i was wondering if when you port a cylinder and then you blow the engine or fry a piston,bore it and rebuild it does the porting fade or go away? do you have to re-port the engine? how about polished exhaust ports?[img]i/expressions/face-icon-small-confused.gif[/img]

 

The port dimensions can change slightly with a bore job (Depending on how much material is removed), exhaust port dimensions can also change with carbon build-up... but for the most part, no...

 

THE HORSEPOWER DOESN'T GO AWAY?

 

A fresh motor will make more power than a motor with piston/rings worn beyond mechanical limits... that along with proper jetting and a good plug could be factors of power loss also...

If you're having a noticeable loss in power after a rebuild... something is wrong.. Did you do the work yourself? or have a builder do it for you?

Have you looked at your jetting? Jetting can make a huge difference in performance. Did your builder do any mods? Head milling, etc?

What caused the failure to begin with??? Did you find a smoking gun? Is it possible the problem could still be there?

 

i just wanted to know if a ported engine stays ported. same hp numbers constant?

 

Porting is a numbers game for the most part. Say a person raises the exhaust port 2mm. As long as you just freshen the motor when it needs it, the actual port dimensions wont change and thus the porting doesnt either. As said before if the cylinder gets bored out, the ports are angled and will change very slightly. Sometimes it can make a good difference. Bubba

 

what about rough intake and smooth exhaust ports? they add power that will stay there right?

 

Porting is done on the intake and exhaust ports, and doesnt fade over time. The piston and rings run along the inside of the cylider sleeve wall. However if you ever happen to need a new sleeve the porting will remain intact but their may need to be some mild work done to the outside portion of the sleeve where the exhaust and intake ports are. LIke someone mention, there will be some carbon buildup that will take a small toll over time but not too significant. The better oil and fuel you use will limit carbon buildup.