Well, I have some more time to mess around with the 304, I'll see what I come up with. If I don't see anything obvious I'm going to pick up a 360 a fellow worker has laying around that runs.
Well, I have some more time to mess around with the 304, I'll see what I come up with. If I don't see anything obvious I'm going to pick up a 360 a fellow worker has laying around that runs.
Has anyone experienced broken rocker pedestals? I've found quite a few that were broken after they were torqued down and engine was rotated around. Maybe the pushrods are too long in this application?
Several possible reasons. Pushrods could be too long, causing the slot in the rocker to hit the base of the pedestal. Too long a pushrod could also cause the valve to hit the top of the piston, the weak link is the rocker bolt. Check that you have the cam timed right, if your cam timing (at the timing gear) is off, the valves could hit the pistons.
What cam and pistons are you using? Have you had the block decked or heads resurfaced? Are you using 360 heads? The valve could be hitting the piston wall if you are.
I ran 0 deck flat top pistons with a .488 lift cam in a 304, and had to have the pistons fly cut because of clearance issues. I always test assemble and clay check EVERY engine I build for valve/piston clearance before final assembly.
Bob
tufcj
Last edited by tufcj; 01-25-2015 at 09:31 PM.
1969 AMX
1967 Rambler Rogue
If you need a tool and don't buy it...
you'll eventually pay for it...
and not have it.
Henry Ford
The 304 is bored .030 over with stock pistons. I'm using a comp cams 252 torque cam with a cloyes double roller timing set. Heads ( stock 304 ) were surfaced along with new valve guides, valves, seats and springs that came in the 252 cam kit. I have rotated engine around a million times to watch TDC of number one piston and rocker movement in association with damper marks, it appears to be on the money. That is the only thing I came up with, pushrod maybe too long for this application now. Coil bind I think would happen before piston interference in this case.
I ordered an adjustable pushrod, I'll see if my pushrod length is off.
I finally got around to pulling engine out and found that I must have been on crack when I put timing set on. It is a cloyes 3 key lower sprocket that I aligned on the wrong key. I lined dot to dot upper and lower sprocket, bottom key was set for advance or retarded.
I agree fully.... :)Originally Posted by jeepsr4ever
Posting Permissions
Reply With Quote
