72 K10 350 skips after warmup

[clyde72]

my first thought was the cam, and it could very well be, Im thrown off by the good compression and visually the rockers look to be moving the same, i have a video of them, Ill try to post it.

[Sheepdip]

Originally Posted by clyde72

my first thought was the cam, and it could very well be, Im thrown off by the good compression and visually the rockers look to be moving the same, i have a video of them, Ill try to post it.

An exhaust lobe won't really affect the compression as it's not a sealing problem it's an opening/exhausting problem. You would have to set up a dial indicator to properly check or compare the difference in the lobes.

[clyde72]

O.k., so a problem has , as they say "manifested itself", wound it out pretty good leaving my driveway, 4500, resulted in a buncha backfires followed by noise, I turned around and slowly drove it back to the garage, noticing that it really wasnt running any different, same skip. noise was coming from #1 side so I pulled the valve cover finding an obvious problem, the pushrod on the very first valve was pushed right thru the rocker.
giving the history of consistant issues with the #1 cylinder what do you think is the cause, Ive had the cover off and have a video of that side running and there alway seemed to be oil shooting out of it

[Steeveedee]

Do you have some way of forcing the valve to move (engine off)? It may be seized? Binding could cause the wear you're seeing. See in the valve stem is the same height s the rest.

[clyde72]

my stubborn self just wasted more time trying to find the lifter with the pushrod to put on a rocker i had here, I cant seem to land it, who knows if the lifter is still in the hole,...Im thinking its time to throw in the towel on this one, its been annoying me because ive been thinking it might be something simple where I wouldnt be tearing into the motor which would end up as a total rebuild, and i have/had a thought I might keep the truck more stock with the 350, Ive had a few smallblock quadrajet vehicles in the past and have good memories along with bad. The amount of time Ive put into chasing this down I couldve had it yanked and been well along with detailing the engine bay for the 5.3., which is going to make it a better truck, why am I fighting to preserve my 9 mpg motor...
I think its time to switch over to the "LS swap" threads. Thanks for all your help.

[clyde72]

O.K.,after picking up the 5.3 and reviewing the work thats going to be needed to do that right,(detail engine compartment, dod delete, fuel tank, etc) I,m putting that off till winter, maybe not even this winter. I couldn't resist taking it apart...definitely some worn cam lobes and a broken valve spring, decided to do the cam and lifters, dropped the heads at the machine shop, rest looks good , no ridge in the walls etc., Will be a good motor for our 57 4wd long bed when I take it out. The 400 thats in there from when we got it is pretty cobbed up.