is your vacuum advance still connected?

ButterFingers

ButterFingers

Active Member
Hi there,
when checking the timing on my V8, I dutifully removed the vacuum hose from the dizzy , plugged it with a wooden pointed stick and on with the timing light....OK that's done.
Then when I put the vacuum hose back on the dizzy, and tested it with the light, no change.
More inspection and I found that the other end of the vacuum line hose was not connected to the carburetor on the passenger side.
I had previously removed the complete distributor to explore why the advance weights were not functioning. I discovered a washer jammed under one of the weights. Reconnected it and tested, and all working again.
Q: how many owners have actually looked at the carburetor end of the vacuum hose to see if it is attached?

Peter
 
Hi Peter,

The arrangement on the Rover uses ported vacuum rather than manifold vacuum. Consequently, there is no vacuum advance provided at idle, so removing and plugging the hose end on the Rover serves no purpose. The instructions that come with timing lights provide that information as manifold vacuum is far more prevalent. The vacuum canister on the Lucas distributor delivers additional advance during light throttle settings only, such as when cruising along the motorway. If provides no advance during hard acceleration, nor does it serve to improve engine performance in terms of power. It is an economy enhancing device only, allowing the engine to consume less fuel when cruising. More often than not the diaphragm will perish after a couple of years and then it will cease to function. You can test by placing a tube over the outlet and sucking hard, see if you can move the distributor base plate. You will also feel suction on your tongue if it is working.

Ron.
 
NADA cars were originally sold with a vacuum retard distributor - must have contributed to their reputation for being gutless..... I run a dual-point centrifugal adv. Mallory.....
 
hi there,
Thank you Ron for your informative reply, I learn something new every time I come to this forum.
I plugged the line because it is a thing that I have always done with vacuum on cars,
I did not realize that the rover vacuum was different and indeed it is as you explained, being accessed from the carburetor manifold than the inlet manifold.
I tested mine by sucking and could hear and feel the weights moving again, after removing the obstruction of a washer!

Peter
 
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