I prefer setting the initial at 8-12°, advancing to 36° at 3200 rpm, and using manifold sourced vacuum advance to kick the idle timing to 18-22°. It idles smoother, sounds deeper, and runs a lot cooler.
I would start with a timing tape and plot the curve. After a basic tune, set timing and idle mixture for highest vacuum. Let the number fall where it may and tune from there. Off idle is important for driveability.It will run a lot better if you set the timing to 34-36 btdc @3000 rpm which makes the timing about 10-12 btdc @ idle
My '80 RX7 had the same choke setup. It worked fine.My '79 Mazda GLC Sport had a nice set-up - a manual choke that came off automatically as the engine warmed up.
That car started amazingly well even in extremely cold conditions.
Not really. Basic cars with few or no options still had manual chokes in '64-including my '64 Falcon.Manual chokes had been pretty much obsolete on US cars at least 10 years by then. (Our base-model '54 Chevy had automatic choke.) Trucks and Japanese cars still had manual chokes later.
I wish my '81 GLC had had that, or a simple manual choke. Instead, it had an electric choke that overcompensated for ambient temperature variations---too much choke on cold days, not enough on hot ones.My '79 Mazda GLC Sport had a nice set-up - a manual choke that came off automatically as the engine warmed up.
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Plug those bad boys. I used freeze plugs in my '68 L36 "Smiley" manifold.Some SBC's of that vintage have an exhaust port under the carburetor that runs across each bank. This provides some pre-heat and these routinely become plugged with carbon causing cold driveability issues as described. Sometimes the carbon plug extends from the manifold into the cylinder head.
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What you say is correct. Every carbureted car I ever had required its own starting regime. Push the accelerator pedal once, three times, not at all, or whatever that engine wants. You will catch on to what works best - and then never deviate.The procedure is: you pull the correct knob out (check which knob is the actual choke knob as discussed above), start the engine. Once the engine catches, you need to ever so slightly push the knob back in a small amount, you will get used to exactly how much eventually. Otherwise the engine will load up with fuel. Once the engine warms up a bit you can start pushing it all the way in. If you flood the truck, open the choke fully (meaning push the knob all the way into the dash), open the throttle and crank to clear it. When I drive manual choked cars, I try and get the choke off as soon as possible but without sacrificing cold drivability.
That was about the crossover time. Neither my '63 Chevy II I6 nor my '65 Comet V8 had a manual choke. And I don't think my '60 Dodge V8 had one either.Not really. Basic cars with few or no options still had manual chokes in '64-including my '64 Falcon.
My 68 scout did have a manual choke. I never needed to use it so I made it into a cruise control.That was about the crossover time. Neither my '63 Chevy II I6 nor my '65 Comet V8 had a manual choke. And I don't think my '60 Dodge V8 had one either.
My wife bought an '82 GLC new. The automatic choke worked well in our cold winters.I wish my '81 GLC had had that, or a simple manual choke. Instead, it had an electric choke that overcompensated for ambient temperature variations---too much choke on cold days, not enough on hot ones.
No pinging with that much advance? I never tried it.I prefer setting the initial at 8-12°, advancing to 36° at 3200 rpm, and using manifold sourced vacuum advance to kick the idle timing to 18-22°. It idles smoother, sounds deeper, and runs a lot cooler.
No pinging with that much advance? I never tried it.
I've also heard of pulling out the choke and using it as a hook to hang a handbag, though I suspect that is more myth than reality.My 68 scout did have a manual choke. I never needed to use it so I made it into a cruise control.
I saw something similar done with an old (1940 or so) Fargo. The truck had a throttle control that could be pulled out to increase the idle speed. (Similar to a manual choke, but different in that it didn't enrich the mixture by closing the choke plate.)I've also heard of pulling out the choke and using it as a hook to hang a handbag, though I suspect that is more myth than reality.
A cruise control would definitely be a better idea.
Yes, that was an old 'mechanics joke' when the lady would pull into the shop with a good starting, but poor running engine. It probably did happen on occasion.I've also heard of pulling out the choke and using it as a hook to hang a handbag, though I suspect that is more myth than reality.
A cruise control would definitely be a better idea.