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Author Topic: PIPE Chart List Setup  (Read 8891 times)

Offline Ted Fancher

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PIPE Chart List Setup
« on: April 08, 2013, 06:08:42 PM »
Randy,

Am I just getting more advanced  Old Timers or did I really used to find that terrific chart of engine types and RPM and Pipe tuning length real easily.  I've been looking for it the last couple of days on your fora and the Aero Products web site and can't find it.     Was I really imagining it??   Where'd it go????

Ted

Don't tell me you've ditched pipes for batteries!  The wussification of America gets closer every day.  Real men have at least one once bloody digit and impaired hearing.
« Last Edit: June 28, 2015, 10:48:53 PM by RandySmith »


Online RandySmith

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Re: What happened to...?
« Reply #1 on: April 08, 2013, 06:14:37 PM »
Hi Ted

Nope  I am still making smoke the old fashion way :-)

I will send you the chart, I am not sure the post will work here, if so I will post it

Randy



             PIPE     TUNING        CHART by   Randy Smith         
                        
   MEASURE taken    from  the   GLO-      PLUG  to  FIRST   BAFFLE                        
   FOR THE P.A. 40 - 61 ENGINES and many others, see timing chart                     
   A Good PIPE Starting Point         16 3\4to 17.5 inches      PROPS 11,5 FOR THE 40,12 FOR THE 51      
   12.5 to 13 INCHES FOR THE 61 3.8 TO 4 PITCH  10,500-11,200 RPMs   For the 61 @      3.8 PITCH    10,500 -11,200 RPM         
   IF  IT IS  TOO HOT OR COMES ON TOO STRONG  MOVE  OUT  toward 17.5  INCHES                     
                        
   IF PLANE SPEEDS UP DURING THE FLIGHT MOVE PIPE OUT ,                     
   IF PLANE SLOWS DOWN DURING FLIGHT MOVE PIPE IN SHORTER                     
best props pipe combo lenghts                        
40   bolly 11.75 x 4.25  cut to 11.3-11.5 inches         pipe 16.75            
51   bolly 12 x 4.25 3 blade as is     bolly 12.2 x 4.2 2 b;ade as is               pipe 17 in to 17.25      
61   12x 4.25 3 blade  13 x 4.5 3 blade  cut to 12.5   or  13 x 4.5  2 blade  as is                  pipe 17 to 17.5   
65   bolly 13 x 4.5 3 blade or  13.75 x 4.5  3 blade            pipe 17.25 to 18         
75   bolly 13 3\4 and 14 inch 3 blades 4to 4 3\4 pitch Bolly 14 to15x 4.5 2 blade            pipe  18 to 19.5         
                        
   Do NOT flip motor over dry or without oil and fuel going thru them                     
« Last Edit: April 08, 2013, 09:55:43 PM by RandySmith »

Offline Timothy Payne

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Re: What happened to...? PIPE Chart List Setup
« Reply #2 on: October 29, 2013, 10:31:54 PM »
There's a book called Two-Stroke Performance Tuning by A. Graham Bell.

Tells you everything you need to know about tuning strokers including expansion chamber dimensions.

Walter Kaaden was the man behind the theory of tuning a two stroke in this way, and during his time with the MZ racers of the sixties, they were the first to break the 100bhp per litre stat with their unbeatable 250s.

A brilliant engineer, and father of the modern two stroke,


Tim

Offline Rob Duckering

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Re: What happened to...? PIPE Chart List Setup
« Reply #3 on: January 09, 2014, 11:55:57 AM »
If you follow Randy's chart, you will have the best engine run.
I remember when I was flying an SV-22 (in my avatar) with a PA 65 and someone remarked it sure has the "perfect stunt engine run", I just mentioned at the time, 'I just did what Randy said in the chart'
Pretty simple actually, kinda like reading the directions instead of trying to re-invent the wheel.
Duck

steven yampolsky

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Re: What happened to...? PIPE Chart List Setup
« Reply #4 on: April 10, 2014, 07:57:22 AM »
If you follow Randy's chart, you will have the best engine run.
I remember when I was flying an SV-22 (in my avatar) with a PA 65 and someone remarked it sure has the "perfect stunt engine run", I just mentioned at the time, 'I just did what Randy said in the chart'
Pretty simple actually, kinda like reading the directions instead of trying to re-invent the wheel.

The only problem is figuring out exhaust timing of a OS 40VF  LL~

Offline Rob Duckering

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Re: What happened to...? PIPE Chart List Setup
« Reply #5 on: May 20, 2014, 01:46:42 PM »
The only problem is figuring out exhaust timing of a OS 40VF  LL~


Actually, the 40VF is on the chart with higher timing than the PA. Use 140-145 degree's and pipe accordingly as per the chart from Randy.
My first PA ship was a magnum winged SV fuselage airframe with an OS 46VF and a Randy pipe set at 18.5" with a launch rpm of 10K. Worked great with no geusswork at all.
Duck

Offline Steve Helmick

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Re: What happened to...? PIPE Chart List Setup
« Reply #6 on: June 18, 2014, 09:16:47 PM »
That's one of the things that has confused me...is the .40VF higher exhaust than the .46VF or lower? Is there more difference between intake and exhaust timing on the .46? They have a rep for being a bit more, uh, 'rambunctious'.
My .46VF is at 18.75", but it's also an AAC...and I don't know if the timing is same as stock .46VF or if it's per the .40VF that so many prefer. I'm launching at 10,450 to 10,500.  Randy?   ??? Steve
In 1944 18-20 year old's stormed beaches, and parachuted behind enemy lines to almost certain death.

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Online RandySmith

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Re: What happened to...? PIPE Chart List Setup
« Reply #7 on: June 18, 2014, 10:03:44 PM »
That's one of the things that has confused me...is the .40VF higher exhaust than the .46VF or lower? Is there more difference between intake and exhaust timing on the .46? They have a rep for being a bit more, uh, 'rambunctious'.
My .46VF is at 18.75", but it's also an AAC...and I don't know if the timing is same as stock .46VF or if it's per the .40VF that so many prefer. I'm launching at 10,450 to 10,500.  Randy?   ??? Steve

Steve  the motors are very close to the same, as long as you are talking the milder timed ones in both 40 and 46, some people have used the higher timed sleeves, Use the 145 list and you will be very close, the 40 VF normally will use a shorter pipe length, than the 46 because the 46 normally will use a larger diameter prop or a 3 blade, ...ie  we used a 12 x 4.5 3 blade, and a 12.25 x 4.25 2 blade with the 46VF,  and  a 11 1/2 x 4 on the  40 in a 2 blade.  The RPM of the 40 was close to 11,100 ,  and the 46 was in the mid 10,000 RPM range.  18.5 length for the 46 and 17 3/4 . They will  vary  but this is close

Randy

Offline Mark Weiss

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Re: PIPE Chart List Setup
« Reply #8 on: July 02, 2015, 07:37:29 PM »
Randy,
I am new to tuned pipes. I just got a Katana with a PA 61 and CF pipe. If my measurements are right, the pipe is 16 and 1/2" from the needle to the wider baffle dimension. I have a very accurate tach as well as your great chart. The PA is running a 12" 3 bladed prop. Here is my question. When run below 11,000, the smoke trail is blue and the engine runs only 5 minutes on the 6 oz tank. With higher rpm, 11,300 the running time of course increases but the smoke trail is now white and the motor is pretty hot. On a pipe, does the motor basically run a strong run or is it expected to do a 2/4 break? I am using 25% oil, 11% synthetic and 14% castor and 10% nitro. Your recommendations please.

Thank you
Mark Weiss

Online RandySmith

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Re: PIPE Chart List Setup
« Reply #9 on: July 02, 2015, 08:23:55 PM »
Randy,
I am new to tuned pipes. I just got a Katana with a PA 61 and CF pipe. If my measurements are right, the pipe is 16 and 1/2" from the needle to the wider baffle dimension. I have a very accurate tach as well as your great chart. The PA is running a 12" 3 bladed prop. Here is my question. When run below 11,000, the smoke trail is blue and the engine runs only 5 minutes on the 6 oz tank. With higher rpm, 11,300 the running time of course increases but the smoke trail is now white and the motor is pretty hot. On a pipe, does the motor basically run a strong run or is it expected to do a 2/4 break? I am using 25% oil, 11% synthetic and 14% castor and 10% nitro. Your recommendations please.

Thank you
Mark Weiss

Hi Mark

you are doing something very differant, and much higher RPMs than most use with a 61, yours is more like a 49 setup.
I would reset it all, set pipe from the center of the chamber..or the glow plug, to the first baffle in the pipe at 17.3/4 inch
Use the prop pitched at 4.3 to 4.5 inches
Launch RPM will be near the 10,000 range, much power than your using.
You should set the needle at the fastest 4 stoke it will run in, then turn it in untill it is bouncing from 4/2

The fuel should be 20% oil, not 25, and  should be mostly synthetic oil. 10% nitro is OK
this should  yield  about a 5.25  lap and should cycle slightly up and downhill

let me know  what you think

Randy

Offline Mark Weiss

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Re: PIPE Chart List Setup
« Reply #10 on: July 06, 2015, 06:19:15 PM »
Thank you Randy. As soon as I get out flying again, I will make the changes and let you know. Very kind of you to take the time and reply. Much appreciated.
Mark

Offline Ted Fancher

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Re: PIPE Chart List Setup
« Reply #11 on: August 26, 2016, 05:49:25 PM »
Randy,

Just noted I never said thanks for reposting the charts.  Thanks! #^ #^

Ted


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