VCCA Home Forums TECHNICAL - 1945 AND EARLIER 1912-1928 1928 ignition timing

hi could some one tell me the correct procedure for timing a a
a chev four ( EG. position of advance & retard lever to marks
on flywheel TDC and 25 degrees before TDC )I seem to be stuffing it up some where as I have it set spark fully retarted on the lever and points just opening at TDC on the flywheel, but motor
knocks under load when advanced and is not a happy chappy idling
when retarded ( this is a Fully reconditioned engine )
Regard
John

Correct timing procedure is 25 deg btdc full advance on steering wheel. Should be tdc fully retarded and 40 deg btdc at full advance centrifical included, although there is no 40 deg mark. I time my 1928 Roadster with a timing light and this works well for me. Hope this helps
Regards Neil

The first important thing is to check for proper flywheel position.Check by turning the engine over with the plugs out,watching No.1 intake valve open then close.Keep turning the engine until No.1 piston is at top dead centre(the U/C mark should line up with the pointer).
With the Delco-Remy model 635-B distributor,the ignition timing is set at 25 degrees before top dead centre,with the advance/retard lever at the full advance position.The easiest way is to turn the engine over with the plugs out,watch No.1 intake valve open then close,then keep turning the engine over until the 25 degree mark on the flywheel is in line with the pointer.Make sure your points are set to between 0.018" to 0.024" before doing this.
With the advance/retard lever up(fully advanced),
the points should just start to open with the rotor button under the No.1 spark plug lead tower on the distributor cap.If they are not just cracking open,loosen the clamp plate and move the distributor til the points just open.It helps if you have the ignition switch on so you can see the spark at the points.Tighten the clamp plate up and you're done.
The engine will run at this setting until the road speed of 22MPH is reached,whereupon the centrifugal automatic advance starts to further advance the spark timing,until it reaches a maximum of 45 degrees;25 degrees initial manual timing plus 20 degrees automatic advance,giving the total spark advance of 45 degrees.

There are six different positions that the flywheel can be installed. Therefore I don't rely on the flywheel marks. I time the engine by locating # 1 cylinder at top of compression stroke. Rotating the distributor so the rotor is under # 1 sparkplug wire and then rotating approximately 15 degrees counterclockwise. Snug the screw on the plate. Start the engine advance the lever on the steering column to full advance. Let the engine warm a little. Now slowly rotate the distributor until you get maximum idle speed and tighten the screw. When you retard the spark lever you should get a noticeable reduction in idle speed and smoothness. If you try to start the engine when cold without retarding the spark it will try to kickback but will spin well with spark retarded. Don't get any knocking with regular gas and have plenty of power considering the horsepower rating of the engine. Haven't used a timing light in probably 30 years. Don't think my light still works. Maybe it retired when I did?

Hay,
Thanks chaps for yours reply's,
i have tried them all. I think Chipper
has solved my problem, our lowest grade
petrol is 91 octane and i don't know if my
RAKXO carby is up to it. Have send my
spare away to be reconditioned
regards
john dix

John
I use 91 regularly, when I can't get 91 I use 95 and sometimes 98. I have done many thousands of miles in my Chev 4's and my 34 and never had any problems. However in saying this, all of them are no good if you don't use your car for about 3 months, the fuel goes off and the car wont start.
Chris from accross the ditch

Hi Chris,
thanks for that info, I just had a [bleeped]
of a time getting the timing wright and as our
American friend said throw away the timing light
and do it by ear, it worked a treat
Cheers
John