'40 Torpedo 8 cylinder

I am perplexed:

What does this knob do?

On a '40 Torpedo 8 cylinder the are 2 distributor adjustment bolts. One for the gaselectic setting mounted on the block. Then lower down beneath the points/condenser housing there is a clamp screw. Once you loosen the bolt and set the gaselectic dial to neutral or 0 and tighten it, then you can loosen the clamp screw and adjust the timing. But that brass knob is loose and the I tried to turn the distributor and it was tight and didn't turn.

Is that knob there so that when you loosen the clamp screw you can tighten that knob to put drag on the distributor housing so you don't lose your adjustment when you re-tightening the clamp screw?

The knob is too low on the distributor for any type of dwell adjustment. Help ....

It is a grease cup. If you unscrew it, you can refill it with "cup grease" and put it back on. If you check in your operators manual or shop manual (both of which you should get) it will tell you to turn it in one turn every so many miles. On mine it is every 3000 miles. I don't think the type of grease is as important as using it. However I know of hundreds of guys that drove thousands of miles and never turned the cap. Originally cup grease was lighter and not fibrous like wheel bearing grease. This is what lubricates the top bearing in your distributor shaft.

Hi,

I just checked the cup for grease. Golly, though there was something that resembled grease it was definitely old and the cup probably had not been turned for a long time. I cleaned it out and refilled it. I turned it in so about 1/2 the threads were showing and then started the engine I slowly turned the cap in until it covered all threads.

Thanks much for the information....