Re: Governors on 345/392 engines...

[eldon_mcf@domain.elided (Eldon L McFarling)]

 jlandry@domain.elided (John A. Landry) wrote:

<<eldon_mcf@domain.elided (Eldon L McFarling) scribbled in the sand:

>      There are two types of governors used on IH gas engines,  both
>operate similarly.
[snip]

Eldon,

Was either type of governor ever used on the IH light line model
vehicles? >>


John,

    Governor's were not used for the Scout  models (except for Diesel
engines), they were optional on all V-8 gas engines for truck models. For
pickup, and Travelall models I don't have a parts book, or any sales
literature so I can't say for sure, but as has been discussed in the past
some of these are built with components  that are also found in many 
truck models, and some of  the drive train options used would  have been
strong enough to be used to build army tanks, so I would not be surprised
if a governor option was available.  If you were ordering a pickup, or
Travelall for heavy towing with a low gear ratio, I could see where a
governor  would make sense to keep from sending pistons,  rods, etc..
thru the side of the block. IH custom built each unit according to the
needs of each customer, and for certain applications in the light line
they do  make sense. Also it would have been possible for a governor to
be TSPC, or dealer installed. There are also aftermarket units available.
Another possibility is a truck engine equipped with a governor could be
swapped  into a Scout, Travelall, or pickup as you mentioned earlier. 

   A little more on governors....

   Limiting Speed Type

   The most common type of governor used for on highway vehicles is a
"Limiting speed" type. This type has no control of engine speed until 
the engine reaches the speed that the governor is set for, at that point
any further speed increase is prevented by the governor.

    Another variation of this type governor is a "Road speed governor".
This is used on some medium, and heavy duty IH trucks. This governor has
no control of engine speed until a preset road speed  is reached. When
the preset  speed is reached the governor prevents any further vehicle
speed increase. (perfect  for teenage drivers!!)

   Variable Speed Type

   The "Variable Speed" governor maintains a constant engine speed as
selected by the operator under varying load conditions. Tractors,
combines, power units, etc.. use this type of governor. This type is also
used on some trucks that use pto's to run equipment such as cement
mixers, refuse packers, etc..

   Close regulation variable speed governors are used for applications
such as electric generators where close regulation of engine speed is
required to keep generator output at the proper cycles, and voltage.

  Full Electronic Type

   This has to be the "Cadillac" of governors. This type governor is used
on the T-444E / Powerstroke, and DT-466E/ DT 530E Diesel engines from
Navistar. This system combines the functions of all the other types and
more. All engine control functions are  handled by the engine control
module. Idle speed, limiting speed, road speed are all controlled by the
ECM. Additionally, things like cruise control, and  variable speed
throttle are available. (no more 2x4's!!!)

   A few thoughts....

    Bigger trucks weigh more, have bigger jets in the carb, lower gear
ratio's, etc.. so they have a greater  potential for conditions that
would cause engine damage due to engine overspeed. consider what would
happen with a fully loaded truck going down a long steep hill at full
throttle, with the load behind pushing it along engine rpm will continue
to increase until something goes into orbit. with a governor the chance
of reaching as high of rpm is greatly reduced, normally the rpm's will
remain at a safe level, greatly reducing the possibility of engine
damage.

   I found these recommended maximum speeds for some  of the popular
Scout engines: 4-196 - 4,000 rpm, V -304A - 3900 rpm, V -345A 3800 rpm.
This does not mean at 4001rpm you are gonad damage your 196, the point
where the valves float, or engine damage occurs would  likely be several
thousand rpm higher.
    As far as lighter vehicles, equipped with automatic transmissions,
higher gear ratio's etc.. the chance of dangerous over speed conditions
are far less than with a heavier vehicle. I do think a governor or rev
limiter could prevent engine damage, under extreme conditions however.

  I scanned a few pic's of a Holly 4150G that shows the governor
components, so everyone can run out and look under the hood and see what
they have. 

    IH GAS ENGINE GOVERNORS   http://members.aol.com/Redbom/gov.html    

     
  Have fun


Eldon McFarling
Ceresco, NE
'80 Scout II Turbo Diesel
Eldon_McF@domain.elided
IH SCOUT DIESEL PAGE    http://members.aol.com/EldonMcf/scoutd.html