Register now to get rid of these ads!

Hot Rods Myth and facts of ignition timing explained

Discussion in 'The Hokey Ass Message Board' started by 2FORCEFULL, Jul 24, 2024.

  1. Dave G in Gansevoort
    Joined: Mar 28, 2019
    Posts: 3,481

    Dave G in Gansevoort
    Member
    from Upstate NY

    Put a magneto in it. No advance curve. Set total timing at 38 to 40 degrees. Run 14:1 compression.

    Oh, did I say you better be running methanol? And get a push truck for starting.

    But I'm much better now...
     
    rattlecanrods and 427 sleeper like this.
  2. ALLDONE
    Joined: May 16, 2023
    Posts: 3,168

    ALLDONE
    Member

    LMAO... so far not one is 50 degrees at WOT.... but lets all thank you for the Jesus part..

    theres a wealth of knowledge post in this thread... and explained very well.... should set a lot of peeps straight...


    maybe you should read the title??? the purpose of the thread is there are a bunch that think they need to set there timing @50 plus degree WOT
     
  3. 69fury
    Joined: Feb 24, 2009
    Posts: 1,696

    69fury
    Member


    Dude NO ONE is recommending 50 at idle! Find 1 instance of that in either of the 2 threads today.

    -rick
     
  4. I see one guy arguing it’s impossible to have 50 plus degrees of timing, he’s the one that started the thread to set everyone straight. Yet he doesn’t seem to understand how it works.

    Where did anyone else say they have 50 at WOT?
     
  5. ALLDONE
    Joined: May 16, 2023
    Posts: 3,168

    ALLDONE
    Member

    Hope thats not to me.. started running A/f fed @ 16, then to AA/BAD in the 70's and back to injected alcohol in to the 80.. then to gas broggie roadster, gilmore fed and a long list of door slammers....

    269174_221567401213571_3261770_n.jpg
    the little guy in the blue shirt built these headers for my model A

    IMG_8807[8523].jpg
     
  6. ALLDONE
    Joined: May 16, 2023
    Posts: 3,168

    ALLDONE
    Member

    were is this guy??? so far every one agrees that @wot you need to be 32 to 36
    and I don't think that guy said he alone was gonna set every one straight....lol keep fishing
     
    HOTRODNORSKIE likes this.
  7. Holy shit you are delusional, you told everyone they were wrong because you didn’t understand. Now you are claiming you didn’t, the fact that you continually feel the need to give your resume says something.
     
    hrm2k, 2OLD2FAST, HemiDeuce and 2 others like this.
  8. ALLDONE
    Joined: May 16, 2023
    Posts: 3,168

    ALLDONE
    Member

    I didn't know rather to believe you or my ly'n eyes, so I went back and checked,...lol this is your first post in this thread so how could I not have listened to , or read the post... but. thanks for posting...
     
  9. ALLDONE
    Joined: May 16, 2023
    Posts: 3,168

    ALLDONE
    Member

    the fact that you keep having all these emotions about some one you don't know says a hole lot more,,, do you always have to attack every one????
     
  10. Oh also total timing happens at an rpm not wot like you are saying. If I put my foot to the floor at 2000r but my mechanical advance doesn’t all come in until 3000 I still don’t have full timing but hey you already know that.
     
  11. I just don’t like people spewing false information is all.
     
    2OLD2FAST, 05snopro440 and 2FORCEFULL like this.
  12. jimmy six
    Joined: Mar 21, 2006
    Posts: 16,691

    jimmy six
    ALLIANCE MEMBER

    I drive an off topic 2018 F150 with a 5.0 V8. I have an Edge monitor. One of the things I watch is the ignition on this totally electronic controlled engine. Under very light throttle on a slightly downhill or level I’ve seen 50+*. Careful driving I can keep the advance between 25 and 35 but it’s constantly moving.
    The biggest surprise is it goes to 0 or even a few degrees the other way when you take your foot off the throttle slowing down for a stop….idle at a light it’s usually 10* before TDC and the rpm is 525.
     
    2FORCEFULL likes this.
  13. ALLDONE
    Joined: May 16, 2023
    Posts: 3,168

    ALLDONE
    Member

    anyway, I think its all crystal clear about the 55 degrees timing, and hope someone understands that it doesn't mean that you put the timing light at a mark of 55 degrees... and I think others explained it way better than I did.... but I still set base with out the vacume degrees figured in as its just a ghost...same with tire pressure, I set at 5.5 lbs, never checked what they were at at the big end... probley 30??? I can't really go out and tell them I run 30 psi... unless I got them in the next round
     
  14. ALLDONE
    Joined: May 16, 2023
    Posts: 3,168

    ALLDONE
    Member

    then don't read it if you can't stay in control... as for me I have no opinion of people I don't know;; and no opinion of you and would like to meet you some day, then decide if I like you or not... any way, like I said... lets post facts about timing... not lets hate the new guy...
     
  15. ALLDONE
    Joined: May 16, 2023
    Posts: 3,168

    ALLDONE
    Member

    I have a I don't know how many thousand dollar snap on engine analyzer that I have no idea how to work, boys said we have to have it so they bought it.. but total amazed at the communication that goes on between it and the car/truck...
     
  16. Ok, I bow down to your greatness. Now we are happy!:)
     
    2FORCEFULL likes this.
  17. ALLDONE
    Joined: May 16, 2023
    Posts: 3,168

    ALLDONE
    Member

    OK here goes, I bow down in total apologies to you, I sped red your post and didn't read it through...
    heres what you post..


    (I'd try to verify you're getting full timing over 50 with mechanical and vacuum added in under part throttle cruise.

    Also maybe rule out timing chain slack. If the cam is retarded due to slack, some people twist the distributor to set the ignition timing, which doesn't resolve the late exhaust event issues. Probably not the entire issue, but a good one to rule out.

    -rick)

    I only read the full timing over 50, and didn't read the rest.... anyway... make it a good life
     
    69fury likes this.
  18. I just line up the dots on the cam sprockets, twist the dist 'till it sounds good and doesn't pop, set the idle screws and rpm for max idle vac, hook up the vac, then enjoy driving it!!
     
    jet996, bchctybob, lilCowboy and 2 others like this.
  19. ALLDONE
    Joined: May 16, 2023
    Posts: 3,168

    ALLDONE
    Member

    LOL... isnt love grand....
     
    57 Fargo likes this.
  20. warbird1
    Joined: Jan 3, 2015
    Posts: 1,297

    warbird1
    ALLIANCE MEMBER

    [QUOTE)



    by Lars Grimsrud
    SVE Automotive Restoration
    Musclecar, Collector & Exotic Auto Repair & Restoration
    Broomfield, CO Rev. B 8-19-0

    Now, to the widely-misunderstood manifold-vs.-ported vacuum aberration. After 30-40 years of controlling vacuum advance with full manifold vacuum, along came emissions requirements, years before catalytic converter technology had been developed, and all manner of crude band-aid systems were developed to try and reduce hydrocarbons and oxides of nitrogen in the exhaust stream. One of these band-aids was "ported spark", which moved the vacuum pickup orifice in the carburetor venturi from below the throttle plate (where it was exposed to full manifold vacuum at idle) to above the throttle plate, where it saw no manifold vacuum at all at idle. This meant the vacuum advance was inoperative at idle (retarding spark timing from its optimum value), and these applications also had VERY low initial static timing (usually 4 degrees or less, and some actually were set at 2 degrees AFTER TDC). This was done in order to increase exhaust gas temperature (due to "lighting the fire late") to improve the effectiveness of the "afterburning" of hydrocarbons by the air injected into the exhaust manifolds by the A.I.R. system; as a result, these engines ran like crap, and an enormous amount of wasted heat energy was transferred through the exhaust port walls into the coolant, causing them to run hot at idle - cylinder pressure fell off, engine temperatures went up, combustion efficiency went down the drain, and fuel economy went down with it.

    If you look at the centrifugal advance calibrations for these "ported spark, late-timed" engines, you'll see that instead of having 20 degrees of advance, they had up to 34 degrees of advance in the distributor, in order to get back to the 34-36 degrees "total timing" at high rpm wide-open throttle to get some of the performance back. The vacuum advance still worked at steady-state highway cruise (lean mixture = low emissions), but it was inoperative at idle, which caused all manner of problems - "ported vacuum" was strictly an early, pre-converter crude emissions strategy, and nothing more. (Quote)

    While these statements apply to some GM engines, they don't apply to other makes of Hamb era vehicles. This guy has obviously never worked on a '57 through late 60's Ford...
     
    Last edited: Oct 10, 2024
    egads likes this.
  21. ALLDONE
    Joined: May 16, 2023
    Posts: 3,168

    ALLDONE
    Member

    funny, my wife just said that to me....lol
     
  22. VI Lonewolf
    Joined: Sep 2, 2017
    Posts: 80

    VI Lonewolf

    Maybe a pic would help? Here is the timing for front cylinder on a HD. Left side low load (high vacuum) right side wot (no vacuum). It's also why I question the all in by 2600-3000 rpm though. timing.JPG
     
  23. squirrel
    Joined: Sep 23, 2004
    Posts: 59,239

    squirrel
    Member

    heh....this I gotta know more about....
     
    Baumi and justpassinthru like this.
  24. ALLDONE
    Joined: May 16, 2023
    Posts: 3,168

    ALLDONE
    Member

    heres one, what do you think the tires in flated to after the burn out??? my rv would start out @90 and going across the desert go to 115

    269174_221567401213571_3261770_n.jpg
     
  25. Dave G in Gansevoort
    Joined: Mar 28, 2019
    Posts: 3,481

    Dave G in Gansevoort
    Member
    from Upstate NY

    We did it in ovals. Never did much straight line stuff. That one looks like it was fun! Tried 12 percent nitro once. Hilborns guy recommended backing the timing off to 32 to 34. And fatten up the idle. And really tiny pill! 35 lap feature, 40 gallons of fuel mix. Ran out with 2 to go! But man that thing flew that night!
     
  26. deuce1932
    Joined: Jul 24, 2006
    Posts: 137

    deuce1932
    Member
    from Australia

    FFS.. I'm stupider for having read this thread !
    Geez.
     
    Baumi, 427 sleeper, RMR&C and 2 others like this.
  27. lilCowboy
    Joined: Nov 21, 2022
    Posts: 144

    lilCowboy

    When I was a younger man, I asked my dad to borrow his timing light, he said “ what for?” I said to set the timing in this car I just replaced the intake gaskets on, he said you don’t need the light for that , he tought me how to move the distributor, watch the fan when you shut it off, (that it doesn’t kick back counter rotation) make sure it doesn’t ping , make sure the starter doesn’t slow crank , ) so many variables change the timing ( I hope I don’t get attacked for sharing my experience :()
     
  28. lostone
    Joined: Oct 13, 2013
    Posts: 3,447

    lostone
    Member
    from kansas

    I watched my dad do timingg and carb setting with a glass of water.

    Adjust the carb and listen to the motor and watch the water in the glass, then play with the timing, then back to the carb and finish.

    Said he just watched to rings in the glass of water until it all smoothed out...

    Old old school. Said when he was a pup not everyone could afford a timing light or paying someone else to do it...

    Almost had forgot about it......

    ...
     
  29. squirrel
    Joined: Sep 23, 2004
    Posts: 59,239

    squirrel
    Member

    hmmmm....I wonder what difference there is between a heavy vehicle driving at high speed for a long distance, and a light vehicle spinning the tires for a very short time?

    I do know that the wrinkle walls are still wrinkled after a burnout, before launch. If you've put 30 psi in a slick, you'll know they sure aren't wrinkly at that pressure
     
  30. MCjim
    Joined: Jun 4, 2006
    Posts: 1,347

    MCjim
    Member
    from soCal

    That works fine, hell I don't even have vacuum advance, MSD box and distributor...it is 2024
     
    willys36 likes this.

Share This Page

Register now to get rid of these ads!

Archive

Copyright © 1995-2021 The Jalopy Journal: Steal our stuff, we'll kick your teeth in. Terms of Service. Privacy Policy.

Atomic Industry
Forum software by XenForo™ ©2010-2014 XenForo Ltd.