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Vacuum guage

Posted: Thu Oct 29, 2026 12:56 pm
by mobylette
Because I had it lying around, I fitted an old Redex Car Care Robot into the engine bay. I tried it out today after warming up the engine. It shows a nice steady 20inHG which indicates the engine is in a good condition. I might play about with the vernier adjuster on the distributor to see if I can fine tune it.

Re: Vacuum guage

Posted: Fri Oct 30, 2026 1:43 pm
by 59Elva
What is your procedure for fine tuning the timing with a vacuum gauge? More advance equals higher revs and high vacuum?
The keyway in my crankshaft pulley is damaged and I don’t have absolute confidence that the timing mark is accurate. Because of the angle I don’t think probing thru the spark plug hole to find TDC is accurate either. At this point I don’t have any other reason to pull the head but if that should arise I could set up an indicator .
Bill B

Re: Vacuum guage

Posted: Fri Oct 30, 2026 2:15 pm
by mobylette
Yes, adjust distributor by ear for fastest/smoothest tickover, then advance or retard with vernier for highest tickover vacuum, finally road test to check for pinking.

Re: Vacuum guage

Posted: Fri Oct 30, 2026 2:23 pm
by mobylette
I have just found a copy of the instructions, they are a bit more involved. I will attach them here if of interest.

Re: Vacuum guage

Posted: Fri Oct 30, 2026 4:58 pm
by 59Elva
Very interesting, thank you.

Re: Vacuum guage

Posted: Fri Oct 30, 2026 6:35 pm
by svenedin
Interesting gadget. Is the main purpose to optimise fuel economy? Nice engine bay. I like how you've mounted the gadget on a new bracket using the existing one.

Stephen

Re: Vacuum guage

Posted: Fri Oct 30, 2026 7:19 pm
by mobylette
I did have it mounted in the car, but to honest it is a gimmick as far as fuel economy is concerned. You know when you have your foot flat on the floor, you don't need an instrument to tell you. But it can be very useful as a tuning aid hence its redeployment to the engine bay.