TA 310 SBB350 Cam Vacuum, Good?

Discussion in 'Small Block Tech' started by MrSony, Apr 7, 2020.

  1. MrSony

    MrSony Well-Known Member

    I got it to be more steady after the video was shot by raising the rpm a tad. Runs good, power brakes are fine. Just wondering what ya'll think. 10"Good? Should I expect more?

    Stock bore (within spec) '71 350, undecked. Crank/rods cut .010, 3.0 flat tops, .0945 in the hole, surfaced heads with valve job, guides cut for .550 lift and small seals. Pat Kelly calculator says 9.75:1 SCR, 7.59:1 DCR, assuming there is some advance ground into the cam. Runs nice on 91.
    TA 310 cam. Card different than the specs on their site. .509/.507 lift, 233/232@.050. Installed at "0" according to the timing set. Hooker Super Comps, straight through exhaust. Healthy lope.

    No fuel drippage from boosters. With 12* initial, it likes 2 turns out on the EverydayPerf. 17057241 Qjet. Likes 850rpm idle.

    Pardon the terrible videography.
     
  2. alec296

    alec296 i need another buick

    What’s timing set at , I would think the 310 would have more vacuum. It’s not a lot of duration. 284 I believe. I have a 310 in mine . Still having carb issues. Dripping from left side Venturi. But otherwise sounds strong. I have .030 over pistons,factory type hi compression. .025 off heads around 9.8 compression. But cam is installed 4 advance.
     
  3. LARRY70GS

    LARRY70GS a.k.a. "THE WIZARD" Staff Member

    I would try another vacuum gauge just to be sure. There can be quite a lot of variation between gauges. If you didn't degree it, there really is no way to be sure where it is. 10" is bare minimum for power brakes. If they are fine, you probably have more than 10"
     
    alec296 likes this.
  4. sean Buick 76

    sean Buick 76 Buick Nut

    Try adjusting the idle mixture screws. I would expect 13-15 inches
     
    techg8 likes this.
  5. Fox's Den

    Fox's Den 355Xrs

    why did you not get a degree wheel and degree the cam in 10 does seem low I get 13 out of my cam maybe 10 in gear.
     
  6. Stevem

    Stevem Well-Known Member

    It's the total amount of the Cams overlap that determines idle vacuum levels, not duration as you can have many different Cam duration number between the lobe used for the Intake and Exh yet still net the same amount of vacuum.
    Another factor is the motors compression ratio, the smaller the Total CC volume is above the piston the more vacuum a motor will have.
     
  7. MrSony

    MrSony Well-Known Member

    The engine runs fine. No nozzle drip, revs good, sounds great, torquey as always the case with a sbb. I have had this gauge for quite a while, but I've never been lead to believe it's incorrect. I did not degree the cam for a variety of reasons, chiefly among them lack of time, and funds. It's not a necessary procedure, but it's just another way of knowing exactly what the cam is and what it should do when. I didn't expect much vacuum from this setup, nor am I complaining. Just wondering if it's "normal" enough for an engine like mine.
    "
     
  8. alec296

    alec296 i need another buick

    I would try alittle more timing is you can.
     
    techg8 likes this.
  9. LARRY70GS

    LARRY70GS a.k.a. "THE WIZARD" Staff Member

    Probably because you have never compared it to anything else.:) I have an Autometer gauge that is the most accurate one I own. All the cheap ones I have, read differently from one another.
     
    Last edited: Apr 8, 2020
  10. alec296

    alec296 i need another buick

    Jordan, did you get a higher converter to match cam? My 310 with a 2200 was So flat down low, that is when I advanced cam 4 degrees and got a 2700 small block rated torque converter and had heads shaved to get more compression.. It feels much better now. But can’t go far, pulled the fluid out of rear to change to rear disc breaks and replace the worn out auburn carrier. Might even bump up to 3.42s from the 3.73.
     
  11. MrSony

    MrSony Well-Known Member

    I've got a 2500 hughes. Cam is installed at the "0" mark on the 3 way timing set. idk if TA has crower grind any advance into their cams or not.
     
  12. J.Staged

    J.Staged My Therapy...!!

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