Jetting advice big car build

Discussion in 'The Venerable Q-Jet' started by AlaskaBuick, Jul 11, 2014.

  1. AlaskaBuick

    AlaskaBuick Well-Known Member

    I am doing a mild head cam build on a 70 electra.

    Motor is stock 58k real miles untouched. I have sourced a set of 68 430 big port heads with stage 1 big valves. I will be running a TA 288 94H cam, stock manifolds with 3" exhaust/x pipe. Installing a 9" ford rear with 3.90 gears, 9.5" stall converter 3200, performer intake (just cuz I had it setting around) and a MSD ignition.
    Thats about it for now and see how it does. I dont plan on pulling it past 5500 as it is a stock short block and I have heard that is where you want to keep it under without any oiling mods.
    The q-jet performed very very smooth and well on the stock motor, was very suprised for a old untouched car, in fact i hate to even mess with it, however Im sure it will need more fuel.

    My question is should I install larger jets and smaller metering rods? I do have an assortment of rods and jets on hand.

    We are at 430 elevation and have very good dry air. I have installed a NGK o2 sensor so it will be easy to see what A/F ratio I am running at.

    The car will just be a fun street car and will rarely see any 3 gear winding 1/4 mile runs, really more of a 1/8 mile type car. Maybe a 1/4 mile track once every couple years for kicks.

    Thanks in advance for any advise.

    Regards,

    Dennis
     
  2. carmantx

    carmantx Never Surrender

    What is the code on the Quadrajet you have?

    I suggest going to a 71-74 Buick 455 Quadrajet for the 800 cfm flow ability.
    I would probably start with a 74 jet and .042 primary rod. DA secondary rods. Also need to pull and drill the air/idle bypass to .036 so it will idle well with the cam.
     
  3. AlaskaBuick

    AlaskaBuick Well-Known Member

    Well I ended up finding a 73 800 cfm that I can clean up.. Are you saying to use the the 74 jets in the 800?

    What other mods need to be done with this car other than the obvious clean up, ect...

    Im running ported irons, 288 94H cam, MSD, and not turning very high rpms.. under 5500.

    Thanks!

    Dennis
     
  4. carmantx

    carmantx Never Surrender

    Yes, the modifications I mentioned in my above thread would be for the 800 cfm Quadrajet.
     
  5. WE1

    WE1 Well-Known Member

    With the O2 sensor you can find out where you need to be at idle, cruise and WOT. Modifying the carb base to get to the APT screw will get your idle along with primary rods. Jet sizes with mph through the traps. Upping idle air bleeds is a good idea for that cam.
     
  6. AlaskaBuick

    AlaskaBuick Well-Known Member


    Thanks, Ill do that!
     
  7. AlaskaBuick

    AlaskaBuick Well-Known Member

    Hey Dave!

    Thanks for chiming in on my post.
    Since we last talked I picked up some nice ported Irons from a form member here. Went with the closest cam I could to your recommendation on long duration and wide lobe separation. It runs good and pulls strong despite the 2.93 peg leg, putting together my 9" ford with 3.90 now.

    For now I robbed my Q jet off my 494 GSX motor to get it going. Turned a 14.1 at 99.5 mph right out of the gate on a 2.30 60' with two people in the car and bunch of crap in trunk. Now for some gears and I think I can hit my goal of mid 13 boat!

    What a nice car to drive, just floats around town.

    Den
     
  8. WE1

    WE1 Well-Known Member

    Great!
    Have you tweaked the distributor for timing improvements? Try to get as much initial timing and mechanical as early as your engine can live with with the fuel. That should help with your off idle response and your launch. Some gears and a good SP converter and trans and you're all over mid to lower 13's. Then you'll be looking for some sticky tires. Sounds fun
     
  9. AlaskaBuick

    AlaskaBuick Well-Known Member

    Picked up a used MSD ProBillet and already had a 6aL box collecting dust on the shelf... running 35 full advance all in by 1900. Have not played with it much on different timing as of yet, but im sure that is about where it needs to be. AF at WOT top of 2nd n 3rd is about 12.66, probably a bit lean?

    Had my 1st kill tonight, nothing real fast, a Dodge avenger was messing with me I dont know much about them but I know they run mid 14's.. The old Electra with 4 people in it, had to take him to school... The guy was laughing so hard at the next stop light, he was shocked that the granpa mobile whooped him.
     

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