Re: I do recommend this method


[Follow Ups] [Post Followup] [Dodge Power Wagon Forum]


Posted by MoparNorm on Sunday, January 02, 2005 at 10:27AM :

In Reply to: I don't recommend this method posted by George in NW Michigan on Sunday, January 02, 2005 at 9:09AM :

Assuming we are talking about vintage trucks, or non computer controlled vehicles:
Setting the timing with a vacuum gauge, places the engine timing at the point where the engine runs the most efficiently and developes the most power. Often that point is a tad more advanced than is perfect for starting the motor and the timimg has to be "backed off" a bit (or retarded) to allow easy starts.
The engine is basically an air pump, the vacuum guage tells us when the air pump is performing at optimum. The timing light only tells us at what point the distibutor is discharging, it is not telling us if that discharge is occuring at the proper moment. If you have changed carb, cam, valves, distributor or any other mechanical feature of your motor from the stock setting, there is no way to use a timing light to tune acurately, as the stock settings are no longer valid, such as when changing to a "torque grind" cam. Assuming that your truck is completely stock, with stock settings, a timing light will tell you one thing, at what point is the distributor firing at the number one cylinder.
A vacuum gauge will tell you if your motor is in good condition, if your rings are shot, if your carb is adjusted properly, if you have a sticking valve, a leaking valve or a burned valve. The vacuum gauge will tell you if the guides are worn, if your intake manifold is leaking, or if you have leaking gaskets in the manifold or carb. It can tell you if your timing set by a timing light is incorrect. It can tell you if your plug gap is incorrect, or if your points are set wrong. A guage can tell you that you have a weak or broken valve spring, a clogged muffler, a bad plug or stuck valve, or a leaking head gasket.

I have timing my vehicles with vacuum gauges for over 35 years, haven't found it to be "dangerous" to motor life yet, and some of those motors had over 350,000 miles on them. I have found very few motors that performed well at "factory specs" when using a timing light at the factory settings. They will run "OK" but with normally poor to average mileage and power because factory timing settings are set to make the motor last, not develope maximum performance. I'd be concerned if you were driving 100,000 miles a year but not at 50,000 or less. Set it where it runs the best and still starts without dragging down the starter.
MN



Follow Ups:



Post a Followup

Name:
E-Mail:
Subject:
Message:
Optional Link
URL:
Title:
Optional Image Link
URL:


This board is powered by the Mr. Fong Device from Cyberarmy.com