How To Set Timing On 383 Stroker

• #2

at idle you should be around 12 deg btdc
by 2000 rpm your dist should exist fully advanced to around 32 deg btdc.
If your higher than that you should expect into changing the advance stops in your dist.

Of course this is with a stock or balmy cam.

Don't forget to plug the vac accelerate pod on the benefactor while your timing your motor.

Equally for your carb 750 is a scrap much for a 383.
I run a 650 and works really well for my 383 with a mild drag cam.
Yous would probably need to supervene upon the jets and rods from the ones that come with the carb to conform for the 6,000 anxiety elevation.
I actually similar the Edelbrock Thunder AVS carbs. I'm running model 1806.

I also recomend taking information technology to a tuner with a chassis dyno and having them arrange your carb, timing and choke properly to get the correct afr for your altitude.

Just my 2cents
-Steve

• #3

I prefer using a vacuum guess to find out what timing the motor wants. Since y'all're new to doing this, I'd say start bourgeois every bit Steve suggested with 12 BTDC at idle.

I'm at ~5640 feet and have a 383 in my '68. Slightly lumpy cam (unknown specs), unknown pinch ratio, 516 heads, Holley Street Dominator single plane intake, one" phenolic adapter, Holley Street Avenger 770cfm (which the motor loves!), Mallory Unilite with vacuum secondary, Mallory Promaster whorl, and Hooker headers (probably one five/8"). When using Fugly's white paper to detect timing (http://www.diamondbackengines.com/technical-white-papers/vacuum-gauges/), I ended up with 24 degrees at idle, 42 degrees all in by 3000 rpms, and 10 degrees in the vacuum advance.

At altitude, the engines like a bit more than initial timing, but you take to make sure you are limiting the corporeality of timing added by the mechanical advance (for example, my Mallory came stock/pre-set to 24 degrees mechanical advance; I had to adjust information technology down to 18 in one case I constitute my numbers). Like I said, if you lot're not familiar or comfortable with doing this, then stay conservative on the timing.

• #iv

Likewise, your compression ratio volition usually dictate how much total information technology likes.....the lower the compression, the more timing. What's your psi on a compression exam? I've never had two engines that liked the same timing bend.

• #v

On a side note, many people find that punch-back timing lights are inaccurate. It's better to use a standard timing calorie-free (or the dial-back light set to 0) with a degreed balancer or timing tape (don't expect information technology to stay there forever though).

• #6

On a side notation, many people find that dial-back timing lights are inaccurate. It'southward better to use a standard timing lite (or the dial-dorsum low-cal prepare to 0) with a degreed balancer or timing tape (don't expect it to stay at that place forever though).

I like to lay out my balancer and so utilise a cold chisel to marking the lines. Information technology'south not '0' perfect just it doesn't have to be. You can also apply the timing tape to lay information technology out with. Just brand punch marks through the lines then cold chisel the dial marks and you don't accept to waylay it with the hammer either. As for timing lights....you only need to exercise some enquiry for what ones are on the money vs the ones that are not. I have a 30+ yr old light that is on the money and accept used it to cheque my punch dorsum low-cal and they are both together. At that place are both that are proficient and then in that location are the ones that are junk. So far I oasis't found whatever skilful most things like that from Harbor Freight etc. Mac tools is mentioned and so is MSD and Ferret. The MSD is going to be around 200+ and the Ferret is more. Craftsman has had some good lights just they as well have had some bad ones. My old one is a Craftsman and I've checked it against some of the better known brands and it right with them. I suppose I could mail the model number but I doubt yous'd observe i on the net simply perchance.....?

• #9

The timing 'bounce' is mutual at idle. How many miles does it have on it? The older the engine is, information technology'll probably have more. The bounce probably isn't as noticeable at higher rpm?

• #10

The timing 'bounciness' is common at idle. How many miles does information technology have on it? The older the engine is, information technology'll probably have more. The bounce probably isn't as noticeable at higher rpm?

Cranky - Is the bounciness specific to points distributors, or is this a distributor shaft/bearing/bushing wear issue that could affect all distributors?

I haven't played with a points distributor in 15 years, so I'm rusty on them and can't remember if there was bounce or not. I merely put in electronic ones and ditch the points.

• #11

The distributor could exist worn and probably is if it'south an original unit but things can stack up like a sloppy timing chain, or worn cam drive/intermediate shaft or all of information technology. How did it run with the 24/42? Unilite with vacuum secondary? You hateful vacuum advance, right? Vac hose disconnected it's running at 24 degrees and so goes to what when you hook it up? Your Unilite is a points unit?

• #12

How did it run with the 24/42? Unilite with vacuum secondary? You mean vacuum advance, right? Vac hose disconnected information technology's running at 24 degrees then goes to what when you hook it up? Your Unilite is a points unit of measurement?

It runs nifty with 24* initial, 42* total. Aye, meant Unilite with vacuum advance. Probably still had the Holley on the encephalon when I typed that!

Yes, 24* with vacuum advance asunder. When I was running the Carter AFB 625cfm, I did what I'm used to doing which is plug the vacuum advance into the timed spark port. So, no advance at idle. After doing some reading on the use of full manifold vacuum as the vacuum advance source (since the Holley I was putting on no longer had the timed spark port due to the race calibration Proform principal metering block), I felt it could do me some good to try it (and I had no choice other than to not run the vacuum advance at all, which I didn't desire to do). The timing does jump up some at idle when using full manifold vacuum, just I don't accept the exact number handy. It wasn't much and a quick idle adjustment brought it back downwardly to where I wanted the idle. I had the can adapted to only provide ~10* when I ready up the timing and didn't impact that adjustment when I went from the ported to manifold vacuum source. IIRC the vacuum accelerate doesn't advance at under 10" of vacuum.

My Unilite has the optical trigger. Like I said, I haven't played with points in a long time! Still have my feeler gauges and dwell tool though. ;)

• #14

I know this is an older thread but I am having timing isssues right now and hopefully I can get some advice. I accept a Pertronix Flamethrower distributor in my 383. Stealth heads with domed KB pistons (KB400). Holley 830 and Torker intake. Voodoo Cam. I finally got my timing tape on it yesterday and got to look at it quickly before information technology flew off! The trouble I am having is that the motorcar runs perfect set at 20 initial and about loftier forty'south full. Everything I am reading says this is too much but if I back information technology down to 12-fourteen and about high 30's it doesn't run every bit good. Any ideas???

Source: https://www.forbbodiesonly.com/moparforum/threads/setting-the-timing-on-a-383.13107/

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