Car wont run for nothing, new heads, fresh intake seal, opened timing cover and found unequal wear on cam gear to dist, and the distrib gear shows irregular wear also , the cam is worn on the fuel pump lobe up and not on the fuel lobe down, , rattles in the distrib, can this be the distrib riding up and down in its casing shaft? and the cam may be bent? anyone help was a great motor well maintained and this comes up and I have never seen any buick motor do this before, it will run give throttle and run in out of gear, when dropped in gear the car drops to a bad lope and wont go and almost dies, the gears are showing minimal wear on the timing chain set, will chaining of the cam and lifters fix this? or is there other things to look for? help, craig minneapolis bca 27925
What oil pump are you running? How long did it run good before this... is this a new engine? Were any changes made to the engine recently? New distributor or high volume/high pressure oil pump? If it has 10,000 miles on it and it suddenly started doing this, then I'd rule out stuff like a bent cam. I've heard of 455's eating distributor gears before but never found out why.
From what i understand, running a high pressure pump will eat the gear, AND the teeth on the camshaft if you are not careful. I know there are other reasons, but that seems to be the biggest. There is a dist gear oiler setup you can buy that will spray a mist of oil on the dist/cam gear area. Sometimes I think they are also used as a safety measure as in the case with my motor. Also too tight clearances in the pump itself will cause a strain on the gear. Some people run the bronze gear so that it will be chewed up before the cam gear since it is easily replaced. If the cam gear is damaged, then you are screwed. New cam time! I think though that mostly racers use the bronze gear as they don't last very long at all! I have a steel gear in mine. If there is too much wear, your timing will be all over the place! Brian
Rattles in the distributor? How do you know this? Did you open it up and find the shaft to be sloppy in the bushings? I've seen this before (bushings worn out). Will cause the timing to be ALL OVER the place.
rattle in dist yes the dist, feels like it is floating up and down in the play of the shaft and causing a rattle or chain slap sound, just started, only ran engine about 15 min and shut down when hot light cam on and could not get timed, chain is good not a high vol pump only a factory gear pump. Going to roll engine over with the starter today and see if can see and play in gear of cam. thanks craig
Just a note to say that it does not take much to tweak or bend the cam between the fuel pump lobe and gear. Check the cam gear eccentricity. also, the biggest cam/dist gear interface failures are generally due to the loss of oil to those gears when the cam moves forward away from the block. If undue wear has occured, you CAN replace the gear on the cam. I think BOP Engineering is making a composite dist gear that may outlast bronze.
uzzled: Last time I checked, the gear that drives the distributor on a Big Block Buick camshaft is cast into the cam itself and is NOT replaceable. uzzled:
Guys, yes the cam gear is cast in the cam core and yes it CAN be replaced-with a little machine work. I've done several (20+) over the past 20 years or so with great success! This operation offers a much more economical alternative to cam/lifter replacement!
