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Old June 20th, 2019, 01:20 PM
randall555 randall555 is offline
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Default vacume or mechical advance on stock engine ??

do these trucks have a mechanical or vacuum advance ???
also how do you set it and know its working correctly ? my engine runs really flat and has no power on level ground or going up hill . I know these engine aren't known for power but its more than the normal problem

Last edited by randall555; June 20th, 2019 at 01:25 PM.
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Old June 21st, 2019, 04:00 PM
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Mechanical advance, the only way I know how to check it would be to use a timing light and see if the timing marks move as the rpm's increase.
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Old June 22nd, 2019, 06:15 AM
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Mechanical advance, the only way I know how to check it would be to use a timing light and see if the timing marks move as the rpm's increase.
I would agree with both statements.
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Old June 22nd, 2019, 07:59 AM
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There is no way to set the mechanical advance...it is a problem that the distributor advance weights get corroded and dont move properly so basically there is no advance at all then.
Sometimes one can take the unit apart and clean and get it working, other times a replacement is needed.

If you want vacuum advance, you can try to find a civilian distributor for the 230. These had vacuum advance and regular, car type, plugs and wires. While you lose the waterproof ability and the stock look, you do gain smoother operation and a bit better fuel mileage...though they arent the easiest things to find and you have to make sure the vacuum advance unit works as the replacement supply is all gone years ago.
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Old June 22nd, 2019, 10:43 AM
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Quote:
Originally Posted by brute4c View Post
There is no way to set the mechanical advance...it is a problem that the distributor advance weights get corroded and dont move properly so basically there is no advance at all then.
Sometimes one can take the unit apart and clean and get it working, other times a replacement is needed.

If you want vacuum advance, you can try to find a civilian distributor for the 230. These had vacuum advance and regular, car type, plugs and wires. While you lose the waterproof ability and the stock look, you do gain smoother operation and a bit better fuel mileage...though they arent the easiest things to find and you have to make sure the vacuum advance unit works as the replacement supply is all gone years ago.
"What he said"....
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Old June 26th, 2019, 06:58 AM
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Quote:
Originally Posted by brute4c View Post
There is no way to set the mechanical advance...it is a problem that the distributor advance weights get corroded and dont move properly so basically there is no advance at all then.
Sometimes one can take the unit apart and clean and get it working, other times a replacement is needed.

If you want vacuum advance, you can try to find a civilian distributor for the 230. These had vacuum advance and regular, car type, plugs and wires. While you lose the waterproof ability and the stock look, you do gain smoother operation and a bit better fuel mileage...though they arent the easiest things to find and you have to make sure the vacuum advance unit works as the replacement supply is all gone years ago.
You will also have to retrofit your stock military carb with a vacuum port, or replace it with a carb equipped with a vacuum port. According to a thread I read on here, the arrangement I'm using (pulling vacuum from the manifold) isn't correct. It seems to work fine, though.
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Old June 29th, 2019, 06:28 AM
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Yes, you are supposed to use ported vacuum for the vacuum advance...this would require a new carb as the stock 1920 Holley is not equipped with one.

I did run the vacuum advance on direct vacuum on mine for a year before I changed out the stock 1920 to a civilian 2 barrel intake and carb...no real difference noted in the performance of the vacuum advance unit though I know the direct vacuum sucks on the diaphragm all the time and ported vacuum only does when the throttle plate is in certain positions...so there is a difference...
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