View Single Post
Old 07-22-2015, 11:23 PM
Davezilla's Avatar
Davezilla Davezilla is offline
Motorized Bicycle Elite Member
Join Date: Mar 2014
Location: San Antonio Texas
Posts: 2,710
Default Re: my journey begins

Yeah, the wide ports are good for making lots of torque...
You can do the intake but leave the surface rough... 80 or 100 grit sanding drum will leave a rough enough surface or just use the rotary files and don't polish which leaves a rough enough finish.just widen the intake 1mm on each side for excellent torque. You can also shave down the head using the sandpaper on glass method or if you got a belt/disc tabletop sander it'll make short work shaving down a head. I did a customer's engine by just widening the intake and exhaust ports then shaved down the stock head for better compression and better gasket sealing and that engine was a torque Monster... strong enough to slip the clutch on pavement or spin the wheel on dirt or gravel. The top speed was around 30 mph but the torque and acceleration was awesome.
Also, for good torque there's no need to raise the exhaust port roof or ramp the piston at the exhaust port, if you already did this tho it wont hurt since that exhaust port is nice and wide. You'll also want to sit your cylinder closer to the bottom end by using a thinner base gasket so the port duration is narrow but the air can get into and out of the engine in large volumes. A straight pipe that's longer will also help make lots of torque so you can extend the stock pipe or get onenof those really long poo poo pipes, this will also make the ride quieter since the noise will be behind you, and using a stock type muffler with 4 extra 5/16" holes drilled into the end cap will help make torque as well as keeping things quiet since we're not going to mess with the internal baffling.
if you choose to use an expansion chamber pipe you'll want a nice long header to keep the power down low. You can get a lot of torque out of these engines by using these tricks while keeping it nice and quiet, and still be able to do at least 30 mph or so on top.
Reply With Quote