I'm building a honda gx200 (200cc 6.5hp pushrod) for a kart and I need to ream the I.D of the valve seat and the bowl, I need to find some reamers with 5.5mm (valve guide I.D.) pilots on them. something from 24-26mm.
I can't seam to find the kind of reamer I'm looking for. Mcmaster doesn't even sell piloted reamers, but if I bought one could it be turned down to have the pilot size I want?
it would have to be ground down. there are so many combinations of pilot/reamers...you should probably call a local tool shop that sharpens drills commercially. buy a reamer and have them grind the pilot on it.
well are you sure you need a pilot? reamers are generally not used to position a hole. the drill or mill used to rough the hole is used to put it in concentric to another hole. reamers follow an existing hole quite well and are generally 'floated' in at a machine shop. only used for more precise sizing and surface finish.
that's more than what you should ream. normally you would drill/endmill and leave about .003-.010" (0.1-0.2mm) to ream. not sure about the positional/concentric requirements in your application, but you may consider just following it with a drill and then reaming it (without using a pilot). but i'll leave that advise to engine/valve experts.
Help me out, is this kart takin'; the place of the Miata? The 450-four-stroke-in-the-125-GP-frame? The hovercraft?
no, it's just a winter project. It's fairly cheap, I got a used motor $118 shipped and there are plenty of rolling chassis for under $500. The miata is going to be a car I drive to get to a job so that I can afford to build the 450 in the 125 frame. I kinda lost interest in the hovercraft since they don't work well in tight hilly areas (my neighborhood....), so maybe when I buy my own house with some land.... BTW, a lot of the question I ask are so I can learn more about the subject of that question. Sometimes I figure out that what I want to isn't very practical or I just don't have the money to do it, right now atleast.
These guys are great for weird drill bits, router bits, etc. Give them a try. http://www.performancelinetool.com/
Contact NewayMfg. Corp. at http://www.newaymfg.com/frame.htm They will make custom sized pilots if you need it. I like their pilots because they are tapered ever so slightly, which helps them install and center well.
Eagle machine in winder,ga if you like I am heading up there soon with a head for just that bigger valves ect I could take it up for you....