Thread: Fixing a strange engine noise and then some

Tweet

Sounds like you made up your mind but, you can borrow my adjustable push rods and tester springs...

Why are you after more pre-load? What am I missing? Did you not just set pre-load to spec?

Originally Posted by 34_40

Sounds like you made up your mind but, you can borrow my adjustable push rods and tester springs...

Why are you after more pre-load? What am I missing? Did you not just set pre-load to spec?

I'm at the 'bitter end' of the minimum of ~.020 (spec is .020-.060). Preload on these pedestal rockers is set by guess and by golly - you bolt the rockers in place, make sure the assembly being adjusted is on the cam base circle, then torque to 18-20 lb ft. If it takes a quarter to half turn after first contact to reach that torque figure, it's supposed to be 'in spec'. Now, this is conjecture - if the oil pressure dips a few psig, the lifters seem to lose their capability to stay pumped up. When that happens, clatter and the engine idle capability dies as well. With a cold engine, carb on high idle (1000 rpm or more, not a whisper of clatter. At 190(operating temp), 800 rpm idle, some clatter, drop it into gear, haul the engine down another 100 rpm or so ---- you get the picture. Now, pull the engine apart. replace the Fel-Pro 10112 .039 compressed thickness head gaskets with the 'recommended' Fel-Pro 9333Pt1, .047 compressed thickness - it will, I'm sure, get worse.

What I'm trying to do is get some adjustability in my valve system - and pedestal mounts aren't what I need

Originally Posted by IC2

I'm at the 'bitter end' of the minimum of ~.020 (spec is .020-.060). Preload on these pedestal rockers is set by guess and by golly - you bolt the rockers in place, make sure the assembly being adjusted is on the cam base circle, then torque to 18-20 lb ft. If it takes a quarter to half turn after first contact to reach that torque figure, it's supposed to be 'in spec'. you get the picture. Now, pull the engine apart. replace the Fel-Pro 10112 .039 compressed thickness head gaskets with the 'recommended' Fel-Pro 9333Pt1, .047 compressed thickness - it will, I'm sure, get worse.

What I'm trying to do is get some adjustability in my valve system - and pedestal mounts aren't what I need

I haven't kept up with this thread so thanks for the additional info. I also don't understand the head gaskets coming into play but no matter..

I will agree with Pat, you already know the length, just insert longer push rods, I'd go .020" 'cause that should get you close to the middle of "the spec". But, that's my opinion, fwiw - ymmv - imho - yada yada yada...

I'll be watching for a conclusion! Should I put on my cheerleader gear now?