From: Bjorn Brandstedt (super_deuce@hotmail.com)
Date: Mon Sep 23 2002 - 09:55:06 PDT
>From: "GOTAM35" <gotam35@sc.rr.com>
>To: <mil-veh@mil-veh.org> (Military Vehicles Mailing List)
>Subject: Re: [MV] Fuel economy....I don't understand
>Date: Sun, 22 Sep 2002 21:13:35 -0400
>
>OK boys and girls, I have a question. This big old engine in my M35 can't
>hold 55 mph up hill empty. My F-250 with a bob cat on a trailer behind it,
>weighs more than the deuce, but can hold 70 mph up hill. My understanding
>of physics may not be the best, but the energy required to move the mass of
>the trucks at a given speed should be the same for the same amount of
>weight. Why can't the deuce hold it's own. If the answer is as simple as
>the torque produced by the multifuel is less than that of a 351W ford
>motor,
>I'm sorry to ask a dumb question.
>
>Here's another concern. I know of a diesel guru that can turn up almost
>any
>pump. He has turned up a couple of pumps on some F-700 trucks we have. I
>am trying to contact him and ask about the multifuel. Others said the
>Fords
>could not be turned up, but he did it. We have had these trucks for
>several
>years and run them all day some days. No problems. Has anyone out there
>been able to get more out of the multifuel and if so will you share this
>secret with the rest of us.
>
>For any one concerned about my safety after last weeks brake discussions,
>I've ordered some parts from Memphis Equipment and plan to do some serious
>work on them (the brakes) this week. Going is good, stopping is a must.
>
>Joe Trapp
>
>From: "tom-nooneofconsequence" <milveh@carr.org>
>
>
> > i think this is a very simple conclusion...your vehicle is already
> > grossly under powered and getting about as poor a mileage as is possible
> > for the size of the engine. therefore increasing the load has no real
> > effect as it cannot get much worse. my m-35 that now has 1000 miles on
> > the clock, still gets 10 mpg, but now at 62 mph rather than at 50. but
> > the engine is now 641 cu in. i'm happy..........
> >
>
>
Hi,
I read somewhere that it takes about 270 hp to keep an 80,000 lb 18-wheeler
moving at 70 mph on a level highway.
To keep the 13,000 lb deuce rolling at 55 takes about 80 to 90hp (based on
fuel consumption).
I know I'm comparing apples and oranges, but it doesn't appear to be a
straight line relationship between weight and power needed to maintain a
certain speed. In other words, it doesn't take twice the power to haul
twice the weight.
It's the acceleration phase that will be differnent, but once at speed the
difference will be less.
My first inclination is always to defend the original design of the deuce.
There are lots of advantages with more power, such as lower noise level,
lower rpm, faster acceleration, higher top speed, but for a vehicle designed
to operate off road and on dirt roads those features may not have been
specified.
An "under powered" vehicle is really only under powered in the sense that it
takes longer to accelerate and longer to reach its destination.
A vehicle can also be considered to be over powered if the extra hp's are
seldom used and/or used incorrectly.
Additional power (= torque) means that drive train components may be exposed
to forces that they were never designed to handle, especially at high loads
at lower speeds.
If you couple a higher torque engine to the existing 101:1 (7.55 x 6.72 x 2
=101.47) low low gear train ratio, some components are bound to be over
stressed at one time or another. The original design is a compromise as are
most designs. In engineering there are usually a large number of solutions
to a given problem and only customer specifications determine the final
result. The deuce was not really designed to be driven much over 45 mph
anywhere.
When you hit that hill you need more torque. With the deuce, you must shift
down to get it (= slows vehicle down), with the F250 you just step on the
gas to add more fuel (= torque) and without changing the speed.
I guess it has to do with having reserve power. The deuce has very little
and the F250 has a lot.
The combination of a lot of "reserve power" and 101:1 gear ratio may cause
some damage to the vehicle if not used with understanding. Perhaps a low
reserve power is a safety measure.
The LD(T) engines may not be terribly powerful, but they can run at full
power just about forever.
The deuce is a deuce until we change it to something else, like an FMTV. The
Marine corps' MTVR (Oshkosh) is more an improved version of the deuce. It
was designed to travel cross country at higher speeds among other things. It
even looks like a deuce, just larger.
Just another collection of my notes and thoughts.
Bjorn
MVPA 19212
1968 M49A2C with 1972 HIAB crane and no tank
>
>===Mil-Veh is a member-supported mailing list===
>To unsubscribe, send e-mail to: <mil-veh-off@mil-veh.org>
>To switch to the DIGEST mode, send e-mail to <mil-veh-digest@mil-veh.org>
>To reach a human, contact <ack@mil-veh.org>
_________________________________________________________________
MSN Photos is the easiest way to share and print your photos:
http://photos.msn.com/support/worldwide.aspx
This archive was generated by hypermail 2.1.4 : Wed Apr 23 2003 - 13:21:24 PDT