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Fan Clearance Issue - Hei Install

Discussion in 'Early CJ5 and CJ6 Tech' started by CJMark, Sep 19, 2020.

  1. CJMark

    CJMark Jeeper

    Anyone know of a fan spacer to resolve the clearance issue between blades and vacuum advance? A 1” spacer should work. Hopefully something from local parts store (Napa, Autozone, O’Reilly, Carquest) or mail order. I did try right angle attachment from my Mitivac kit but still need more space.

    If you have other solution that would be helpful too. I would rather not move plug wires, everything was installed per CRT Performance instructions, Jeep starts and runs awesome, everything is timed right, mechanical and vacuum advances working.

    I still have to finish plug wire holders and install relay for the 12v feed. It was an easy install, just need to get my fan back on.
    Thanks
    Mark

    [​IMG]
     
  2. Fireball

    Fireball Well-Known Member 2024 Sponsor 2023 Sponsor 2022 Sponsor

    One thing that helps is getting the vacuum advance for a 1976 Buick Skyark V6 that came with the HEI. The spigot comes off the side and shortens the unit considerably.

    Here's mine:
    [​IMG]

    The part number is AC Delco D1366C. Here's an Amazon link: https://www.amazon.com/ACDelco-D1366C-Professional-Ignition-Distributor/dp/B000EQVYCS

    That picture is with a longer 231 water pump and no spacer. These days I'm running a 225 length water pump with a 1/2" spacer and the same vacuum advance.

    Current picture, but the shroud makes it hard to see any details:
    [​IMG]
     
  3. Keys5a

    Keys5a Sponsor

    I've never seen a vacuum advance on an HEI where the vacuum line sticks straight out. All the OEM units have the line come out at an upper angle to clear the fan.
    -Donny
     
  4. CJMark

    CJMark Jeeper

    Just to get closure on this issue, here’s how I remedied the issue.

    I purchased a 1” fan spacer from Oreillys (they have 1 and 2” spacers on wall behind counter) and then replaced my 16” 5 blade fan with a 14” 6 blade one I had from a parts Jeep. This gave me the required 1/2” clearance on back side and I still had 1 1/4” space front side.

    Thanks Fireball for increasing my knowledge on side ported advance. CRT distributor has adjustable advance so to get 3/32 Allen wrench in port to adjust, port must be straight out. I still have to go through adjustment procedure, I want to get Tach installed first.

    The electronic ignition change the whole personality of the dauntless, fun to drive, touch key and it fires right up and so much more power on the road, no more chasing miss-fires and replacing tune up parts.
    Mark
     
    LayemStr8 and Fireball like this.
  5. nickmil

    nickmil In mothballs.

    Many HEI’s had them straight out and are an issue in this application. This has been discussed on this site many times and for many years. For example, Buick Regal’s had a long shroud with a fairly long thermostatic fan clutch so clearance was not an issue.
     
    Fireball likes this.
  6. brunester

    brunester Member

    I ran into that issue as well, I ended up clocking the distributor to maintain clearance with the fan. Just be careful when clocking, because its an oddfire and you need to make sure your firing correctly.
    Seems to work ok so far... :)
     
  7. Buildflycrash

    Buildflycrash More or Less in Line. 2024 Sponsor 2022 Sponsor

    Anyone make a simple 90* or 180* fitting to help this?
    Is a v6 5/32" or 7/32" ID hose?
     
  8. timgr

    timgr We stand on the shoulders of giants. 2022 Sponsor

    Is it a regular Delco vacuum can? I'd get a replacement and see if I could modify it. Soldering is probably out, but epoxy might work. Cut off and plug the offending nipple, add another on the side like the above picture. I might try solder on a sacrificial unit to see if the diaphragm survives.