How many of you are running ported saws

[Al Smith]

Oh I forgot to mention ,on the 038 mag which I've been into 4 times .The first go around I spent hours polishing and it was like a mirror ,ran okay .The next three times it was with the craytex but of course with some more port work included .Of course it runs better but as such with no comparison from just smooth to shiny I have no data to compair .

 

[HolmenTree]

Good questions here guys. I'm no expert on the subject, but I remember when I built my Yamaha 125YZ bikesaw almost 30 yrs ago, I bought a brand new cylinder for it and noticed the interior walls of the exhaust port had a dimpled surface of what looked like a thick coat of black paint. I checked the old cylinder and after having many hours on it its paint was still like new and had no carbon on it.
Always thinking shiny would be better I polished the new cylinders exhaust port, after lots of use the port stays shiny and clean but I often wonder if I should have just left the rough paint on which may have helped heat transfer.
I have heard to leave some roughness in the transfers and intake which helps keeps the air and fuel well mixed for better combustion

Willard.

 

[woodworkingboy]

Isn't the roughness on the intake an advantage in giving that 'swirl effect' already mentioned? As a rule, I polish the exhaust and leave the intake and transfers with a course wire brushed finish. Breaking down the saws later, there is usually a layer of carbon stuck to the exhaust port walls, so a mirror finish may not be that practical.

 

[HolmenTree]

Isn't the roughness on the intake an advantage in giving that 'swirl effect' already mentioned? As a rule, I polish the exhaust and leave the intake and transfers with a course wire brushed finish. Breaking down the saws later, there is usually a layer of carbon stuck to the exhaust port walls, so a mirror finish may not be that practical.

The "swirl effect" is made by reshaping the transfer ports or adding spiral finger ports to better help deliver the fuel/air mixture into the combustion chamber and exhaust exit.

Willard.

 

[Al Smith]

Bell ,Jennings and Mac Dizzey pretty much agree with a smooth surface but not a mirror finish .Some though that make some pretty hot running saws polish the dickens out of them so who's right is anyones guess .

 

[MCW]

Yeah it's a tough call. I'm sure if it was actually a mirror finish the "golf ball effect" would actually mean something. Just finishing it off nicely still means there are microscopic ups and downs. An old race engine builder (cars) that I once spoke to said the only heads etc he polished up to a really shiny finish were those run on Methanol. Why that makes a difference I'm not sure but he said he'd seen testing done somewhere to back it up. This is 20 odd years ago now. In all honesty though I'm not sure the really smooth finish offers much of a benefit as straight off the grinder but have never seen this comparison done. If I went out and polished up all the ports on my modded saws I'd probably not notice.

Then again if it does make a difference I'll be in for a long night and some blistered fingers

 

[Al Smith]

These comments are nothing new because I recall having the exact conversaions in the mid 60's and nobody could agee on what was best even that long ago .It was hot rod engines in those days though .

 

[MCW]

These comments are nothing new because I recall having the exact conversaions in the mid 60's and nobody could agee on what was best even that long ago .It was hot rod engines in those days though .

You were around in the 60's?

 

[Al Smith]

Yesere buddy ,sure was .Leather jacket, ducktail hair cut,the whole nine yards .

 

[MCW]

Yesere buddy ,sure was .Leather jacket, ducktail hair cut,the whole nine yards .

Please do not post photos Unless you wore flares. They were cool...

 

[sotc]

Shoot, I wanna see Uncle Al with a Fonz doo!

 

[CurSedVoyce]

Cigs rolled up in the sleeve... DA..

 

[Al Smith]

Unless you wore flares. They were cool...

What,bell bottoms? They didn't come into fashion until the 70's .However in the late 60's I had the real McCoy . US navy issued too .

Now the duck azz haircut,I quit combing my hair about that time but the damned stuff fell out anyways ,that kinda sucked .So here it is ,hair falling off the top but growing out the ears ,nonsense .No big deal, I wear a hat most of the time anyway except for those special occasions that are best left unsaid .