another total timing question

Small Block Mopar Engine

  1. challenger57

    challenger57 cuda57

    Messages:
    207
    Likes Received:
    15
    Joined:
    Sep 21, 2007
    Location:
    york, pa.
    Local Time:
    3:42 PM
    I replaced the cam in my mild 360 for better vacuum for my dash controls inmy 65 cuda. I am using a vac advance dist. with a 11L arm in it. My carb is a 600 edelbrock and I am using the left timing port for my vac hose. If I use the full vac fort on the right it pulls to 45 degrees. I turned the set screw in the vac diafram CC wise 2 full turns and no change. I set the initial timing at 14 degrees with a advance dial timing light and it conferms the total timing at 45 degrees at 2800 rpm. Without tearing dist apart is there another hole in dist plate for vac arm to connect to to change timing advance or do i need to change spring tension or is the total ok as is, it seems to run ok. I know 34 is the normal . Without pulling dist out again I am not sure of its type, it was in car when i got it. Thanks
     
  2. 67Dart273

    67Dart273 FABO Gold Member FABO Gold Member

    Messages:
    46,644
    Likes Received:
    14550
    Joined:
    Oct 14, 2010
    Location:
    Idaho
    Local Time:
    1:42 PM
    I have to tell you I have no idea at all what you are doing, here

    You can't throw numbers around without a starting point.

    WHAT IS the total timing with the RPM "up" (advance all in) and the vacuum disconnected?

    "Total timing" under WOT does NOT use vacuum, as no matter which port you use, they both go "dead" under WOT. Therefore mechanical advance + initial is what you will have.

    Vacuum is only generated under med--to high RPM LIGHT throttle, on ported, and of course full advance with manifold vacuum connected. But it all goes away with heavier throttle. Common figures for "stockers" used to approach 55 degrees in some cases with initial +mechanical + vacuum and light "cruise" throttle.

    Also don't get confused by distributor and crank degrees. Most all "original" distributor and parts literature used to be specified in "distributor" degrees, which are half "crank" degrees.
     
  3. Mattax

    Mattax Just the facts, ma'am FABO Gold Member

    Messages:
    11,277
    Likes Received:
    7139
    Joined:
    Feb 7, 2013
    Location:
    Phila. Pa
    Local Time:
    4:42 PM
    To add to the above.
    Initial timing (aka Base Timing). Usually set below the start of mechanical advance rpm.
    Mechanical advance: the timing added. The 11 stamped slots will allow roughly 22 degrees.
    Total Timing: Almost always refers to Initial+maximum Mechanical Advance.
    However, the factory engineers were sometimes more clever than hot rodders and racers appreciated. Some distributors have a very heavy secondary spring so the weights don't hit the end of the slot until 5000 rpm or higher. So, just pick a reasonably high rpm, like 2800 or 3000 rpm and just be consistant in using it.
    example: Set the initial timing at 600 rpm to 10 degrees BTDC. Using the distributor you have, expect Total to be 5+22 = 32 degrees. At what rpm it hits 32 or even 30 will depend on the springs.

    Vacuum advance: Usually not used when setting initial. On an original engine, you'll find some use manifold source and others a timed (aka ported) source depending on year and engine. The ported vacuum is sourced so it provides zero vacuum at idle. Otherwise it is the same as manifold vacuum.
    The vacuum pod's adjustment does not change the degrees added. It only effects when the pod starts (and finishes) adding advance.
     
    • Like Like x 1
    • RustyRatRod

      RustyRatRod Lemmie see your b00bs. FABO Gold Member

      Messages:
      67,826
      Likes Received:
      42147
      Joined:
      Jun 7, 2010
      Location:
      Georgia
      Local Time:
      4:42 PM
      The vacuum advance does not work "like that". Turning the adjustment screw does not change the amount of timing the vacuum can pulls in. It changes WHEN it pulls it in.

      Probably be better if you actually READ UP and learned what you are doing instead of just plowing ahead without understanding.

      They make these things called books. You can access them any time you want and not have to wait for someone on a forum who may or may not be correct to answer your question.
       
    • challenger57

      challenger57 cuda57

      Messages:
      207
      Likes Received:
      15
      Joined:
      Sep 21, 2007
      Location:
      york, pa.
      Local Time:
      3:42 PM
      Hey Mattax you were helpful but as for rustyratrod some of us do read up on things before coming here but when what you read is clear as mud then we come here for supposedly a helpful answer not sarcasm. If you are going to add scripture to your timeline maybe you should read up on sarcasm Ephesians 4:29 its in the Good Book.
       
    • 72bluNblu

      72bluNblu FABO Gold Member FABO Gold Member

      Messages:
      11,231
      Likes Received:
      5753
      Joined:
      Nov 28, 2008
      Location:
      NorCal
      Local Time:
      1:42 PM
      That's the problem with the stock distributors. When you exceed 10* of advance at idle you can start to have issues, because most of the stock dizzy's have 22* of mechanical advance built in and weren't really designed to work with more than 10* of advance at idle. Unfortunately most of these cars run better with at least 12* of advance at idle, and if you have a hot cam even more. I run 20* advance at idle on the 340 in my Duster. Heck I run 18* in the almost stock 318 in my Challenger. It shouldn't like having that much, but it does, so what the heck.

      You can limit the mechanical timing to allow for more initial advance. It used to mean tearing apart the distributor and welding up the slots in the advance plate to make them the right length to get the amount of advance you want. Not super hard, but kind of tedious to get the advance slots the right length and it requires a welder. And of course, if you want to change the initial advance again you either have to weld more or file more.

      FBO ignitions now makes a limiting plate that can be installed into the stock dizzy's to limit the mechanical advance. The plates have multiple slots so you can tailor the mechanical advance to what you need to keep your initial and not end up with 45* of advance with the vacuum all in. You still have to partially disassemble the distributor, but you don't have to make any permanent changes to the slots and can dial in whatever amount of mechanical advance you need based on your initial advance.

      http://www.ebay.com/itm/Mopar-Distributor-Ignition-Timing-Limiter-/321755083510?hash=item4aea18f2f6:g:6yAAAOSwQJhUdOgX

      Also, keep in mind the total advance number isn't the only thing to consider. If you aren't detonating, 45* may be ok for total advance including the vacuum advance. You'll only end up with that much when the vacuum advance is working at full, and under those conditions 45* might be ok. Depends on your engine, compression, fuel, altitude, etc. Whether or not the engine is pinging (detonating) is more important than the advance number by itself.

      ps- Don't worry about RRR, he does that to everyone. He just likes pushing people's buttons.
       
    • RustyRatRod

      RustyRatRod Lemmie see your b00bs. FABO Gold Member

      Messages:
      67,826
      Likes Received:
      42147
      Joined:
      Jun 7, 2010
      Location:
      Georgia
      Local Time:
      4:42 PM
      I was being totally serious.

      When you ask a question like this on the internet, get ready for a thousand different answers. Rather than go through that headache, I simply suggested reading.

      I wasn't being sarcastic at all. You were being sarcastic when you read it.

      And the first place you should point a Biblical finger is at the sinner staring back at you in the mirror.
       
    • threewood

      threewood Well-Known Member

      Messages:
      407
      Likes Received:
      242
      Joined:
      Nov 11, 2014
      Location:
      Yuma
      Local Time:
      2:42 PM
      Unhook and plug vacuum advance before setting initial and total.

      If you have a vacuum gauge, use it to set initial timing by finding the highest vacuum reading from manifold barb. Adjust idle down as you go so the mechanical doesn't kick in and screw you up. Advance 4 degrees, set idle, set idle mixture, repeat as necessary. But any excessive initial you add has to be subtracted from the total. Ballpark total advance should be around 33 to 36 btdc.

      A plate marked 11 = 22 crank degrees, so....22 + 14 = 36 total degrees. If you go more than 14* total you will/may need to shorten the mechanical slots so you are not detonating.
       
    • 72bluNblu

      72bluNblu FABO Gold Member FABO Gold Member

      Messages:
      11,231
      Likes Received:
      5753
      Joined:
      Nov 28, 2008
      Location:
      NorCal
      Local Time:
      1:42 PM
      Some of the stock distributors had as much as 30* of advance built into them (they would be stamped 15).

      Here's an article the covers how to recurve the distributor, but the plate FBO makes is by far the better way to go. Most of the info in the article is in the text with the pictures, not the body of the article.

      http://www.hotrod.com/how-to/engine/mopp-0301-mopar-electronic-ignition-system/
       
    • jimjimjimmy

      jimjimjimmy lobsterman FABO Gold Member

      Messages:
      4,533
      Likes Received:
      1352
      Joined:
      Nov 2, 2010
      Location:
      p. e. i.
      Local Time:
      5:42 PM
    • Mattax

      Mattax Just the facts, ma'am FABO Gold Member

      Messages:
      11,277
      Likes Received:
      7139
      Joined:
      Feb 7, 2013
      Location:
      Phila. Pa
      Local Time:
      4:42 PM
      Good.
      If you don't want to pull the distributor out yet, go measure the whole mechanical curve, vacuum plugged.
      With a dialback timing light (built in tach) I like to note rpm at every degree over initial as I increase throttle. But more often, especially with seperate timing light and tach I'll just note timing at every 200 or 250 rpm increase.
      To figure what the vacuum advance is doing, a vacuum gage is needed, and a vacuum pump is even better.
      Then you'll know what you've got. From there you can make changes.
       
    • Rapid Robert

      Rapid Robert Well-Known Member

      Messages:
      1,119
      Likes Received:
      147
      Joined:
      Aug 6, 2006
      Location:
      Lincoln Nebraska
      Local Time:
      3:42 PM
      No way that ain't sarcastic. Denial is a Hell of a tool my man (its in the Bible!) Alright back to business: OP (I would suggest) set the initial with the vac gauge method. then get the FBO $25 plate & limit total to 35 (initial+ slots) then play with springs then plug in to ported & work with the can. IN ORDER. More info on springs/can how to later later
       
    • RustyRatRod

      RustyRatRod Lemmie see your b00bs. FABO Gold Member

      Messages:
      67,826
      Likes Received:
      42147
      Joined:
      Jun 7, 2010
      Location:
      Georgia
      Local Time:
      4:42 PM
      Ok, I concede maybe that was a little sarcastic, but my entire post was serious. If someone reads and learns from a good source, they are devoid of lots of wrong and erroneous information they may get online.

      As for the other argument, please use the PM feature as this is cluttering up his thread.
       
    • xLURKxDOGx

      xLURKxDOGx "An angel fat, at satan's feast" FABO Gold Member

      Messages:
      4,038
      Likes Received:
      1381
      Joined:
      Dec 27, 2013
      Location:
      PHX
      Local Time:
      1:42 PM
      :cheers::angel12::glasses7:
       
    • challenger57

      challenger57 cuda57

      Messages:
      207
      Likes Received:
      15
      Joined:
      Sep 21, 2007
      Location:
      york, pa.
      Local Time:
      3:42 PM
      Enough said, thanks for everyones input even yours ratrod. I know where i made my mistake.
       
    • krazykuda

      krazykuda Well-Known Member FABO Gold Member How-To Section Editor

      Messages:
      57,433
      Likes Received:
      23073
      Joined:
      Aug 20, 2007
      Location:
      Orland Park, IL
      Local Time:
      3:42 PM
       
    1. This site uses cookies to help personalize content, tailor your experience and to keep you logged in if you register.
      By continuing to use this site, you are consenting to our use of cookies.