Ys 60fs with tuned pipe
10-26-2015, 04:49 AM
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Ys 60fs with tuned pipe
I was recently given a 30? Year old Super Kaos with a ys 60fs and a macs tuned pipe.
i have replaced the bearings and checked the diaphragm everything looks good.
the engine starts easily and runs good with great transition to wot.
My question is regarding the length of the header for the tuned pipe.the header on it is uncut.the engine will come on the pipe intermittently at wot and at different throttle settings.i don't think that this pipe has been tuned.
Macs website gives tuning information for various engines -the header length.
They give the length for a ys 60 pumped rear exhaust a 3 inches.would this measurement be the same for a side exhaust?the header on it now is 61/2
un cut.any help with this would be great.
I have read the tuning guide and would hate to chase the correct setting 1/4 inch at a time
i have replaced the bearings and checked the diaphragm everything looks good.
the engine starts easily and runs good with great transition to wot.
My question is regarding the length of the header for the tuned pipe.the header on it is uncut.the engine will come on the pipe intermittently at wot and at different throttle settings.i don't think that this pipe has been tuned.
Macs website gives tuning information for various engines -the header length.
They give the length for a ys 60 pumped rear exhaust a 3 inches.would this measurement be the same for a side exhaust?the header on it now is 61/2
un cut.any help with this would be great.
I have read the tuning guide and would hate to chase the correct setting 1/4 inch at a time
Last edited by Cbfn1; 10-26-2015 at 04:52 AM.
10-26-2015, 05:26 AM
#2
You may hate it, but it's really the only way to find the optimum set up. I'm getting ready to do it too, so I feel the pain! I'll probably go in 1/2 " increments, leaving a littler extra length in the coupler. My macs header is ~8" long, but I'm going to chop it a bunch before starting. Assuming (a lot...) you're going for max rpms somewhere in the 13-14K range,a reference would be that 11-12k will tune in the 15" range from glow plug to 1st cone, so that's a conservative starting point. The math would say that a 20% rpm increase would tune at 20% shorter than that or about 12". Sneak up on it though..., and if you overshoot, there's always longer silicone couplers!
10-26-2015, 06:12 AM
#3
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Try 14.5" from the plug to the reflector plate in the pipe; measuring around the bend of the header. That should get you pretty close. If you are happy with it at that length then leave or you can go a bit shorter for more performance. 14" is the shortest I ever ran, but I preferred the length a bit longer to make the needle setting less critical. Good Luck!
10-27-2015, 03:18 AM
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Ran the engine with the pipe set at 15 inches.experienced a lot and I mean a lot of on burnt fuel and oil coming out Of the pipe.the high speed needle as set to max rpm.
Is the pipe still to long ? Bad diaphragm gasket? The engine does pressurize the tank very well
1st time running a ys and a pipe starting to feel like a blonde looking in the mirror
Is the pipe still to long ? Bad diaphragm gasket? The engine does pressurize the tank very well
1st time running a ys and a pipe starting to feel like a blonde looking in the mirror
10-27-2015, 08:35 AM
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I'm using an 11/11 prop,os8 plug.
Haven't tacked the engine my tack is out of commission I do have a good ear and the high speed needle is set to Mac rpm. It fluctuates though do to excessive oil and fuel blow by.
Could the pipe length be causing this? Though it was doing it before
I cut the header.
How do I check the diaphragm regulator?
The transition seems to be good
After it blows out excessive oil and fuel..the high speed needle is set to max rpm
Haven't tacked the engine my tack is out of commission I do have a good ear and the high speed needle is set to Mac rpm. It fluctuates though do to excessive oil and fuel blow by.
Could the pipe length be causing this? Though it was doing it before
I cut the header.
How do I check the diaphragm regulator?
The transition seems to be good
After it blows out excessive oil and fuel..the high speed needle is set to max rpm
10-27-2015, 09:17 AM
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If the idle is ~2k rpm and the transition is good, the idle set screw should be fine. The set screw is on the underside of the diaphragm regulator protrusion on the bottom of the engine. Typically, on 60 FS/FR engines, the set screw is flush with the aluminum body.
I would step back the prop, you are likely overloading the engine on the shorter pipe length you have at the moment. Try an APC 11x8.
What fuel are you using? Nitro? Oil?
David
I would step back the prop, you are likely overloading the engine on the shorter pipe length you have at the moment. Try an APC 11x8.
What fuel are you using? Nitro? Oil?
David
Last edited by doxilia; 10-27-2015 at 09:21 AM.
10-27-2015, 10:16 AM
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YS don't require castor and the engine probably is not liking it. I would switch to an all synthetic fuel with 15-20% nitro. There is a typical YS fuel usually referred to as 20/20 (oil/nitro) - buy some of that. Also try a couple of different plugs.
Also, if you're buying props, I'd suggest also picking up an 11x7 and an 11x9 APC and Falcon. Try them out and see which one you like best on the model.
David
Also, if you're buying props, I'd suggest also picking up an 11x7 and an 11x9 APC and Falcon. Try them out and see which one you like best on the model.
David
Last edited by doxilia; 10-27-2015 at 12:14 PM.
10-28-2015, 03:16 AM
#11
If the idle is ~2k rpm and the transition is good, the idle set screw should be fine. The set screw is on the underside of the diaphragm regulator protrusion on the bottom of the engine. Typically, on 60 FS/FR engines, the set screw is flush with the aluminum body.
I would step back the prop, you are likely overloading the engine on the shorter pipe length you have at the moment. Try an APC 11x8.
What fuel are you using? Nitro? Oil?
David
I would step back the prop, you are likely overloading the engine on the shorter pipe length you have at the moment. Try an APC 11x8.
What fuel are you using? Nitro? Oil?
David
The unburnt fuel coming out of the pipe is likely caused by the combination of the wrong pipe length and prop. for that motor. But, just to be sure, I'd check the liner to be sure it's in good shape. It can turn the exhaust black just like bearings going bad. 30 yrs is pretty old!
10-28-2015, 07:20 AM
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No doubt on an 11x11 and a 15" pipe length, the engine is completely out of resonance and is not combusting properly. Besides, this engine is great at 14-15K rpm.
Keep the prop load on the light side (11x8), use the right fuel, tune the pipe length and then if desired try both 11x7 and 11x9 to see which you prefer in the model and flight.
All this of course after making sure the engine is in good internal condition.
David
Keep the prop load on the light side (11x8), use the right fuel, tune the pipe length and then if desired try both 11x7 and 11x9 to see which you prefer in the model and flight.
All this of course after making sure the engine is in good internal condition.
David
10-28-2015, 04:09 PM
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Thanks for the info.
the macs tuned pipe measures 17 inches end to end.
the header measures 4/12 inches from glow plug to end.
the coupler has a gap of 1/12 inches.
Where is the restrict or located?
total lengh of pipe 17 inches
the macs tuned pipe measures 17 inches end to end.
the header measures 4/12 inches from glow plug to end.
the coupler has a gap of 1/12 inches.
Where is the restrict or located?
Last edited by Cbfn1; 10-28-2015 at 04:15 PM.
10-28-2015, 04:34 PM
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Why are there two couplers? You should use one and keep the gap to about 1/8". The second blue coupler appears to be lengthening the exhaust by over an inch! A squeeze like that in the exhaust is not good.
If your header is cut too short, then add alum tubing as you have but use the couplers as such not as pipe lengths. The length of importance is the one Will described. You want to be at ~15" from plug to end of expansion cone around the header on an 11x7 or 11x8 and YS 20/20 fuel and tune from there.
David
If your header is cut too short, then add alum tubing as you have but use the couplers as such not as pipe lengths. The length of importance is the one Will described. You want to be at ~15" from plug to end of expansion cone around the header on an 11x7 or 11x8 and YS 20/20 fuel and tune from there.
David
10-28-2015, 05:39 PM
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The pipe is 17 inches long the header around 4 without added piece.
where is the expansion cone located?
the blue coupler was put back on temporarily to see if excessive
fuel and oil would decrease.
could you tell me where the expansion cone is located.
This is the my first tuned pipe.Im sorry if I'm causing any confusion .
where is the expansion cone located?
the blue coupler was put back on temporarily to see if excessive
fuel and oil would decrease.
could you tell me where the expansion cone is located.
This is the my first tuned pipe.Im sorry if I'm causing any confusion .
Last edited by Cbfn1; 10-28-2015 at 05:50 PM.
10-28-2015, 07:05 PM
#18
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With the apc 11x11 or 11x12 i used to run about 11000 rpm with a hatori pipe and a 15 in length. 10percent nitro red max fuel and a fox idle bar plug. You tune a pipe for an optimum rpm you want to run. Different pitch props will require different length headers. For the 11x8 you probably want to be down around 13-14 inches. Macs can tell you where to measure your pipe from.
10-29-2015, 03:07 AM
#19
...To find the cone, run a dowel or balsa stick into the entrance of the pipe until it hits the cone. It's a 'cone' so try to keep it against the wall of the pipe. Mark the stick, and take it out and lay it on the pipe. That's where the cone is.
10-29-2015, 08:40 AM
#20
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I don't recognize the particular pipe on your model CBN.
There are different pipe types available and they all work in similar fashion.... they all use the exhaust gas fronts or slugs if you will, which are generated at the frequency of the rpm of the engine, to boost the engine's output. They provide the boost through resonance of the exhaust fronts versus distance from the exhaust source, ie- the exhaust port of the engine.
One type of pipe popularized by MACS Products has a diverging cone and converging cone welded together at the large diameter. These often had a short, straight transition segment installed between the two cones. The exhaust gas front exiting the exhaust port at X rpm will resonate in the pipe as first expands in the first (divergent or expanding) cone and reflects off the second (convergent or constricting) cone. We usually used the weld area between the first cone and the transition straight segment to make the referenced measurements discussed by some of the posters. This is usually easy to find on the MACS pipes and Hatori, Webra or other pipes of the day. It's the area where the first cone or diverging cone, ends.
Other pipes use a reflector baffle instead of the second or converging cone, at a point inside the pipe. The reflector position can't be seen from the outside of the pipe typically. We found the reflector baffle (a disc with a hole in the middle welded or glued into the pipe's large diameter) by inserting a dowel into the pipe and running it along the pipe's shell. That length is the important one for measurements. Note that the two types of pipes are using different reference points so the measurements for one will be different than the other type of pipe.
In your pipe, you may insert a dowel following the contour of the shell and "feeling your way down the pipe. If yours has the double cone design, you should be able to tell; it may take a few tries to make sure. As the dowel goes from the first cone to the transition piece, it may be hard to tell. As you move the dowel further entering the converging cone, you should be able to tell easier.
If yours is the baffle design, the dowel will stop when you hit the baffle.
Hopefully that helps you. It isn't magic and we all had to learn in order to use piped set-ups.
There are different pipe types available and they all work in similar fashion.... they all use the exhaust gas fronts or slugs if you will, which are generated at the frequency of the rpm of the engine, to boost the engine's output. They provide the boost through resonance of the exhaust fronts versus distance from the exhaust source, ie- the exhaust port of the engine.
One type of pipe popularized by MACS Products has a diverging cone and converging cone welded together at the large diameter. These often had a short, straight transition segment installed between the two cones. The exhaust gas front exiting the exhaust port at X rpm will resonate in the pipe as first expands in the first (divergent or expanding) cone and reflects off the second (convergent or constricting) cone. We usually used the weld area between the first cone and the transition straight segment to make the referenced measurements discussed by some of the posters. This is usually easy to find on the MACS pipes and Hatori, Webra or other pipes of the day. It's the area where the first cone or diverging cone, ends.
Other pipes use a reflector baffle instead of the second or converging cone, at a point inside the pipe. The reflector position can't be seen from the outside of the pipe typically. We found the reflector baffle (a disc with a hole in the middle welded or glued into the pipe's large diameter) by inserting a dowel into the pipe and running it along the pipe's shell. That length is the important one for measurements. Note that the two types of pipes are using different reference points so the measurements for one will be different than the other type of pipe.
In your pipe, you may insert a dowel following the contour of the shell and "feeling your way down the pipe. If yours has the double cone design, you should be able to tell; it may take a few tries to make sure. As the dowel goes from the first cone to the transition piece, it may be hard to tell. As you move the dowel further entering the converging cone, you should be able to tell easier.
If yours is the baffle design, the dowel will stop when you hit the baffle.
Hopefully that helps you. It isn't magic and we all had to learn in order to use piped set-ups.
10-29-2015, 09:22 AM
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To extend Matt's comments, what is often misleading is the cylindrical shape of pipes aft of the diverging cone stemming from the header/pipe junction. These pipes are often referred to as "muffled" or "quiet" tuned pipes because they consist of a cylindrical outer shell welded about the converging cone at the widest diameter, or aft of the baffle(s) in the case of a pipe with such a design. These sections act as a silencer when the tuned exhaust passes from the converging or baffle exit hole. Because these longish muffled sections don't contribute to the resonance aspect of the pipes function, the length of importance of the pipe can often be hard to assess by simple inspection. In this case Matt's and Tim's system must be used to determine the "resonance length" of the pipe.
A good example to look at are Macs aero pipes since they have three different types: tuned, muffled and quiet. The first, "tuned", is a pure double cone resonance pipe with no muffling ability other than that offered by the virtue of the pipe presence over an open exhaust. These pipes are sometimes referred to as "speed pipes" as they are purely performance oriented. The second "muffled" type is the kind that has a cylindrical aft muffling section and are therefore quieter than the tuned version. The last, "quiet", is a muffled pipe with a longer muffling section and either a baffle in the muffling section or a second stage muffler (i.e., two concentric muffling sections).
In principle, the muffled and quiet versions of the pipes offer most of the performance advantage of a pure tuned pipe while also offering substantially quiter operation. Muffled pipes are sometimes used on sport models while the longer quiet pipes are often used in 2-stroke engine pattern designs like the classics discussed in this forum.
The pipe images below might help to better understand the comments.
David
A good example to look at are Macs aero pipes since they have three different types: tuned, muffled and quiet. The first, "tuned", is a pure double cone resonance pipe with no muffling ability other than that offered by the virtue of the pipe presence over an open exhaust. These pipes are sometimes referred to as "speed pipes" as they are purely performance oriented. The second "muffled" type is the kind that has a cylindrical aft muffling section and are therefore quieter than the tuned version. The last, "quiet", is a muffled pipe with a longer muffling section and either a baffle in the muffling section or a second stage muffler (i.e., two concentric muffling sections).
In principle, the muffled and quiet versions of the pipes offer most of the performance advantage of a pure tuned pipe while also offering substantially quiter operation. Muffled pipes are sometimes used on sport models while the longer quiet pipes are often used in 2-stroke engine pattern designs like the classics discussed in this forum.
The pipe images below might help to better understand the comments.
David
Last edited by doxilia; 10-31-2015 at 11:33 AM.
10-31-2015, 05:03 AM
#22
This is a pic of Robert's pipe, and the one I also have. I am using a Macs 15deg. header though. Notice how short the header is!? This pipe is the one I referred to as having a baffle at 13" from the inlet; quite long! I'm going to examine a little closer before cutting again, based on the input above, but I'm still 2-3" longer than Robert's set up here, and shooting for the same rpm/engine/pipe/prop combination. 14000rpm's on an 11x9 will carry any classic design around well. Even at 13600, the Brushfire I saw fly last weekend had a great hookup; nearly the same speed through maneuvers at ~8.5lbs.
11-01-2015, 11:01 AM
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I took the pipe off the plane today.looked inside and it has what looks to be a washer welded or glued 9 inches back from the front of the pipe.looking through the washer I can see one more with an offset hole around 4inches further back.
I want to measure to the first washer or baffle that is at 9 inches right?
I cannot see through the pipe.
Im waiting for the 11/7 and 11/8 props to arrive.
I want to measure to the first washer or baffle that is at 9 inches right?
I cannot see through the pipe.
Im waiting for the 11/7 and 11/8 props to arrive.