Announcement

Collapse
No announcement yet.

My friend Curtis Boggs from RFD talks about heads

Collapse
X
 
  • Filter
  • Time
  • Show
Clear All
new posts

  • My friend Curtis Boggs from RFD talks about heads

    My friend Curtis Boggs from RFD talks about heads :o

    http://www.engine-builder.com/ar/eb90754.htm
    2007 SBN/A Drag Week Winner & First only SBN/A Car in the 9's Till 2012
    First to run in the .90s .80s and .70's in SBN/A
    2012 SSBN/A Drag Week Winner First in the 9.60's/ 9.67 @ 139 1.42 60'
    2013 SSBN/A Drag Week, Lets quit sand bagging, and let it rip!

  • #2
    Re: My friend Curtis Boggs from RFD talks about heads

    Good stuff :D

    That answers the question you posted at Speed Talk a couple weeks ago doesn't it ;)

    Comment


    • #3
      Re: My friend Curtis Boggs from RFD talks about heads

      Yes and No, LOL I have a answer to that one now, from pipemax software.

      when does gaining flow, but at less cfm per sq in of area, lose power, and when does it gain power.

      As an example,
      CFM per SqInch of Valve Area,
      like a recent Thread about #781 BBC Heads,
      i gain HP every time i go from 2.190 to 2.250 or especially 2.300 valves
      even though the 2.190 valve might be at 79.64 CFM/Inch (300 CFM)
      -VS- 2.300 at 77.0 CFM/Inch (320 CFM)

      Same results in a bunch of different Head types,
      like a series of tests with Vortec cast-iron SBC #906 castings
      going in steps from stock OD to 2.020 then to 2.055 then to 2.080
      the CFM per SqInch of Valve Area numbers will be declining but
      the overall CFM will gain and so will HP.


      Like in Comp or ProStock, you should always strive for the highest
      CFM/SqInch as this becomes more important in these applications,
      but there are many instances where gains in overall CFM Flow
      gain more HP at a slight decrease in CFM/Sq Inch when trying out
      a larger valve.

      to further improve VE, the speed, cfm per sq in of csa, velocity profile etc, all become as, or more important than total cfm.

      Velocity FPS + Velocity Profile thru the Port, along with
      overall Port Shape and correct CSA for the application,
      are very important, as important as Total CFM

      Too fast or too slow FPS hurts Torque and HP and RPM potential
      regardless of FlowBench CFM Numbers.

      The FlowBench tells you Flow CFM Numbers
      and the FlowBench can also tell you many other things
      while you are Flow Testing if you know what
      to look for or how to measure it..like using a Pitot Probe
      to measure Velocity Profile thru the Port.
      Theres so much more a FlowBench can tell you
      than just Flow CFM Numbers.

      On the overall maximum Flow an Engine can use at any RPM,
      in other words, "Flow Saturation" at a particular RPM,
      you can use PipeMax's Piston CFM Demand Column's numbers
      to see whats the maximum CFM an Engine will ever want or use
      at a given RPM.

      If your Heads Flow more than the Piston CFM Demand,
      it will never use all of that Flow,
      instead you will need to find a way to move Peak HP RPM higher
      in an attempt to use all your Cylinder Head Flows.
      _________________
      Meaux Racing Heads
      MaxRace Software
      ET_Analyst for DragRacers
      2007 SBN/A Drag Week Winner & First only SBN/A Car in the 9's Till 2012
      First to run in the .90s .80s and .70's in SBN/A
      2012 SSBN/A Drag Week Winner First in the 9.60's/ 9.67 @ 139 1.42 60'
      2013 SSBN/A Drag Week, Lets quit sand bagging, and let it rip!

      Comment


      • #4
        Re: My friend Curtis Boggs from RFD talks about heads

        Hey I have a head ported buy Curtis, Little 4 cyl head. Motor puts out some pretty good numbers.

        Comment


        • #5
          Re: My friend Curtis Boggs from RFD talks about heads

          Yes Curtis is getting very popular
          2007 SBN/A Drag Week Winner & First only SBN/A Car in the 9's Till 2012
          First to run in the .90s .80s and .70's in SBN/A
          2012 SSBN/A Drag Week Winner First in the 9.60's/ 9.67 @ 139 1.42 60'
          2013 SSBN/A Drag Week, Lets quit sand bagging, and let it rip!

          Comment


          • #6
            Re: My friend Curtis Boggs from RFD talks about heads

            Curtis has my heads because all the stuff you just posted is greek to me! Cant wait to get them back and see how much I gain!

            Comment


            • #7
              Re: My friend Curtis Boggs from RFD talks about heads

              Yours are almost done. Andy
              2007 SBN/A Drag Week Winner & First only SBN/A Car in the 9's Till 2012
              First to run in the .90s .80s and .70's in SBN/A
              2012 SSBN/A Drag Week Winner First in the 9.60's/ 9.67 @ 139 1.42 60'
              2013 SSBN/A Drag Week, Lets quit sand bagging, and let it rip!

              Comment


              • #8
                Re: My friend Curtis Boggs from RFD talks about heads

                I think like always that you have to look at the whole combination and also when looking at the results you have to look at the results in the fields that matter to you.

                For, example, a head that flows a higher total cfm but has the same cfm/in^2 or cfm/cc might make a better peak hp but could lose out in mid range torque (or HP, however you want to call it) that would get a heavy, low-lift cam, low rpm street car down the track. The same head on the same size engine with a bigger cam and more compression might well take advantage of the extra total flow and fly down the track with the extra total cfm. Picture two 302 engines, both 8:1 compression, both 185/[email protected] .050 hyd flat tappet cams in a generic mid 80's mustang. On my bench a 4bbl cleveland head flows about 280 and had about a 245cc runner, a generic 302 head flows about 158 with a 127cc runner. I don't know the cross sectional area but using cfm/cc we get 1.14cfm/cc for the Cleve and 1.24cfm/cc for the 302 head. Put a 4bbl cleveland head on one engine and a 302 head on the other. Which will make more peak hp - it would be close and the cleveland might just edge it out up top. Which would make more average hp and torque over the usable rpm range - I'd put money on the 302 heads. Which would go down the track faster - again, I'd put money on the 302 heads as the engine wouldn't want to go above 4800rpm for best track time. Now change the combination to a solid flat tappet or roller with around 250 @ .050 and 13.5:1 and I'm pretty sure the Cleveland head will stomp on the poor 302 heads. The airflow requirements of the engine have changed and even though the small valve/small runner 302 heads probably have a better cfm/cc ratio, the overall airflow needs of the engine will just win out.

                I think that looking at the efficiency of the runners like you're talking about is a very important aspect of building an engine, but it is just one aspect and you just have to keep going back and getting the wider view of the situation so you don't kill your combination by remaining microfocused. Going back and forth, looking at the big picture and then trying to optimize the smaller components within the requirements of the engine will in the end give a better overall outcome.

                Comment


                • #9
                  Re: My friend Curtis Boggs from RFD talks about heads

                  Thanks for your post, and this is the line of thinking that had brought the post that Eric is talking about in the first place. Pipemax takes the cam and heads, and RPM into its thinking. I know I need a different cam and have a couple of sets of heads to pick from. Trying to sort out what to put with what to make a better combination out of all of it. I agree with your post, but I prefer to slightly over head a motor with high Velocity still then be able to use cam valve events to tune the motor not the other way around. Think of a sprint car head (these are what I tend to use) lots of lift and shorter duration, thats why I dont like my current cam way to much duration, mainly on the exhaust and overlap and a 114 lobe center for a N/A Motor but using pipemax it seems to be under headed for the RPM I am turning it because of the cam so I will be de-camming it some and not spinning it so high so the engine should be a better package.
                  2007 SBN/A Drag Week Winner & First only SBN/A Car in the 9's Till 2012
                  First to run in the .90s .80s and .70's in SBN/A
                  2012 SSBN/A Drag Week Winner First in the 9.60's/ 9.67 @ 139 1.42 60'
                  2013 SSBN/A Drag Week, Lets quit sand bagging, and let it rip!

                  Comment


                  • #10
                    Re: My friend Curtis Boggs from RFD talks about heads

                    Originally posted by JeffMcKC
                    Yours are almost done. Andy
                    YEAH!
                    I should have the short block together this weekend.

                    Comment

                    Working...
                    X