1. This site uses cookies. By continuing to use this site, you are agreeing to our use of cookies. Learn More.

Changing Carburetors...comparing advice

Discussion in '40- & 55-Series Tech' started by TJDIV, Dec 2, 2003.

  1. TJDIV

    TJDIV Back in The U.P.

    Messages:
    2,063
    Media:
    9
    Albums:
    1
    Likes Received:
    2
    Joined:
    Jan 28, 2003
    Location:
    Upper Michigan
    I'm running a Holley 750 right now and it's a little much for me. I've tuned it about as far down as I can and it still dumps too much fuel through. Not too mention the fact that I'd like a choke for winter cold starts and I haven't even looked to see if this one has a choke.

    Leading to....electric or manual choke?

    Also; I've been told to go with a 650 cfm. I don't climb hills, go vertical, or require a carb that can operate in a climate similar to Mars. So, for a practical purposes, what are your recommendations.

    I'll take this advice to the dealer with me, so pour it on. Thanks.

    IV
    ;)
     
  2. toddslater

    toddslater

    Messages:
    1,498
    Likes Received:
    3
    Joined:
    Oct 31, 2002
    Location:
    Kennett Square
    Assuming we are talking a stock to mild 350 sbc the 650 is a good cfm-wise choice.
     
  3. Gumby

    Gumby Supamod Staff Member s-Moderator

    Messages:
    11,960
    Likes Received:
    393
    Joined:
    Dec 13, 2002
    Location:
    Knee deep in hookers and gin
    Hey, Todd.

    You didn't happen to see this weeks SI cover?

    Really nice pic. :D
     
  4. hammerhead

    hammerhead

    Messages:
    1,995
    Likes Received:
    2
    Joined:
    Jul 5, 2003
    Location:
    Central, Utah
    Get a Quadra-jet 8)
     
  5. woody

    woody unhelpful spotter Staff Member Admin

    Messages:
    10,619
    Media:
    317
    Albums:
    7
    Likes Received:
    1,859
    Joined:
    Jan 15, 2002
    Location:
    Toquerville UT
    Ran a holley for 2 weeks....returned it
    Ran a Carter for 7-8 years, spent a lot of time tweaking it to work halfways decent offroad....downgraded from a 750 to a 625 and that helped, still not perfect
    Ran a Q-jet, $100 including rebushing the baseplate primaries, the gasket set, and the junkyard purchase....loved it until...

    TBI baby... :flipoff2:

    Give us some engine specs. My old 350 was .060 cast flattops, chromoly rings, balanced, 1.6 roller tips. .020 shaved heads, 2.02 exhaust, weiand dual plane, Accell HEI, 272 Comp Cam, advanced timing, peened rods, and more....$3500+ in that thing, and a 750 was really more than it needed...
     
  6. toddslater

    toddslater

    Messages:
    1,498
    Likes Received:
    3
    Joined:
    Oct 31, 2002
    Location:
    Kennett Square
    bwaaaaaaaa

    flat tops...peened rods...weiand....common Woody this is some of what you need relieved domed pistons....polishied rods.....bwaaaaaaa

    bored with digi camera
     
  7. TJDIV

    TJDIV Back in The U.P.

    Messages:
    2,063
    Media:
    9
    Albums:
    1
    Likes Received:
    2
    Joined:
    Jan 28, 2003
    Location:
    Upper Michigan
    Running a stock 350 with headers and flow masters. (sorry, forgot that part).

    It's just a little much on the gas is all. I've heard a 650 should suffice, but then the names flew out at me, then the applications, etc.

    I live within pissing distance of the Gulf of Mexico, we have more sand here than Jenna Jameson's ass crack shooting beach porn, and I've got little to no interest in driving to Tennessee to wander the mountains. Don't get me wrong; minus business obligations, I'd love to remain in Upper Michigan and enjoy the outdoors more.

    So; I'm at the mercy of the board. Which brand, and I suppose a 650 or 625.
    Let 'er rip.

    Thanks to all.

    IV
     
  8. TJDIV

    TJDIV Back in The U.P.

    Messages:
    2,063
    Media:
    9
    Albums:
    1
    Likes Received:
    2
    Joined:
    Jan 28, 2003
    Location:
    Upper Michigan
    And yes, I can still track a deer with a bow and arrow and give my grandfather some venison to can.
     
  9. woody

    woody unhelpful spotter Staff Member Admin

    Messages:
    10,619
    Media:
    317
    Albums:
    7
    Likes Received:
    1,859
    Joined:
    Jan 15, 2002
    Location:
    Toquerville UT
    Edlebrock used to have a nice calculator spreadsheet you could download and determine flow needs for carbs based on your engine specs...haven't been able to find it tho....

    Carter AFB is offroadable, and with their mechanical secondaries can be a real road screamer. I've got some mods teched up that help it out (see tech section). 625-650 is perfect IMO for your motor...might even get away with a 500 for 90% of your use.

    If you want fuel mileage, Q-jet no question....tiny little cute primaries for driving, mongo vacuum secondaries for phat feet. ~750 in size, but their tiny primaries allow it to run on anything from a 305 to a 454.

    I still vote a junkyard trip for a Q-jet...
     
  10. Rice

    Rice SILVER Star

    Messages:
    4,370
    Media:
    10
    Albums:
    1
    Likes Received:
    5,092
    Joined:
    May 2, 2003
    Location:
    GSO NC
    The Q-jet Woody is making mention of is a nice choice with no downsides except a little harder to rebuild. Your other question was about choke ... I'd not recommend electric in a cold climate. The choke warms up and opens on its own whether the engine is ready or not. It's good for me here in NC but otherwise I'd do manual (or a heat riser).

    For reference I'm using only a 600 (Edelbrock) on my 383 and very happy with its road manners and response. It breaths well until about 6500 RPM, plenty for my needs. If wanting 7500 RPM a 750 would be more in order.