bananas
06-27-2005, 01:33 PM
What is cylinder boring?
Boring refers to the process of enlarging a cylinder to clean up scoring or scratches due to piston or ring failure. Most new 2-stroke cylinders have a hardened thin plating of nickel-silicon-oxide, or nikasil. Once this plating is damaged the cylinder needs to be replated or sleeved. Most 4-stroke cylinders on the other hand have a steel sleeve which can be bored. Depending on how deep the scratches, nicks, or scoring is, determines the size overbore. In most cases the next size, 20 thousands or .020” or .5mm will clean up. General sizing is .020, .040, .060, .080 thousands or .5, 1, 1.5, 2mm over the stock bore. Other than 4-stroke cylinders the twin Banshee cylinders have steel sleeves yet.
What is cylinder honing?
After a cylinder is bored a few thousands are left to be honed. Honing uses stones to reach the final measurement and to put the crossed hatched finish on the bore of the cylinder.
What is cylinder sleeving?
When cylinders reach their maximum overbore, or are nikasil plated, sleeving is required. This involves boring the cylinder to match a pre manufactured steel sleeve. Once the sleeve is installed it is then bored to stock size. It is then basically a new cylinder again. Then can be bored several times over. (See Cylinder Boring)
What is a flowbench?
A flowbench is a device that measures the air flow in and out of cylinder head ports with the valves opened at multiple simulated valve lifts. The flowbench gives the porter(see porting) an accurate measurement of the progress he or she is trying to achieve.
What is porting?
Porting is the removal of material and reshaping of the cylinder or head ports and cylinder head valve pockets to achieve better air flow into and out of the combustion chamber. The more volume of air/fuel mixture and the increase of air/fuel velocity produce more horsepower.
Boring refers to the process of enlarging a cylinder to clean up scoring or scratches due to piston or ring failure. Most new 2-stroke cylinders have a hardened thin plating of nickel-silicon-oxide, or nikasil. Once this plating is damaged the cylinder needs to be replated or sleeved. Most 4-stroke cylinders on the other hand have a steel sleeve which can be bored. Depending on how deep the scratches, nicks, or scoring is, determines the size overbore. In most cases the next size, 20 thousands or .020” or .5mm will clean up. General sizing is .020, .040, .060, .080 thousands or .5, 1, 1.5, 2mm over the stock bore. Other than 4-stroke cylinders the twin Banshee cylinders have steel sleeves yet.
What is cylinder honing?
After a cylinder is bored a few thousands are left to be honed. Honing uses stones to reach the final measurement and to put the crossed hatched finish on the bore of the cylinder.
What is cylinder sleeving?
When cylinders reach their maximum overbore, or are nikasil plated, sleeving is required. This involves boring the cylinder to match a pre manufactured steel sleeve. Once the sleeve is installed it is then bored to stock size. It is then basically a new cylinder again. Then can be bored several times over. (See Cylinder Boring)
What is a flowbench?
A flowbench is a device that measures the air flow in and out of cylinder head ports with the valves opened at multiple simulated valve lifts. The flowbench gives the porter(see porting) an accurate measurement of the progress he or she is trying to achieve.
What is porting?
Porting is the removal of material and reshaping of the cylinder or head ports and cylinder head valve pockets to achieve better air flow into and out of the combustion chamber. The more volume of air/fuel mixture and the increase of air/fuel velocity produce more horsepower.