I was thinking the same thing Saturday on the way home from the CVA Convention. Mine have not been adjusted in 10,000 miles and now seem quieter than they used to be.

Only thing I can think of that woud tighten them up is valve seat recession from unleaded fuel. I used to use a lead additive till around 5,000 miles ago but stoped after an internet debate convinced me it was not needed.

Will report back after I adjust them

Thanks Joe, I saw where it said to perform with the tune up but missed the mileage. Looks like I'll be doing it every couple years.

Mike

1956 Fairlane Victoria (ORREO)

 

Overlooking Beautiful Rimrock AZ

The 1957 Shop Manual calls for valve lash adjustment as part of a tune up, which is recommended every 5,000 miles.  I've never done it that frequently and have had no adverse effects in 40+ years, but that's what the book calls for.

My 312 now has 1300 miles on it after rebuild so I took an hour and adjusted the valves. They were originally set at .018 and were now .019-.020, I was very happy with this. It got me to thinking though, what is the adjustment interval? I couldn't find anything in the service manual or with a search on the board. I was thinking every 4000-5000 miles? What seems to work for you?

Mike

1956 Fairlane Victoria (ORREO)

 

Overlooking Beautiful Rimrock AZ