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View Full Version : Consider asking a vacuum tap for tune-up.



Barry Wolk
08-03-2022, 07:38 AM
Timing marks on old cars are unreliable. Wear on the timing gears, or belt, changes the orientation of the cam to the crank, and the pointer can be easily bent or mis-aligned. A TDC tool will indicate that the piston it at its peak height, but, due to wear of the components you can map TDC, but what's the point?

An ICE engine only works as a compromise between fuel, air and spark. Pony Carb pushed vacuum timing. It's really quite simple. Adjust the timing so that you have the maximum vacuum at the lowest RPM and you're pretty much done. You may get some "knock" on acceleration simply cured by backing off on the timing advance and then lock down the distributor.

I install barbed fittings on the manifold vacuum tap BEFORE the vacuum pump. On a '56 install a T in the line with a barbed fitting for the vacuum meter in-line in the distributor feed.

https://hosting.photobucket.com/images/gg18/barry2952/IMG_0116.JPG

It's a little more visible with the air cleaner on, on the '57, but the distributor tap on the '57 comes off the carb, not directly off the manifold.

https://hosting.photobucket.com/images/gg18/barry2952/IMG_3943.JPG

It's a simple matter to cut out a section of tubing the width of the center of the T, keeping the overall length of the tube intact.

https://hosting.photobucket.com/images/gg18/barry2952/IMG_0417.jpeg