Performance timing

Electrical and Ignition

  1. Mattax

    Mattax Just the facts, ma'am FABO Gold Member

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    OK for first go.
    Presumably you have timing tape or similarly marked damper - hence no need for the dialback feature. That's fine.
    24º at 600 rpm
    25º @ 900 rpm
    30º at 1000 rpm
    34º at 1150 rpm
    44º around 3000 rpm.

    That's enough to get a sense of what's going on.
    With just the 600 and 900 readings, if they are even ballpark, too much initial.
    Try around 20* @ 900, readjust idle fuel mix screws.
    Graphicly, it looks like this.
    upload_2020-1-5_14-11-43.png

    Tips for next time:
    Try to get timing measurements around 1500 and 2000 rpm.
    Vacuum in gear at idle is more useful than knowing the vacuum in neutral.
    The vacuum source for the vacuum advance needs to be blocked. its fine for the canister to be open. You may already know that - just wasn't clear in your post.
     
    Last edited: Jan 5, 2020
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    • Mattax

      Mattax Just the facts, ma'am FABO Gold Member

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      400 RPM drop going into gear suggests timing too advanced and idle mix too lean. For straight up efficiency in terms of power, idle needs to be relatively rich. Even more so with a high overlap cam.
       
    • Mattax

      Mattax Just the facts, ma'am FABO Gold Member

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      Maybe its helpful to explain the key things I looked at on the graph.
      upload_2020-1-5_14-56-27.png
      edit:corrected typo in graph
       
      Last edited: Jan 5, 2020
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      • Idaho

        Idaho FABO Gold Member FABO Gold Member

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        The graph is nice. I'm learning from this.
         
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        • crackedback

          crackedback FABO Gold Member FABO Gold Member

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          The timing changing when in gear and out of gear, 600 vs 1000 is HUGE problem...

          It needs to remain STATIC, no change.
           
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          • dazedand confused

            dazedand confused Well-Known Member

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            So richen the fuel mixer screws till i just start to hear the engine/idle start to slow down or see the vaccum gauge decrease in psi? 512Stoker was talking about knocking timing down at idle at 15 º but didnt say what the rpm is suppost to be at then take it for a drive and see if it pings and if not bump it up 2º each time till it does start to ping then back down 2º or until it stops but didnt say which vaccum port to hook up the vaccum advance to on the edlebrock carb???? I was not great at book work in school / mathematics . Im great at being hands on so what is the basic way to tune this engine? I cant seem to get any of the "mopar people " in my area to help me even though they have their stock or modified engine tuned up? Then i get on here and get like 20 different suggestions . I gave a basic discription of my engine build/parts all i want is a basic way of tuning this engine for example: start engine ,let fully warm up, unplug vaccum advance set dial on timing light to zero, adjust timing to this degree and set idle in park at this rpm etc.
             
            Last edited: Jan 5, 2020
          • 512Stroker

            512Stroker We are all here because we are not all there.

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            The rpm is going to be different form engine to engine.
            My 340 idles at 850 in neutral and around 700 rpm in gear. Alot of it depends on the torque converter and how loose it is setup.
            My vacuum advance is connected to full manifold vacuum - below the throttle plates - Edelbrock carb.
             
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            • Mattax

              Mattax Just the facts, ma'am FABO Gold Member

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              No.
              Turn the distributor so you take 4* out of the curve.
              Then adjust fuel mix incrementally to see if rpm picks up a little. Then give mix screws another 1/8 turn richer and put it in gear. You want the least drop in rpm when putting in gear. It will take several tries to be confident you have actually achieved the best mix for a given throttle postion and rpm and timing.
               
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              • Mattax

                Mattax Just the facts, ma'am FABO Gold Member

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                Turn the distributor and remeasure timing at one of the rpms you measured previously.
                Something between 600 and 950 rpm will be best.
                Then check a couple other points.
                Put that all in your notebook.

                Example: Turn the distributor 'til timing at 950 rpm equals 4 less than before; that is 21* BTC.
                upload_2020-1-5_17-42-32.png

                Then see what you can do with the fuel mix etc.
                Note how much you turn each screw and the effect.
                 
                Last edited: Jan 5, 2020
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                • Mattax

                  Mattax Just the facts, ma'am FABO Gold Member

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                  Listen. I gave you step by step what to do. In addition I provided the basic concepts right from Chrysler's Master Tech series. That way you can understand why.
                  Crackedback, 318willrun, 67Dart273 and other posters are pretty much giving you the same advice and the same procedures.

                  Because you have a hot rodded engine, it will have to be tuned in iteratively. In other words, a series of trials where adjustments are made to produce a stronger stroke. It can't be done in one shot. Timing and fueling are related. They also relate to load and rpm. We're giving the best approach to this series of trials, so each one builds on a good foundation. That doesn;t guarentee sometimes it will require a step or two back, but it reduces the times that will happen.

                  Not sure what else we can offer.
                   
                  Last edited: Jan 5, 2020
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                  • crackedback

                    crackedback FABO Gold Member FABO Gold Member

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                    I think he said the timing dropped when it went from 1000 to 600 RPM that will enhance the idle drop issue as well. Unless I missed something.
                     
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                    • dazedand confused

                      dazedand confused Well-Known Member

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                      MaxTax : i went out today got the motor fully warmed up and vaccum advance still plugged off and at idle in park i turned the distributor till the timing on the tape read 15º on the 0 mark on timing cover and idle is at 800 rpm . When i hook up the vaccum advance i can hear the rpm's come up and the timing reads 42º at the 0 mark on the timing cover and rpm is at 1000. Where do i go from here?
                       
                    • yellow rose

                      yellow rose Overnight Sensation FABO Gold Member

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                      The question is why is it pulling timing at idle if you are picking up vacuum for timed vacuum? You shouldn't pull any timing when you hook the hose up to ported vacuum unless there is something else wrong. Or, you are hooking the hose up to manifold vacuum.
                       
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                      • 512Stroker

                        512Stroker We are all here because we are not all there.

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                        You must have the vacuum line connected to manifold vacuum.
                        Your vacuum advance is adding 27 degrees, that is alot. Mine adds 22 degrees.
                        I am not saying that any of this is wrong, your engine may like that much timing.
                        How does it drive? Does it ping under load?
                        What is the mpg? fuel economy?
                         
                      • dazedand confused

                        dazedand confused Well-Known Member

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                        I had it hooked strait to the port on the intake. I didnt know if i needed to hook it up to full vaccum on the base plate of the carb or the timed vaccum port on the base plate of the carb? So is the 15 º i set at idle in park correct?
                         
                      • Mattax

                        Mattax Just the facts, ma'am FABO Gold Member

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                        If your talking to me (Mattax), I have no idea why you did that.
                        RPM came up with the additional timing because there's no load on the engine (other than internal friction). Under light loads the engine likes low density mixtures and timing. Its pretty much useless data point other than demonstrating that relationship. You can add a ridiculous amount of timing out of gear before you stop seeing rpm gains. None of us here suggested that as 'tuning method'.

                        If your engine will idle in gear at 15º BTC, that will be very interesting.
                        I suggested taking out only 4* because of the cam's advertised duration and size of the engine.
                        And also because we don't really know the rpm where timing begins to advance.

                        Vacuum advance is way down the road. Please. If you want our help in a step by step fashion, then you have to follow the steps.
                         
                        Last edited: Jan 6, 2020
                      • Mattax

                        Mattax Just the facts, ma'am FABO Gold Member

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                        that is post 58 & 59.
                        snipped and edited
                        When you achieve the least drop in rpm when putting in gear, then stop fiddling with that combo.
                         
                      • Mattax

                        Mattax Just the facts, ma'am FABO Gold Member

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                        Another way that may be a better fit for you is follow 512stroker's procedure on page 1, post 12.
                        Set the timing at 15 and take for a drive, see how it feels and if it pings at WOT in 3 or up a hill.
                        Then try it at 17*
                        You'll still want to adjust the idle fuel mix if needed.
                        When testing for ping going up steep hills and at WOT, no vacuum advance.
                        If it pings, reduce it back to 15* at whatever rpm it was for the first test.
                        When its OK without vac advance, then connect ithe vacuum and test again. If it pings at part throttle or light loads, vac advance will need to be adjusted. If no pinging, you can call it done.
                         
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                        • 512Stroker

                          512Stroker We are all here because we are not all there.

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                          Mattax
                          You Sir have the patience of a Saint.
                          Me not so much, I am bowing out.
                          OP needs to listen if he wants to understand and play with old cars.
                           
                        • dazedand confused

                          dazedand confused Well-Known Member

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                          First of all I've been listening to " OP " on here for a week now ! When OP have made comments like check while at idle nobody told me if idle was to be in park ,neutral or drive while adjusting the distributor
                          " timing" to 15 º BTDC till possibly now in their postings.then i get people saying to hook up the vaccum advance to a full vaccum source then get others telling me no that it should only be hooked up to a port on the carb but witch port on the carb? Im working on this by my self with no prior training on engine builds /performance timing /distributor modifications. I wasnt being a smart ass or not wanting to listen in my prior postings . Like i said before im a hands on person. Its confusing getting at least 6 different ways to tune/adjust timing /distributor ect. So i am bowing out as well and removing my self from this web site !
                           
                        • 66fyssh

                          66fyssh Don't Stop Believin' FABO Gold Member

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                          Please hang in there man. It's soooooo challenging trying to "teach" some of this stuff on a forum. There are lots of very knowledgeable folks on FABO.

                          Look at the steps laid out about and ask for clarification on anything you don't understand. Step by step is very important when timing an engine. And, as noted above, you often have to go back and repeat steps many times. That's what makes timing these cars so much fun. And when you start to feel a difference, you know it's because of what YOU have done. A real sense of accomplishment!

                          Can't do this with the new vehicles.
                           
                        • 512Stroker

                          512Stroker We are all here because we are not all there.

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                          Hang in there partner.
                          I said I was bowing out so not to confuse the issue which happens far to often on forums.
                          The last thing you want to do is give up, that will get you nowhere.
                          I would suggest that you stick with the best suggestions from one or two posters, write them down and systematically go thru it until you feel comfortable with the way your engine runs.
                          Do listen and learn, just dont try to absorb it all from everyone, it will drive you nuts.
                          But understand it never ends you will always want to make changes.
                          Good luck
                          PM me if you get stuck
                          Edit: OP remember when I said it would be easier to show you how then explain it to you on here. Now you know what I meant
                           
                          Last edited: Jan 6, 2020
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                          • crackedback

                            crackedback FABO Gold Member FABO Gold Member

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                            Simple, Leave the vacuum advance can TOTALLY out of this for now. DO NOT HOOK IT UP. That problem is solved.

                            You go from step one to step 5 back to step two, all over the place.

                            Get the idle squared away FIRST. Try it at 15-18 BTDC is park and about 800 rpm if possible. Pull it in gear and see where the idle rpm drops and if the timing stays static. You DO NOT want it pulling timing out when it goes in gear. That should be your FIRST mission to accomplish.
                             
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                            • RustyRatRod

                              RustyRatRod Bla de blizhibliz de blatde blizi bla bla FABO Gold Member

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                              Go find my post where I gave step by step instructions by bumping the timing up 2* at the time at idle in PARK and do it. You will begin to understand what's going on if you will just DO IT. You will see the effect of timing on an engine if you just DO IT. You can always put it back, and you will need to because you have no way to limit total timing yet. But in order to get it done, you have to DO IT.

                              Now, the reason your distributor is pulling so much timing in at idle is because you have the advance can hooked to the wrong port. You need to find the port that has no vacuum on it at idle and has vacuum on it when the throttle is opened. THAT is the correct port. It's called ported vacuum. BUT, as of NOW, you don't even need to worry about the vacuum can YET, until you figure out how to adjust timing and what effect it has on your engine. You're not going to hurt it. But in order for you to learn, you have to DO IT.
                               
                            • cuda66273

                              cuda66273 Well-Known Member

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                              Set initial timing at Idle no vac connected at 16*
                              Use our limiter plate on the 18* slot + the 16* Initial = total of 34* Mechanical
                              Start with our silver springs and adjust from there to achieve all timing in at about 3200 RPM.
                              Now plug in the Vacuum Can and adjust it to get the timing to about 30* at idle.
                              MP wanted the part number as they haven't made a distributor for Probably 20 Years and what you have is probably a Chinese ProForm and not a MP distributor.
                              Pull the cap and rotor, if the shaft is bronze it's a real MP distributor if it's steel it's a Imported Fake.

                              MP distributors have a 2 screw limiter system and the plate is not required as you loosen the screws and slide the plate in the slots to limit the timing. (the gauges for setting these are discontinued, I have at least 50 sets in stock)

                              Real Mopar distributors also have rotating spring anchor pins as you turn the pin it will slide .060 in either direction to tighten or relieve the spring resistance to fine tune the all in timing numbers. Most of the copies do not offer this feature.

                              Just because the vacuum advance can has the Large Hex molded into it, which is the SAE standard designation for an adjustable vacuum canister, doesn't mean it is actually adjustable. The imports use that can style but there's nothing inside it to adjust, just another way of making it cheaper and they're betting on the fact you have no idea how to adjust it or why anyhow.

                              Your 214 @ 50 cam should generate easily 18 to 20" of vacuum at idle with 30* of initial or Idle timing and the engine should idle nicely around 750 RPM.

                              Stock vacuum cans usually won't activate with less than 12" Vacuum so big cam motors can't take advantage of the vacuum canister to achieve a good tune-up. We hand build a Vacuum Can for Mopar big and small blocks that will read and fully engage at 5".

                              That little motor of yours MUST run a Vac Advance and it needs to be set-up to the 30* at idle and previously mentioned and also pull the timing up to the mid 40*s at part throttle cruise or you'll get 8 MPG.

                              Assuming you have hopefully removed all the emissions crap you can now connect your vacuum to a constant manifold source to tune your distributor so you can run today's pump gas.

                              Now once you get it all dialed in you need to look at your ignition box.... is it the Famous Orange box as supplied with the distributor? That box will retard the timing starting at 3200 and by 5200 it'll have it backed up 8* and output will drop to 15 to 20KW so all your work is lost, sort of like trying to get drunk on Non-Alcoholic beer.

                              I also engineered and designed the HRR688 Computer controlled Ignition box that solves all the issues that ALL transistorized ignition boxes have.... and comes with a 5 Year Warranty!
                              Do it right the 1st time, it's cheaper in the long run.

                              All FBO Ignition parts are also available from Mancini Racing.
                               
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