Assuming that your engine is more or less the way the factory built it -usually called "stock", the ignition timing is specified by the engine manufacturer; a Buick engine's timing would be specified by Buick. The answer to your first question would be yes. This is officially known as "base timing" but is usually just called "ignition timing." If the engine has been significantly modified from stock, you are kinda on your own as to base timing. Sometimes a manufacturer of a high-performance camshaft will have a base timing suggestion, but you will have to find out what works either by yourself or with someone who has experience doing something called "power timing." That's a whole nother can of worms and is best left to the experts. Ignition timing is a simple concept. but in the real world it is critical for the best engine performance. And just to complicate things further (someone in an earlier post touched on this) just because base timing is correct doesn't mean that it is correct at higher engine speeds. As a practical matter, if the engine is stock, we check to see if the mechanical (sometimes called centrifugal) and vacuum advance mechanisms are working. If they are, we assume that the total range of engine timing is correct as long as the base timing is correct. Too much information? BTW: There are no stupid questions, but lots of stupid mistakes. Use the former to avoid the latter. The latter is often expensive and may lead to the use of shoe leather.
Back in 2002, I authored a thread called "Power Timing your Buick V8". Just about everything you need to know about ignition timing is in that thread, BUT, in order for you to understand what is in that thread, you have to be familiar with the VERY basics. Otherwise, that thread might as well be in Chinese, because you won't be able to follow any of it. I'm not trying to be a tool here, but we shouldn't have to school anyone in the most basic automotive knowledge. A question like "what is ignition timing?" is one you really shouldn't be asking, because you can Google that right on your computer, and reading for maybe a half hour should familiarize you with the definition. https://en.wikipedia.org/wiki/Ignition_timing Ignition timing is simply the timing of the spark in relation to piston movement. Timing requirements change with changing piston speed (engine RPM), and there are two mechanisms inside the distributor which change ignition timing. (mechanical advance, and vacuum advance). The chassis manual for your car has a great section that describes in detail, all the basics you need to know, to follow what is in this thread. http://www.v8buick.com/index.php?threads/power-timing-your-buick-v8.63475/
When that hash mark on the harmonic balancer is lined up at the 0 degrees marking, your #1 piston is at top-dead-center (TDC). The initial timing is how many degrees before that 0-degree marking that the #1 plug fires with no advance at all (no vacuum to the distributor, and the mechanical weights in the distributor are fully retracted). This is the reason the shop manual for your vehicle advises to disconnect the vacuum line to the distributor when setting initial timing. Read Larry's thread & it will all become clear.
Larry, Len, John and everyone else. I have read and re-read all your posts and comments and can say that I have a much better basic understanding of these questions. Thank you! This will help me considerably as I begin to reassemble my engine in the next few weeks, and when it comes time to turn the key in over a year. Gulp! I have people asking constantly when I'm gonna have it back on the road. I will have a ton of other question, which I'll post in their respective sections. I've never done a tear down to the drive train before so this is a first and I'm a bit nervous that I will/have drastically screwed something up or overlooked something. I took a lot of pics during disassembly. Perhaps I'll create a progress thread... as if there aren't enough. Another question: What is the advantage or reason someone would switch to an HEI distributor? I'm not planning on it at this time, but see it a lot so figured I'd ask. Oh yea, one more thing: How do you know so much about swallows?
I know that when I swallows beer it tastes good! As to the HEI, there are no wearing parts (sorta) such as points and condenser. The entire ignition system is in one unit. The GM HEI distributor still has both mechanical and Vacuum advance, so both can be adjusted (by replacing weights, springs, or the vacuum diaphragm). It will provide a hotter spark - if you ever get nailed by one you will not soon forget it. The factory breaker point ignition systems are capable of generating about 20,000 volts, which is plenty for a stock engine, I'd probably leave the factory breaker point distributor in place unless there is a good reason to change it to the HEI. A good reason would be that someone stole your original distributor. The HEI was first used in 1974 by GM because to meet the emission standards of that time, they needed a wider spark plug gap. A longer gap means more voltage (air is a good insulator) the stock breaker points simply could not produce enough voltage to reliably arc across the wider plug gap. The HEI can produce up to about 35,000 volts.
Jeff, I think that is your name anyway?, Royale Oak isn't that far from Rochester Hills, if in you think you need any help with your engine let me know I could take a ride out? Maybe even help you get it back on the road for THIS year's Woodward Cruise? Derek
There is a very good chance I'll be contacting you. None of my friends know anything about cars so I need all the knowledge/help I can get. Thank you. And yes, my name is Jeff.
About that unladen swallow..... If he goes pooop (unloads).... just as he launches into flight....that's an unladen swallow. Other swallows: ...don't follow the first swallow too closely or you may swallow what follows that swallows' launch...for your lunch. Now, if my expert answer is too complex to swallow, give it a little time to digest.
Larry's power timing thread really helped me. I first set my timing according to Larry's instructions, couldn't have done it without that thread, but ignored the last part about the adjustable advance kit. the car ran better but I was never completely happy with it. I went back and spent the $40.00 and bought the adjustable advance kit from Summit, spent an hour installing it and re-power timed my 350. Man what a difference! It really woke that small block up. I am also running the Crane XR-I points eliminator. Very easy to install and cheap, I think it was around $100.00
So as I have the engine dismantled, I've noticed that the pistons do not appear to be stock. They have a 030 marking on them. Does this mean that the cylinder has been over bored .030? If so, why? Is this a performance upgrade? What other reason would someone do this?
I got the Crane Cam kit Larry mentioned in his thread so I will be doing my very best to digest his information and time it. I read the stories of how much power this relatively simple tweak can produce so I'm excited to give it a go.
When an engine is rebuilt, it is normally overbored enough to clean up any cylinder wear to make the bores perfectly round again. It means the engine has been rebuilt once.
A 2 series gear refers to the size of the ring/pinion gear in the rear end housing. A 2 series would be a 2.56,2.73,etc size gear. A 3 series means it would be a 3.08,3.42,3.73,etc gear in the rear end. The higher the number, the lower the ratio ("steeper" as some say). The higher your rear gear ratio, the more acceleration your car will have, but at the cost of reduced top speed. For example, with a 2.56 your car may do 65mph with the engine turning at 2500 rpm, while with a 3.73 your car would turn something like 3600 rpm at 65 mph (these are not hard calculated numbers, just off the cuff example). The lower the gear ratio (higher numerically), the faster the car will accelerate, but will cruise at higher rpm. Hence why drag cars usually have very low rear gear ratios like a 4.11,4.56, etc. To launch harder/accelerate faster.
