Re: Alvis Stalwarts OT

On 1 Jul 2006 21:35:29 -0700, "Weatherlawyer"
<Weatherlawyer@xxxxxxxxxxx> wrote:

The Alvis military amphibian "Stolly" used an engine dated from WW 2
(Rolls Royce B 81 6.5 l 220 hp petrol.) Anyone know why?

It's not really WW2 - definitely a project that kicked off after the
dust of WW2 had settled.

Basically it was standardisation (as that had worked well during WW2).
All engines would be designed (not necessarily manufactured) by R-R and
anything smaller than a tank engine would be a "B series". These were a
standard 2 cylinder block design, available in 4, 6 & 8 pot versions
(B40, B60, B80). Most were vertical, the Stolly's B81 was laid-down
flat. Right from the beginning Leyland were also involved in
manufacturing them (they could cast the bigger crankcases, which R-R

As with most R-R vehicle engines, they were a dog. Too complex, too
heavy, inefficient, and _far_ too difficult to service. R-R only ever
made aero engines, but sometimes they installed them in vehicles. They
weren't quite as bad (ie fussy) as the '80s and '90s engines like the
Condor, nor were they as hand-fitting-intensive to work on as the
Meteor/Meteorite. And at least they weren't the god-forsaken L60!

The engines were infamously heavy, slow-revving and inefficient. Power
to weight would have looked tame back in the '30s. When R-R developed
the B60 as a car engine (best known through the Austin Vanden Plas
Princess 4-litre R) they re-designed it in aluminium, shrank the stroke
to lose 1/2 litre of capacity and still produced a third more power.

Standard books on the subject are

Bill Munro's "Alvis Saracen Family"

and for the B engines
Pat Ware's "In National Service"