Hello Mike Wiz

I had a Kawasaki 100 when I got in to drit biking way back when. As I remember it din't have much power at all. ( had fresh top end done when I received the bike ). Next bike was a Yamaha 360 with reed valve and man that thing felt like it could climb a telephone pole with no problem !

Oh man, Don't look now I think we are off topic.


Doug

Also off the mark--stomper!
If you had a good Kow 100 -you would have noted it was very good as compared against other 100 cc stuff.
I had Hodaka -which was good - but nat as good.
as for Mike - Save your money-
If your 80 single is simply broken in properly - with even th downspout muffler -you will fing the power in the same ballpark as the 100's - with a pipe that tunes - It is VERY close.
and beats some of them.
This in not just my two bits worth - and for power to weight - or power to cost - well -- .
If you get cold feet tho and your budddies convince you that is is a bad choice - put it up for sale.
Should take ---- 1/2 hour?

Sorry Dick. While it was easy for me to unload the Hitec digital servos (peace of mind issue for me) you'd have a hard time prying that ZDZ 80 outa my hands. I really want to give that engine a try! I suspect I'll be very happy with it. Still, I'd like to compare things on my own

Just for the record, there is nobody back channel trying to get me to switch.

Oh and there is a picture and a few paragraphs about the '74 Hodaka Super Combat in that MXA issue as well. If you were into dirt bikes in the last 3 or 4 of decades this issue is a real treat....lots of old bikes....lots of memories. :-)

Wiz

Don't get me going on Kawasaki, I was a dealer for 5 years in the '70s. I still have a softspot in my heart for them, but my last bike was a Honda CBR929RR, so I guess I'm not too brand loyal, as I've stated about these R/C engines. I've been accused of being brand-blind with the Taurus, but it just isn't true, I buy what I think is the best at the time for the application I need it for.

Wiz wrote:

>>Oh and there is a picture and a few paragraphs about the '74 Hodaka Super Combat in that MXA issue as well. If you were into dirt bikes in the last 3 or 4 of decades this issue is a real treat....lots of old bikes....lots of memories. :-)

My first bike was a Hodaka 90 in 1965. I think it was one of the first years it came out. It kicked everyone's rear in that class at the time. I loved the big chrome tank. I wish I had a restored one right now.

Now that wasn't off topic was it.

Dick: You are right about the reed spitting back into fuse, but maybe a veocity stack or a simple air plenum could take care of that. I like the idea of the rotor valve, but it seems like the close fit they have would wear out and the performance may be lost. How long do these rear rotors last?? As far as tunned pipes go how many rc ,ers use them on gas. It is more$$ and weight. Biggest problem is how to fit one on/or in plane. Cap,n John

Tuned pipes -or silent cans- most of the guys here use em- seriously -
However - we encourage others to reduce noise - nicely-
it is easy - they see the setup -it is easy to do and it works ---very well.
I have met engines I hated
#1 -460 Fords-
#2 460 Fords-
Early Enyas
Abitar "four cycle"
#5 460 Fords.

Dick: Do you have any pictures you can show of these setups you are talking about? Thanks Captin john

My web site -address on my profile here

Well DICK,with youre vast knowledge and endless experience with tuned exhaust systems,you might let the rest of the rc world in on youre methods and requirements to tune any engine,with out modifying the airframe,possibly keeping the the system in cowl,not having to buy a lathe and mig welder,keeping the power band somewhere below the rev limiter, and intact after the third flight,with my wife not banning me from the credit card.I realize every engine, no matter what type of fuel induction sytsem utilized will require different methods and set ups for peak performance and powerband ranges.Maybe JETT ENGINEERING will build a universal in cowl that will increase power and mid range for gassers?It still appears that TAURUS is an engine that would not require another loan to "tune it in" so I can go flying. I've spent enough years in the garage tweaking the exh. systems on cars and dirt bikes. I'm ready for a install that does not require finding the power band with a one of a kind pipe.

Looks like you have your head made up.
I hope you enjoy your engine.
However - proper pipe setups are not peaky - Not at all.

More coals on the fire. The ZDZ-40 is a 3-port motor, the ZDZ-80 is a 6-port motor. Which one do you think would show the best HP/weight potential? A rotary valve or a reed valve engine both have good potential for top end horsepower, but we really don't need power at very high rpm for airplane motors. One of the problems that some reed valve motors have is puddling of the mixture in the crankcase. I have heard people claim that the midrange gurgling of some of the 3W twins (like the 3W-100) is caused by fuel collecting and puddling in the reed cage. I don't know if that's true or not. I do know that 3W did some redesign of their new 150-SS to smooth out the midrange. Apparently, they changed the forward cylinder (left for right) to get less puddling. Reed valves dominate motocross engines (except for the Yamaha 4-bangers) because they need a fat torque curve to accelerate in the dirt. That's also the reason they use exhaust powervalves, to lower the exhaust duration at low rpm and fatten the low rpm torque curve. Since we don't fly our planes in the dirt, we really don't need a fat torque curve at 3,000 rpm, so a powervalve would only add extra weight. For GP roadracing, both Yamaha and Suzuki flirted with rotary valves over the years. Some years they used rotaries, some years they used reeds. Both have potential, but the devil is in the details. In the last couple of years, they started to detune the motors to be easier on the tires. That's why Honda went to the 3-cylinder bikes. Max HP wasn't their goal, but a fast lap time for the whole race was.

The first engine I hopped up was a Kawasaki Bighorn 350. Kaw had a kit that included a big carb, longer duration rotary valve, and a tuned pipe. Hmmm. same as it ever was.

I think we (me and thee) have jumped way off the "Taurus price list" topic .
But I sure like sharing info on making engines run--tho obviously some see it as something else.
Maybe we better re thread the machine, (rimshot)
under giant engines -

Dick Hansen: I must say you sure made a wonderfull webbsite that really shows what you are talking about. I enjoyed reading about and looking at all the nice setups that can be done. I am sure I am going back and study everthing you have done. Now I am getting a definte engine & plane with ,yes a good tuned exhaust in mind to get or build. I sure wished I lived near by, to see these planes fly and hear the engines hum. WoW!! Best site I have see on the webb. You are modest for not letting everyone know about your webbsite. Thanks very much. It is a privilege for sure.. Best Regards John

Thank you - If you can use any pics/info - feel free to do so.

Holly Kaw, been gone a few days and you guys are still beating a dead horse, tuned pipes,cantilever cranks, motorcycles, can't wait tosee you do outboards next. like an old Mercury 25 with a Quick-Silver lower unit and a 9-1/2 X 10 prop turning 9K. didn't have no cantilever crank in it tho.

Beating a dead horse?!? All I see is the natural progression of a discussion. Personally, I have enjoyed every bit of it and have learned a few things along the way.

Wiz

I'm with you 100% Wiz. This has been quite informative and interesting for me.

hey DICKH I want to apologize for the gruff remarks.if you enjoy researching and designing tuned exhaust systems,then more power to you.It's people like you that keep the hobby growing. In fact if it wasn't for your info on the ST2300 system I probably wouldn't have put that rocket in my CG SUKHOI.
I geuss what eerks me is the fact if your not running what other people think you should be using then youre not up to there standards. Then again if we didn't feel so strong about what we are useing we probably would'nt be saying anything at all. Thanks for everyones input.
still gonna get a taurus.......... lol

to Mike Wiz.
& bpryor

the dead horse bit was because of the 3pc. vs 5pc.vs cantilever crank etc. mine is better than yours and on and on. needless to say I am all for technical information. It just seemed as though it was getting too long in the tooth. sorry if i stepped out of line.

have fun that is important, bye