I run 18 degrees on the dampner or initial ,38 total at 3000 rpm ..... I am at 8700 foot elivation , we run more timing up here for lack of air ...........
Does anyone at my elevation Have some input. Thanks Ratso Ill be taklin to you in a few days. I cant wait to get the headers and start working on them. I put a Holley Strip Dominator intake on yesterday. Now the headers and some more air (not through the radiatior) under the hood and I think Ill be satisfied w/ the proformance part, engine wise anyway. Next on to the Trans then a posi in the 9 and Ill be on to makin the rest glossy black
Get a timing light with the dial on it or use a timing tape. Every combination likes a different tune up. Stock timing specs were slow and usually had too much mechanical advance to get the initial where the motor wants it. Aftermarket dizzies are usually in the ballpark. Stock ones need a curve kit(with the advance limiting bushing) and the end play shimmed(leave a little so it don't seize up) and get an adjustable vacumn advance(these are for cruising mileage, not for race cars). Follow the instructions in the kit, you get the mechanical right(this takes a few test drives but is very rewarding) then you hook up the vacumn and play some more. When you are done you'll have a very smooth motor that makes great noises when you stand on it, it will be crisp and run nice under all conditions. You will also be an expert on YOU'RE motor's tune.
This is the type of response I was lookin for sort of. I have an aftermarket diz w/o ajustable advance. Also if all Im doing is ajusting the timing after each test drive whats the timing light for? I know that may sound dumb unless its just so I know what to start at on the next tune up. Squirrel what do you have to offer on this subject?
You want to use the timing light to get the timing in the ballpark first, then play with it and make it run as well as it can, then again check the timing with the light and record the initial timing so you can reset it easily next time you work on it. A BBC with factory iron heads will want total centrifugal timing to be somewhere in the 36 to 40 degree range. You can play with the advance curve to adjust how quickly it advances, and where the initial timing starts, and how much vacuum advance it gets, but in the end it still will work best if the total timing is in that range.
I would like to offer bottom line basics so you know why you are making adjustments. I may scatter brain and not stay in a set pattern. Tuning and tune up have so many different variables, you need to know as many as possible. If you do not stay on top of anything you do, you will forget. So, I am trying to stay in tune myself by remembering. Here are some things you might think about as you make engine adjustments, plus moving parts and their actions and what they do. You have a tuning window. That window is starting a flame at a certain time. You open the gap of the points because the degree is always looking for that window to spark in. So find the widest gap is the first step in the points adjustment. This is by design that the gap needs to work in. Follow the gap closing as the rubbing block wears down. The degree is now closer to top dead center, (TDC). This is where your lose power because the time it takes to burn the fuel needs crank degree time. That is also a design as to where the fuel must fire. Think in time. It takes time to pull the fuel out of the carb. It takes time to initially begin to create the vacuum be strong enough to lift liquid thur a tube. If you slow things down in the engine, you can see the steps taking place as you pick up the timing light, chasing for the next part of the tune. I try to write for the novice so when the pro's talk, hopefully killing two birds might help the answer to the question of the author? I'm also trying to show a picture as if someone never lifted the hood to a car.... It is just basic theory. Was this the kind of the stuff you were looking for? Anything you didn't understand? I sort of haven't even started. Any of this make sense? Am I in the right direction? 4-Stroke Theory is really boring. I can put you to sleep with it.
Mine is exactly like Ratso's and Squirrel's advice: 17 degrees initial, 38 total. I use the MSD billet dist, have not fooled with it. Iron head BBC. We usually run at or near sea level. Alcohol injected, no carb. Tried it at 35 degrees and man was it slow!
Here is where, I Drag, is chasing tune. I think he went out of the tuning window in degrees. This quantifies I Drag's tuning and could tell the difference. There are 3 ways to set the points timing. One is the timing light, the other is by eye, the last is by a static drag of hamburger paper (as a visual) wrapper through the gap braking at the opening of the ignition points. Once you find the highest gap at the points, your next step is to follow the advice from, I Drag and Squirrel. The timing window is your base middle mark, meaning, if 36 - 40 is the timing window, then base is 38 degrees. Rotate the crankshaft to 38 degrees, then go back to the distributor for your 2nd adjustment to the ignition. Place the thinnest material that you can drag between the points. Rotate the distributor rotor (full lock advance) unto your finger grab at the (points gap) cellophane (for example) all of a sudden moves. In theory, the points have opened at full advance. This is close, but a timing light will bring 38 degrees on the money. If you find the material did not move after the full advance throw, then move the distributor until the mechanical part of your work sort of moves as explained. Meaning, hold the advancer full lock, move the dist until you feel the cello move. Did this make sense to where now you set the points to the correct gap as per manufacture recommendation? You now have set the ignition without a timing light and have set the ignition fire to almost where you just need the light to check your work. If you touch the starter and the car fires right up, I think you're close. If the car heats up, the advance is not working and you are closer to TDC and the heat of the engine will tell you are too retarded and the advance is sluggish as, I think, I Drag pointed out with his being out of the window of tune.
Thanks for the info. Ive heard what Squirrel , I Drag & Ratso said from a few of the well known mechanics in town I just forgot to ask for the numbers. They said if you set it at the stock timing specs then test drive and ajust untill it runs best it will be right for what I want to do. Im not drag racing or any thing I just want it to run well and sound like it is supposed to. Thanks guys I knew I could count on the HAMB for help
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