11-03-2018, 03:30 PM
Several have observed that timing with many aftermarket gears varies greatly. But few seem to have closely observed any effect.
The first Sevens were very light and were not expected to be driven much beyond 25-30 mph, so if any model suited advance it would have been these in their day. The later heavier cars expected to be driven faster relied on revs to go at all so any advance would seem less appropriate.
The inlet timing duration of the Seven is modest but other cars have been less ie Morris 8 ohc and early sv. The LIP Vauxhalls circa 1950 4 34 47 4 is similar the Seven advanced. (The timing of Mercedes about 1980 2.5l 123 is given in manual as 15ATDC 21 21 11 and the 2.7l 110 engine as 7ATDC 21 30 12!?)
When checking timing cam wear somewhat confuses. The mid point of two places of reasonable lift the best indicator.
The first Sevens were very light and were not expected to be driven much beyond 25-30 mph, so if any model suited advance it would have been these in their day. The later heavier cars expected to be driven faster relied on revs to go at all so any advance would seem less appropriate.
The inlet timing duration of the Seven is modest but other cars have been less ie Morris 8 ohc and early sv. The LIP Vauxhalls circa 1950 4 34 47 4 is similar the Seven advanced. (The timing of Mercedes about 1980 2.5l 123 is given in manual as 15ATDC 21 21 11 and the 2.7l 110 engine as 7ATDC 21 30 12!?)
When checking timing cam wear somewhat confuses. The mid point of two places of reasonable lift the best indicator.