marcusgunby
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- Jan 9, 2000
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Dyno for cujet
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marcusgunby
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If people think a cr500 is hard to hold onto imagine that ktm big bore-the power goes vertical in 10mph it goes up 40hp!!!!
marcus,
Looking at that 612 graph, it looks to me that either the cam timing is wrong, or it has too much compression, if i was to guess, i would say it had lobe centres in the region of 115 and betwwen 95 and 100 you should try 108/109 you will gain a whole lot more top end and loose nothing thru the middle, i think you will find that 12.5:1 is about the most you want to go on the comp , as temp is the main killer on these engines in sidecars anyway. from all the testing i have done in the past , that 612 enginge should be up around the 65 hp at the rear wheel
Looking at that 612 graph, it looks to me that either the cam timing is wrong, or it has too much compression, if i was to guess, i would say it had lobe centres in the region of 115 and betwwen 95 and 100 you should try 108/109 you will gain a whole lot more top end and loose nothing thru the middle, i think you will find that 12.5:1 is about the most you want to go on the comp , as temp is the main killer on these engines in sidecars anyway. from all the testing i have done in the past , that 612 enginge should be up around the 65 hp at the rear wheel
marcusgunby
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wow thanks for those tips gwr, i know this stuff is still fairly new to KP and i will pass on the info-thanks again.
marcusgunby
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the only thing i know is when that engine is in a bare chassis with only a few bolts holding it in, i would not want to sit above it!!!!
LOL dont mention to chris you have 83hp or he will be all over you trying to buy one to put on the street :yikes:
LOL dont mention to chris you have 83hp or he will be all over you trying to buy one to put on the street :yikes:
marcusgunby
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LOL chris will be looking at a big bore cr500 to try to match it:) BTW does the g stand for glen?
:blah: He can try , he can go as big as he likes, then he will run into the usual problems, like incomplete combustion, detonation, and crankshaft failure from the extra 200 grams he has added to the piston weight without adjusting the balance factor to suit blah blah blah, sometimes its just easier to admit defeat, big four strokes are better than big two strokes( singels) in the same way small two strokes are better than small four strokes.
to answer your question , yes
to answer your question , yes
Hmmm. Maybe I need to look into those overweight diesel fuel burning 4 strokes. I hear they can make tons of power also.
I have been following the Aprilia V twin project. It seems thay have exceeded the HP numbers of the original goal set for the design. Now that is my kind of design.
I have no hang up about getting a 4 stroke. Power is power, no matter the way it is made.
For many years now, I have considered a variant of the RZ/banshee engine to be installed in a dirt bike. The engine would only be a viable option if the trinity cylinder system was installed. Those engines seem to perform well enough, but they are huge.
There is no easy answer, I guess that is why I keep fooling with the big two strokes. I even considered casting/machining my own case and cylinder assy to make a 180 degree opposed 2 stroke. The cylinders would be fore/aft and pistons would rise/fall together. The desire for power is that strong.
Edit: I know the Trinity guys built a 500+cc 2 stroke single cylinder that was a trick modern unit. From what I hear, the engine made more than 100RWHP. I will try to find the link to the dyno or the test results.
Edit: try this link 98.4 HP 61.6 lb/ft TQ. Nice flat curve too, never below 50 lb.ft. 496cc!
http://twostroketech.com/index.php?act=Attach&type=post&id=221
FYI, my car (miata) is now having traction problems in 3rd gear.
Chris
I have been following the Aprilia V twin project. It seems thay have exceeded the HP numbers of the original goal set for the design. Now that is my kind of design.
I have no hang up about getting a 4 stroke. Power is power, no matter the way it is made.
For many years now, I have considered a variant of the RZ/banshee engine to be installed in a dirt bike. The engine would only be a viable option if the trinity cylinder system was installed. Those engines seem to perform well enough, but they are huge.
There is no easy answer, I guess that is why I keep fooling with the big two strokes. I even considered casting/machining my own case and cylinder assy to make a 180 degree opposed 2 stroke. The cylinders would be fore/aft and pistons would rise/fall together. The desire for power is that strong.
Edit: I know the Trinity guys built a 500+cc 2 stroke single cylinder that was a trick modern unit. From what I hear, the engine made more than 100RWHP. I will try to find the link to the dyno or the test results.
Edit: try this link 98.4 HP 61.6 lb/ft TQ. Nice flat curve too, never below 50 lb.ft. 496cc!
http://twostroketech.com/index.php?act=Attach&type=post&id=221
FYI, my car (miata) is now having traction problems in 3rd gear.
Chris
Last edited:
cujet,
Undoubtably if you have been to any of the major sand dunes lately you have seen the newest Cheetah motors running that produce well over 100 HP... those things are blazing fast in a quad chassis. I would be SCARED to ride a bike with that kind of motor in it, even with a reasonably long extension!!! It would be cool though. It would definately be a good option against the streetbike motor equipped bikes.
What bottom end did they use for the 100 H.P. single? That would be the way to go in a dirtbike.
Undoubtably if you have been to any of the major sand dunes lately you have seen the newest Cheetah motors running that produce well over 100 HP... those things are blazing fast in a quad chassis. I would be SCARED to ride a bike with that kind of motor in it, even with a reasonably long extension!!! It would be cool though. It would definately be a good option against the streetbike motor equipped bikes.
What bottom end did they use for the 100 H.P. single? That would be the way to go in a dirtbike.
I believe the bottom end is the TRX250 quad engine. It is a variation of the oilder CR250 engnine. I even think the CR500 is similar and could be used.
I took a good look at that cylinder when I visited Trinity. I was impressed at the swiss cheese port design. There were more ports than I could count! A very impressive design indeed.
If that unit were to be used on a dirt bike, a counterbalancer would be a must. That makes the Suzuki Quadzilla engne a good donor starting point.
Chris
I took a good look at that cylinder when I visited Trinity. I was impressed at the swiss cheese port design. There were more ports than I could count! A very impressive design indeed.
If that unit were to be used on a dirt bike, a counterbalancer would be a must. That makes the Suzuki Quadzilla engne a good donor starting point.
Chris
Chris,
I currently have a mod. LT500. Do you think that the bottom end could handle that kind of HP? It seems like it might grenade frequently... It would definately require a temp gauge of some sort and bigger radiators... Don't get me thinking, that kind of setup would probably cost me more than a new bike! :p
I currently have a mod. LT500. Do you think that the bottom end could handle that kind of HP? It seems like it might grenade frequently... It would definately require a temp gauge of some sort and bigger radiators... Don't get me thinking, that kind of setup would probably cost me more than a new bike! :p
