Ignition Timing
#1
Ignition Timing
What should I set the ignition timing at on a '74 360? It's supposed to be 8* stock, correct? I have it at 12* and was wondering if there would be any gains if I went higher?
Also I run my stock 352 in my '66 at 12*. Would I gain anything more on if I went higher on it? It will outrun the 360 a fair bit the way it is.
Also I run my stock 352 in my '66 at 12*. Would I gain anything more on if I went higher on it? It will outrun the 360 a fair bit the way it is.
#4
Also, did the 360's have a retarded timing set like the 400's did?
#6
Total timing is more important. On a FE, 38 to 40 degrees of total advance (initial + mechanical) are reasonable. As long as the engine does not knock.
Disable the vacuum advance. Rev the motor up until the timing stops advancing, hold it there and then advance/retard the distributor to set the total timing, say 38 degrees. Make sure it is not knocking. The initial timing will end up the difference of the total timing you set minus the mechanical advance of the distributor.
If you want more initial advance, then you will have to be able to adjust the mechanical advance in the distributor to keep total timing in the 38 to 40 degree range. Or whatever advance your engine can hold without knocking.
Disable the vacuum advance. Rev the motor up until the timing stops advancing, hold it there and then advance/retard the distributor to set the total timing, say 38 degrees. Make sure it is not knocking. The initial timing will end up the difference of the total timing you set minus the mechanical advance of the distributor.
If you want more initial advance, then you will have to be able to adjust the mechanical advance in the distributor to keep total timing in the 38 to 40 degree range. Or whatever advance your engine can hold without knocking.
#7
Total timing is more important. On a FE, 38 to 40 degrees of total advance (initial + mechanical) are reasonable. As long as the engine does not knock.
Disable the vacuum advance. Rev the motor up until the timing stops advancing, hold it there and then advance/retard the distributor to set the total timing, say 38 degrees. Make sure it is not knocking. The initial timing will end up the difference of the total timing you set minus the mechanical advance of the distributor.
Disable the vacuum advance. Rev the motor up until the timing stops advancing, hold it there and then advance/retard the distributor to set the total timing, say 38 degrees. Make sure it is not knocking. The initial timing will end up the difference of the total timing you set minus the mechanical advance of the distributor.
Would there be any gains to swap the timing set out for a new one or were the originals straight up?
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#8
#9
Keep in mind, advancing the initial timing will gain some power, up to a point. Beyond that point you will start to loose power. By manually adjusting the timing you are trying to improve the efficiency of the ignition system.
#10
#11
My 65 w/352 got set to 24 initial time because of a loose dizzy bolt, it started fine and idled fine but going down the road it made a Shhhhhhhing sound and acceleration just wasn't there. When I checked the timing it was set @ 24 btdc so I set it back to 12 and it runs great. So I'd start with 12 and go from there.
#12
#14
The first thing you want to do is make sure your timing chain and gears are good. Then set your total timing at a maximum of 38 degrees when using regular gas. Get rid of the points and go to a petronix electronic setup.
Click on the below.
Ignitor
Click on the below.
Ignitor
My FE isn't in a truck, but in a 2500 lb kit car, so things can be different. Plus I have Crane Fireball cam installed. But I had a bog that I couldn't get rid of through idle stop setting, idle mixture setting, or accelerator pump tuning. I finally started playing with timing and found 20 deg BTDC at 850 rpm worked great. Springs were light so it cranked at 15 deg BTDC. But always, I kept the max advance at 38 deg BTDC by adjusting the distributor internals.
Now perhaps I should have kept playing with the carbs, but the timing worked and those figures arn't unique; they have worked for others. (Oh, I forgot to mention; I don't use a vacuum advance distributor).
I've mentioned all this to show what a variety of intial timing settings will work, yet always keep that 38 deg total in mind. It can vary too (and if so, generally lower, not higher), but it's a good rule until you get things fine tuned.
But if you are stock, or close to stock, start with the factory specs and even after fine tuning, you shouldn't be very far away from that. If the stock settings are suspect, then do as suggested and set the timing for 38 (or 36 to be safe) max advance, and then see where it is at idle. From then on, you can use that idle reading when doing a tune-up.
Of course, with a Pertronix unit, you won't need to fix the timing during a tune-up!!! Well, it's rare...
#15
Just in case you happen to go to a Pertronix, the coil choice has nothing to do with compression ratio, and you don't necessarily need a different coil, it depends on how your vehicle is wired & equipped, primary resistance wire, ballast resistor, full 12v etc. Read the directions from Pertronix carefully and use what they tell you and you shouldn't have a problem, but if you run the wrong setup it can cook pretty quick. One great application for a Pertronix is if you have a distributor that's sloppy and eats points, you can put an Ignitor in there and it will start like new. We put one in an old C800 with a 391HD governor distributor with a worn-out dizzy and it pops off like a new truck now