Adjustment of the Ignition System of my BN6

[Jim 58 BN6]

Jim, thank you for the detailed clarification. But I still did not get the reason for the three numbers (i.e. 5, 10, and 12 degrees before TDC) to adjust the ignition.

Til now my understanding is that there is exaclty one value for the degree before TDC for static timing (e.g. 6 mentioned by john and in the waorkshop manual) and probably another for strobe timing. I am looking for these two values for a BN6 engine.

Sometimes I know what I meant to say, based on what I thought the question was, but I do not do a very good job of it!

1: There is an initial timing advance that can be set by the static timing method. This same setting can also set and checked by using a strobe at a specified engine idle speed (6 degrees).

2: The timing will then further advance as the engine speed increases. This additional advance is added by the mechanical advance mechanism in the distributor working with the vacuum advance mechanism. This additional ignition advance is checked using a strobe timing light, and is designed to occur within a specific engine RPM range.

So, there is initial timing advance, followed by some additional timing advance as RPM increases, up to a maximum advance at a specified engine speed.

I'm not sure what the numbers quoted exactly meant. They are distances from the TDC mark on the pulley, that correspond to degrees, to allow you place reference marks on the pulley.

I don't have my manual for the Healey available here, so I can't tell you what the exact maximum advance numbers are, but specifications in the book (or on the web) should tell you.

I hope this helps to answer your question.

 

[BN6_2197]

Gents, I complete understood the procedure now. Just one final question: does anybody know the exact diameter of the crankshaft pulley? By this I can then easily determine the marks for timing adjustment using the fundamentals of mathematics from school ;-) Volker

 

[steveg]

Crank pulley diameter: 6.25"