Manifold Vacuum
 

For your info, I just finished connecting a vacuum gauge to the windshield wiper fitting on the firewall of my Victoria. Idling at 160F, the gauge reads 22 InHG which is an excellent reading. The engine is a Model B with a 6:1 compression cylinder head, stock Model B camshaft and a Model A Zenith 2 carburetor. This engine has approximately 2500 miles on it since it was completely rebuilt. The vacuum gauge is a 2" diameter unit made by Auto Gage and it will stay in the car.
I do not use the stock windshield wiper, and this year the stock wiper motor will be replaced by an electric unit.

Re: Manifold Vacuum
 

Indeed 22 inches of Hg is good. Air pressure at sea level is 29.92 inches of Hg. That is a good gauge to keep in the car. You can use it to diagnose troubles and feather the engine for good mileage.

Re: Manifold Vacuum
 

Caution! This is where the last discussion on Vacuum gauges ended...

https://www.fordbarn.com/forum/showt...+Minder&page=2

Re: Manifold Vacuum
 

Electric wipers are the way to go. Not just on an A, but even later cars.

Re: Manifold Vacuum
 

When Dad owned his 29 RPU, the car had a vacuum wiper.

He was 18-20 at the time and had discovered "smoking." He would regale his friend on how his truck was "smoking hot" and using the rubber vacuum hose on the mouth end of the cigarette (no filter) and it would "burn it right down" in about 20 seconds.

"Waste of a good cigarette" his friend's reply.

Joe K

Re: Manifold Vacuum
 

My '55 Ford Ranchwagon had vacuum wipers. What a PITA with the "dual action" fuel pump to provide enough vacuum on acceleration. It has electric now

Re: Manifold Vacuum
 

The vacuum windshield wipers are a form of vacuum gauge. Step on the gas and they slow down or stop. Let up on the throttle going down a grade and they fly back and forth at an impossible speed. (Early variable speed wipers?). I used to enjoy using them on a car that I had years ago. I was intrigued by the technology.

Re: Manifold Vacuum
 

A friend owned a '24 Buick that had been Professionally rebuilt but never ran correctly for many years. He bought it and wanted to fix it. I put a vacuum gauge on it and it showed retarded cam timing. He was positive I was wrong as he knew the rebuilder. Months later he pulled the cover of and HE discovered the cam was off 3 teeth. I am a believer in what the gauge says.

Re: Manifold Vacuum
 

Yesterday I made a 24 mile run cruising at 50 MPH. While cruising at a steady speed, the manifold vacuum was steady at about 17 InHG. The slightest change in the throttle drops the manifold vacuum near zero. This sensitivity is due to the small (undersized) CFM of the Zenith carburetor. That is to say, it takes a large throttle change to accelerate the Model "A".