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Hi all, I just finished an overhaul of my Rochester carb on the 49 Olds. The factory manuals told me every thing I needed to know but made no mention of the idle screws setting. Can anyone help me with that? I don't know what the setting should be or how to test them. What's the proper gauge to use to test and set? A vacuum gauge? Any advice is welcome!
Last edited by maineolds; November 19th, 2020 at 02:57 PM.
Adjust them for highest vacuum at idle speed and then turn in 1/8 turn.
Far as setting idle speed rpm, DK where you'd find a dwell tach that operates off 6-8 volts. You may have to power it and timing light off another 12v car. If it has inductive pickups it should work.
Or did we determine this car had been converted to 12v?
Thanks for the advice! My Olds is still 6v. I recently replaced the points with a Petronix unit so checking dwell isn't necessary any more. Right? I do have these two old dwell and tach units. Both plug into house power. Neither say anything about being 6 or 12v. I found info online about the Allen and it's for both 6 and 12v! The Penske unit is from the 1980's. The Allen is much much older.
Last edited by maineolds; November 19th, 2020 at 05:10 PM.
I recently replaced the points with a Petronix unit so checking dwell isn't necessary any more. Right?
Correct.
BTW, I don't really think the term "idle screws" is the best term. I prefer them to be called A/F (Air/Fuel) mixture screws since that is what you are adjusting.
Now you've done it. I have drooled all over meself like Mr Pavlov's pooch. I love me some vintage test equipment and I think I have a similar Allen.
Anyone notice the Penske unit can handle up to a four-rotor Wankel?
I did happen to notice the Wankel Rotor. I just looked at it and didn't want to dwell on my lack of knowledge about the 3-rotor Wankel. I got the orientation of the difference between the 2-rotor and the 4-rotor, but I don't understand a 3-rotor Wankel.
Haha, looks like if found a home here. Kindred spirits that love the vintage gear and wheels! I choose to live a big part of my life with “vintage” gear. It’s not about the cool factor, it’s an appreciation for things that can be taken apart, examined, understood and made to work. Thanks everyone
You might try adjusting the screw (RPM) fast enough so the car won't die at a stop light at a sudden stop but low enough so it won't crawel away with your foot off the brake. I have no idea what RPM that is but that is what you are trying to achieve..... Tedd
November 19th, 2020 | 02:55 PM
