I'm sure the two different crank designs would have advantages for different power need characteristics.
there is a lot to like about this type of motor. Less pipes, lighter crank, less vibration 2 carbs. As far as power pulses, the Harleys do well "from what they say" from the power pulses being close together, giving the tire some "rest" to grab traction. This configuration would do the same, and have a lot of torque, just think of a big 2 stroke 500 and the massive torque, but the reving capability of a 125! And that might work well on an outboard pulling a hard prop. I am betting Kay's race bike had the crank type in the video, I don't think the tires of the time could handle the "4 fire".
If I had the means, I really would like to design a motor like this, with late model 125 cylinders, that would be pretty darn cool!
Are you going to dyno the same bike with stock pipes to compare with the 3 into 1 results? That's what I'd be interested in seeing.
Yes it would. Dyno time is getting expensive and harder to schedule with spring approaching. Racer and Harley owners are all competing for time on the same dyno which isn't helping me. We have one pipe to test now and another later and who knows after that.
ja-moo wrote:This configuration would do the same, and have a lot of torque, just think of a big 2 stroke 500 and the massive torque, but the reving capability of a 125!
It shouldn't make any difference in torque by firing all at once. Torque is literally a direct result of the cranks moment arm length. If you decrease a big single's stroke and increase the bore, you'll lose low end torque. In a multi, the total power produced at any RPM is the sum of it's combined cylinders regardless of firing order. You may double the torque at one interval but you're taking it away from the other. If it were that simple, there wouldn't be all those complex ways devised to broaden the powerband.
ja-moo wrote:This configuration would do the same, and have a lot of torque, just think of a big 2 stroke 500 and the massive torque, but the reving capability of a 125!
It shouldn't make any difference in torque by firing all at once. Torque is literally a direct result of the cranks moment arm length. If you decrease a big single's stroke and increase the bore, you'll lose low end torque. In a multi, the total power produced at any RPM is the sum of it's combined cylinders regardless of firing order. You may double the torque at one interval but you're taking it away from the other. If it were that simple, there wouldn't be all those complex ways devised to broaden the powerband.
My description was not totally accurate, I was just trying to get a point across. The desigon allows all 4 cylinders to fire at once, "big big bang motor?" without the balance problems of a V or straight 4. Plus the advantage of less complexity. The torque may remain the same, but makes a big difference in "delivery". thought the 2 2 arrangement might be better for road use.......
ja-moo wrote:The torque may remain the same, but makes a big difference in "delivery". thought the 2 2 arrangement might be better for road use.......
I believe it's solely in the power delivery that also explains why 3 into 1s seem to work on snow and especially water. They can "slip" thru any RPM range without notice. With the positive traction of a bike, you can easily detect flat spots.
ja-moo wrote:The torque may remain the same, but makes a big difference in "delivery". thought the 2 2 arrangement might be better for road use.......
I believe it's solely in the power delivery that also explains why 3 into 1s seem to work on snow and especially water. They can "slip" thru any RPM range without notice. With the positive traction of a bike, you can easily detect flat spots.
I totally agree, I call it soft or hard "traction". Even with a 3 into 1 or a 3 into 3, it's easier to tune for a certain RPM specific pipe and not have to worry about dips and peaks as as you said, would show with hard traction.
8,500 IS low for an RZ. Ignition retards at around 10,500 (depends on the year and market) and mine with Spec11 pipes starts to come on strong at &,000 and is singing from 8.5 to 10.5.
tz375 wrote:8,500 IS low for an RZ. Ignition retards at around 10,500 (depends on the year and market) and mine with Spec11 pipes starts to come on strong at &,000 and is singing from 8.5 to 10.5.
Took the RZ out for a fang last night. Well more of a slow ride but boy does riding a bike wake you up - especially when it's night and cold...
Back to that RZ. The thing is doesn't sound very responsive on the dyno but that could be any number of reasons. The pipe is really interesting - check his other videos. I'd like to see the dyno chart on that one.
The thread is here http://www.rzrd500.com/phpBB2/viewtopic ... sc&start=0" onclick="window.open(this.href);return false;
Appears they decided to stop work after a promising start. More HP at 5500 and 6000 and peaks at 8k and then nothing. All done.
The interesting thing to me was A that he tried it and B that someone ran the sims in EngMod2T. Sims suggested it would run hard to 10k and looks like reality was that it hit a wall. Why does that sound familiar????
And that's a twin, that would work better than a triple as the opposite port would be closed. A ton of work on that one..........
That's one reason I get a kick out of guys buying a 20 dollar pipe program thinking they are going to make a killer pipe. Even with a lot of work on good programs with guys that know their stuff, real world kickes em in the balls........sometimes........
I think that sometimes, the results you get from the finished pipe can be used to fine tune or "calibrate" the program rather than the other way around.
That's true. Our tests even on single pipes are not always close to the simulations, so I have to go back and understand why and use that to fine tune the next time.
For a twin, he should have been able to get it closer, but the design appears to me to be all wrong. A single pipe has a volume 15-20 times the cylinder it works on, but if you have a huge pipe with that much volume for all three, the waves are just lost in a huge empty cavern.
Specifically I'd speculate that the header taper is too much and the collector creates a problem. That one is far too large and disruptive of flow and sound waves. From a gas flow perspective collector outlet on a 3 into 1 should be somewhere around 50-70% increase over a single pipe and that appears to be larger than both pipes. From a wave perspective it needs not to "look" like a change in section at all, so it needs to be a merge collector. My guess is that they tried to use the same cone angles as a single pipe on that pipe but starting from a larger base of teh collector, so they just compounded the error.
Look at Sled pipes 2 into 1 versus singles. They appear to be slightly larger but not by a lot and the tail pipe is only slightly larger as a rule.
At least that's how it looks to me from a distance without talking to the OP.
i see in the video that the konig engine has megaphone pipes on it. makes alot of noise and how do they work. I have an old 1980 rd 350 motor if anyone interested.
