Assembling my A7 engine with the help of Woodrow's book, I notice he specifies 6 and 7 thou for the valve clearances, that seems awfully tight to me, any comments?

He also gives a complicated method of setting up the ignition timing. The dizzie leads weren't marked on dismantling. Can't I just swivel the dizzie to suit?

I have always used 6 thou on all, without issue, if that helps.

Agreed.

Bill in Oz

Location: Euroa,Victoria

I have recently completed the rebuild of my 1932 engine and used the Woodrow figures without any problems.
Have a look at the Dorset A7 Clubs webpage under Technical Pages, then Setting The Ignition.

Location: Near M1 Motorway Jtn 28

Hi Shuttle

At the risk of yawns from many...

The large clearances customary on later cars are due to lifting and closing ramps. These give moderate accelerations over a range of clearances, render these less critical, and a settled valve does not promptly burn out as with small clearance. The Seven has a simple tangent, with no merging ramps, and accelerations become severe with large clearances. The small clearance is typical for the pre ramp era.

The correct orientation of the distributor is limited, particularly for manual advance. With Sevens it is seldom worth the effort to try and keep track of exact position prior disassembly; easy to sort on final assembly by remeshing the distr drive.

Location: Auckland, NZ