Do forged pistons need more clearance?
Quote: Consequently, there’s a common misconception that forged pistons always require greater skirt-to-wall clearances. This isn’t always true because clearances depend on the type of alloy used in the piston, the design of the piston itself and the profile of the piston.
Does forged pistons increase horsepower?
Forged pistons them selves don’t increase horsepower. But the extra strength of forged pistons allows you to run a bigger camshaft, perhaps higher compression ratio, or lower compression ratio for supercharging.
How big of a piston do I need for a 4 stroke bike?
Is the engine two or four stroke. A small (50mm bore) cast piston, 4/stroke may have half a thou (.0005″ or .0127mm ) piston clearance, while a big, forged piston, 2/stroke (73mm, 2.874″) can need .003″ (.075mm) or more. You will need a shop manual to find the clearance for your bike. Now this is the minimum.
What kind of piston do I need for a new cylinder?
For a worn cylinder you may need a C or D grade piston. Do not use C or D grade pistons in a new or re-plated cylinder without checking the clearance carefully. Do not assume that because you have taken a B grade piston out, you should replace it with a B grade piston.
How is the size of a Namura piston measured?
Before installation, the size of each individual piston should always be checked. In general pistons should be measured at a 90 degree angle to the wrist pin and at 25% of the piston length from the bottom of the skirt. The piston and cylinder size should result in correct piston to cylinder wall clearance for the specific model.
How is the clearance of a piston determined?
Subtract piston diameter from the biggest bore diameter. This gives you the piston clearance. Piston clearance varies due to a number of factors. Diameter of the piston. Type of metal the piston is made of. Is it a cast or forged piston. Is the engine air or water cooled. Is the engine two or four stroke.
Is the engine two or four stroke. A small (50mm bore) cast piston, 4/stroke may have half a thou (.0005″ or .0127mm ) piston clearance, while a big, forged piston, 2/stroke (73mm, 2.874″) can need .003″ (.075mm) or more. You will need a shop manual to find the clearance for your bike. Now this is the minimum.
What should the clearance be on a two stroke engine?
I tried to find out what the piston clearance should be and .005 inch is the most I could find anyone recommending (including my 05 YZ250 manual) for a two stroke engine. According to my calipers, that is a very small clearance.
How to measure 2 stroke piston clearance for motocross?
Measuring 2 stroke piston clearance. Nikasil bores are .0015-.002″ for motocross bikes. Measure the bore with a bore gauge top and bottom, front to back and side to side, 4 measurements to make sure the bore is within .0002-.0004″ round. Measure the piston with a mic (not a caliper) at the widest point of the skirt.
Subtract piston diameter from the biggest bore diameter. This gives you the piston clearance. Piston clearance varies due to a number of factors. Diameter of the piston. Type of metal the piston is made of. Is it a cast or forged piston. Is the engine air or water cooled. Is the engine two or four stroke.