Lifter noise after head gasket replacement
Thread Starter
Drifting
Joined: Dec 2009
Posts: 1,349
Likes: 34
From: Porterville Ca
Lifter noise after head gasket replacement
My 69 427 had a leaking head gasket after sitting for much too long. I replaced them and had the heads checked and valve job done. I had one or two bent push rods and the heads were basally ok, They didn't need to be surface, it was just a freshen up and the local machine shop. Ever since then I have what I'm considering lifter noise. I'm a former tech and never had any problems adjusting hydraulic valves on V8 Chevys. I've adjusted the valves probably 6 times and they're still noisy.
The process i use is to turn the engine over by hand and adjust whatever valve is next to a compressed (open) valve. Snug and 1/2 - 3/4 of a turn after that. I am getting oil to the top of the engine, but it wasn't really making a mess as I expected. I was thinking I'd pull the distributor and run an oil pump driver and see how much oil I get. Then just go ahead and replace the lifters. It doesn't appear to have any flat lobes and I've been running Redline oil with zinc. I really haven't driven this in the 20 years I've had it and I need to get it on the road!!
The process i use is to turn the engine over by hand and adjust whatever valve is next to a compressed (open) valve. Snug and 1/2 - 3/4 of a turn after that. I am getting oil to the top of the engine, but it wasn't really making a mess as I expected. I was thinking I'd pull the distributor and run an oil pump driver and see how much oil I get. Then just go ahead and replace the lifters. It doesn't appear to have any flat lobes and I've been running Redline oil with zinc. I really haven't driven this in the 20 years I've had it and I need to get it on the road!!
Melting Slicks
Joined: Sep 2005
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From: Warminster PA
Le Mans Master
Joined: Aug 2017
Posts: 8,336
Likes: 2,810
From: Cool Northern Michigan
central,
Only 8 pushrods will match each other on a BBC.
For a pushrod to bend something was bound-up. Perhaps a valve stem stuck in its guide.
Or, a valve head struck a piston top.
The Intake valve pushrod is 8.280 long.
The Exh rod is 9.250 long.
If someone put that Exh pushrod in the Intake lifters position, guess what happens?
And vice versa, you will never get the lash correct.
If you are getting oil flow at each & every rocker arm at idle, then there is no need to prime the pump or pull the lifters.
Some people think pushrods should shoot oil all the way across the garage. Seldom does that happen. Just need good flow, that's all.
Only 8 pushrods will match each other on a BBC.
For a pushrod to bend something was bound-up. Perhaps a valve stem stuck in its guide.
Or, a valve head struck a piston top.
The Intake valve pushrod is 8.280 long.
The Exh rod is 9.250 long.
If someone put that Exh pushrod in the Intake lifters position, guess what happens?
And vice versa, you will never get the lash correct.
If you are getting oil flow at each & every rocker arm at idle, then there is no need to prime the pump or pull the lifters.
Some people think pushrods should shoot oil all the way across the garage. Seldom does that happen. Just need good flow, that's all.
Last edited by HeadsU.P.; Feb 25, 2025 at 03:17 PM.
