WHat exactly is porting an engine. What does it do, why is it done, how much does it cost? If I were to have my engine ported, what else would I have to get?

Thanks

Mike

 

Well Mike it's like this. If you are talking about a two stroke, you are talking about changing the port timing usually by rasing the port roof in the cylinder. This will change the disposition of the engine. It will change the power and where the power comes in at. Some port jobs will make the engine very peaky and the power band will be very narrow but it will hit VERY hard. Changing the port work on a two stroke is like changing camshafts in a 4 stroke.

If you are talking about a 4 stroke then people are talking about opening up the intake tract all the way to the valve head. The bigger the intake tract, in theory, the more air it will flow. The more air it will flow the more power an engine will make. Now if you do the intake it also makes sence to open up the exhaust port to the pipe. Again, the same theory.

 

Yeah, Im talking 4 stroke, how do you go about opening the intake tract all the way? Do you have to buy anything? Im very interested if its not something you have to buy. ANd I guess, If i do this how do you open up the exhaust port to the pipe?

Thanks again

Mike

 

Mike the only tools you would need is a flex grinder and a steady hand. I can not recomend doing this if you have not done this before.
Some people grind the hell out of the port and think they will pick up a ton of horsepower. What they have done is kill the velocity of the port and probably loose some if not a bunch of horsepower.

If you deside to take this project on the best advice I can give you is just "clean up" the port with the grinder and port match (make the port the same size as the gasket) the port to the gasket.
Doing any more than this is asking for trouble if you don't know the basics of port work.

 

Just send your head to an engine builder, such as Curtis Sparks, CT racing, Duncan, ESR, etc...,etc....

 

Not sure if its going to be worth it on a 250x, at least not without notable engine work to begin with.

 

I think Im just gonna leave it. I wont work on it unless it needs to be worked on, and I might mod it when the time comes to fix it. But I have to give props to honda for making an extremely reliable bike. My borhtes and friend have yamahas and kawasaki and mine is always running the best when we get out there. Its not the fastest, the warrior is, but they admit that it wins the overall best bike award. [img]i/expressions/face-icon-small-smile.gif[/img] The only thing that bothers me is how high the center of gravity is.

 

Porting is more than just hogging out the openings... It is creating the most efficient path from the carb to the combustion chamber, within the chamber and then into the exhaust. This includes removing metal in some places, welding in others, and polishing the surfaces smooth. Many people will also modify the head to provide better combustion... there are hundreds of tricks for any engine combination (compression, cams, intake and carb, valves and springs, lightened pistons and rotating assemblies, stroker cranks, etc). If you feel the need to port your own engine, start small like polishing the exhaust surfaces. This can give some increased performance and is pretty hard to screw up.

There is hope for a 250X just look at this: http://www.off-road.com/atv/250XRS.htm

 

that link doesnt work. Does it work for anyone else?

 

Sorry, the hyperlink doesn't work in this forum for some reason... Copy and paste it into your address bar or "open" window. Pretty neat article on a Sparks stroker 250X that out runs Banshees on a regular basis.