firemanjim
Just kartin' around....
to my attempt at a tutorial on big cc engines on kart. First off, there are different types of karts. Simple yard karts, semi off road karts, pure off road karts, race karts, just to name a few. They are purpose built machines, designed to operate within certain parameters. Only so much external force being exerted on the kart, from typical "normal" use. And then there are mini buggy's.These karts are designed to use a certain HP engine. The engineers forethought allow us to swap a 3.5hp engine for a 6.5hp on a yard kart, but you're not gonna slap a 18 hp engine on it and not have frame issues. Before I go any further, it's NOT the HP but the TORQUE of a motor that will make the biggest difference. The torque from a 6.5hp won't rip a yard kart frame apart. But if you put a 600cc crotch rocket engine on a yard kart, the frame will only last so long before you start to see cracks. You like to spin tires till they smoke? That's torque doing the work.....
Most karts are made with 1" x. 063" tubing. The bigger purpose built off road karts are made with 1.25" x .063" tube. Then there are the mini buggies with 1.25"x.093-.100" tube. The buggies use a larger cc engine so the frame material used is gonna be bigger/thicker.
Done lost track of my thoughts.
anyway, if you want more speed, try gearing. If 30-45 mph isn't fast enough, step up to a 125-250cc dirtbike engine. You will have more than enough power to hit a 100mph (don't do it on a yard kart!!!!) . Even at this size engine, you run the risk of frame cracking / bending due to the torque being applied.... Engines of this size offer tire spinning/smoking torque in the lower gears then switches to speed , the higher in gear you go. A lot of you think you are gonna put a 500-1000 cc engine in a yard kart and be cool to thrash it around. Absolutely WRONG..... To use any of the torque the engine has, the frame and drivetrain must be able to withstand it. Look at the Edge piranha or barracuda. They use big tube frames, lots of lateral supports, and gussets. The frames is DESIGNED to handle the power of a turbo 1300cc 'Busa engine. It will not fold in on itself, won't bend,cracks, or rip apart. It is designed for the power of the engine to be used to its fullest potential. You can hammer down on the throttle and KNOW your gonna be safe, ESPECIALLY at high speeds and tight turns. A lot of ENGINEERING went into them things to make them the beasts that they are.
To use these engines, you need to use your brain (or borrow one) and come up with a safe frame design. Copy a manufactured model. Just DONT slap a big ^$$ engine on a yard kart and hit the streets. It's NOT safe or smart.....
I'm done rambling..... Some one else take over..... (Doug, Tony??)
Don't get me wrong, I've put 80cc and 125cc engines on simple yard karts and had a blast. And a bigger engine does equal MORE fun,.... BUT let's be realistic about it. Are you gonna stuff a twin turbo LS7 in a Chevy colt (small car) ? NO because it will just destroy the car and it's drive train....
Ok now I'm done.....
WoW! Thats a lot of power.