timing a 85 flat

G

gayle marlowe

Member
New guy here. just bought a 38 sedan and local old guys tell me that because of the altitude we are at i should advance the timing by 2-3 degrees. car came from the plains about 3500 ft lower.
how do you change the timing? where are the timing marks?
 
I will assume the car has original engine? original distributor? if the answer is yes to both then on the pass side of the distributor there is a advance adjustment screw with a slide plate marked in degrees--loosen screw and move the plate-- be sure to mark the original location as a point of reference
 
My thoughts are that you should not have to do any adjustments to the ignition timing. But the two main jets in the carburetor may have to be downsized (smaller) to compensate for the rarer atmosphere where you live. I would however leave it alone for now and just drive it a bit and keep your eye on the spark plugs to see if it is running rich or not. Regards, Kevin.
 
thanks for the advice. I will start with Koates advice and drive it as much as possible to get accustomed to it and start checking plugs. I had thought of smaller jets possibly and may have to look into that. That distributor sure is a lot different than what i am used to seeing. :)
 
The engine has no timing marks. The correct way to time it is to remove the distributor and set it up on a distributor machine.
 
Ken/Alabama said:
The engine has no timing marks. The correct way to time it is to remove the distributor and set it up on a distributor machine.
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For those of us for whom there is no timing machine within a hundred miles, the old-fashioned way to time a flathead is to first be sure the points are not burned or pitted, and then be extremely precise in setting the points at .015. Then adjust the vacuum brake to a light touch, set the timing adjustment to center and bolt the distributor back on the engine. Then road test, listening for any pre-ignition ping. If none heard on moderate acceleration in second gear, advance the timing (move the little plate up) one mark (2 degrees) and test again. If still no ping, advance the timing another 2 degrees and road test again. Rinse and repeat. You will probably pick up a little ping as you approach 6 degrees advance. When you get the ping, back off one mark (two degrees), and call it a day. Unlike the machine, this approach takes into account every operational aspect of the ignition, like compression, plugs, fuel blend, fuel/air ratio, altitude, combustion chamber condition, etc.
 
drolston, sounds like good advise to me. As you said, takes into account the variables in my particular engine. I’ve been afraid to touch my distributor after it was set by a pro on a machine, but I think I will try what you suggest. Any down side to consider if advancing two to four degrees beyond spec?
 
No downside. Considerable up-side. Like more power, better fuel mileage, and less prone to overheating.
 
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