Unleaded

[Mike Wattam <101714.1343@domain.elided>]

Unleaded
The valve seats are fine, any year of Stag.

The inlet valves also are fine.

All TR7 and later Dolomite slant 4 were built with hardened 
exhaust valves 155524 and are suitable for running on unleaded.

Stag us supposed to be fitted with unhardened exhaust valve 
148093.  Some later Stag engines have been turning up with
exhaust valve 155524 fitted, direct from the factory.

Therefore, it can be deduced that a set of 155524 exhaust valves 
is all you need to sort it out to Triumph spec., and these seem to 
be available from the main parts stockists.  Look at your engine 
first, it may already have these valves fitted.  I have the strong 
suspicion that an number of Stag owers have thrown away
perfectly good exhaust valves and fitted expensive 'conversion' 
valvesor worse!

Some notes about fuel, as I keep my ear close to the European 
Community goings-on;
1.  EC is considering relaxing requirement to axe leaded in 2000, 
so leaded petrol may still be available - you can bet they put up the 
price and restrict supply though - this is at the request of the UK 
and France.  The latter runs a lot of old bangers and there would be
 a national strike if the EC got away with this one, e.g., lorry 
drivers...................
2.  Leaded is not good, so convert your engine anyway!  Just don't 
panic.
3.  There is a consultation paper out on a lead-substitute fuel to 
replace leaded, straight out of the pump.  I am talking to people 
about this.
4.  There are perfectly good lead substitute additives on the market, 
routinely sold at petrol stations in Europe (Germany, Austria).  My 
Stag went very well on this (better than with leaded?) cruising at 
00mph and going up to 120 on occasions.  It seems to add about 
6-7p to the cost of a litre of unleaded.

Hope above helps

Mike Wattam