Setting adjustable tappets

[Hunter1953]

Been here for quite a while, but no need for questions asked because all the answers to my mechanical problems were found here in the forum. Thanks a lot to all of you.
Now I own a California import A 29 Speedster with a rebuilt motor that needs to have the valves adjusted. The motor has new adjustable double self-locking-style tappets ( see Mac`s catalog page 84 ) installed and I am not sure how to set them right.
Do I just have to holt the tappet with a 1/2" wrench and turn the adjusting screw on top with also a 1/2" wrench in or out without holding the 7/16" wrench size split nut? Or do I have to hold the 7/16" nut and turn the adjusting screw in or out ?

[David R.]

The bottom nut is a jamb nut. The top one gives the adjustment. The bottom nut you tighten against the tappet to lock the setting. Recheck them after locking to make sure nothing moved. You need two tappet wrenches. I like to use two fielders gauges and do a go and no-go with one size over and one under the desired clearance.

[old31]

More info on adjusting the valves.

If you have adjustable lifters, the best method is the "Rule of Nine" method.

Number valves from front to back 1 through 8.

It is fairly easy to determine when a valve is at the top of its lift visually. When #1 valve is at the top of its lift, the valve you adjust is “9” minus the valve number at the top of its lift, in this case #1, so 9-1=8. So you adjust valve #8.

Continuing, just watch for the next valve that comes to the top of its lift, subtract its valve position number from 9 and adjust the corresponding valve. You only need to rotate the crankshaft through 2 revolutions to complete the adjustment. You’ll be adjusting the valves in non-numerical order. I put a piece of masking tape along the bottom of the ports and mark the settings there and cross them off as I finish each valve lash setting.

Valve 1 at top adjust valve 8 (9-1=8), 2 at top adjust valve 7 (9-2=7), 3 at top adjust valve 6 (9-3=6), 9-4=5, 9-5=4, 9-6=3, 9-7=2 and finally 9-8=1.

If you use different clearances for intake and exhaust, you need to pay attention.

http://www.fordgarage.com/pages/ruleofnine.htm

[wmws]

I just take all the plugs out so the engine is easy to turn. Then get the valve all the way open Then make exactly one revolution of the crank which is 1/2 revolution of the cam so I know the lifter is on the heal of the cam. Then make my adjustment.

[PC/SR]

What WmWs says. You can eyeball the top of the lift, turn crank from there, but cannot eyeball the dead bottom.

[Jim Brierley]

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You say they are self-locking, but the picture shows what are commonly called "double-nut", which are not self locking. Either way, use the rule of 9's as WmWs says. If the speedster has a performance cam installed, the valve clearances may be different than stock. Good luck!

[Kurt in NJ]

Use 3 tappet wrenches, hold the tappet with one, loosen the middle nut some, hold both those wrenches, turn the top to adjust, tighten middle nut while holding top and bottom wrenches

[Hunter1953]

Thanks a lot.
I will do what Kurt NJ says.
Already knew the rule of 9, but the tappets were new to me.

[Jim Brierley]

I've only seen that kind of tappet once before, the split nut is a wedge that tightens around the adjusting screw. They work but are difficult to adjust.