(01-01-2019, 03:11 AM)jansens Wrote: Since my flywheel was chopped up to be lightened I don't seem to have any markings on it. I would like to mark on the TDC and starting timing marks. If I am reading the books right you should start setting the timing with the flywheel 1 1/4 inches before TDC on number 1 cylinders compression stroke.
I made a little extension to my dial gauge and used that to find TDC on number 1 compression stroke. 1 1/4 inches seems to be 4 teeth so do I make the marks where the pieces of tape are in this picture? The one on the left being the BTDC mark and the one opposite the block nut is the TDC one.
I have also read (somewhere I can't find now) that with a automatic distributor the maximum advance is about 28 degrees which would be 6 teeth. Should I make the second mark there?
I know fine tuning needs to be done adjusting the distributor with the engine running but I want the marks there to get me in in the right starting spot.
Simon
Simon,
It's a great idea to mark TDC on your flywheel. To be honest this would have been done more easily before the engine went in. Once in the car it is harder to identify exactly where on the flywheel is the top, don't try to do this while standing outside the car or you'll be miles out, get in and view from the centre line. It is roughly in line with that rear block stud. It doesn't actually matter much as long as you have a consistent point of reference.
A couple of points though.
1. Where you set you timing depends on whether you have an auto advance or manual distributor. An auto advance DK4A should be initially set at 0 deg (TDC).
2. There are a large number of DK4A (and other) distributors which will fit an Austin Seven, many have been fiddled with and most are worn to some extent. So don't blithely assume the auto advance is 'correct' or even as marked on the unit.
3. The advance degrees marked on the distributor are translated to degrees at the flywheel by doubling - the distributor runs at half engine speed. i.e 28 degrees of advance AT THE FLYWHEEL is 14 degrees of advance AT THE DISTRIBUTOR.
4. My own car has about 12 degrees of auto advance (distrib) and runs comfortably if not dramatically when set with points opening at TDC - it's a good starting point.
5. 28 BTDC sounds a bit racy for an average road car to me - it's OK if you have a good solid bottom end.
It's worth setting up some time with a strobe light and observing what happens as you increase engine speed - the amount of timing scatter is astonishing. That I would say is the main justification for going down the electronic ignition route. However it is possible to improve things a bit by making sure the distributor bushes are in good shape, rotor arm a good fit and by replacing the drive gears if they are badly worn.
Sorry if teaching you to suck eggs! I hope something there is useful to you.
(01-01-2019, 09:26 AM)bob46320 Wrote: I am no expert, but how will the starter work on your engine ? Looking at the previous post, it looks like the clutch assembly would get in the way of the bendix, or that the starter ring was on the wrong way round. I am sure I am wrong, but interested to know how it will work.
Bob
Forward facing starter?