I am new at tunning an engine. I have an old sears RPM / Dwell / etc needle meter. I have the mustang book. What is the best way for tunning the engine when changing the timing of the engine. What is the more import one to look at, the Dwell or the sound of the engine when you rev it up?

FYI, I have a 68' 302V8 4BBL Holley

 

Simple basics...Set the tiimng per the book with a timing light. The dwell is used to check the point gap. RPM is used to set the idle speed. All the numbers are in the book for these settings. However, depending on the age and wear of the engine and the altitude you are at, timing may need to be fine tuned. Here is an old timers way of setting it juuuuusssst right. Set it to the book then take the timing wrench with you and go for a drive. Find a nice steep hill and get on the throttle going up the hill. At the factory setting, you will probably not get any "pinging" sound (like golf ***** in a tin can bouncing around). Stop and go in and advance the timing just a hair and tighten down the dist bolt. Run the hill again. Continue this process untill you get just a slight bit of "rattle" sound coming out of the engine. At this point you can either back off the timing just below where it started rattling, or you can step up to a higher grade fuel octane that will burn faster....your call. Once you determine that you have it where you want it, go back and put the timing light on it and record where it is set at. Years ago I would install a dist after a rebuild, eyball it close, then start the car. manually advance the timing until the car lost a little idle and then decrease it to the point that the car lost a little idle. Half way in between these high (advanced) and low (retarded) positions is where I would tighten her down. I then would head out to a hill and dial it in just below the rattle sound. After several years of doing this, getting back to the shop and checking with the tining light, I relized that the timing was always very close to the book suggested value. Now the only time I do this process is when the engine is real worn (stretched timing chain) or I do not know the factory setting.

Good Luck.

 

Thank you for that post. I will try to do this once it gets warm over here. Also, it sounds very simple and easy to do.
Thank you again.