polishing intake tubes?

[Farther]

I tried a search with little joy.  I think that my O rings need replacing and while they are off would be a good time to polish them.  So my question is what has been peoples experience with polishing the intake tubes?

[Robert]

Save your time not really worth it and just for kicks look how big the hole is that comes out of the carbs.

[Farther]

So have you done this?

[Jay]

Sounds familiar.  I did mine when I replaced the O-rings.  I don't notice any difference, but it was something to tinker with.

[paul]

I did mine when I replaced my o rings,they are  Really rough castings on the inside....No diff. noticed but it was easy to do and i know they are smooth as frog snot inside..clean em out good and blow out the vac.ports good with alcohol 

[Daniel Meyer]

Some say rough is better...as long as the ports line up. Rough creates microturbulance that yields a more thorough fuel/air mix.

[fstsix]

I have had a few heads opened up and Ported, I have seen this topic a few times and always thinking the Exhaust would be the port to polish, the intake ports of the heads i have had done always seemed to have a sandpaper texture, and the exhaust would be polished so carbon would not stick as easily, Port match the intake would be thing i would do to improve air flow....http://www.eddiesvalvegrinding.com/port-polish.htm

[98valk]

Some say rough is better...as long as the ports line up. Rough creates microturbulance that yields a more thorough fuel/air mix.

only true of the intake port of the head and single carb manifolds.
this is not correct for an individual intake runner system (IR) as the valkyire and most other motorcycles. most are smooth rubber intake manifolds.

320 grit, finest wheel flapper available and 60 grit on the short radius will increase idle rpm and 1-2 mpg better.  IR manuals call for 400 grit.

[fstsix]

Some say rough is better...as long as the ports line up. Rough creates microturbulance that yields a more thorough fuel/air mix.

only true of the intake port of the head and single carb manifolds.
this is not correct for an individual intake runner system (IR) as the valkyire and most other motorcycles. most are smooth rubber intake manifolds.

320 grit, finest wheel flapper available and 60 grit on the short radius will increase idle rpm and 1-2 mpg better.  IR manuals call for 400 grit.

Not trying to start a pissing match, but one of the motors i had done was a VW dual port welded Ported heads, port matched and Turbo charged, do you have a Pro web site or link to help us out here for some info ?TIA

[John Schmidt]

Never been inclined to polish the intake runners, but I've read that porting the rubber sleeves to match the opening in the runners seems to help. Never tried it, just read about it. Might give it a whirl sometime down the road when the spirit moves me. The spirit hasn't been too active lately. 

[Robert]

I have done it to mine really no difference except the tinker factor was quite high a really satisfies that urge. Like I said the port that comes out of the carb is in no way a match to the intake of the head. Like has been said here the dimples in the casting may actually be better. If you had a carb that had a port the same size as the head then I maybe could see it but with the diameter of the carb roughly half the size of the port on the head forget it.No matter what you do you will have uneven air flow in the runner and like was also said the runner is a slightly smaller diameter than the head to even the two out may be good. Even at full throttle I would doubt that the runner in any form restricts the flow and may even add to turbulence because of the varying diameters that the air has to go through. Suddenly going from small to big will slow the velocity of the air down and not allow any kind of flow to really get going. Not to mention Honda designed everything to receive a very even smooth flow of air into the air filter housing and then into the cylinders. Most bikes have ram air no such luck on the Valk about as close as you get to that is the supercharger boys.

[NITRO]

Dag did it: http://www.valkyrienorway.com/Polishing%20Intakes%20NEW.html

I seem to remember him agreeing that it didn't do anything noticeable.

[fat6man]

Porting the Heads on the exhaust side will give you the most increase in power as stated earlier. As far as a 2 mpg increase for polishing intake runners DON"T HOLD YOUR BREATH!!!!!
When I polished mine on my 97 Tourer I noticed a possible 1/2 mpg Increase. Matching your Intake Runners to your Intake ports on the head will do away with miss matched sizes and help to minumize tubulance.
IT"S ALL ABOUT FLOW>>>>

[98valk]

Some say rough is better...as long as the ports line up. Rough creates microturbulance that yields a more thorough fuel/air mix.

only true of the intake port of the head and single carb manifolds.
this is not correct for an individual intake runner system (IR) as the valkyire and most other motorcycles. most are smooth rubber intake manifolds.

320 grit, finest wheel flapper available and 60 grit on the short radius will increase idle rpm and 1-2 mpg better.  IR manuals call for 400 grit.

Not trying to start a pissing match, but one of the motors i had done was a VW dual port welded Ported heads, port matched and Turbo charged, do you have a Pro web site or link to help us out here for some info ?TIA

not right now, knowledge is mainly from books (anything by david vizard, weber carbs, engine design etc) I have read over the yrs before the www.
 A search should bring up some sites and just go to a local mc slavage yard and check out all of the different intake manifolds always smooth if an IR system.
somebody did flow work few yrs ago and posted that the 60 grit on the short side helped some. might still be in the archives. I org did just 60 grit and gained 200rpms at idle, when I went back and did the 320 gained another 100 rpm increase.
The first time I also cleaned up the casting flash of the intake port of the head with 60 with the head in place.