Skip to main content

I am joining the modern world, and getting rid of my points system.
I have bought a Petronix system that will fit to my existing Autolite distributor. The kit should arrive on monday next, Having taken the dizzy out of the engine I thought I would check the advance vacuum system by sucking on the pipe in the pic.

My lungs aren't what they were but nothing seems to happen. When I try and rotate the plate that the vacuum rod is attached to its not easy to move but does move with a little pressure applied.

My question is this, is this normal?

Car ran fine previously, so I imagine it was working but I have no experience here, all help appreciated.
Original Post

Replies sorted oldest to newest

The hose is connected to "vacuum retard", the other connection that is capped with a black rubber plug is the "vacuum advance". It appears your Pantera's engine was only using vacuum retard, that's not so good.

Swap the position of the hose, leave the previous hose connection open to atmosphere. Don't use the little rubber cap at all. The unused side of the advance/retard mechanism must be able to "breathe" otherwise nothing will move. That's probably why nothing moved when you applied suction to the hose. That also explains why the effects of vacuum retard upon the engine's performance were no worse than they were.

There's also a good chance that the rubber diaphragm in the advance/retard mechanism has hardened, making it inflexible, and has also cracked and is leaking ... or on the verge of doing so if it isn't already. The advance/retard mechanism is something to be replaced. Crane used to manufacture a nice adjustable advance mechanism for Ford distributors (no retard provision provided, none needed). I'm not sure whether or not its still available.

The advance plate should move very easily, but with age & heat cycles the grease becomes sticky and things become more difficult to move. The entire distributor needs to be cleaned, rebuilt, and re-greased with a light synthetic grease.
Incidently, Peter- the Ford distributor is adjustable for the amount of vacuum assist your engine needs. Remove the hose from the vacuum side and stick a 3/32" (I think) allen wrench down the pipe until it engages a setscrew deep inside. Turning the wrench one way opens the adjustment for more advance under vacuum while turning it the other way cuts down the amount of assist. Comes in handy sometimes while tuning.

Add Reply

Post
×
×
×
×
Link copied to your clipboard.
×