Valve lash is not holding steady after first few runs:

First run: lash opened .006 Second run: the same thing. Third run: I adjusted lash again at .020 cold and then ran the engine for 5 seconds. The lash has opened up again, this time after just a few seconds. I think that if there is something failing at this fast of a pace it would be gone/done already.

The threaded adjusters measure .4360 on the OD of the threads, the ECG rocker ID measures .4395 on the groove. That is a .0035 difference without the depth of the grooves added.

I found two postings that both mention either damaging the threads or using oversized adjusters. Any words of wisdom will be greatly appreciated.

Rocker adj nuts
Loose rocker adjusting screws. - 332-428 Ford FE Engine Forum

Harland Sharp makes these screws but I'm not sure they will fit, threads are +.004 wider and the ball is +.0125 wider, If the 1.200 is the length of just the threads seems like they should be a tighter fit: 7/16 - 20 x 1.200, 3/8 Ball, Ford FE 






.150 Stroked Y-Block:327.25 ci @ >1hp per ci
 

From the pictures you have posted, your ball end of the adjuster is not riding true in the cup of the push rod. Once you have some wear between those two parts because the ball is trying to seat, that is what is giving you the extra lash.

Daniel Jessup

Lancaster, California

aka "The Hot Rod Reverend"
check out the 1955 Ford Fairlane build at www.hotrodreverend.com

The supplier told me that the problem is that the cup is not machined perfectly and the roughness in the cup is grinding the ball.

I have Smith Bros. rods on the way and Harland Sharp had some fat adjusters (.438) with 3/8” ball. Both made in the USA!

famdoc3, you nailed it. , DryLakesRacer I could not find a fatter bolt to try, they are all skinnier, real good idea. The mfg leads helped. Ted, as always, many thanks! 2721955meteor, when I had the covers off and primed the system there was oil at all of the rockers, after the short runs upon inspection everything appears wet. Daniel Jessup, the wear was opening the lash so quickly it seemed dangerous to keep running it. As a result of this group, I have again made another step in the right direction.

I hope you all have a great day!




.150 Stroked Y-Block:327.25 ci @ >1hp per ci