porting


7 replies to this topic
  • tshe1

Posted October 26, 2005 - 01:02 AM

#1

i have just remove the head and before rebuilt it i wanted to porting it.
i read in the articles that it's forbidden to polish the intake port because the surface texture that comes from the casting is necessary for turbolent the air/fuel mixture before it comes to the engine.
i wanted to polish the port to reduce drag force and to create More easy breathing engine.
now I'm comfuse?
what to do? what is correct ??

  • Brettv

Posted October 26, 2005 - 02:58 AM

#2

ive heard various opinions, theres a difference between 'polishing' the head and 'porting' the head.
polishing is just making the ports shiny, it may help evavuate the exhaust gases quicker on the exhaust side, but i doubt by much.
i have also heard the same as you that polishing the intake ports will result in less 'atomisation' or whatever, of the fuel

whereas on the other hand, porting the head for better flow, has much better results, this entails putting the head on a porting flow machine thing that can tell how to get better flow, by building up the intake and/or exhaust with epoxy.

tt memeber hamish did this to his head i think
i have been thinking about polishing my exhaust ports, but after a while i would assume that the carbon would just come back as before.
here in AUS, to get my head ported ranges from $300 - $500 depending on how much time the head spends on the flow machine

hope this helps
cheers - Brett

  • GCannon

Posted October 26, 2005 - 07:24 AM

#3

Polishing the exhaust ports is to prevent or reduce the propesity of carbon forming or sticking to the ports

  • simon@vic

Posted October 26, 2005 - 07:31 AM

#4

Dont pollish the intake!!!!!!!!!!!

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  • tshe1

Posted October 26, 2005 - 08:22 AM

#5

Dont pollish the intake!!!!!!!!!!!


explain please... :banghead:

  • motocross10113

Posted October 26, 2005 - 07:55 PM

#6

Yes do not touch your intake your self it will not run right or like it used to
now polishing your exhaust ports is a good idea and will help mabye even porting it a little to get even better flow but not to much other wish you will lost back pressure witch is needed......you should be able to find some templates online that you can buy and will tell you what to do if you want or you can just send your motor to procircuit....they do some sweet work can be kinda $$ but its worth it in the end

  • Birdie426

Posted October 26, 2005 - 08:38 PM

#7

You don't want a mirror polish finish on the intake port because you do get less atomization of the fuel. The hot ticket is to do whatever reshaping you need to do on the intake, polish it to smooth out all the transitions and get rid of the casting marks, then, finally grit blast the surface to get a rougher finish that promotes breaking up the boundary layer and keeping the fuel atomized. Of course, you should do all this work before you replace the valve guides and seals, or do that valve job.

The flow bench measures flow thru the port (in cubic feet per minute), but doesn't tell you where or how to remove or add material to improve or change performance. That's what you're paying the $500 for!

  • Gadsen

Posted October 26, 2005 - 09:34 PM

#8

i have just remove the head and before rebuilt it i wanted to porting it.
i read in the articles that it's forbidden to polish the intake port because the surface texture that comes from the casting is necessary for turbolent the air/fuel mixture before it comes to the engine.
i wanted to polish the port to reduce drag force and to create More easy breathing engine.
now I'm comfuse?
what to do? what is correct ??


Polish the exhaust port. Polish it as smooth as you can. Exhaust exiting easily naturally pulls in more air. Usually intake is just dressed up, ie knocking down obstructions, but some texture is good. Too smooth or obsructions can condense the atomized fuel turning it back into fuel droplets. Also, under the valves, you can clean that area up, knock down the edges. Same deal, smooth on exhaust, trimmed up in intake. Be careful on how much material you remove. Might hit "water" Check Eric Gorr, he will do this all for you, send in the head and a check. I think he is at http://www.ericgorr.com




 
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