Nowadays I read about boost and ignition retard is required. I realize todays world is different with quite a few lbs of boost FI and computers but what was done in the old days, pre '65? Ford had supercharged option in '57, Stude in early 60's; did they have ignition timing retard? What if we go back even before '57 there were quite a few cars that had superchargers, Gram, Cord. Plus in the late 50's there was Paxton type kits so where is the point of boost to needing ignition retard?
Yes on some , & No On some , Octane was much higher and had four or five different octane ranges on pump gas. Some learn to have A distributor "locked out some Not " distributor base loose with springs attached to it Full Advance, and a cable attach to distributor " Pull Cable " To retard timing under boost, Release cable back to full advance . 1 to 1.5 deg's of retard per 1 psi & also depends on static Compression & boost , A 9:1 engine with 4ish No retard needed most on 91-93 oct.
Yes, it depends on a lot of things. I never ran boost retard in Plan II, it had about 8.5 compression with a 6-71 and ran fine on pump gas with up to 38 degrees advance in the 427. About 6-8 psi boost. I think you'll find the engines in those old supercharged cars had low compression and low boost, and also not enough carb or cam to let in enough air to make much cylinder pressure. The turbocharged Olds in the early 60s had water injection, but also not much boost.
I’m pretty sure the F code had a vacuum can that did some boost retard. On my blow thru F Clone, and the SN series on my bird, I used an MSD, a Hobbs switch, and 2 degrees at 3lbs. I know that’s cheating, but easier in today’s world. Had Chevron Supreme or Sunoco 260 from the 60’s been available I probably wouldn’t have needed it. Those were 5-8lb engines.
I think the amount of boost 5-7 psi wasn't enough that boost retard was needed as compared to today 14-20 psi typical. Add in carbureted that was probably a little on the rich side to also be bit forgiving. Plus the higher octane fuel inherently more detonation resistant.
I remember seeing the Corvair advance unit, it had a port on both sides of the diaphragm, advance and retard.
I found a new Accel advance canister that also provided 2* retard per pound of boost at a swap meet when I was building my 350 with a 6-71. The original application was a Delco advance canister for the ‘68 Ram Air GTO, Accel duplicated them for their turbocharger kits. Photos are from eBay- My blower is pretty loose, doubtful that I ever needed it.
My 72 Comet Disributor had a dual advance canister, I wonder if it could work like the above Accel unit? In my Comet application [probably same as GTO] was actually a temperature controlled Vacuum retard and advance. I'll have to find it in the shed test if it will work. In hindsight if a regular vacuum advance canister is spring loaded with some advance then if boost pressure is applied it should retard. However if the pressure taken after carb and the canister leaks..
Just sayin'. I have used the MSD Boost Timing Master in the past. It requires a manifold vacuum line and goes inline with the points trigger wire. Doesn't change your current set up and is adjustable from 1 to 3 degrees of retard per pound of boost. I rarely used the dial after I found the sweet spot, (usually when I got ripped off for "premium" gas), you could easily hide it. I was stunned to see the price now, I played with this stuff 25 years ago. Mike https://www.speedwaymotors.com/MSD-8680-Adjustable-Timing-Control,104290.htm
An old alternative to pulling the timing out under boost is to add water, or some methanol. ... or even cooler, this: Cheers, Harv
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