A polished intake is only a smoothened intake??
A ported intake has had the intake size increased??

What should a trail rider that has a stage II get??

I am HIGHLY conisdering getting some head work done while the head is off. But I am not realy sure what head work is [img]i/expressions/face-icon-small-smile.gif[/img]
Help me out....

 

porting most typically refers to the smoothing of burs and casting flash in the intake and exhaust ports, and the matching of the intake manifold ports to the head ports so that there is no obstruction to hinder air flow. This is the minimum that should be done, and is pretty much the cheapest portjob you can do for minimal money with great results.

Porting can also refer to the enlarging of ports as well. There are ideal intake to exhaust flow ratios that a knowledgable machinist will try to obtain if he has a flowbench that can measure air flow, and the mathmatics involved would also take into consideration the cams if the guy is really into it deep.

Polishing refers to the polishing of the EXHAUST, but you DO NOT polish intake because too high a polish on the intake will hender air/fuel atomization. Polishing of the combustion chamber is also sometimes done. The polishing of the exhaust not only improves the exhaust flow, but also helps reduce carbon buildup. The intakes will sometimes get a spiral hone, to actually aid in atomization, I have this done on my head.

 

good job hightower you made that one simple

 

how much did it cost to have your head done??
Will I notice a differance with the 42 carb??
Or shoudl I wait until I get the carb to do the porting and polishing?

 

mine cost about 200 for boring and renikasil,almost 200 for the piston,,about 150 for porting, i would say as long as you have it apart now you might as well do it all

 

yes it will make a difference with a 42 as well. I know people who have done the basic porting while still using the stock carb, and even they claim a very nice improvement in top end, but i can't describe exactly how much gain you get from porting alone because I had my porting done while my head was off for valve spring replacement and piston install. Don't expect too much though, any one thing done isn't much, but all of them added together are huge.

I payed $200 for my portwork, I know a guy that knows a guy so i got it discounted. This machinist did a great job - ported intake to match carb, port head to match intake perfectly, cleaned up and smoothed all head ports and finished with spiral hone to aid in atomization. he as done many Rotax heads.
How much you pay depends on the who does it and their experience level I guess, $250 is probably average for the work i decribed here on a DS head if done by an experienced professional, some may do it for less if they are still growing, and others charge more if they advertise and feel like their experience warrants a higher level of precision.

And then there also plenty of guys who do their own portwork at home with a diegrinder and files, with some having better success than others, so if you do this be certain you are comfortable and experienced with the tools at hand because you can slip up and screw up all too easy.

 

Yup some do![img]i/expressions/face-icon-small-happy.gif[/img]

 

what kind of a tool do you use to get the spiral hone in the ports

 

I've talked to three people and porting and valve job was around 400-440$! remember you get what you pay for!

 

I don't know Crazy, I've never done it, but it sure is pretty.