewed from the rear of the plane. “Reversed rotation� is turning counter clockwise when viewed from the rear of the plane.

A twin engine plane with both engines turning in conventional rotation has a greater reaction when losing the left engine than when losing the right. When the right engine only is running the torque reaction tends to roll the plane to the left, adding to the off center thrust. When flying with the left engine running the torque still tends to a left roll, but with the thrust on the opposite side of the plane the effects are subtractive rather than additive as when the right engine is the one running.

The reason for counter-rotation is to make the plane respond the same with he loss of either engine. With the right engine running in reversed rotation the torque reaction tends to a right roll, subtracting from the off center thrust.

So. Our normal twin with counter rotating engines has conventional rotation on the left, and the reversed engine on the right. Left and right being from the pilot’s perspective.

The P-38 was not a conventional plane with conventional counter rotation. The prototype XP-38 did have the normal set-up, but it had extreme aerodynamic buffeting, somebody had the idea to switch the engines, and it worked. This did make it more of a handful with a dead engine, but as Tony LeVier and many others demonstrated, it could still be flown safely on a single engine.

Anyway, KH, to answer your question (finally) the right side engine, seen from the pilot’s perspective, is the one that has to be assembled for reversed rotation. Except on a P-38.

Bill.

loughbd

Constant bearing and decreasing range?? I recommend turning and quickly.

FFOURU

Then, the left engine would be the CRITICAL engine, is that correct?

jlkonn

My Feedback: (1)

Back in the mid '80s a club member had a Midwest TwinStik.
Don't recall the engines or size.
This person had terrible luck with stuff.
Lost a lot of planes.
One day he asked me to fly his twin and when I did one engine died of course.
I flew enough full size and did enough hangar flying to remember "dead foot, dead engine" so it was a simple matter of giving it full rudder trim in to the still running engine.
The owner of the plane just knew it was going to crash but it flew well.
Way down on power but it was very controllable all the way to touch down.
JLK

William Robison

My Feedback: (3)

F4U:

With both engines in "Conventional" rotation, the left engine is the critical engine - meaning it's the one the plane flies more easily with in an engine out situation. With "Normal" CR engines neither is critical, the plane flies equally well with either engine out.

Vmc, the lowest air speed where full control can be maintained with one engine out, is often published as a single number, but some builders give two different numbers. With conventional rotation on both engines Vmc (left) will always be lower than Vmc (right. Depending on the aircraft design this difference may be too small to matter but with widely spaced engine and a short tail moment it can be quite large.

Bill.

HDB

Thanks for the assistance this last week in reference to my FA-65 which seemed to not have adequate compression, etc. I put some Marvel oil internal and things seem to be ok now. Now one more question = I pulled the 65 out of a 73" Goldberg Cub and than I got to checking and the instructions call for a minimum of a 90/4c or a 40 to 61/2c! So - I decided to switch the 65 out for a new fa-80. Seemed a simple thing to do since I live at sealevel and the power would be probably adequate. However, the throttle control is on the opposite side of the motor and I really don't want to modify the plane to accept it. Question is - is it possible that the 65 would be adequate power for the cub at sealevel??

If not then I will have to make some changes and come up with one large enough to do the job.

William Robison

My Feedback: (3)

HDB:

I'd think the FA-65 flew the Cub in the past, since it was in the plane when you bought it.

If you want to put the FA-80 in it there should be no problem. Throttle lever on the wrong side? Just reverse the carb. Two screws out, swing the intake szideways and rotate the carb, swing it back in and reinstall the screws.

Bill.

HDB

Bill, Thanks again! That shows how much work I have done on engines! Just looked at the 80 and looks like no problem. I don't know whether the Goldberg came with the 65 or what. I purchased it from a guy in Arizona who had built it from a kit, did a good job, but was afraid to fly it after that much work!!! He had put the 65 in, taxied it up and down the driveway and then I bought it. That was about 4 years ago and I am just now getting around to getting it ready for first flight. I will go ahead and try the 65 if you feel it is adequate or if you feel that it is marginal then the 80 is availiable..

Harvey


Bill, I will give you an assessment of twin engine machines in awhile - have a Twin Star with os46's so will see how it does. Have seen one fly before and seems to be a real zipper.



Just reversed the carb and what a simple movement to solve such a seemably complex problem!! The unit seems to be the same physical size as the 65 so will probably be a direct fit. However, I have the 65 sitting here and if it will do the bill, I will mount it and see how it flys.

loughbd

A 90 is grossly overpowering a CG Anniversary Cub. I have had three. The first had a saito 45 on it. Flew just like a real Cub. Had to dive into a loop. The second had a Saito 50 and it flew absolutely perfectly. It would loop from flat and level flight. The third had a OSFS 61 on it because I used it on floats. A Piper Cub was never intended to be a PYLON racer which is what a 90 makes it.

William Robison

My Feedback: (3)

Harvey:

The FA-65 will almost definitely be marginal power for the big Goldberg Cub. I didn't realize it had not flown. I'd still give it a shot, you can always change the engine later.

Regards the Twinstar. 46 engines are WAY over the top for that plane. They have been flown with 46s, but keep a finger cocked on the throttle lever. Loser one and it could screw itself into the ground before you have a chance to react. Keep a good eye on the airframe too, others using 46 engines have commented on the plane literally coming apart from the excess power.

If yours are the LA engines it wont be quite so bad, but it will still be a wild horse anxious to bolt at the first bit of carelessness.

But however long it lasts, it should be a real blast.

Bill.

FFOURU

HDB,
I flew a Goldberg cub with floats for a year on a Saito 50. It had plenty of power, would loop and roll, and do everthing that could be expected. I now have a 72 on that airplane, and it is way too much power. I would stay with the 65 if I were you.