Adjusting Model "A" Valves

If your car is equipped with Model A Ford tappets you will need the previous instructions to find the heel of the lobe, but you will adjust the valves by grinding either the face or heel of the valve depending on the direction you will need to adjust.
 
If you have adjustable lifters, the best method is the "9" method.

Number valves from front to back 1 through 8.

It is fairly easy to determine when a valve is at the top of it's lift. When you have reached that position on #1 valve you adjust the corresponding valve to equal "9". In this case it's #8 valve.

Continue with 2&7, 3&6, 4&5, 5&4, 6&3, 7&2 and finallly 8&1.

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

Good Luck

Richard
Anaheim,CA
 
I've adjusted valves on our Open Pickup but have the tough part to go. The truck's tappets are adjustable but have the double nut locking setup. The block has not been machined to make holding the tappet/locking down the nut a simple task. In fact, I think I will have to grind a 1/2" tappet wrench down to the thickness of a dime to geterdone.
Any tricksy methods to make this easier? Gotta finish the job to get back on the road in time for Fox Valley's Model A Day drive to Starved Rock State Park on Saturday.
 
Roadster he will need to grind the valves. A slight tick is not a big problem. As a matter of fact when you cannot hear them they may be set too tight causing them to burn prematurely due to not having enough time on the seat to cool properly.
 
Bruce said:
I've adjusted valves on our Open Pickup but have the tough part to go. The truck's tappets are adjustable but have the double nut locking setup. The block has not been machined to make holding the tappet/locking down the nut a simple task. In fact, I think I will have to grind a 1/2" tappet wrench down to the thickness of a dime to geterdone.
Any tricksy methods to make this easier? Gotta finish the job to get back on the road in time for Fox Valley's Model A Day drive to Starved Rock State Park on Saturday.
Click to expand...

I feel your pain. It's especially bad with reground cams with a small base circle. I had to rotate the cam to a minor lift to get at them and back to the heel to measure. Lots of turning, but it gets it done.
 
There is a way to know just how many thousands to turn the tappet by figuring how many thousands a complete turn of the adjusting screw makes and then working out how much an 1/8th of a turn adds to the measurement. A quarter/20 nut does 20 revolutions in one inch of travel so 1 turn of the nut travels 50 thousands, an 1/8 turn just over 6 thousands. figure out what adjustment you need, make the adjustment at the bottom of the tappet travel and it should be spot on. You can do a 16th rev if you take a little time and get a 3 thou adjustment.
 
I was never very good at math but I think that a hex flat will equal .083". I guess I need to find my caliper and see just what it comes out to.
 
Bob, your method is pretty much what I did, except I eyeball the portions of the .007 per flat of the adjuster for intermediate readings. I am not looking forward to doing it with the motor in the car with the manifolds in place.
 
If the head is off, you can get real close by using a dial gauge to measure valve lift. It should be lobe height minus lifter clearance at the top of the lift. Works real good when reassemblying the engine before putting on the valve springs.
 
Many thanks to everyone for the info and advice. I will tackle the valve adj task next week and let you know the results.
Bill Lee/Virginia Peninsula
 
In looking at the lifters while the side engine cover has been removed, I see a bolt that the valve rest on that screws intot he lifter. I do not see a nut on this bolt to lock the bolt once adjusted. Is this normal? will the pressure from the valve spring keep the bolt located hwere it is adjusted to?

Thanks
 
Dave in Denver said:
In looking at the lifters while the side engine cover has been removed, I see a bolt that the valve rest on that screws intot he lifter. I do not see a nut on this bolt to lock the bolt once adjusted. Is this normal? will the pressure from the valve spring keep the bolt located hwere it is adjusted to?

Thanks
Click to expand...

Sounds like you might have self-locking tappets; where the threaded-part goes into the tappet: are there two flats ground on the tappet so that you can hold it with w wrench while adjusting the hex-head part ?
 
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