Canisters or Tuned Pipes??

[forgues research]

Why bother with pipes, just get the proper engine , no messing with tricky tuning.

Roger

[forgues research]

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[KrisW]

	Quote: Originally Posted by forgues research
	Why bother with pipes, just get the proper engine , no messing with tricky tuning. Roger

Please define "proper engine". . . . the loud one, the quiet one, the heavy one, the light one, the more powerful one, the one with better midrange. . the cheaper or more expensive one . . .

[forgues research]

	Quote: Originally Posted by KrisW
	Please define "proper engine". . . . the loud one, the quiet one, the heavy one, the light one, the more powerful one, the one with better midrange. . the cheaper or more expensive one . . .

Kris, we are talking power here, so the proper engine would be one that you don't need a tune pipe, simple isn't it

Roger

[KrisW]

	Quote: Originally Posted by forgues research
	Kris, we are talking power here, so the proper engine would be one that you don't need a tune pipe, simple isn't it Roger

Well. . . .not really. it depends on how much power you think is adequate. . Imagine a 3W 240 on the nose of a 35% yak. POWER. . . and a touch nose heavy, eh?

Then, Imagine an IMAC event, where you march up with your 3W170 powered 40% plane, on diverters, and they ground you. . .hmmmmmmm. . for the same money you could have a used 150 with pipes in it and be making more power for only a few more ounces of weight. . .

Actually, truth be known, a smaller engine, on pipes, that saves you 3-4 lbs over a bigger engine on diverters, makes for a better flying plane. Yuri Higuchi told me that my BME115 powered MX-2, with Pipes, flew better overall than another MX-2 with a DA-150/diverters in it. . about the same speed and power-weight ratio (being 4 lbs, or 15%, lighter helps) more precise flying, lower speeds before stall, overall better performance. . . .

So. . . it's not always a bigger, or louder engine that is necessary. . sometimes pipes make all the difference in the world. . .and a better flying plane on top of it.

[icicles]

I had a Comp ARf 260 ( with had being the operative word) with a 3W85 CS running a K & S 1090 tuned pipe. I was running a 28x10 Mejzlik prop at 6900rpm on the ground (yes i know it sounds too high, but it was verified with three different tacho's) This was with 32:1 running in fuel and a day temperature of 38 degrees celcius

Well the performance of this thing was unbelievable. If you compare my total weight with respect to the DA, 3W twins etc i was miles in front. One less header one less cylinder one less pipe. Yes i agree a DA 85 would have been lighter, but i would have had problems with the C of G. The 3W actually helped me there.

If you are prepared to play with tuned pipes they can be very rewarding. They are also quieter to boot. Heck, i reckon i nearly spent 30-40 flights getting it right. But when i got it, it was awesome. I even embarrassed a few twins. I was turning that prop at the same rpm as a mates 3W 106 on twin K & S 1060's.

Chris

[dick hanson]

completely believeable to me - some others will deny it is even remotely possible - but then - they never even tried it!

[icicles]

People don't believe me when i tell them the power i was getting.

I believe the results are there for the taking if you are prepared to spend the time. You can't bolt a pipe on and expect it to work. Okay it will, K & S give you a great starting point. Then it's just a matter of reading, learning what your engine needs.

I won't lie, my 3W 85CS was an absolute pig when i first ran it. At full power in level flight it was rich, pull vertical it was perfect. No amount of tuning, needle fiddling will fix that. I could have been lazy and bolted on a canister, but heck i'm greedy i like my horsepower. I get a lot of satisfaction when my motors are tuned properly.

I used to fly an OS 160FX in F3A with a tuned pipe setup. Again that motor took a lot of work to make work properly. That motor is the smoothest best running two stoke i have ever owned

[swheaton]

	Quote: Originally Posted by dick hanson
	completely believeable to me - some others will deny it is even remotely possible - but then - they never even tried it!

[KrisW]

	Quote: Originally Posted by icicles
	I had a Comp ARf 260 ( with had being the operative word) with a 3W85 CS running a K & S 1090 tuned pipe. I was running a 28x10 Mejzlik prop at 6900rpm on the ground (yes i know it sounds too high, but it was verified with three different tacho's) This was with 32:1 running in fuel and a day temperature of 38 degrees celcius Well the performance of this thing was unbelievable. If you compare my total weight with respect to the DA, 3W twins etc i was miles in front. One less header one less cylinder one less pipe. Yes i agree a DA 85 would have been lighter, but i would have had problems with the C of G. The 3W actually helped me there. If you are prepared to play with tuned pipes they can be very rewarding. They are also quieter to boot. Heck, i reckon i nearly spent 30-40 flights getting it right. But when i got it, it was awesome. I even embarrassed a few twins. I was turning that prop at the same rpm as a mates 3W 106 on twin K & S 1060's. Chris

There's no reason to doubt the numbers. . .here's why:

1) a single cylinder engine, with equal porting efficiency and intake sizing per CC, is 10-15% MORE efficient than a twin. that right there makes your 85 the equivalent, all things considered, of most 100's on the market.

2) Tuned pipes can increase peak scavenging as much as 30% when tuned properly, resulting in an additional 10-15% power at the top. . so that's what. . another 1-1.5 horsepower? Suddenly your 8 hP 85 is right there with the BME110/115's and 3W 106's on canisters, and far ahead of the DA-100's, all because you took the time to add a pipe setup.

3) concerning weight ..a single pipe will add about a pound over a single diverter, so your 4.5 lbs 85 still weighs LESS than a DA-100 or 3W 106. .by about 1-1.5 lbs. . lighter, equivalent power=better performance.

For the same weight of powerplant, about the only thing that is going to be at the top of the pecking order, over the piped 80's and 85's, is a piped BME115, since it actually starts out weighing less than the 80-85cc singles. Tests have shown the 115 to be 3-400 rpm stronger (or more)than the 6900 rpm you quoted with the MEj 28-10, when using pipes. I've personally seen the high side of 7250, hot, on KS-1060's, after landing. The DA and 3W twin guys are sighing in relief that the 115 is no longer being produced. . .


The ONLY problem when quoting RPM numbers, is that people do not tell you they are running tuned pipes, and that they spent a month or so dialing in the setup to get those peak rpm numbers. That gives for an instant credibility check .. because people know a stock engine just will not do it, and then everyone distrusts you after that because that one time you didn't 'fess up and give all the information. Repeatedly doing that gives you a severe black mark concerning people trusting what you say on the subject for a long time to come. It's like. . you did it once, and many more times, how can we believe you?? But when people openly list what they've done, the credibility factor gets very good, and people understand what happened and are glad for the information.

So, yeah, it's easy to accept a 3W 85 on a pipe turning numbers like that. Good job getting the power out of the engine!!!

[dick hanson]

It is now officially --a fact -----------

[forgues research]

Well if Dick Hanson and Kris Welter gangs up on tune pipes, I guess I'm sold


Roger