KNOCK KNOCK

[50starlite]

My '50 champ has developed a ignition knock under load that I can't get rid of. I've reset the points, checked the dwell, retarded the timing a bit, added Chevron techron to the 93 octane gas. Still knocks. My next thought is to take it out of o.d. and run it about 60 m.p.h for about five miles. Also there may be the chance I got a bad tank of gas? It could be carbon detonation, but it's just started knocking.

Anyone have any ideas I haven't thought of?

Thanks,
Dick

[dpson]

Some of the early Champions had an "Octain Selector" on the side of the distributor that could be adjusted to eliminate ping, check to see if you have this and where it is set. Also check your distributor vacuum advance. The diaphram in these go sometimes and they stop working.

1960 Lark Convertible
1962 GT Hawk

[Roscomacaw]

Did this "knock" start all of a sudden or was it a gradual thing? If you've retarded the timing a bit you've done essentially what Dan was talking about.
It COULD be the beginnings of a rod bearing going south or a piston that's damaged. Taking it to 60 in straight 3rd for an extended period may well lend a clue to what's wrong but you'll not like the way the diagnosis is delivered![xx(]

Miscreant at large.