Can anyone provide the number stamped on the "football" and on the centrifugal weights of a 1966 L79 engine. I am unable to get the full centrifugal advance from my distributor. Any help is certainly appreciated. Have been unable to turn up any printed information about what was originally intended.
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Re: Distributor parts identification ?
You might find the following thread useful - how to do a "blueprint/overhaul" of a L-79 distributor and optimizing the spark advance map in the process. This applies to any single point Delco distributor, but the spark advance map will be different depending on the engine's configuration. More on this in my tuning seminar that is included in the database of restoration documents... second to last thread in the "sticky" section.
DukeLast edited by Duke W.; May 13, 2024, 11:33 AM. -
Re: Distributor parts identification ?
Hope that someone has a "530" cam assembly they would like to sell. Zip lists one but when I called they looked and said all are stamped 726. which does not seem to be of any help in this situation. Also can anyone furnish the number stamped on the "football" of the main shaft of a L79 (1966) distributor? Mine is stamped 203 or possible 209 and so far have not been able to verify what the proper shaft would be. Anybody have any advice to offer? Thanks for any help!Comment
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Re: Distributor parts identification ?
I listed the various part numbers for a '65 L-79 distributor in the link I provided in my previous post. Granted you have a '66, which has a different distributor number, but the spark advance maps are identical, and I don't know what parts are different. Don't worry about the football. It affects the shape of the centrifugal curve, but not the total advance. Just make sure the mainshaft you have has a good tach gear and football weld.
Some weight geometries will not allow the weights to close totally against the football before they interfere with each other and this will affect total centrifugal. Many of these distributors have been modified over the years - not always to good effect - so at this point try to obtain the applicable proven setup that I've developed over the past 60 years - all of which are outlined in the tuning seminar.
There's nothing sacrosanct about the OE L-79 spark advance map. In fact, it's rather ill-conceived given that it has the least aggressive centrifugal - same (30 @ 5100) as the base 300 HP engine and the most aggressive VAC (16 @ 8") from the 365/375 HP 30-30 cam engines, which is more aggressive than necessary.
A 26 degree cam assembly is fine along with a 12" VAC (NAPA VC-1765 or equivalent in another brand) Use light springs to get all centrifugal in by 3500 or less and then set total WOT advance (VAC disconnected) as high in the 36-40 degree range as the engine will tolerate without detonation. This will put the total idle advance at 26-30 (assuming the centrifugal starts at more than typical L-79 idle speed, 750 @ 14-15, which puts it in the optimum ballpark for the amount of L-79 valve overlap, more than base engines(low to mid 20s), but less than mechanical lifter engines (high 20s to low 30s).
You can buy used cam assemblies from David Socolowski (see in ad in The Driveline), but a lot of them appear well worn.
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