performance ideas

[scootspeed]

been building briggs 5hp racing kart engines for 10 years, we get 9hp out of them. a lot of little tricks, all working together. the ruckus engine is the same concept.
some things i am going to try.
new cdi, w/o rev limiter. the motor will rev to 10000,so this is a must. good kart oil. very tight valve lash, more cam lift. 3 angle valve job and head port cleanup. here is the biggy. bigger carb, 22mm., but flowed for alcohol. yes, methanol. this will make 20% more power if set up correctly. motor will run cooler, and never detonate. alky likes timing advance, so i will try this by filing the coil holes. havent heard anyone talk alky on here, but it should be tryed. post with ideas or thoughts. email me if you dig this motor stuff. the ruckus motor is untapped potential.

[Robo-Mod]

Where can I get methanol?

[chanito]

I was not going to get involved in this, but i think i should get some facts out, in the mid sixties there was a big crash at Indy and a couple of drivers got burnt to death, because the fire engines have to go all the way around the track before they could put out the flames, they figure out that if they were running alcohol the pit crews could have put out the fire by simply spraing some water on the fire, so for safety reasons they decided to run alcohol from them on, alcohol have less specific power output than gas, but it vaporises a lot quicker so is a great heat reducer in engines, that turn out to be a great advantage in draggster engines that only need to run for minutes at a time, some even got away with liquid cooling altogether, the briggs and straton engines in 4cycles go karts, are prone to hot spots and preignition, both can be overcome with alcohol very easilly, however nothing in life is free, alcohol is very mean with the metals our carbs and engines are made of, eating them up, in go kart engines they remove all the alcohol and then have them run in WD40 (the smoke kills all the go kart race loving mosquitos)at the end of a race, also since alcohol make less power than gas they have to run way more alcohol than gas to make up for this little incovinience something in the neiborhood of 50 % more (think about a 120 main jet), but the killer is that we have to switch to gas before stoping our engines to make shure that the methanol does not eat our gas pumps, carburators and engines, so we have to drive around with two fuel tanks, one for gas and another with methanol, some switching valve and we will end up with an scooter that makes probably 1/4 of a horsepower more (that is being very optimistic) uses up a lot more gas and stimks terrible, my opinion is that is not worth it, more than that i think it would be STUPID

[zoomerman]

;D ... and that there is Chanito's opinion.


Very good, keep the ideas and information flowing!

Zoomerman

[scootspeed]

alky is corrosive, yes. the problem with the kart motors is they leave the alky sit for long periods, ie 1-3 weeks. this is a problem. i ride my scoot daily, so with me corrosion is not a problem.

alky does use twice the amount of gas. carbs would have to be jetted roughly twice the size as gas. alcohol is available at farm stores, race shops, so getting it for some would be a pain.

you bring up good points, no doubt. but speed is not free.
we have to use proven methods to get the ruckus up to speed, a speed we can live with.

the fact is alky will produce 30-50% more power. it will be more like 1hp +. so for me it is worth a try. it is for sure not stupid. anything someone does to advance this game is good for us all.

here are my mods to date; uni filter pod, 85 main, 38 pilot, shimmed needle, good FHS kart oil, and .002 valve lash all around. good for 40 mph, with better acceration.
think outside the typical box.

[chanito]

Scoot you bring a great point about thinking outside the box, actually i make a living by doing so, however some stuff obviouslly pass me by, and yes any performance trick you find does benefit all of us fellow rucksters, but as someone who for a while made a living working in profesonal racing teams i think i should make you aware of some points, of course you are more than welcome to proof me wrong.
You tend to think that our engine is similar to your alcohol burning racing Briggs, that is not so, the briggs is a side valve, air cooled engine, with splash lubrication of about 250 cc, wich produces 5 hp at 3700 rpm, when modified for racing makes 9 hp at 6000 rpms. Our ruckus engines are overhead valves engines, water cooled with presurized oiling system of about 50 cc, wich produces 4.9 hp at 8000 rpms, so if our engines were the size of your briggs we would be talking stock 24 hp (not the 9 hp you are so proud of, and with good reazon), getting more power out of a briggs is easier than getting it out of our hondas, the normal compression ratio of a briggs is between 7 and 8 to one (lot of factory tolerances in an air cooled engine), the ruckus is 11.9 to one, so playing with the timing is a lot riskier in the honda, also you can shave a lot of a briggs head and increase compression to about 11 to one, use alcohol and get away with it (that alone bumps your hp nicelly) not so in your honda, also the briggs being a bigger engine have a nice reserve of torque to accel your go kart from a standing stop, so you can use very wild cam profiles, we on the other hand need a flatter torque curve because we do not have much to begin with, so cam profiles have to be more conservative and valve lashes make a very significant diferences in the characteristic of the riding experience, that said is nice to know that fuel injection bumps the torque up nicelly. Our engines have way more in common with a sports car engine than with a lawn mower one, i am afraid that you will be disapointed with your performance tricks in our engine, but the again i might be wrong
Let us know how is the performance of your scooter with the alcohol (keep an spare fuel pump handly just in case)

[pomeruck]

PLEASE TRY IT AND TELL US WHAT HAPPENS! ;D