350 Olds Timing

[Guest 66olds]

So I was able to get the 350 into my 66 Cutlass minus the headers I wanted. Too expensive so I went with the stock manifolds. Not bad drives ok and sounds good. My question is timing. The motor is a 73 350 with Edelbrock heads, intake, and 650 carb, with a crane cam. I am using an hei distributor. I have it timed at what my book says at 12 degrees before tdc but it doesnt want to be there. Further in the book when it goes to the hei years it calls for 20 degrees before tdc but the pointer on the motor stops at 14. Any idea how I can accurately get to the 20 mark? Timing tape, a new harmonic balancer? Any help or suggestions would be greatly appreciate. This board has always been helpful and never let me down. For that I am truly greatful. I only wish I had more knowledge you guys do to give back but I am learning! Thanks in advance

[joe_padavano]

Since your combination is not stock, it's not clear that any book will help. Just keep advancing the initial timing a couple of degrees at a time and drive it for a while. If it works, advance a little more. If it pings, back off. Yes, a timing tape is an easy way to go, but be sure the balancer you have hasn't slipped at all.

[RocketDude]

The better timing lights have adjustable advance built into the light. There is a dial on the light which you set to the advance you wish, in your case 20 degrees. Then you simply adjust the timing so the stationary pointer lines up with 0.

With the light dialed in to 20 degrees, you time the engine to 0 degrees, and it will be at 20 degrees...!

That is the most accruate way to set timing...

[joe_padavano]

That is the most accruate way to set timing...

I'm not sure why that is any more accurate than a regular timing light. If the balancer and timing tab were not checked for accuracy when the engine was assembled, then it doesn't matter what timing light you use, the timing will still not be accurate. If the required initial timing doesn't exceed the limits of the timing tab (or if a degreed balancer is used) then a regular timing light is just as accurate as a dial-back one. I'm not sure why aligning the marks at 0 degrees is any more or less accurate than aligning them at 20 degrees.

In any case, I'm not sure this addresses the orignal (and somewhat old) question of correct intial timing for a modified engine.

[RocketDude]

The original question was how to time his engine at 20 degrees when the tab only goes to 14, so it definitely addressed the question. I didn't say 20 degrees is the advance that will make his engine perform to the maximum, that was the OP's idea, I just explained the easy way to do it.. It goes without saying a matching balancer and tab must be used, and in proper condition.

Is an advance light more accurate..? No, but is certainly much easier to use and eliminates mistakes. You can't get easier than timing to zero, and let the light figure out the advance. Even easier than using a degreed balancer. If advance lights weren't better, they wouldn't make and sell them..!

You can also easily check and set total advance with an advance light, which is very important when working on a high performance engine.

Professional mechanics use advance lights. It is perfectly OK with me if you prefer to use the old school back yarder light.

I have read many of your previous posts, and I know if I, or anyone else, say black, you say white. You are more interested in trying to impress people with your knowledge, which is somewhat limited. If you ever used an advance light you would be a believer, but then you don't come here to help, you come here to argue, so go for it. I promise not to offer advice any more. Let the people get their advise from a BSer and see how far they get..

I used to come here every day, now only once every month or so, and after today, probably never again. There are good knowledgeable people in here, but enough blow hard BSer's that have chased me away. There have been threads in here asking why participation is low, well now you know why I don't come around any more...

[joe_padavano]

You are correct, the original question was about timing at 20 degrees, and I apologize for my comment about that. I should have reviewed that post before opening my mouth (or keyboard). Your answer was appropriate in response to that part of the question.

I maintain, however, given the decidedly non-stock engine setup in the original question, that trying to set the timing to some "book" value was not productive.

[Guest JRZYBOB442]

Joe's answer is correct. Frankly, there are so many things affecting what timing a particular engine may want to "see" to run correctly that initial advance is just a starting point.

Consider, camshaft, cam advance or retard, distributor play, compression ratio, fuel octane, even exhaust back pressure. Last, what is the advance curve of the distributor?