Olds 350 engine rebuild

[Hypn0tic]

Hey there, so ive recently obtained a 350 rocket that had some timing issues. Now before i get into this, the engine is hopefully a canidate for a complete rebuilt, with the stock crank and rods. It has also been rebuilt once before (.030 over bore, .010 under crank gave it away).
The issue with this engine is that there is major cam end play. So much play that it would move forward and throw the timing out to the point of killing the engine. Iam assuming the loose timing chain had something to do with it, but iam not too sure? What causes this? Can this issue cause major harm to the block where it would take alot of $$ in machining to fix? Thanks for reading!

 

[Gwarren79]

you could run a timing cover with a thrust button

 

[olds307 and 403]

I have never heard of this issue, not that severe. A thrust button might be the answer as said.

 

[fleming442]

Sounds like someone neglected to put the thrust button back in.

 

[oldsmobile joe]

i didn't know this could happen on a stock flat tappet olds engine.
could it be excessive crank shaft end play? or possibly a worn distributor shaft and bushings?

 

[olds307 and 403]

i didn't know this could happen on a stock flat tappet olds engine.
could it be excessive crank shaft end play? or possibly a worn distributor shaft and bushings?

This my understanding as well. Supposedly the flat tappet lifters and distributor pull the cam toward the rear of the block. Supposedly a roller cam does the opposite causing the cam to push forward. I would carefully inspect or better yet replace the distributor. I assume the cam, along with it's bearings and probably 24cc crappy cast pistons will be replaced in the build?