Valve adjustment

[JayJay]

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Originally Posted by Joe K

The problem is you may have original "non-adjustable" lifters. If that is the case you need to "tear down the engine" and one by one measure and adjust each individual valve. KRW made a nifty "gauge/grinder" for doing this - and getting the adjustment right the first time. Quite ingenious their system. But few and far between either in those who have the system - or those who use it.

MOST engines once they have been rebuilt probably have "adjustable" lifters. Yours is most likely to be of this ilk. One of the modern "improvements" over the KRW system which allowed ANYONE with a single or pair of open end wrenches - and a feeler gauge now able to set their own valves. It put valve adjustments into truly "shade-tree mechanics" level.

There are two basic types of adjustable valves. The first and original version involved a lock-nut system where the two adjustment nuts "worked against" each other to "lock" the adjustment in place.

The downside of this system is that the mere act of adjusting tends to "upset" the adjustment as any "free-play" is found in restraining the system and happens as this free play gets taken up. You adjust for the proper clearance, and by the time you've put the lock nut in place and torqued it to value - you've changed the clearance. Very tricky and intricate to use.

The second and only slightly later system involves a single lock-nut - but the nut is designed to be "self-locking" - and can only be moved under the influence of the wrench. Think "Nylalock" nuts which are similar.

When it came to me to make a choice between these two, the rebuilder (Richard Knight) recommended I go with the nylalock system as "easier" and probably (overall) more reliable. Which is where I went and where I remain to this day.

Richard may dial in here and confirm my decision and offer any "since then" improvements to that recommendation. Everything has a tendency to be "Improved upon" given time.

Joe K

All the overhead valve cars I've owned with solid (adjustable) lifters were the locknut type. After a while you do get a feel for them, but it's not all that easy. The trick I found was to rotate the engine with the starter (but disconnect the coil wire) while you adjust, feeling the resistance on the feeler gauge. You folks of a certain age, remember adjusting the valves in your VW Bug every 3K miles?

The flatheads I've had and reconditioned (mostly Model As), I've always put in the "single nut" type of lifter with the interference in the adjusting bolt. I've never had cause to regret going that way. In fact, I've had more issues with the locknut type opening up than ever with the single bolt type.