im getting ready to port my stock moby fast cylinder.i see lots of posts about porting, but no mention of what tools people are using. i have read on some sites not to use a dremel. so whats everybody using?
im getting ready to port my stock moby fast cylinder.i see lots of posts about porting, but no mention of what tools people are using. i have read on some sites not to use a dremel. so whats everybody using?
My tool of choice is a Sioux pneumatic micro die-grinder. But my tool of reality is a dremel with a flexi-shaft. You can find useful porting bits for ferrous & non-ferrous applications in a machine shop supply catalog, such as Machine Shop discount supply. -Or you can do what everybody usually does and just make the normal dremel bits work.
Did you read the article on motobecane porting in the wiki? Carbide dremel bits like the dremel 570 work good, bit moderate porting can be done with needle files. It'd take longer but you can be more careful. Be sure to chamfer port windows when finished and thoroughly wash the cylinder to remove any metal shavings.
This is where you buy real porting tools and equipment. A 90* tool is the only accurate way to get into the transfers & boost ports.
yeah im just gonna do a simple porting job like this -> <url>http://forum.mobcustom.com/vt46063-tuto-preparation-simple-cylindre-av7<url>;
nothing too extreme,keeping it simple.
Then you're probably OK with the usual Dremel stuff unless you want to invest in some real carbide burrs. Use double cut carbides for steel, and single cut (open fluted) for aluminum with wax to keep them from loading up. Follow up with stones for a nice, slightly rough finish on the intake ports. On the exhaust side, many tuners feel that polished is best to prevent carbon buildup. The other school of thought is that the slight layer of carbon helps to insulate against heat build up in the cylinder and send it to the expansion chamber where it does more good.
Take it easy, you can go too far and you can't put it back. You can always buy an extra cylinder to experiment with for more extreme porting mods.
i have a couple severely gouged cylinders to practice on, before i try it on the real thing.
the best tool is a pneumatic die grinder as you wont wear or burn any motor out..... dremels do get expensive if you have to keep replacing them ......
If you are getting a rotary tool keep in mind that Dremel is not the only brand; Dremel tools are kind of the chevy cavalier of rotary tools, they work fine for a while but with heavy use you throw them away. I have a Proxxon rotary tool (Cadillac, or benz) and love it. Its really only a little bit more expensive than a dremel and much better quality. Check them out on Amazon or your online store of choice.
Eric, that mob custom preparation article is solid. I followed it on two cylinders I modified. I got a 20mph cylinder to ~30mph and a 30mph cylinder to ~40mph following it, both with the stock exhaust and a 15 sha carb. I did a much better/cleaner job porting the slow cylinder then the fast cylinder, and still got stellar results out of the fast jug!
It's a bad idea to try and modify the transfer windows in the cylinder, they are usually angled for the best scavenging results. If you want to increase their timing, raise the entire cylinder up and shave off the top.
Yeah, do it with a Riffler file...It'll be harder to screw up, and you might even become an arm wrestling champion.
i have a dremal that is 6 years older than me... its 21 years old and still works like new. unless maybe the quality of dremals have gone down since then...
i have it case matched,and am not going to mess with the transfer ports.
Hey Eric. I am in Inverness, and can help you with it, if you want. bkuzisa@aol.com I have the tools , and have done it a few times ; ) Brent
I have a friend that has been porting for over 40 years now and yup he showed me that sioux tool the other day has said it was very cheep but it works good and is small. As far as sanding he finnishes with a shaft he makes slit in the end of it then uses a strip of sand paper put through the slit and puts it in a air die grinder so it just flaps around it works good some times puts mothers polish on it as well.
cool, ill send you an email.
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