I got a tri-power I am putting on my SBC. The carbs need rebuilt. My question is-Where do I get over size throttle shafts for my bases? I found new bases and found carbs all set up for tripower. But my carbs are nice and thought I would do myself. Thanks for any help.
i dont think you want new shafts, you get bushings to go in the bases, you have to ream out the shaft holes and press in the bushings, you may then have to ream the bushings so your shafts will fit, then your old shafts will fit tight, i have in the past just cut groves in shafts and installed small o-rings, but shafts bushings is more common.
SPEEDWAY thats where i got all the new shafts for my carbs. The ones from speedway are slightly oversized to fix worn bases. No need for bushings or trying to drill the bases... take out the old shaft and reinstall with a new one from speedway and it slides in, nice fit no drilling... key here that i have been TOLD... DONT DRILL YOUR BASES, thats a fast way to ruin your carb!! Right ****STER27 ??... Hes the go to guy in my opinion, and thats what he told me.
Most of the bases that get rebushed, don't need it; and are bushed simply due to lack of knowledge or experience by those doing the bushing. On Rochester carbs (THIS IS DIFFERENT FOR OTHER BRANDS!!!) the design clearance of throttle shaft to throttle body was 0.004 ~ 0.006 inch. In practice, wear to a clearance of 0.009 would be acceptable for the hobbyist (a professional shop is probably going to use the design clearances). This clearance can easily be measured by using a dial indicator. Many who actually install bushings mess up the job. When installing bushings, the original throttle bore should not be disturbed, thus retaining the curvature where the shaft enters the throttle bore. Using a reamer or drilling through will result in a tiny triangle of "internal vacuum leak" on the load side where the square end of the bushing meets the curvature of the throttle bore. Bushing in this manner will normally result in difficulty in acquiring the specified idle speed. Jon.
heres a link to some info on tripower setup. http://www.jalopyjournal.com/forum/showthread.php?t=199455&highlight=tri+power+setup+2g