----- Original Message -----
From: <JeepBoy350@aol.com>
To: "Military Vehicles Mailing List" <mil-veh@mil-veh.org>
Sent: Wednesday, November 22, 2000 1:14 PM
Subject: [MV] Ferret Fluids
>
> Thanks to all who have provided such great information. I need
clarification
> on the coupling fluid.... I get that it is a mineral based oil.... but
what
> weight?
>
Mineral hydraulic oil is correct. You cannot use the common US term
"weight" to mean a SAE viscosity index as the oil is defined by an ISO spec.
As a well-guided GUESS it is about SAE 5 - 10.
>It was suggested to try a motorcycle shop for a Silkolene product...
> they have three pages of products, but the closest thing I can find is
> SILKOLENE ATV which is "100% mineral base multi-grade 4 stroke engine oil
> formulated fo use in ATV's" available in 10W40 and 20W50.....
>
There has been talk of a Silkolene (Fuch's Lubricants) rep commenting that
the correct UK Mil OM13 is virtually the same as Silkolene Fork Oil SAE 5 (I
think), I _cannot_ personally confirm this. Hence the suggestion to try a
motorcycle shop as they may well have fork oil.
>there is also
> SILKOLENE Motorcycle "Mineral-based multi-grade oil with excellent
anti-wear
> and low-friction properties" available in the same weights...... Are
either
> of these good for using in the Ferret Coupling?
>
No. Definitely not. This is engine oil.
>If not can I get more
> guidance on specific product names, weights, and or suppliers in the US?
>
OM 13 is commercially a "ISO 15 Hydraulic Oil", most likely manufacturers
have a trade name for their product.
You need to contact a professional, commercial oil supplier, they will
recognise ISO 15.
Fuchs use the Silkolene brand name for their domestic products, commercial
ones are marketed under the Fuchs name, their Renolin HV15, HVZ15, AF15 and
CL15 especially would be acceptable but take advice from them. Silkolene
779 is a fully def-stan released direct equivalent to OM 13 and will cost a
fortune.
Shell Aero Fluid #1, also fully released and qualified, 747's are full of it
and also will cost a fortune. Shell Tellus 15 is the commercial equivalent
and I know it is available over there.
Fina Cirkan 15
Note that fluid flywheels (torque converters) are naturally very tolerant of
oil viscosity, they have no fine-bore oil ways or relief valves etc. You
Americans have far more torque converter driven cars than we do here where
the ratio of auto to manual is reversed; converters work happily on quite
low spec domestic fluid from a cold start in Alaska to towing a trailer
across Death Valley in summer.
Standard ATF would _work_ fine in the Ferret converter BUT the shaft seals
will let go almost immediately being _incompatible_ with this fluid.
The steps in the ISO grading system are very small so ISO 32 is quite close
to ISO 15, visibly identical actually. ISO 32 grade seems to be a world
standard for hydraulic crane fitted self-loading trucks, excavators and
back-hoes, ask a driver what hydraulic oil they use and who supplies it.
The spec for ISO 15 kinematic velocity at 40 C, in mm squared/sec to IP 71
spec is 15, for ISO 32 it is 32. At 100 C to the same parameters ISO 15 is
3.8 and ISO 32 is 6.5, ISO 32 in the Ferret fluid flywheel just looks like
ISO 15 at a lower temperature.
It may be you would have problems operating a Ferret on ISO 32 or even ISO
15 at the minus 50 C spec that the Mil applied, OM 13 was specially made for
extreme low temp operation like the Aero fluids. Should you actually
operate your Ferret at or below minus 15 C (5F) I would very much like to
hear of your experiences of the compatible engine oil necessarily used
(Artic oil to US MIL-O-10295) and the way you have connected the Ki-Gas
(ether) manual priming system to the inlet header injectors already fitted.
For 5F and down operation RR B Range Engine Manual TSD 702 requires the
ignition to be re-set from TDC to 2 deg after, to TDC to 4 deg before, plug
gap opened to 0.018" to 0.020" and starting using 2 strokes of the manual
Ki-Gas primer before cranking with another 2 strokes whilst turning. (Based
on a 10cc pump, for 20cc pumps only one stroke is needed.)
Richard
Southampton - England
This archive was generated by hypermail 2b29 : Sun Dec 03 2000 - 20:29:56 PST