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manual choke
https://slantsix.org/forum/viewtopic.php?t=32220		 Page 1 of 1
Author:  Russ [ Tue Nov 11, 2008 6:08 pm ]
Post subject:  manual choke
72 slant six valiant,
how difficult would it be to install a manual choke?
the old thermostatic coil that mounted on the exhaust manifold has rusted away until it crumbled into a rusty pile.
With the colder weather its getting tough to start some mornings.
I just took a look at it earlier this evening, but am thinking there may be some issues with the rest of the assembly. 1920 carb.
any other solution?
thanks, russ.
Author:  steponmebbbboom [ Tue Nov 11, 2008 6:27 pm ]
Post subject: 
i use a manual choke and am very pleased with it. i used a new PTO cable (a vernier throttle would be even better for the right price if you mounted it off a bracket under the dash) threaded through the clutch cable plug and rear defrost hole on the dash, and looped it around the front of the engine to come at the carb from the choke stove side. the only downside is that the choke operates in reverse; that is, push in to choke, and pull out after warmup. there does not seem to be a practicable way of approaching the carb in the other direction without modifying the choke arm on the carb.
i will say this, the cheap choke cable kits offered by motormite and the like with the spiral wire sheath will corrode and jam-up very quickly and are not worth the money. i paid $20 for the PTO cable and it is fully sealed and stout enough to provide a positive feel and also locks in any position.
in all weather conditions i still rarely have to fully choke the engine to start it; two full depressions of the throttle will supply enough fuel to start the engine without touching the pedal. i tip in the choke 20 to 50% depending on outside temp, and usually have it fully open within 30 seconds.
automatic chokes, particularly the electric ones, work quite well and allow painfree warmups, but the less fuel you put in the engine the less wear occurs. i am willing to sacrifice some cold-weather driveability to that end, YMMV.
Author:  SlantSixDan [ Tue Nov 11, 2008 6:43 pm ]
Post subject: 
I like manual chokes on carburetors designed and configured for them. I don't like manual chokes hooked to carbs originally intended for automatics. Count me firmly in the Electric choke kit camp.
Author:  steponmebbbboom [ Tue Nov 11, 2008 6:47 pm ]
Post subject: 
I do not disagree, but could you elaborate on the problems manual cables present when replacing automatic chokes?
Author:  SlantSixDan [ Tue Nov 11, 2008 6:58 pm ]
Post subject: 
Carbs originally equipped for manual choke have a much longer choke lever so that there's a great deal more travel from fully-open to fully-closed, and they are widely spring-staged so that the choke flap can be forced partly open by airflow even if you don't touch the choke control when the engine fires. Automatic-choke carbs have a very short choke lever, so they have relatively very short travel from open to closed, and lack the spring staging. The result is usually very "touchy" choke that's difficult to set exactly where the engine needs it, which results in wasted gasoline and other unpleasant effects. The lack of spring staging makes it easy to flood the engine. Of course it's pretty easy to unflood by opening the choke, but a nuisance nonetheless.

You may want to do another general checkover; if your engine starts and runs easily from cold without needing the choke fully closed, the extra gasoline is coming from somewhere else, and you're probably sending money out the tailpipe.
Author:  steponmebbbboom [ Tue Nov 11, 2008 7:16 pm ]
Post subject: 
thanks for the explanation,
it is very easy to stall the engine without frequent squirts of the throttle on takeoff and acceleration for the first 30 seconds, i should have mentioned this. i have used this method to start and run other machines with disabled or inoperative chokes and no it is not easy, it requires a lot of monitoring that most people do not want to deal with.
Author:  THOR [ Tue Nov 11, 2008 8:02 pm ]
Post subject: 
Quote:
thanks for the explanation,
it is very easy to stall the engine without frequent squirts of the throttle on takeoff and acceleration for the first 30 seconds, i should have mentioned this. i have used this method to start and run other machines with disabled or inoperative chokes and no it is not easy, it requires a lot of monitoring that most people do not want to deal with.
I have been doing a similar thing for quite some time. My carb has no choke on it left whatsoever (no plate, no rod, no fast idle cam). It doesn't bother me, however, when working on other's cars, I get the choke working. I would agree completely that most people do not want to mess with not having a choke.

The odd thing for mine is that I give 2 squirts in the morning, hit the key, it comes up and idles no problem. Hmmmm. Of course, I don't live in quite as cold an area as you gentlemen.

~THOR~
Author:  65Dodge100 [ Wed Nov 12, 2008 2:45 pm ]
Post subject: 
Quote:
I do not disagree, but could you elaborate on the problems manual cables present when replacing automatic chokes?
Also, the fast idle cam is smooth on manual choke carburetors and stepped on auto choke carburetors. I don't know if they are all the same. That's how it is on the two I'm comparing.

With a stepped cam, you'd have to press the accelerator pedal to pull the choke cable.

Danny
Author:  steponmebbbboom [ Wed Nov 12, 2008 4:21 pm ]
Post subject: 
thats right, it's a good idea to do so anyway to get a shot of fuel down the throat.
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