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chain-drive L134 and distributor

Discussion in 'Flat Fender Tech' started by evanjm, Oct 20, 2007.

  1. evanjm

    evanjm Yeah, it's got an F-head.

    Hey I'm building my chain-drive L134. I've have a few old distributors laying around out of F134s, would I be able to use this with the chain drive L-head? I know that the chain driven L-heads rotated in the opposite direction, so that got me wondering if this would even work...

    Thanks,
    Evan
     
    evanjm, Oct 20, 2007
    #1
  2. Glenn

    Glenn Kinda grumpy old man Staff Member

    Doesn't seem to me that it would matter which way the distributor rotates.
     
    Glenn, Oct 20, 2007
    #2
  3. w3srl

    w3srl All-around swell dude Staff Member

    :iagree:

    Off the top of my head I don't remember if the rotation of the distributor is different between the two engines, but reversing the firing order of the plug wires is easy enough to accomplish..

    What does your FSM say on this? :?
     
    w3srl, Oct 20, 2007
    #3
  4. sammy

    sammy Coca-Cola?

    Can't the drive gear change some?
     
    sammy, Oct 20, 2007
    #4
  5. Glenn

    Glenn Kinda grumpy old man Staff Member

    Unless there's some other factor the rotation would have to be different. Gear drive turns the cam opposite of the crankshaft and chain turns it the same direction. I would imagine distributors are designed to turn either direction.
     
    Glenn, Oct 21, 2007
    #5
  6. Howard Eisenhauer

    Howard Eisenhauer Administrator Staff Member

    Trust me, changing the drive gear (actually its on the oil pump) ain't no fun. in my case after attempts on two different pumps it ended up scouring North America for someone who actually stocked the gears, not just complete pump assemblies :(


    AFAIK the oil pumps are the same design between the engines so I figure that means they (& by default the distributer) spin in the same direction.

    H.
     
    Howard Eisenhauer, Oct 21, 2007
    #6
  7. w3srl

    w3srl All-around swell dude Staff Member

    The more I thought about this the more I realized that the chain-drive cam almost HAS to have a different oil pump drive gear set in order to turn the oil pump in the correct direction, so the distributor HAS to turn in the same direction on both engines. If the oil pump turned in the opposite direction, there would be no lubrication. The caveat here is that there MAY have been a different oil pump for the earlier engine... If this is the case then the the chain-drive cam simply spun the oil pump & distributor "backwards" from the cam rotation in order to spin it the same direction as the gear-driven engines.

    Confused yet? R)

    <edit>

    The only oil pump that is really available these days says it is specifically for engine serial numbers 44417 and later, this corresponds with the info on the CJ-2A page which lists this as the cutover point to the gear-driven engine.
     
    Last edited: Oct 21, 2007
    w3srl, Oct 21, 2007
    #7
  8. Glenn

    Glenn Kinda grumpy old man Staff Member

    Good points there! Someone around here must know the answer to this.
     
    Glenn, Oct 21, 2007
    #8
  9. jalbrecht55

    jalbrecht55 Member

    I had always assumed the 'chain drive' distributors spun the opposite direction. Now I'm not so sure!

    I can say this for a fact though: The early (chain drive) oil pump gear is not compatible with a gear drive camshaft. I've had both oil pumps in hand (both made by mallory) and other than the gear, they looked the same. It stands to reason that the pump would then have to spin the same direction (for gear drive or chain drive), and if that's the case, the distributor would also spin the same direction.

    The shape of the gear on the oil pump is basically a mirror image between the two styles, so that also suggests in my mind that both pumps would spin the same direction.

    In any case, the only reason I can come up with, for why it would matter, would be the advance mechanism. It would try to retard timing at higher rpms. So I think you should be safe trying it out.
     
    jalbrecht55, Oct 21, 2007
    #9
  10. CJ-X

    CJ-X Member

    You can interchange the distributors. They spin the same way on both engines.
     
    CJ-X, Oct 21, 2007
    #10
  11. Mike C

    Mike C Member

    Ignorance is bliss...

    When I first got my A1 I had no idea that the L heads were gear or chain driven. But I knew I was going to ditch the 24v distributor and go with a 12 volt setup. I dropped in a WWII distributor that I had used and is what I am running now. The only problem is I have not quite been able to get the correct advance. It's a couple of degrees short of where it needs to be. I will mess with it more when I finish paint and wiring.
     
    Mike C, Oct 21, 2007
    #11
  12. 1960willyscj5

    1960willyscj5 Well-Known Member

    Moses Ludel states that the oil pump and distributer of the chain drive L134 turns opposite of the direction of the gear drive L134. Advance mechanism works opposite, too. And the camshaft lobe profiles are different. Page 140 of CJ Rebuilders Manual, 1946 to 1971.
     
    1960willyscj5, Oct 22, 2007
    #12
  13. CJ-X

    CJ-X Member

    I don't know Moses Ludel,......... but he might want to re-think that.;)


    What is that statement. "Don't believe everything you read"......
     
    CJ-X, Oct 23, 2007
    #13
  14. 1960willyscj5

    1960willyscj5 Well-Known Member

    The CJ books all say that too.
    Moses builds these things as a profession up there in Oregon somewhere.
    :):coffee::hurrican:


    Page 140 of the Jeep CJ Rebuilders Manual for the years 1946 to 1971.
     
    Last edited: Oct 24, 2007
    1960willyscj5, Oct 24, 2007
    #14