doxilia

My Feedback: (3)

Does anyone have any idea how well a 4 stroke OS FS48 or a YS FZ53 would respond to a tuned pipe?

If it makes sense, what would the source and required type of Hatori pipe?

I know that "tuned mufflers" are used on YS 4-strokes in F3A and I've seen Rusty put one on his YS FZ63 on a Zlin.

David.

AllTheGoodNamesAreTaken

My Feedback: (180)

I was always under the assumption that a tuned pipe only works for two strokes. The tuned pipe helps the engine run more efficiently by using sound (or pressure) waves to prevent intake mixture from being sucked through the engine un-burnt by the low pressure of the exhaust pulse. A four stroke could never take advantage of that system. A "tuned exhaust" must be a low loss muffler?

rcpattern

My Feedback: (45)

It is essentially a low loss muffler, and also a much better silencer than standard 4 stroke mufflers. They are primarily to keep the noise down. They also give a much deeper/throaty sound when running,

Arch

KrisG

I use tuned pipes on my 4-strokes, but only to lower the noise. I use a .60 pipe on a .91 or .120 4-stroke, and you can hardly hear them in flight. No real performance gain to be expected ( except it is a low-counterpressure muffler) as there is not this standing wave supercharge effect.

Kris

Prairie Mike

David,
check your PM's

doxilia

My Feedback: (3)

Thanks for the info guys.

Does Hatori make 4-stroke "tuned mufflers" for the smaller engines I have in mind (OS 40-48 & YS 53-63's)? If so, what are the model numbers?

Kris, I've come across an older Hatori tuned pipe which is designated to go with 120 size 4-strokes. The pipe is about 8-10" long and looks just about right for a 10-12 sized 2-stroke! When I saw it I immediately thought of using it on a Webra 12 that I have but now I'm wondering what performance loss and/or noise silencing effect it would have on a 48-53 size 4-stroke. I guess I should go to my LHS and pick up that rare little pipe.

David.

doxilia

My Feedback: (3)

Mike,

PM replied.

David.

doxilia

My Feedback: (3)

Alright,

according to this page:

http://www.tokyo-hobbies.com/hatoriair.html

Hatori used to make a #530 muffler and #577/588 flexible connecting pipes. One is references as "inside" the other as "outside". Not sure what the difference is.

I read in another thread that Central was apparently selling Macs 1020 (25-32 2-stroke) quiet tuned pipes for use with the YS FZ 53/63's [X(]

I wonder how the YS 53 would do on a 32 sized Hatori #300 tuned pipe?

David.

rcpattern

My Feedback: (45)

David,

As long as the volume is equal or greater, it would be fine. You wouldn't gain any power from it, but it wouldn't be robbing any either.

Arch

doxilia

My Feedback: (3)

Arch,

Provided they are not too restrictive, it sounds like putting cans of just about any sort doesn't really affect 4-strokes one way or another other than for noise.

What about those hose couplers? Is there any magic to using the right kind on these motors? The flexible kind sound like you can route them more or less where you want but I see that there are also some solid ones made for the same application.

I'm basically thinking of an inverted installation of an FZ53 with a wrap around "header" which would mate to the pipe/muffler in the center bottom of the fuse - much like it would be done with a 170DZ on an F3A model. Would prefer to keep it light so not sure whether the muffler would be preferable to a smaller pipe.

David.

rcpattern

My Feedback: (45)

David,

The only reason I can think of to run a "can" type muffler/pipe is for noise a 4-stroke. I have never been a huge fan of the flexible ones as they will break over time. I also know that they will last longer if the motor isn't soft mounted. One issue we ran into with the larger 4-strokes was that as we went to softer and softer mounts to compensate for the vibration that we broke more headers. This is when we started to see the more rigid headers and the pipe immediately behind the motor. This arrangement worked great and was basically bulletproof.

Most of the purpose built mufflers are very light, so I don't think you'd have an issue running either.

Arch

Roary m

My Feedback: (67)

Tuned exhaust works for multi cylinder four strokes (headers). The individual exhaust pipes meet into a collector pipe/can and as the exhaust charge hits the collector pipe, it creates a vacuum in the other individual pipes, scavenging for the next exhaust valve to open.

doxilia

My Feedback: (3)

Wanted to thank everyone for their input.

Also, can anyone tell me what size fuel tank is needed on a YS 110/115? 12 oz ok?

David.

petec

My Feedback: (58)

David, for a 1.10 or 1.15 you are looking in the neighborhood of 1.25-1.75 oz. per minute of fuel consumption. Tha's a wide swing that depends on airframe drag and how much time you spend at WOT.

doxilia

My Feedback: (3)

Pete,

thanks for the reply. So if I average that to 1.5 oz/min, a 15 oz tank would give me a 10 min flight? The fuse is draggy but the plane would be flown in typical pattern style so probably 2/3 throttle on average I'd imagine (don't know, never flown a modern pattern plane).

What is the size tank that is put in the typical 110 size pattern plane (the F3A trainers if you will)?

David.

petec

My Feedback: (58)

I really don't know what the "norm" is but 12 oz will give you about 8 minutes and with the YS you can put the tank right on the CG so your trim won't change during the flight as fuel is consumed. If you have the room in the plane 16oz will give 8 minutes flying like you stole it.

doxilia

My Feedback: (3)

I like that - fly like heck!

I guess up it goes from 12 to 16 - its not that much larger.

David.