1. What does Port & Polish mean?
2. What does Bore & Stroke mean?
3. What is a 3 angle valve (or whatever that term is)
4. How do all these help your engine.

Could someone post any other "Lingo" terms not listed here that can be done to an engine. I need to get up to speed with this stuff.

Thanx

 

I see that you have 4-strokes, so i'll talk mainly about them here.

Port & Polish: This is where excess material is gound or cut off of the intake and/or exhaust side to create a larger passage for less resistance. Then polishing the whole area slightly reduces air resistance further

Bore is the size of your piston, and stroke is how far up and down it moves during a cycle. Sometime people "Bore and stroke" their motor to a larger displacement via a larger piston and cylinder, and crank work which makes the piston travel further.

A three angle valve job is where the valve surface and seat are ground into three angles for a better, and longer lasting seal.

The port and polish will help if done well, the bore and stroke....well, that depends on exactilly whats done, and the 3 angle valve job will help reliability on a modded motor.

 

1. Porting is when they make the intake and exhaust ports in your head on a 4 stroke or cylinder on a 2 stroke larger. This allows for more air and fuel to come into the cylinder quicker. Polishing is when the exhaust and or intake ports are smoothed out so the burnt air fuel mixture can quickly escape the cylinder to allow for the new mixture to come in quickly. This allows your engine to "breathe" and exchange gases quickly.

2. Bore is the surface area of the piston. How large it is. Stroke is the distance that the piston travels up and down. Big bore is cheap horsepower. If you want the most out of a big bore get a stroker kit. This increases your stroke.

3. A three angle valve job is when your valve and valve seats are ground down to three specific angles allowing it to seal the most. This is more a reliability issue then anything else.

4. See above answers.

Hope this helps!

 

How much does "stroke kit" cost? I'm thinking about bumping to a 426- what above mods would you reccomend? Which are required for a 426?

Thanks

 

Some people even make a "back cut" in the valve (4 angle) for more flow-age....

 

Can someone send me a picture of a 3 angle valve? Is it cut into the valve, valve stem or what?