The rods are fitted to the crankshaft using a tube of Prussian Blue and a bearing scraper, and LOTS of time! Spread a thin layer of blue on the bearing surface, snug the rod cap slightly, and turn the crankshaft a little. Tight spots show up as bright streaks on the bearing material. Scrape a thin layer of Babbit away at the high spot, spread more blue, and do it again- - -and again- - - -and again! It will take an hour or more per bearing to get a perfect fit between the shaft and the bearing, after which shims are added to establish the proper oil clearance. I've watched my father do this dozens of times, and I've done several rod-fittings myself. The insert bearing conversion is a lot less work, and nobody will know the difference unless the engine is torn down.
Jerry
Edit: I just looked at the Egge site, and the "semi-finish" they mention is for poured-in-place main bearings, like a Model T engine has. They say they can final-finish babbited connecting rods if you provide the crankshaft rod journal diameter. Hand-fitting with Prussian Blue is still the best method of assuring a perfect fit. When I worked for Standard Motor Parts in Nashville, Tennessee I machined stovebolt rods for insert bearings. John Rippetoe, Jr. is running the rod room now. Give him a call and he can probably do your rods quicker than Egge can. (615-297-1622)
Jerry
Last edited by Hotrod Lincoln; 07/12/2008 4:00 PM.
