View Single Post
  #53   Report Post  
Posted to rec.crafts.metalworking
David Billington David Billington is offline
external usenet poster
 
Posts: 856
Default Why use heavy oils in gearbox?

Ted Frater wrote:
Gunner wrote:
On Sun, 23 Dec 2007 08:26:52 GMT, Ted Frater
wrote:


Don Young wrote:

"RAM³" wrote in message
0...


"Ivan Vegvary" wrote in
news:yPUaj.12$ML6.5@trndny04:



which makes me wonder, why
we use heavy gear oils for similar applications when not unitized
with
an automatic tranny?

The '62 MG Midget that I once had used 30-wt. motor oil in its
4-speed
manual transmission.


For what it's worth, the late 40's Chrysler electro/vacuum shifted
transmission used 10 weight motor oil to lubricate conventional gears.

Don Young



This busines of 35mpg is quite simple to acieve.

The technology is there,
It needs a tax? incentive for the car MFG's
to change their design references.
So lets look at these.

1.
a steady state speed on a straight level road,
take any one it doesnt matter.
the energy needed to keep the car at this speed is equal to the drag.
this is from several areas.
rolling resistance,
engine/transmission friction losses,
engine efficiency
aerodynamic drag.
Each one can be optimised with current technology.

Next,
2.
accelerating from one speed to another, this could be from 0mph to
30mph or whatever.
This requires the engine to accelerate the total mass of the car.
the enegy needed to do this is primarily dependent on the the time
you want to do this in and the weight, in addition to 1. above

The former is in the control of the driver and the second is again
in the hands of the maker..

So if you want to optimise your car for maximum miles per gallon it
will need to be

very light,
all aluminium , composite construction
very aerodynamic
very low rolling resistance, no soft sqiggy tyres
ie throw away your fancy wide fashion
statment tyres
and run on the old design michelin"X" as made in the 1960's
super effient turbocharged common rail pulsed fuel injection
diesel aka VW polo or Smart car
all aluminium engine transmission castings,
lightweight glass in windows,

made in 2 seat tandem configuration ,
as well as 4 seat and larger.

With these specs I predict at a steady state speed of 70 mph a mpg
on US gallon of over 70. with current technology,
Give me the authority and funding and ill have one ready for mass
priduction for you in 24 months.

Any takers?
Ted Frater
Dorset UK.






Now the next question, will the occupants survive a collision with
anything larger than an opossum?

Gunner


point taken,
lets go back a bit,
I was lucky to get my engineering training in aviation aircraft
structures,
So im aware of the bird strike risks as well as the automotive
collision risks.

We have a serious deer problem here in the UK,
the overall nos have trippled over the past 30 yrs and deer strikes
are a weekly occourence here in this part of the UK
makes quite a mess of the front of the car as Ive had it happen to
me!!!!.
modern design techniques and constructions will give the energy
absorbing reqirements of the statutory crash tests.
So it can be done.
It depends on whar risk assessment has been made, and what are the
statistics?

Compliments of the season anyway,

Ted

Might cost quite a bit tho.
Ted

They have something of a deer problem in the US as well. My mother had a
Chevy Impala written off by a collision with a dear in the late 1970s,
IIRC that was a good sized car.

Nobody yet has mentioned the various tests showing that occupants of
large 4x4 or vehicles with chsssis often end up with more severe
injuries than the occupants of the passenger vehicles they collide with
due to the higher decceleration rates resulting from the lack of
significant energy absorbing structures in the 4x4, pickup etc. While
the passenger car might be a write off and the larger vehicle not
damaged much the larger vehicle occupants may suffer far more severe
injuries than those in the passenger car.