jackshaft gearing

When I raced we used the higher octane leaded gas available on gas stations. Personally I always got Shell, which seemed to have a higher quality over there than others, but price was a little higher. For Nationals they used to provide gas, with big controversy since sometimes if they didn´t get all the gas same time of the day and gas station had to get truck load it might change. At local level some people were actually running special Elf Racing gas, very very expensive, since even gas from gas stations was extremely expensive, and now it is even worse. To my knowledge now at International level they run 98 unleaded pump gas, either supplied by track/organization or from designated gas station. I have to check with someone to give you more details. Actually there is a kid from Spain I have been asked to help who are running FIA/CIK World and European Championships so I´ll ask. Their sponsor is very interested in bringing the kid to race dirt ovals too in the US to support a possible future NASCAR career. The kid seems to be really good on asphalt sprint tracks with less experience than most. He is gonna be racing all around the World this year and once back in Spain this summer I might either travel with them or run some special testing at my favorite track. I also have to talk to sponsors. They are big companies able to put him on top if he has what is needed to get there.
 
alvin l nunley said:
and what did you race? And what was your reason for using the higher octane?
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He raced euro type CIK stuff, you would know that Al, its not like Santiago came on here yesterday. ICA type engines typically run 7-8.5cc in the head volume and turn sometimes 20K+ rpm on the straights. This is for 100cc. So yeh, you kind of need the good fuel.
 
arc100 said:
He raced euro type CIK stuff, you would know that Al, its not like Santiago came on here yesterday. ICA type engines typically run 7-8.5cc in the head volume and turn sometimes 20K+ rpm on the straights. This is for 100cc. So yeh, you kind of need the good fuel.
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Thanks. Al, I raced ICA (100 cc direct drive, air cooled). You can probably explain us why we all raced higher octane available for those 2 cycles. Or you might want to discuss your disagreement with the engineers who designed those engines. :D
 
rainman said:
Thanks. Al, I raced ICA (100 cc direct drive, air cooled). You can probably explain us why we all raced higher octane available for those 2 cycles. Or you might want to discuss your disagreement with the engineers who designed those engines. :D
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you address this post to Al, so I'm not really sure who you're talking to. You're not quoting anything I said. But if you are addressing me;
what makes you think I can explain why you raced higher octane? Tell me, what is "higher octane" in your understanding. And where did you get the impression that I have a disagreement with the engineers who designed the engine?

I raced a K78, direct drive, with a 9+ cc head and I used premium leaded gas. I don't remember the exact octane but I purchased it at a gas station. I don't even know if there was anything better than that in 1977. I won the Northern California season championship and got 2nd at the nationals that year. I had no problem with detonation, so I have to assume the octane was high enough.

Tell me something, what is the octane of the spec fuel, used in Europe, in the hundred cc Rotary valve class? Is there a rule for minimum CC's combustion chamber volume? I just find it hard to believe it's as low as 7.0 – 8.5 but I don't know that for a fact.

Comments compliments criticisms and questions always welcome.
If the data does not support the theory, get a new theory. (Al Nunley)
 
We have a 1/8th mile local. 7.77 is my normal gearing for that track. 22/63 I believe (clutch side). 21/57 belt drive. Take what u will from that.
 
Bentaft63 said:
We have a 1/8th mile local. 7.77 is my normal gearing for that track. 22/63 I believe (clutch side). 21/57 belt drive. Take what u will from that.
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I call the ratio from the engine to the Jack shaft the primary ratio. If the clutch is on the Jack shaft, I call the ratio from the clutch to the axle the secondary ratio. If I assume that the 22/63 ratio is from the clutch to the axle, and the 21/57 is the ratio from the engine to the Jack shaft, than the former is a secondary ratio and the latter is the primary ratio. My gear ratio chart says you are right, the overall ratio is 7.77 – 1.

I don't understand what you're referring to when you say "Take what u will from that.".

I don't understand the need for a Jack shaft with that overall gear ratio. I'm sure you have your reasons, it's just that I don't understand them.

Comments compliments criticisms and questions always welcome.
If the data does not support the theory, get a new theory. (Al Nunley)
 
alvin l nunley said:
you address this post to Al, so I'm not really sure who you're talking to. You're not quoting anything I said. But if you are addressing me;
what makes you think I can explain why you raced higher octane? Tell me, what is "higher octane" in your understanding. And where did you get the impression that I have a disagreement with the engineers who designed the engine?

I raced a K78, direct drive, with a 9+ cc head and I used premium leaded gas. I don't remember the exact octane but I purchased it at a gas station. I don't even know if there was anything better than that in 1977. I won the Northern California season championship and got 2nd at the nationals that year. I had no problem with detonation, so I have to assume the octane was high enough.

Tell me something, what is the octane of the spec fuel, used in Europe, in the hundred cc Rotary valve class? Is there a rule for minimum CC's combustion chamber volume? I just find it hard to believe it's as low as 7.0 – 8.5 but I don't know that for a fact.

Comments compliments criticisms and questions always welcome.
If the data does not support the theory, get a new theory. (Al Nunley)
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Why do you ask questions that you answer yourself? I don´t love getting into an argument for the love of it. Only women like that, lol.
 
I was meaning not all tracks are the same Al, that ratio works for me on that particular track.....driving line, Grip, weight of driver and engine rpm target are all factor into final drive. You are more then likely correct on definition of gear sides. I simplify things for better understanding usually, engine side,clutch side is pretty self explanatory when referring to jackshaft setups. I also should have included my target rpm at 14,000. Not disagreeing with u Al just trying to explain myself.
 
A clutch can be on the primary side (Birky) or secondary (4 cycle dry clutches). Primary is the engine output to jackshaft. Secondary is jackshaft to axle.
Mike
 
rainman said:
Why do you ask questions that you answer yourself? I don´t love getting into an argument for the love of it. Only women like that, lol.
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it seems you can't answer the question, otherwise you might answer them instead of trying to make fun of me.

Are your ideas such that they can't be questioned?
 
I beleive that the ratio was selected to make the CLUTCH work properly. The clutch will work properly in a select range of rpm based on design.

Just a thought, (;-) TP
 
Vmax said:
I beleive that the ratio was selected to make the CLUTCH work properly. The clutch will work properly in a select range of rpm based on design.

Just a thought, (;-) TP
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you might be right, but you might replace, "properly" with "most efficiently". I wouldn't want a clutch that only works "properly" at just one ratio.

Comments compliments criticisms and questions always welcome.
If the data does not support the theory, get a new theory. (Al Nunley)
 
Try 20/60..; i've run that for 12 years with no problems and great sucsess. Makes the math easy too.
 
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