10-09-2020, 01:38 PM
"Does it have Zinc added "
Not at all sure that zinc is needed in an unmodified Seven engine. Modern oils don't have zinc as it damages catalysts.
My son's Maserati engine has cams 25mm dia with a 10mm lift. It revs to 6,500rpm so the rubbing speed of cam on flat follow is huge. Zinc is essential and unworn 2nd hand cams are very rare.
The Austin with small cam, lower lift, curved followers and max 4,500rpm is in a different league.
Not at all sure that zinc is needed in an unmodified Seven engine. Modern oils don't have zinc as it damages catalysts.
My son's Maserati engine has cams 25mm dia with a 10mm lift. It revs to 6,500rpm so the rubbing speed of cam on flat follow is huge. Zinc is essential and unworn 2nd hand cams are very rare.
The Austin with small cam, lower lift, curved followers and max 4,500rpm is in a different league.
Jim