Buick 350 Head Airflow Numbers

Discussion in 'Small Block Tech' started by wovenweb, Jul 25, 2017.

Tags:
  1. wovenweb

    wovenweb Platinum Level Contributor

    My computer crashed over the weekend and while reassembling my data files, I found this one. The table below shows all the airflow numbers I've run across over the last couple years for Buick 350 cylinder heads. The PAE ported head numbers came from the Hot Rod article, Jim W's numbers are from his thread. I think the stock references (Stock and Stock #2) came from the same places, but honestly I didn't write it down. Also on the second row of data you will see the numbers for the heads I purchased from someone else on the board. Ultimately, those heads were a Level 3 port job by Greg Gessler. In an e-mail conversation, Jim W. mentioned that Greg never used a header flow tube when he tested exhaust flows, so he suggested I make a correction of up to 10% of the flow. Since doing that on the low lift numbers would produce exhaust number higher or equal to the intake numbers, I used lower correction factors there and stepped them up until I reached the 10% correction(at lift values of 0.500 and above). Keep in mind that all these numbers were developed using different air flow meters so can't be directly compared. I would say that it appears that Jim Burek, Jim Weise and Greg Gessler all got to about the same place. When I find the numbers for the flow balanced intake manifold, I will post those also.

    PS when I type the numbers in, everything lines up. When I submit the actual post, that's when the spacing issues start. If someone else knows a better way to post these, please let me know.

    Code:
                        Stock                             Burek PAE ported                         Jim Weiss Ported  
    Lift    Intake   Exhaust                   Intake    Exhaust                          Intake    Exhaust
    0.100      66            44    66.7%             74              55     74.3%               66                55    83.3%
    0.200    119            93    78.2%            135            110     81.5%             131               105    80.2%
    0.300    169         124    73.4%            187             145     77.5%            188               131    69.7%
    0.400    198         128    64.6%            241             167    69.3%            229              141    61.6%
    0.500    198         130    65.7%            243            176     72.4%            255              167    65.5%
    0.550                                                      251            178     70.9%      
    0.600                                                     254            181     71.3%             256              170    66.4%
    0.700                                                     263            171     65.0%
    
                         Stock #2                          Gessler Ported                  Corrected
    Lift    Intake    Exhaust    Ratio      Intake    Exhaust                 Exhaust       Ratio
    0.100      58              44    75.9%              62          59       95.2%          60         96.1%
    0.200    116               91    78.4%            122        106       86.9%        109        89.5%
    0.300    158             118    74.7%            183        132       72.1%         140         76.5%
    0.400    180             127    70.6%           226       146       64.6%         158         69.8%
    0.500    188             137    72.9%           248       154       62.1%          169         68.3%
    0.550                                                        250        157       62.8%         173          69.1%
    0.600    189             139    73.5%          250        161        64.4%         177         70.8%
    
     
    300sbb_overkill likes this.
  2. wovenweb

    wovenweb Platinum Level Contributor

    Maybe this will work better:

    Head flow numbers.PNG
     
    300sbb_overkill likes this.
  3. wovenweb

    wovenweb Platinum Level Contributor

    Here are the intake airflow numbers. I include the average, standard deviation and the balance of flow numbers. The last of those are directly from the sheet Greg provided to the prior owner of the intake, I have no idea how it is calculated.

    This was on a TA Stage 1 350 intake. I don't have any stock comparables.

    Intake Manifold Balancing.PNG
     
  4. sean Buick 76

    sean Buick 76 Buick Nut

    Very interesting! One thing to remember is that CFM flow is only part of the equation... Many other aspects effect the actual performance... I'm sure your heads will work awesome by the way...
     
    Gary Farmer and 8ad-f85 like this.
  5. MrSony

    MrSony Well-Known Member

    Someone correct me if I'm wrong, are all Buick heads the same, flow wise? If I remember the later late 70s heads had bigger exhaust valves, memory is a little fuzzy on the topic.
     
  6. Stevem

    Stevem Well-Known Member

    In comment to those numbers and power production if you where only running a Cam of .550" lift then the heads with the fatter flow numbers at .300" and .400" lift would make the most power, this assuming all of the Intake ports where within 8 % of the minimum port area between each other, and the chosen Intake and Carb whether not the choke point.
     
    8ad-f85 likes this.
  7. sean Buick 76

    sean Buick 76 Buick Nut

    There is no confirmed answer to this question however I have looked at the various castings and they are different over the years. I am taking a set of 68, 70, 71, 73 and 75 heads to be flow tested and then I will have real data on which year exactly the heads lost the flow numbers. I do know that the 75-80 heads flow badly compared to the 68-70 heads... BUT the real question is which year did the head flow decrease. I need this info for my book.
     
    MrSony likes this.
  8. Gary Farmer

    Gary Farmer "The Paradigm Shifter"

    The newer heads (75+), much like the newer blocks, had more iron in them and so the passages didn't flow quite as well, but you can still make them perform with the correct components.
    They're less prone to cracking and give more material to work with.
    I see no downsides to using them, and would actually prefer them myself.
     
  9. Fox's Den

    Fox's Den 355Xrs

    Wait until that Aluminum block comes out.
     
    Mark Demko likes this.
  10. Stevem

    Stevem Well-Known Member

    Ok , I'am game!
    So what does a Aluminum block have to do with what's being talked about in this thread?
     
  11. wovenweb

    wovenweb Platinum Level Contributor

    Maybe he meant the Aluminum heads? That is why I posted this thread. As a reference point when they do hit the market.
     
  12. Fox's Den

    Fox's Den 355Xrs

    Don't take things so seriously it's a joke.
    Maybe this will happen one day
     
    Mark Demko likes this.
  13. wovenweb

    wovenweb Platinum Level Contributor

    The aluminum heads you mean? ;)
     
  14. Fox's Den

    Fox's Den 355Xrs

    That should happen soon they have been working on it for a long time now.

    My ported head I got from TA flowed 235 intake and 176 exhaust. I sent my heads to them in 1993.
     
  15. MrSony

    MrSony Well-Known Member

    Awesome! I have a '70 (SP Motor), and my blue '76 and I'm looking forward to those tests. Also, gonna buy that book for damn sure.
     
  16. Mark Demko

    Mark Demko Well-Known Member

    LMAO:p
     

Share This Page