Re: Low oil pressure, 12vane waterpump, engine rebuild

[RICHARD_HUDSON/AMA_UK_LTD_at_AMA__XCHGPO@domain.elided]

Ralph

You are one lucky man, Two stags, some people may say two lots of trouble
but if you are smitten who cares...

here are my views on your questions...

1) I ran my car for two years on low oil pressure.. 25-35psi from 1500rpm
up and 5-10psi at idle (mine is auto therefore idles at 650rpm, nearly went
mad trying to get the idle that low) I changed the pump (for a high
pressure Saab item), tensioners and chains. I also "back flushed" the
cooling system and this kept the whole thing reliable.. I even tried
another oil pressure gauge??? eventually I hauled out the motor and rebuilt
it.. You didn't mention the oil pressure you are getting but I did find
when I had a problem that the actual figures other owners had varied
hugely.. What you need to look for is the oil pressure dropping i.e. one
day you are getting 30psi at 3500rpm when hot and the next day you are
getting 25psi at the same revs etc etc..

2) re the 12/6vane water pump, there has been loads of discussion re the
benefits of each item and I will dig out
some articles for you..

3) Leave the gearbox cooler attached to the gearbox, it does need it.. Re
engine oil coolers;I was told,

Obviously the only reason to fit an oil cooler is to cool the oil.. In the
Stag engine it takes a long time to heat the oil to the "correct operating
temperature". Up until that point engine wear is occuring due to the lower
viscosity of the oil. If you cool oil to below it's normal operating
temperature then you may induce un-necessary engine wear but you will
notice higher oil pressure.. The way it was explained to me, it seemed like
a false economy.

I kept my standard rad because it was clean and had good flow, but there
are upgraded rads on the market..

4) The automatic transmission seems to realy wind up to shift and when it
does the shift is very hard.  Any suggestions?

Mine used to do this.... It was caused by a bunged up breather pipe.. The
breather on the BW35 autobox comes from the top at the rear end on the box
and feeds up the transmission tunnel. on a RHD car it comes out on the
drivers side of the car feeds over the top of the Brake servo and dangles
into the inner wing area.. It is a real flimsy black plastic tube and can
be easily crushed by tie wraps etc. Mine had been "deliberatly" clamped by
PO and a gearbox specialist told me that people used to do this to get the
box to hold gears to much higher revs.. Hey sports mode changing on a
stag..

Didn't Rolls Royce once use the BW35 autobox??

Anyway my breather is now unblocked and the car has a silky smoooooth
change..

5)  While I have the engine and transmission out for rebuild what other
items should I upgrade?

I installed a tufrided crank in mine for extra strength, I also rebuilt
both heads, guides, valves etc with AE parts that are suitable for use with
Unleaded fuel

Take care and have fun..

Richard Hudson
73 Stag (Triumph V8 and white)