Posted by Sherman in Idaho [72.47.153.29] on Sunday, December 14, 2014 at 16:48:19 :
In Reply to: Re: Did you grind the valves? posted by Don in NH [96.61.88.160] on Sunday, December 14, 2014 at 12:04:34 :
I remember the discussion, but didn't know what you ended up doing. Nice to know you can get the compression up substantially by just re-ringing without having the cylinders bored. Given that most of these old truck were run into the ground, and that now we just want to drive them around a little bit for fun (maybe a few hundred miles a year in most cases), a shade-tree rebuild like that will probably be just fine. Or at least whatever condition you got it into now will stay that way as long as you have the truck.
I bet a lot of bearings got shimmed back in the old days. Remember the guys who used these trucks were used to all kinds of stationary machinery with poured babbit bearings, where you start out with a thick stack of shims between the bearing shells and then remove them one at a time as the babbit wears down. The previous generation of automotive engines had poured bearings as well, so it was a familiar scheme. I know one old-time sand and gravel guy who once had a truck with an out-of-round con-rod journal which he shimmed with beer can metal, clamped the rod bolts down tight, drove until it started knocking again, repeated, and so on until he had finally managed to wear the crank back into sufficient roundness that it quit eating bearings. You can get away with a lot with these old low-stress engines.