The Ford Barn - Screw size?

The Ford Barn (https://www.fordbarn.com/forum/index.php)

- Model A (1928-31) (https://www.fordbarn.com/forum/forumdisplay.php?f=3)

- - Screw size? (https://www.fordbarn.com/forum/showthread.php?t=211449)

What size screw goes into the block to lock cam? Mine rusted out. Merry Christmas!!

A spring and plunger push the cam rearward, but there is no screws and plate such as found on a Chevy 6.

If you mean the oil passage plug, it's a 1/8" pipe thread. All the dealers sell the correct slotted plug for the hole.

Are you referring to the binding head like screw that fastens the distributor cam to the shaft? If so, you really need to buy the special screw from a model A parts supplier with a hole drilled in the head of the screw, so the bushings can be lubed without removing the screw/cam. You would need to drill a hole down the middle of the shaft to the crosswise hole for the oil to reach the bushings. Ford didn't do this, but I think the minor alteration is a good idea. There are strings on Fordbarn that describe the process, if you do a search.
Rusty Nelson

Quote:

Originally Posted by wrndln (Post 1404555)

10-4 that's the hole right below distributor. Thanks! I'll order one!

the distributor lock bolt is 3/8 NF

Boy what a confusing thread, talking about three different things.
Camshaft plunger, distributor cam screw, and distributor lock screw.:eek::D

Bob

Note: there is no screw involved with the camshaft plunger, just the plunger and spring. The original post was a little confusing, mainly because the post mentioned "block", instead of distributor shaft.
Rusty Nelson

I don't think he meant the distributor shaft as he says "10-4 that's the hole right below distributor."

Quote:

Originally Posted by Bob C (Post 1404653)

I don't think he meant the distributor shaft as he says "10-4 that's the hole right below distributor."

X2 on that. :confused:

I haven't purchased a repo dist. lock screw in 20 plus years but when I did the diameter of the cylindrical projected part of the screw that fits in the groove, machined around the dist., was too large and would not go in the groove. I had to turn the size down to fit. Maybe they are the right size nowadays from the vendors but don't count on it.

The area near the groove where the lock screw makes contact is enlarged and distorted on many a dist., so I don't know if the maker of the repo lock screw thought a larger diameter on the end would work better or they just goofed and made them the wrong size. More than likely it's the latter.

The groove on many would not be goofed up if people would not strong-arm the screw when they install it. Also, some engine blocks have been decked so many times as well as the head resurfaced so many times that all the clearance in the slots on the ends of the lower dist. shaft/shafts is used up and then some, slightly, when the dist. is installed. This prevents the lock screw from being centered in the dist groove because the dist. cannot be fully seated down its hole. The lock screw hangs on the edge of the groove and goofs it up when the screw is strong-armed.

When the dist. is fully seated in its hole and makes contact with the boss on the head,
the lock screw just needs to go in far enough for the end to go in the groove, and the jamb nut locks it and keeps it in position. Also, the threads on the hole are fairly delicate, so strong-arm can strip them and sometimes even crack the dist. housing. It's not the pressure of the tightened screw that keeps the dist. from trying to pop out of the hole when going over a bump in the road, it's the end of the screw being seated fully in the groove

Embarrassing question :o: I have just spent a very frustrating 30 minutes trying to seat my distributor properly in its hole. I know it will go down onto the head because it just came off there, but now it will not go back down flush with the head. Is there a knack to this?

I have just discovered that it WILL go on, but only if the distributor is rotated 180 degrees so it now faces the wrong way - ie the ignition cable now comes in from the RHS side. Does this mean the motor is timed 180 degrees out?

Mac set the distributor in its proper position and turn the rotor until it drops in. check mating parts for burrs too.

Quote:

Originally Posted by J Franklin (Post 1412163)

Mac set the distributor in its proper position and turn the rotor until it drops in. check mating parts for burrs too.

Got it! Thanks J Franklin. Its problems like this that make me realise (again) that I have no ability with auto-electrics. And what a great resource this forum is!
Mac