Good starting range of jet sizes on holley carb?

Discussion in 'Engine Topic' started by AllGoNoShow, Oct 18, 2019.

  1. G72Zed

    G72Zed Veteran Member

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    Sep 8, 2015
    Reading your post, your basically getting everything right and are in the "right' place with mostly everything.

    Word of advise, put some black tape over that darn AFR gauge especially at cold idle startup!! Trust me, I have 3 complete O2 AFR kits I use to tune race engines/customer cars, and no less than 10, yes 10 oxygen bungs on my own personal car!! it will drive you nuts lol.

    A carb'd engine will smell "rich", especially without cats, some more than others, cam overlap,timing and heads play a part, and play havoc with you and the AFR gauge. Once your good at idle, take "note" of the AFR gauge to give you your baseline, that's it, do not tune to a predetermined AFR #!!

    A "cold start" tip I tell all my customers with my custom built (no choke)carbs/engines, few good pumps, start it up, keep you foot in it for 2-3 minutes at 1,500 rpm or so, and shut it down for 5 minutes to heat soak. Fire it back up, the heat will get into the pistons (especially 2618's) valve springs, and put some heat into the intake, you need heat to vaporize the fuel.

    I'm North of you, and have a few customers who drive there cars late, but there is a limit to driving in the cold, especially without heat crossover in the intake, that's what your experiencing. Wait till next spring/summer, it will change, for the better, and you will not need a choke.
    72'z'steve likes this.
  2. 72'z'steve

    72'z'steve Veteran Member

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    Oct 15, 2000
    waukesha wi usa
    The heat soak trick IS great advice! My wife 's 67 is totally stock and the intake crossover actually runs up thru the intake under the carb and back down,it is notorious for rotting the carb bases.Well I tapped and blocked the passages 30 years ago,only to find the choke did not heat up while normally driving for quite a while,only a heat soak would open the choke.So I do exactly what g72 zed said for 30 years,Id run it for 3-5 minutes on fast idle and shut it down and the choke opens after the soak and it does indeed seem to run better from the soak [stock 327 275 hp] I never thought of the benefits of the throwing heat into the engine itself just getting the choke some heat.Later Steve!!

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