Specialized 8 Speed Rocket

View attachment 79978 specialized 8-speed rocket

 

[Street Ryderz]

It's funny you mention that clutch issue , I did some radical cylinder work on this engine, I removed the cylinder wall from the transfer Port area , made a very big third transfer port the exhaust Port timing isn't that radical at all , I'm guessing around 165 ? didn't measure anything just took out a big old air powered die grinder and some carbides and went to town all by eye and experience and it works finally I found the right combination , it felt like I doubled torque and horsepower and that's when I started melting clutches , dropped and broke a fin on this cylinder and didn't really care how it was going to perform , I put in a used piston with a big window cut in it , and whatever the port timing is I will clone it as soon as the motor starts to rattle , hopefully not explode . I can get back to you with some port timing numbers but so far I've got 6 months on this engine and it is got some serious nut I'm sure it's days are limited but I don't feel like going another engine just yet not around the holidays plus camera Rhode Island we're getting high temperatures of 45 degrees BURR !, I did some speed runs while it was fresh, now I just enjoy the torque wheelies in first second and third gears , cruise at 45 to 50 all day but she drinks a lot of fuel at that speed , I'm not trying to get another speeding ticket !!! , my first and hopefully last speeding ticket was 10 over 55 in a 45, the cop fortunately did not know the law of motorized bikes that are not supposed to exceed 20 miles per hour but he did write me a $95 ticket. I thought they was going to impound the bike ,I've got $350 into the wheels and tires alone , I run a Kenda high pressure tire @ 125psi when I was making the speed runs , I now run the recommended 100 PSI with teny mags hope rotors and hydraulic brakes , I added it all up at around $900 that includes the fox terralogic front fork , the frame I picked out of my friends scrap pile chromoly specialized Hardrock from 92 .the complete bike weighs in around 40 lb I weigh around 180 lbs. I was expecting this motor to grenade a long time ago , but if it's not broke then I don't want to fix it just yet I've ported cylinders in the past with up to 192 exhaust duration that had very short power bands and not much torque , they would love to rev but wrist pin and piston ring flutter was an issue and ring lands were getting hammered was running into detonation issues and piston overheating . as far as the clutch goes I was melting clutches with the red high temp pads , switched to some Zeda pads that helped ,when I build the Clone to this engine I will be installing a spring stronger than the factory maybe a car valve spring ?. The clutch slipping actually keeps the engine on the power curve longer but in higher gears sometimes won't totally locked up . I intend to machine some semi-metallic sintered pads from Automotive brake pad material ,I would like to try the sintered pads on this motor before she lets go that way I don't need to split the cases to install the heavier spring ,these things take a lot of time I don't have to tell you that , my friend likes to bust my balls and say it's a 10 to 1 scale model work on it for 10 hours write it for 1 hour and blow it up , and I'll admit I was doing that for a while till I figured out the combo , you got to run a shift kit I'll never go back to a single speed .I've bent a few axles by popping the clutch and riding wheelies , but that's when I beat on it . I've been running the JL engine with the big crankshaft main bearings zl con rod with full complement needle bearings (no) (cage)Integral ignition ,

Very cool! I personaly use brake linnings cut and shaped from front disk pads they work very well,The spring I use is a heavy valve spring,Next will be the retainer pin that holds the two parts of the shaft together because once the clutch has good bite that pin bends or even shears also the clutch plate holes elongate and bend those pins so I replace them with hardened drill bit shanks.I personaly like the Idea of having gears but cant deal with the derailer being weak and chewing up freewheels or cassetes with high output builds, Gary is using a variable hub and I think for me that would be a better solution.That said I am quite impressed with my current set up, I like that it will cruise at 50 and rpm is only 6,300 due to the ratio used and fuel use is still reasonable around 40 miles on a two liter tank holding at 50.My goal is to have sufficaint torque to maintain the high speeds at lower rpm sitting upright against the drag because I'm not cool with having to lay out on the bike for it to get to top speed LOL.Also with the numericaly low ratios many builders have to peddal like mad to get it going due to lack of bottom end torque and I dont wanna peddal hard or much LOL (getting old) so again making it pull hard right out of the hole is more important to me.

 

[Mrmotion]

 

[Mrmotion]

Was out tearing up the town tonight !!!
66 Mph was a breeze !! , and smooth like A baby's butt , how are you doing.I hope these photos are a lot clearer than my previous ones

 

[Mrmotion]

primary chain has about 4 months on it getting a little stretched , other than that Got 34 miles on one quart of fuel , !!!! VP 94 octane 40:1,Napa gets it to me for around $450 a quart under my commercial account , $569 if you don't have an account

 

[Street Ryderz]

primary chain has about 4 months on it getting a little stretched , other than that Got 34 miles on one quart of fuel , !!!! VP 94 octane 40:1,Napa gets it to me for around $450 a quart under my commercial account , $569 if you don't have an account

WTF did you forget a decimal point? We get ethanol free 94 octane here from the pump at $1.30 per liter witch is a little more than a qt.

 

[Mrmotion]

Yea , I live in Rhode Island where do you live in Texas where they make the stuff

 

[Mrmotion]

Tru Fuel runs pretty good too 92 octane

 

[Street Ryderz]

Yea , I live in Rhode Island where do you live in Texas where they make the stuff

No man I live in Hamilton On.Canada about a 50 min ride from Toronto.

 

[Street Ryderz]

Yea , I live in Rhode Island where do you live in Texas where they make the stuff

OIC your using the premix,still thats kinda expensive.

 

[Mrmotion]

OIC your using the premix,still thats kinda expensive.

I know the area played hockey there with you Canucks , back in the 70s and early 80s you guys are born with your hockey skates on ,lol