Above the carb
 

What is it?

Re: Above the carb
 

Vacuum port.
For wippers

Re: Above the carb
 

Does it go into the valve cover. crankcase vent of some sort?

Re: Above the carb
 

Bigger photo http://topclassiccarsforsale.com/upl...il-truck-9.jpg

Re: Above the carb
 

Holy Smokes !! That looks like something left over from the 70's California smog era.

Re: Above the carb
 

Vacuum operated governor maybe?

Re: Above the carb
 

Interesting that the GAV rod seems to line up.
Paul in CT

Re: Above the carb
 

plus 1

Re: Above the carb
 

It's a GOVERNOR, so them Thanksgiving Dinner Delivery Kids don't wreck your rusty engine!
Bill Burp!

Re: Above the carb
 

Hey, how about a close-up the same size as the second pic?

That sure looks like something Jerry Brown cooked up as a smog device.

Also, just an observation, but you might want to take a look at the alignment, judging from that spare, you got some problems :)

Re: Above the carb
 

Note: It is on an unrestored Mail Truck. What would a governor be used for?

Re: Above the carb
 

it limits the engine speed ----back then mail was deliversd in better shape, the truck speed was limited so the packages didn't get damaged

Re: Above the carb
 

To limit the top end speed at a desired setting.
Many commercial vehicles utilized the device

Re: Above the carb
 

Here you go! all the above

Re: Above the carb
 

Thanks, and here I was thinking how slow they would be with all the extra body and go figure they slowed them down even more

Re: Above the carb
 

All the mail trucks came with a governor. In the pictures you can see
the bracket to lower the choke rod and a hole lower in the firewall.

Bob

Re: Above the carb
 

I think the governor I have works off the Timing Gear, at the rear of the cover. Or do I have something else, altogether different?

Re: Above the carb
 

I have one like that also. They were used for saw rigs and air compressors. I'd bet they were also used on the Gleaner combines.

Re: Above the carb
 

This is a "velocity" governor that only limits how fast the engine will rev (so the mailman won't blow the engine as he climbs that muddy hill in low). Engine speed is directly controlled by the foot or hand throttle.
The governor that is gear (or belt) driven is a load-sensitive unit. It maintains a set RPM regardless of load for industrial/agricultural use, where the RPM needs to remain constant, like welders, air compressors, combines, etc. Here engine speed is controlled by the governor; the hand or foot control is connected to the governor, not the carburetor, and the governor controls throttle opening. With no load on the engine the governor closes the throttle plate to maintain say, 2200 RPM. Under a load, the governor opens the throttle plate as needed to maintain the same 2200 RPM.

Re: Above the carb
 

40 Deluxe, a good summation of the differences of application.