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When I put my new reeds in awhile back, I noticed that there was alot of casting flange in the intake area.....I mean alot. If I were to go in there and clean the flanging off, whould I be hurting anything? I would'nt disturb the contour of the ports, just cleaning and smoothing the intake runners.

Jon.

You do not want to "polish" intake ports. For the simple reason fuel and air needs the turbulence to mix well and the rough walls help this process. Casting slag can be cleaned up somewhat but usually if it's not in the way, I wouldn't mess with it.

Jon,

I noticed the exact same thing as you a while back. Being completely ignorant of porting issues, it seemed to me that getting rid of all that casting would have to help. I was even going to post some pics to find out if my bike was a fluke, with the large casting ridges in the intake ports.

So I did some searching re: "porting" and came up with some interesting info.

URLONE[url]

URLTWO[url]

URLTHREE[url]

My reading says that Indawoods is right. It's possible to do more harm than good.

I can see it both ways. All engines are like air motors so to speak. The faster the air in and the faster the air out the more the power. Theres a ton of other spects to this such as torque and so on I know. A smaller intake port should equal more torque but cut the top in. I also no the more turbulance you cause in the intake runner the more it costs you power also. This is some of the problems that plague throttle body intake systems on some old Chevy truck engines. It's just stuff that I've picked up along the way from performance magazines and a good friend of mine that races and builds engines. If this were an automotive engine, I would'nt have any problem cleaning the casting flanging out. So being new to motorcycle engines, I may just leave it alone because it runs pretty good now. I'd hate to do something that would kill the performance it has now. I have to remind myself that it's a trail bike and not a flat out drag bike or MX bike where it will see alot of top-in, because it does'nt see alot of top-in. Sometime you have to look at what your particular situation is and what you will be doing with the bike the most, Motocross track or trail riding and hill climbing. I trail ride and hill climb more than playing on the track where my bike is not meant or designed to be. So I'll take your alls advice and leave it alone.

Thanks guys, Jon.

re: ' just cleaning and smoothing....'

Uh-oh. Probably not.

Towit:

'Smooth out any bumps...'? (urlone) That's bogus. Which is why EG said:

In fact thats one of the three observations that Rich and I use to critique a tuner's expertise when we examine ported heads. ...... 3) removing the anti-reversion steps in the exhaust port

re: Surface finish is irrelevant to flow or atomization. (urlone) That's bogus. Which is why EG said:

Or polish the snot out of the intake port so the fuel just dribbles into the combustion chamber...

Just a couple of 'facts' that you can find here and there that are WRONG.

Point is to agree with what Jeff said (farmerj)..it's possible to do more harm than good.

I would probably say 'likely' instead of 'possible'.

Take a look at my gallery. There are before and after-port pics of my cylinder. You might get an idea of work done by whom some consider to be the best kdx port-guy there is (Fredette).

cc, are you saying that Eric Gorr said it is bad to polish the ports? This is purely for informational purposes only. I do well to stay away from working on areas of the bike I should not touch.

Thanks.

Never ever polish ANY internal combustion intake tract that you expect fuel to stay in atomized supension in. Be it your 2 stroke engine, a four stroke motorcycle engine, or even an automotive engine.
The surface tension of a liquid will smear across a polished surface and collect rather than be wisked off rough texture surface and re-atomized.
The more atomized the fuel droplets are the more efficiently they will burn. Exhaust ports are a different story. They need a smoother surface to flow air better.

kinda sorta ya.
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Kinetic Honda history

BJH wrote: The more atomized the fuel droplets are the more efficiently they will burn. Exhaust ports are a different story. They need a smoother surface to flow air better.

kinda sorta ya.

kinda sorta---gets pretty technical when discussing flow characteristics and the boundary layer---more critical at higher rpm, drag vs. flow---i'm in the texture intake smoother exhaust camp. please correct me if i'm wrong, but doesn't a textured surface flow better via disrupting the drag caused at the boundary? like a golf ball?

Those dimples actually are there to give the ball lift while spinning. That's why if you hit it wrong ie put the wrong spin on it. The ball will hook left or slice right. Kind like the stitching on a baseball allow you to throw a curveball.
I could be wrong...but I believe strictly air will flow better on a polished surface. I know for a fact that pure liquids will flow better on a polished surface. At higher speeds. At severly low speeds the "Reynolds effect" does not take effect and it doesn't really matter what the surface is. But that is at VERY low speeds.
I also strongly believe that atomized fuel pushed / pulled by air flow will stay in suspension or be re-suspended upon impact with a boundary that has a textured surface.
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MAC GAME

re: 'are you saying that Eric Gorr said it is bad to polish the ports?'

HE said it, not me. It's a quote from the first link that farmerj posted. Pretty much, 'polish good?' Answer, 'No!!'

Of course, that doesn't take into account the possibility of pronouncing that 'pole-ish' or Polish. That has to be good.

...but then, my name actually ends in '..ski'.

Take into account that, considering EG's post, snot may well be an issue!

There was a comment in those posts saying 'polishing is good' that is wrong. And the whole idea of 'removing bumps' is likely not a good thing. Sometimes those bumps are there for a reason and a purpose; and to remove them thinking you are making the port free-flowing' is....

BOGUS!

Thanks for the info. I appreciate it!