How Does A Governed Engine Work ?
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Tuned
Joined: Mar 2011
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How Does A Governed Engine Work ?
Holley carb - I got 2 vacuum lines to the distributor + a vacuum advance line - where do they really go ? And what do they do ? What do things on the side of the carb really do ? Can parameters or max rpm be adjusted ?
Super Moderator
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Since you have a non-oem carb, it's hard to tell what the things on the side of the carb do.
Can you post a picture?
There were governors that were a separate plate with butterflys below the carb.
And there were governors built into the carb, where the throttle plates could be controlled by a linkage or vacuum signal.
In both cases, a vacuum signal came from the distributor. One vacuum line went to the distributor, and at a certain rpm, a mechanism allowed vaccum to return to the carb to pull the throttle plates back.
This post has links to factory shop manuals explaining how they work and showing illustrations.
For reference, OP has some kind of carb issue on his 361:
https://www.ford-trucks.com/forums/1...l#post21214819
Can you post a picture?
There were governors that were a separate plate with butterflys below the carb.
And there were governors built into the carb, where the throttle plates could be controlled by a linkage or vacuum signal.
In both cases, a vacuum signal came from the distributor. One vacuum line went to the distributor, and at a certain rpm, a mechanism allowed vaccum to return to the carb to pull the throttle plates back.
This post has links to factory shop manuals explaining how they work and showing illustrations.
For reference, OP has some kind of carb issue on his 361:
https://www.ford-trucks.com/forums/1...l#post21214819
FTE Community Team
Joined: Nov 2001
Posts: 1,854
Likes: 260
From: Oak Harbor, Washington
. . . there were governors built into the carb, where the throttle plates could be controlled by a linkage or vacuum signal.
In both cases, a vacuum signal came from the distributor. One vacuum line went to the distributor, and at a certain rpm, a mechanism allowed vacuum to return to the carb to pull the throttle plates back.
For reference, OP has some kind of carb issue on his 361:
https://www.ford-trucks.com/forums/1...l#post21214819
In both cases, a vacuum signal came from the distributor. One vacuum line went to the distributor, and at a certain rpm, a mechanism allowed vacuum to return to the carb to pull the throttle plates back.
For reference, OP has some kind of carb issue on his 361:
https://www.ford-trucks.com/forums/1...l#post21214819
My '73 F600 361 2V has a Holley 2300 LIST 6548 and has the integrated vacuum diaphragm on the throttle body, opposite side (passenger side) from the accel linkage connection. A picture I happen to have handy:
A sleeve in the distributor base slides via flyweight to open/restrict vacuum to that carb diaphragm.
That said, allowing the FT to rev higher is really counterproductive, as the torque falls off fast, and they crack (pistons? rods?) if run regularly beyond the governed speed (or even at the governed speed) according to (destroked?) what I've heard. They're not built to rev.
Cargo Master
Joined: Dec 2015
Posts: 2,545
Likes: 324
From: Harned, Ky
Without photos and numbers from the present carburetor it would be near impossible to determine what you need to do the make the carb work properly on that engine
Ford vacuum governor uses a centrifugal weight in the distributor to control vacuum being drawn on the carburetor mounted governor diaphragm thus regulating max rpm
If the carb you have is from a IH truck I’m not sure if that governor works the same, it should but each mfg seamed to have their own idea on how to govern the their engine
On a Ford a vacuum line connects to a port in the main body above the throttle shaft, this line runs to a vacuum port in the distributor housing. Originally another hose with threaded fittings runs from a threaded port in the distributor back to a threaded port in the governor control on the right side of the carb, this completes the circuit
The centrifugal weight controls the amount of vacuum being drawn on the governor diagram which in turn moves the throttle blades thus limiting the engines max rpm
If a carb is installed that will not work with the factory governor some type of electronic rev limiter should be installed to protect the engine from over reving
Ford vacuum governor uses a centrifugal weight in the distributor to control vacuum being drawn on the carburetor mounted governor diaphragm thus regulating max rpm
If the carb you have is from a IH truck I’m not sure if that governor works the same, it should but each mfg seamed to have their own idea on how to govern the their engine
On a Ford a vacuum line connects to a port in the main body above the throttle shaft, this line runs to a vacuum port in the distributor housing. Originally another hose with threaded fittings runs from a threaded port in the distributor back to a threaded port in the governor control on the right side of the carb, this completes the circuit
The centrifugal weight controls the amount of vacuum being drawn on the governor diagram which in turn moves the throttle blades thus limiting the engines max rpm
If a carb is installed that will not work with the factory governor some type of electronic rev limiter should be installed to protect the engine from over reving
Fleet Mechanic
Joined: Jul 2004
Posts: 1,516
Likes: 198
The above post is right. Newer Ford medium duty trucks had a vacuum solenoid to control the governor rather than the flyweights in the distributor, but the carburetor was basically the same. It is really a mistake to replace a governor type carburetor with an aftermarket type on a FT or Super Duty truck engine, you won't get any more power out of them and run a good chance of blowing the engine up. Ford put them on for a good reason.
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You current post, and a prior post as well as some others are in the Tech Section up top, posts 9 and 19:
https://www.ford-trucks.com/forums/8...-1-2020-a.html
https://www.ford-trucks.com/forums/8...-1-2020-a.html
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Mountain Pass
Joined: Aug 2015
Posts: 215
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You current post, and a prior post as well as some others are in the Tech Section up top, posts 9 and 19:
https://www.ford-trucks.com/forums/8...-1-2020-a.html
https://www.ford-trucks.com/forums/8...-1-2020-a.html
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