Author Topic: Qjet recipe  (Read 3053 times)

Offline RamAir455

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Qjet recipe
« on: January 05, 2015, 05:32:01 PM »
I have a 17057256 carb off a 403 olds. It's going on a friends fresh 30 over 455 Pontiac. Stock 7k3 heads 9.5 compression ,cast iron intake and ram air exhaust manifolds 068 cam 288 302 duration 413 lift 1:50 rockers HEI dist with 12 degs in@ 2800 with 12 initial for 36 mechanical plus 14 degs vacuum. Turbo 400 with a shift kit And a 3:23 posi rear end what 15 inch rallys and 225 70/15 tires The carb specs are as follows main  bleeds in the body. 064 air bleeds in the air horn. .064 idle down channel. .034 idle tubes haven't been pulled so they are unknown I'm putting on an electric choke stat replacing the hot air one so I added idle bypass holes the size of. .060 and drilled the idle screw holes to .090 the stock jetting is 73 jet 49k rod , secondary rods are CV we're going to use this for ower base line to start with. we are going to dyno this engine and that should tell us what we will need for jetting. Cliff any recommendations you can give me would be appreciated. Thank you

Offline Cliff Ruggles

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Re: Qjet recipe
« Reply #1 on: January 06, 2015, 04:17:06 AM »
I would put one of our kits in it, so it has the high flow N/S assembly and modern accl pump with the good seal on it, new secondary plastic cam/spring, etc. 

The 73 jets are fine, but use our .044 tapered rods instead, the 49K's are too lean and not enough adjustment for what you are doing.

I would NOT touch any airbleeds, idle or main, but I would put larger idle tubes in it, .036-.037", and .055" DCR's to help the idle/off idle out some.

Those carbs did not have .064" DCR's in them, that's HUGE for what you are doing.

CV secondary rods are fine, E-choke is a nice addition to those carbs. 

I've built hundreds of those units, and use them for a lot of our "custom" big cfm e-choke models......Cliff