Does the engine need to be warmed up? hot? or does it matter when setting the timing?

 

To set the timing you should let the engine warm up and reach normal operating temperature. Since that is where the motor will be running most of the time you want everything set from that temp. Lars has a good paper on setting timing that can be found at http://www.corvettefaq.com.

 

Yes, it needs to be at operating temperature.

 

The timing doesn't change with temperature. Mechanical timing will read the same hot or cold. The only consideration is that you need to rev the engine up around 3000 rpm in order to set and verify the total timing, and I would hesitate to run a dead-cold engine up like that. But once the engine has run for a few moments and the oil is circulating, the engine does not have to be at operating temp to set the timing - it makes no difference.

 

Ok, when the engine is at 3000 rpms, how do you read the timing? I hear 34-36 degrees is what it should be set around, correct? Do you multiply the marks by 3?

 

I set mine at any temp after the idle is smooth.Saves burnt hands.The trick is setting the right total. I went through a few tanks of gas playing with different advance spring kits and ended up with the Crane blue/silver springs on the stock weights. This will give a 21 degree mechanical advance.
Knowing the total mechanical,I now can adjust the initial while idling,and get the same results you would see if you reved the engine to 3000,and set it.
The problem is with stock springs you may have to hit 4000 or more for the total mechanical to hit.So you will be running way too much timing if you don't know what your advance curve is,and try to just rev it to 3000,then set for 36 degrees.
BTW if you run an 8" balancer,measure 2 1/2" clockwise from the stock balancer 0 degree mark,and make a new mark.Then when you rev the engine to 3000 rpms use the new mark and reference the timing tabs 0 degree mark. When the new balancer mark is at 0 degrees on the tab,you have reached the golden 36 degrees total mechanical.(Vacuum advance whole new story.)
Check out my site for details.

 

Brad -
I just e-mailed you a how-to paper on setting up the timing right. Contact me if you have questions or if you need assistance.

 

If you're running a stock distributor, you'll probably need to rev it a lot higher than 3,000 rpm to find total timing. Many stock distributors don't reach total until well past 4,000 rpm. Be sure to rev it until the marks stop moving before you set it. 36º is close to optimum for most engines and a good place to start. Once you've set your total, take a reading at idle. The difference will be the amount of mechanical and in future adjustments you can use idle readings to set timing.

 

Temp may not be important when setting timing but it sure as heck is important for other tuning like carb idle mixture adjustment. Since timing can effect idle mixture, its probably best to adjust them both whenever doing either. So therefore a warmed engine is always the best bet.

 

The faq web site seems to be down right now. I'll try again tomorrow. The reason I was asking about warmed up or not is that it is just easier if the engine is not blazing hot. I have only tuned mine by vacuum gauge. Hopefully I will be getting an adjustable light this weekend. :cool: