Timing By Vacuum

[sailortaylor]

I just discovered my timing pointer is missing. I have read that it is possible to set the timing using a vacuum gauge. Has anyone used this method and if so where is the gauge connected and what is the proceedure? Many thanks!

[Lifer]

Here's an "old-timer's trick" for ya: Start the engine and let it warm up to operating temperature. Then, set a dish of water on top of the head and adjust the timing. If it's out of time, the vibration of the engine will have water sloshing around pretty good. The sloshing will abate as you get closer and closer to the optimum timing for your engine. When the vibration results in concentric rings (like you dropped a pebble in a puddle), your timing is about as close to "perfect" as it will ever get.

[cuz]

Unless you have a valve issue or other compression issue causing a cylinder imbalance which will continue to vibrate no matter where the timing is.

Yes you can set timing by vacuum reading just connect the gage and adjust for the highest steady reading.

I don't particularly like to advise folks without technical experience in engines to use the time by ear or vacuum methods because they can err to far from the correct point too easily.

It is best to find TDC and install a new pointer or mark as needed.

If you must use the alternated methods the smoothest idle or highest steady vacuum reading is actually a starting point. Once you find that point you need to allow for starter operation. If the timing is a tad too far advanced it will cause the starter to turn slower by loading it up. This gets the starter hotter and drags the battery down quicker. Not good for the starter or the batteries. So when you find that sweet running point then you must lock the distributor down and try starting it again while the engine is still warm. If you get a very slow starter turn you will need to back the distributor (retard) a tad and try again.