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Thread: 351C timong settings

  1. #11

    Default 351C timong settings

    I tried 77 F250's suggestions on the settings from another post and the motor is running much better now. I am still however unable to get the IAC count down to where MSD recommends. It's around 50 now down from 150. Also I noticed that if I move the dizzy while the timeing is enabled I can get the motor running smoother and the vacuum reading on the gauage improves a lot.

    Question, is this acceptable to do. I would think that you should be able to get the same results without changing the dizzy timing a little. Another unknow is whether I have the phasing rotor at 15* retard since there are no markings on the rotor.

    MSD, are you going to fix this issue with the rotor that you are recommending to get?

    attaching a clip of motor running under full timing control. At the end you hear a small backfire, what setting needs to be adjusted there?

  2. #12

    Default 351C timong settings

    The rotor that you are using I think is 15* when fully adjusted. Reality is that the only way to truly have your phasing correct is to phase it with a timing light. The 15 degree setting is real close but not always perfect. Mine was right on at about 13 degrees tested with a light.

    I assume you have verified that when locked out you are indeed at 15 degrees on the balancer. If this is correct and the phasing is also correct you should not need to adjust the distributor. The same effect can be done on the handheld.

    I am also assuming that the distributor is locked out correctly. If not this could also cause many issues in getting it to run right.

    I think if this was me, I would start the car and get it as close to what the settings should be, and then if moving the distributor make it run better, I would do so and get it to where it runs best. At this point, set the handheld to locked out and read the timing at the balancer. Not how far it is one way or the other from 15 degrees and then put the distributor back to 15 degrees and modify your timing settings on the handheld accordingly.

    For instance. If you have to take 3 degrees out to make it run right. IE 12 degrees noted at the balancer, and your initial timing is 14 degrees and all in is 33, then I would change the initial timing to 11 degrees to see if it now behaves the same as it did when you moved the distributor. It should be identical. Moving the distributor in the current condition of locked out and phased is the exact same thing as changing the settings on the handheld if everything is hooked up correctly.

    You noted before "with timing enabled" and without timing enabled. You do realize that in order to do this you need to change wiring and settings on the handheld right? The tach triggers should be different if I remember correctly.

    In any case, once it is configured for timing control, that should be the only setting you use.

  3. #13

    Default 351C timong settings

    Watched your video, now I'm jealous... Your car sounds really good. I suspect you need to go out and enjoy driving your car to get the learning process going and I think everything will work out just fine, referring to the backfire at the end of the video.

    I didn't hear much sucking in the video but you say your IAC is still at 50? You should only need to open the butterflies a little bit more with the screws and your IAC should be right on. How much have you adjusted the screws from right closed?

  4. #14

    Default 351C timong settings


    When I say timing disabled I mean on the handheld. Yes every thing is set up per MSD's instructions.

    Here is what I have so far and it seems to be running fine now. I will check cold start tomorrow morning to see if there are any issues there.

    IAC count is now 0 in drive and it doesn't stall so I'll leave it there for now.

    My settings:

    The dizzy is set to 15*BTDC when the controller has timing locked

    Target RPM is 850

    Idle RPM is 950

    Idle Advance 13

    Total Advance 34* @ 2500RPM

    Cam set to Street/Strip, did not like performance as much


    Idle 13.0

    Cruise 13.9

    WOT 12.8

    Pump Squirt 25%

    Power Valve Enrich 15%, I did this because I had a slight backfire on quick engine decel

    Fuel pressure is 50psi with pump set at pwm with regulator. Is this pressure ok?

    Note when engine is idling the timing on the handheld indicates 1* to 2*'s, what does this mean?


    The motor has a slight vibration at idle but smooth's right out when throttle is applied, engine temp is around 190*, outside temp is 100* and the AFR is 13.1 which is spot on at idle. The motor definitely likes this setting much better as suggested by 77 F250.

    My Motor:

    351C bored .030 over, 10.4 CR.

    Ford 4V heads closed chamber 63cc

    Blue Thunder Intake

    Hooker Headers

    C6 with 2800 stall

    I have a return fuel line with regulator installed

    Cam 225/235 @.50

    MSD 8580 Dizzy locked out with 8421 rotor that modified to get the 15* retard

    MSD 6AL

    I posted my setup in case other Ford guys are having issues too. I see that GTR750EVO is having issues too so I hope this helps.

    Lastly my thanks to all that have offered suggestions to get this fixed.



  5. #15

    Default 351C timong settings


    For the IAC adjustment I have about 1 1/2 turns to open. When I look in the TB throat you can definetly see that there is a gap now. The cnt is "0" but the car seems to like that setting so I am not going to fool with it anymore for now. Also the exhaust system is not installed yet so I want to make sure everything is buttoned up before I try to fine tune it anymore.



  6. #16

    Default 351C timong settings

    Seeing the 1-2 degrees timing at idle tells me that the blades are open too far for the IAC to adjust to the described Idle RPM. So the Atomic is lowering your timing to try and get to the defined RPM. So one of two things here. Either your cam wants more RPM at idle (it does not sound like that in the video)

    All this tells me is your creeping up on the perfect setup. I would go back to start on the IAC setup and try again. Remembering that any changes in timing will effect this. Make very small adjustments, 1/8 turn front and back until you get it where you want it. This is a real tedious setup, but it is worth it in the end.

  7. #17

    Default 351C timong settings

    You are right that the motor is idling higher than target RPM. In the morning I'll give the adjustment one more shot. What happens if it doesn't affect the RPM and it remains abot 100 above target?

    Out of curiosity, in the advanced setup what is the initial timing setting for? With the factory ignition the timing was set at 12* BTDC, is this what this setting is for?



  8. #18

    Default 351C timong settings

    The initial timing setting on that page is what you would have set at the balancer as a starting point so yes, if you were set at 12, chances are you will set it close to that. Note that the Atomic will adjust timing below your initial RPM setting to achieve the target RPM. This is one reason that you set your target about 100RPM lower than your initial RPM target in the timing page. This way as long as the RPM at idle is below your initial RPM timing setting, the Atomic can manipulate timing to achieve your desired settings.

  9. #19

    Default 351C timong settings

    So what you are saying is if the timing was set to 15* BTDC on the balancer with timing control disabled on the handheld then this initial timing setting in advanced setting should be set around 15* too?

  10. #20

    Default 351C timong settings

    Like to get an answer to my last question in my previous post before I start adjusting the IAC again.

    Another question, is it ok to adjust the IAC in park to get in in the ball park and then fine tune it in drive? Seems like that would work to me but I'd like confirmation before I do this.



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