porting questions

[845mx5]

What is unshrouding a valve? When you do this a bigger valve is not needed. Correct? Can anyone show me a picture of what material needs to be removed to do this? Maybe a before and after. Also, what is short side porting?

 

[minibikedude]

One what kind of engine are you porting a OHV or Flat head.

 

[minidragbike]

What is unshrouding a valve? When you do this a bigger valve is not needed. Correct? Can anyone show me a picture of what material needs to be removed to do this? Maybe a before and after. Also, what is short side porting?

It would be best if you can go to any local performance machine shop and ask these question.

But I'm gonna tell you what they are.
Unshroud is the head surface material that is blocking the flow around the valves, and seats.

The shortside is also called the shortside radius and that is where you get the biggest improvent in flow. It's the shortest turn from the begining of the port, to valve head. Removing material from this area will pick up flow, but make sure it's a smooth turn into the valve head when doing this.

 

[845mx5]

its an ohv. 6.5 clone. Any pictures? I may do this in the future but i may not.

 

[minidragbike]

its an ohv. 6.5 clone. Any pictures? I may do this in the future but i may not.

You would need to have a fully ported head in hand to really understand. It's best if you can go to a local performance shop and they can explain it better, and maybe even show you.

 

[65ShelbyClone]

Someone didn't try Google before posting this thread...

Google

 

[845mx5]

You got me. Thanks for the help. i was just hoping for some before and after pcitures of a gx200 or similar head.

 

[845mx5]

Sorry for another post but, what are the best mods for a gx200 head? im looking for good power and torque gains. I dont have tools to install larger valves. Aside from that what are my options? Oh and on a stock head.

 

[minidragbike]

Short side radius on the intake and exhaust, don't make the ports any larger.

Install a much better breathing after market carb. The factory carb even holds back the head stock flow.

 

[spacecoast]

Let me google that for you

 

[845mx5]

Yea, i could search google but that would be dumb. Because i want opinions. Opinions on what is best for MY setup. So searching on this site, is better then google. I know all of the mods. I want to know what is bet for my setup and what other parts/work would be involved with each mod.