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wanted.. fan shroud

Discussion in '1969-1972 K5 Blazer | Truck | Suburban' started by jamie72, Apr 1, 2001.

  1. jamie72

    jamie72 1/2 ton status

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    i`m in need of a decent fan shroud,for myk-5.
    thanks
    jamie
     
  2. 1Blazin71

    1Blazin71 1/2 ton status

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    For a small block or big block? With AC or not?

    I have a decent one that came off my 71 K5 smallblock with AC; went to electric. It's been a while since I looked at it, but I think its in pretty good shape.

    If you want a new one, LMC Truck carries them. (800) 222-5664.

    If you think you can make use of my old one, name your price and I'll look into shipping. This thing is just taking up space in the garage and I dont have any use for it or aspirations for making a killing off it.


    Matthew Meyer
    matthewm@inhollywood.com
    '71 K5 - 4" Lift 35"s
    ZZ4 350 - 700R
     
  3. JST12

    JST12 1/2 ton status

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    Jamie,
    I also have a shroud (in Dallas). Where are you.

    Mathew,
    What model and CFM rating is your electric fan?. Any temperature issues? I have a ZZ4 also. I see recommendations for 5000+ CFM , but that gets expensive.
    Thanks,
    JT
     
  4. 1Blazin71

    1Blazin71 1/2 ton status

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    Re: wanted.. fan shroud (and now some ZZ4 ?s)

    I have a Flex-A-Lite Black Magic Heavy Duty. It pulls around 2800 CFM and with the 160 deg. thermostat, I havent had any troubles with it. I have a mechanical autometer temp gauge probe between the #6 & #8 plugs on the head. It runs around town at a cool 180 deg, and Ive never seen it above 210 even when hammering it. I bought mine for about $200, if I recall correctly.

    I have been thinking about installing a second electric fan to have some redundancy in case one of them fails while out in the sticks, but there's always something to do on these rigs and maybe someday I'll have dual batteries, spare axles, and dual fans.

    On the subject of ZZ4s, I'm wondering if you ran into the same problem I did with the stock timing module on the HEI these things came with? It seems that they run a rediculous 47 deg advance at around 2200 RPM. That might be great for drag racing and balls out driving, but with the 700R and 3.73s on 35s, I tool around town at what feels like 1500 RPM and the stock timing pings like crazy.

    I've gotten around this for now by not running any vaccum to the distributor while in daily driver mode. I have the distrbutor fixed at around 11 deg advance, which keeps the ping away, but sucks for mileage and ooomph! I simply reconnect vaccum to the distributor when we want to hammer it.

    I'm considering changing the Holley 750 for a 650 Quadrajet and either getting a new module for the HEI or going to an adjustable advance electronic unit from MSD or someone.


    Matthew Meyer
    matthewm@inhollywood.com
    '71 K5 - 4" Lift 35"s
    ZZ4 350 - 700R
     
  5. JST12

    JST12 1/2 ton status

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    Re: wanted.. fan shroud (and now some ZZ4 ?s)

    Mathew,
    Thanks for the info. I have not fired up the ZZ4 yet so I can't comment on the pinging. I will certainly let you know. I was wondering about the advance you mentioned. After looking through the manual, I thought of something. When you adjusted the timing initially to 10-11 degrees, did you have the vacuum advance disconnected and plugged, and were you running 600 rpm (to ensure no mechanical advance)? If your carb has two vac adv ports, (timed and ported) are you connecting to the timed port which has no vacuum at idle. I'll get the manual out again, but I think the max advance is supposed to be 32 degrees. If you were to set your initial timing to 3-4 degrees, does the top end feel better?
    JT
     
  6. Steve_Chin

    Steve_Chin 1/2 ton status

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    Re: wanted.. fan shroud (and now some ZZ4 ?s)

    47 degrees of advance? Wow! That's a lot. I don't know much about the ZZ4, but I thought that it was not computer-controlled... If that's the case, the ignition curve is controlled by weights and springs, not by any electronic module. All you need to do is take the distributor to a good distributor shop and have a curve set up for your camming, compression, transmission, vehicle weight, and gears. I would suggest a curve that allows about 8 degrees of initial advance and tops out with 34 degrees total (no vacuum) at about 2400-2600 RPM. I've gotten a lot of center advance cams and weights out of HEIs in wrecked cars in order to get the advance profile I wanted. I then got an aftermarket advance curve kit and set the springs up to get my total coming in at the desired RPM. Then I put a good vacuum advance can on it (one that had the total advance and sensitivity to vacuum that I wanted). Works pretty good...
     

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