Re: Stag vs Saab water pumps

[Mike Wattam <101714.1343@domain.elided>]

Be very careful when talking about Saab interchangeabilities.

Saab started taking the standard slant 4 engine in 1971 at 1750cc, fully
built from Coventry.  The agreement was that they would start local
manufacture of as many items as possible, paying Triumph a royalty per unit
and using technical assistance from Coventry as and when engineering
upgrades were required..

They fairly rapidly found the engines broke too easily, and started a
progressive redesign of the whole thing, starting with the cylinder head,
surprise, surprise.

The water pump was moved off the top deck pdq and a remote belt-driven pump
fitted.

The original oil pump was pure slant 4.  As an interim measure they had
Hoburn-Eaton make the identical pump (to look at) made to much closer
tolerances so it was capable of shoving much more oil through (or
sustaining higher pressure) and then went on to fit a whopping great oil
pump nothing like the Triumph object, a year or two on.  It is the
'interim' oil pump which is often fitted to the Stag.

To finish off the story, Saab have consistently uprated the engine over the
years to 16-valve and turbocharged, through to 2.3 litres and 230bhp with
balancer shafts.  Until 3-4 years ago the block was still fitted 'slant'
but then this too was eliminated, almost totally destroying any family
resemblance at all.  The modifications they have made along the line point
very clearly to the short-comings of the original design.

The 2.3 turbo 230bhp powers the rather heavy 9000 Aero very well indeed, in
fact the Aero is a superb car.  

I would like to think that had Triumph had the money and the will to
succeed, they would have developed the engine along similar lines so
perhaps Saab is spiritually the old Triumph company.  What a dreamer!!!

Sorry, what's the question?

Mike Wattam
Triumph Stag Register