38 Special Ignition Timing

[jeff]

I have a pretty quick and simple question.

On the flywheel housing of the 248 cu in engine there is an opening or window to see the timing marks on the flywheel. Is there supposed to be a cover for that window, or some other type of insert that would indicate what to line up the timing mark to? My engine does not have any cover over this window, nor does it have a mark to use when timing. I have assumed the flywheel mark should line up with the center of the window, but I would like to know if this is correct.

Can someone describe this feature, or, take a quick picture?

Thanks,

Jeff

[Guest imported_JPIndusi]

I can tell you that the 1948 small engine might be similar. On my 48 Special there is a small pointer that looks like the point of a nail on the top of the opening. This is not prominent or easy to see. The timing mark on the flywheel is not easy to see as well. Here I removed the lower bell housing cover, rotated the flywheel by hand with a screwdriver and found the timing mark. I painted it and the pointer white. Then with a power timing light I set the timing to the shop manual specification.

My impression is that there were covers but they were removed early in their lifetime and never replaced.

Joe, BCA 33493

[The Old Guy]

The cover was a small sheet metal piece with 2 ears that locked it in the hole

[West Peterson]

Jeff

Just an aside, but when setting your timing, be sure to have your rpms set to the level recommended in the shop manual. You could have a difference of between 6 and 12 degrees if you have it set too high. While it may sound good while idling, it won't work for darn out on the road.

[jeff]

Thanks for the responses!

Joe, I assume the mark is in the center of the window, right?

Old guy, thanks for the insight, that piece sounds like it was easy for the mechanic to loose.

West, great and timely feedback, as usual. I will be sure to check the rpms when I do this. It turns out that there is a great graph in the shop manual that shows the advance curves of the mechanical and vacuum advance systems, with respect to rpm. The mechanical advance effect begins right at 400 rpm. So, based on your insight (which is right in line with the book!) I will keep the rpms below 400.

Jeff

[Guest imported_JPIndusi]

The pointer is in the center of the window as I recall.

Joe, BCA 33493