The great nailhead intake comparison

Discussion in ''Da Nailhead' started by 66gsconv, Mar 12, 2013.

  1. 66gsconv

    66gsconv nailhead apprentice

    Well I dont know if its great, but it is a nailhead intake comparison.:grin: I learned that when you flow a intake manifold by itself it wont mean anything till you flow the head with intake on it.Also the lower runner sounds turbulant and dont flow as much as the upper plenum runners. But that dont matter once you put the intake on the head. I have been working on a factory sqaurebore and am getting really good numbers per runner and wanted to see where it stands with the stock eelco 2x4 and a stock 1x4 bolted to a head. Had a test head with some intake work done on 2 of the runners. The 1st and 2nd runners on the left side of the head, a end and middle runner. They flowed defferantly from the amount of work done on them.
    1- head without manifold
    2- head with stock factory middle upper runner
    3- head with stock factory middle lower runner
    4- head with bobs dual plane upper middle runner
    5- head with bobs dual plane lower middle runner
    6- head with stock eelco 2x4 upper middle runner
    7- head with stock eelco 2x4 lower middle runner
    8- head with doc dual plane q- jet upper middle runner
    9- head with doc dual plane q- jet lower middle runner

    lift - 1----------2---------3--------4---------5---------6---------7------8-----9
    100 - 73.5 -- 74 -- - 73.4 --- 74.4 - - - 74.4 - - - 71.2 - - - 74 --- 73.6 --- 71.7
    200 - 133.4 -- 127 - - 130 - - 132 - - 133.2 - - 129.6 - -- 134 --- 129 --- 130
    300 - 180.2 -- 160 - - 164.5 - - 168.3 -- 170 - - 165.2 - - 167.8 -- 164 -- 165
    400 - 210 -- 181.7 ---- 188 - - 194.3 - - 195.5 -- 191.3 - - 190.6 -- 188 -- 190
    500 - 232.6 -- 195.5 - - 203 - - 211.3 -- 213.2 -- 208.2 -- 204.4 -- 203 -- 208
    600 - 244.4 -- 203 - - 212.3 - - 223 - - 224.8 - - 220 - - -- 212 --- 213 --- 219

    The next set is the end runner of the head, lower and upper runners of the manifold. I just swaped the intake around on the head. It was not worked on as much and the heads numbers were not the as high. Just as above for upper and lower just these are corner runners.

    lift- 1------ 2-------3-------4------5------6-------7------8------9
    100- 73.5-- 69 -- 71.3 --72.5 --73.6 --73.3 --73.5 -- 73 -- 71.7
    200- 132.5- 126-- 125 ---129 --- 129 -- 130 -- 127 -- 129 -- 126
    300- 176 -- 162-- 155 -- 167 -- 168 -- 167 --- 159 --- 166 -- 158
    400- 210 -- 187 -- 174 -- 193 -- 186 -- 193 -- 180 -- 190 -- 178
    500- 215 -- 200 -- 185 -- 205 -- 200 -- 207 -- 191 -- 202 -- 190
    600- 226 -- 206 -- 191 -- 212 -- 207 -- 213 -- 195 -- 207 -- 195

    Hope this all makes sense

    Hope that is understandable. I have more to come. I am also going to add a doc dual plane Q- jet intake. more to come soon

    I see after posting this it did what I hoped wouldnt do. Its all jumbled up . I will try and fix this
    Last edited: Apr 7, 2014
  2. 300sbb_overkill

    300sbb_overkill WWG1WGA. MAGA

    Excellent!!! Can't wait to see the rest of your results,and thanks for your hard work to get these numbers!!! :beer

  3. Bigpig455

    Bigpig455 Fastest of the slow....

    Cant wait to see the Q-Jet Numbers (Cause I'm pretty much convinced thats the best combination ever.....)

    Nice work!
  4. gsgtx

    gsgtx Silver Level contributor

    Bob great testing, amazing flow numbers on you head porting.:TU:
  5. 66gsconv

    66gsconv nailhead apprentice

    Lots of work, wish I could get it more readable. It looks like even a small amount of air will help in the case of the nailhead.
  6. gsgtx

    gsgtx Silver Level contributor

    looks like your right the q-jet does flow well.
  7. 401Riviera

    401Riviera Well-Known Member

    I got the regular 4 barrel intake that i'm doin the Doc mod on and port matching it to the head. Looking to port the hell out of the heads and get some good numbers. Thanks for the numbers :TU:
  8. funkyriv

    funkyriv Well-Known Member

    what is "bob's dual plane," the 1 x 4 squarebore with doc's dual plane hog-out and runner work? How much more work did you do on this intake vs. Qjet 1x4 with doc dual plane mod?

    nice results with your porting work! thx for sharing the data
  9. Bigpig455

    Bigpig455 Fastest of the slow....

    My prediction was totally based on carefully researched scientific conjecture....or based on I have one and like it. And it looks cool.
  10. 66gsconv

    66gsconv nailhead apprentice

    My name is Bob, its is a sqaure bore with a really good clean up. No it doesnt have a doc dual plane job on this intake. I am running a Doc dual plane on my car right now, I do like the way it runs.
    Big Pig, I always thought the q-jet manifold was a little better, I know they are the same so it must be somthing with the huge plenum:Do No:
    I flowed these intakes by them selfs and was getting really good numbers. so then you put them on a head and even the really good runners are only as good as the worst runners. Now when I get time to figure this out:Dou:
    I was really surprised at how the eelco didnt flow much more on the head. I dont know what it would take to get all the air from the head you are useing.
  11. Bigpig455

    Bigpig455 Fastest of the slow....

    Bob, so your "cleaned up" still has the bore dividers intact? And it flows that well from radiusing the turns, etc? But you didnt do that same work, only the Doc plenum work on the Q-Jet manifold, right?

    I dont know anything about flow or all that, but I seriously do like the Q-Jet manifold. I did the plenum and took the sharp edges and turns out, and that car moves with it. It'll be very interesting to see what ET I lose when i go back to the AFB and box stock square bore intake this season.
  12. 66gsconv

    66gsconv nailhead apprentice

    Rhett, my" cleaned up " intake has the 4 holes. I am radiusing the hell out of it and smoothing everywhere I can reach. I wasjust flowing the intake. I have been advised to flow a head with the intake on and carb and filter. Just thought the intake was a good referance to see what was going on. I am gonna try and figure out what is happening here. It would be nice to get a intake to let the head use all or close to all the air the head is capable of flowing. I have a few ideas, takes time I have honey do's already starting.:Dou All this time I thought the bottle neck was the head but turns out the intake needs lots of help even a eelco 2x4

    Rhett, no the q-jet doesnt have as much work done, but does have the doc dual plane which really opens up the plenum on the q-jet
    Last edited: Mar 14, 2013
  13. snake

    snake Well-Known Member

    This may help,

    image.jpg image.jpg image.jpg image.jpg
  14. 66gsconv

    66gsconv nailhead apprentice

    Snake, my thoughts are that is going to give you really good top end. How far up in the runners were you able to clean it up?
    Looks good:gp:
    This should make big pig :grin:
  15. snake

    snake Well-Known Member

    only far enough to where my mandrel bit or other bits can reach thats about it on the runners.
  16. gsgtx

    gsgtx Silver Level contributor

    Bob, your 100% right the intake is the bottle neck, your head will only be as good as your intake flows with head and intake together. i have an ideal i will pm you with, to see if am barking up the wrong tree.
  17. 66gsconv

    66gsconv nailhead apprentice

    This testing and the old thread "flow numbers" That Mike Attwood and I were posting on had a little info also. I recently read somewhere that a head was flowing 330 cfm at .600. Then with the manifold on it it droped to 285 at .600. I googled some intake manifold flow stuff and was reading a test on a sbc with the newer rpm air gap manifold and 950 carb. The set only flowed 88% of the bare head flow. Then put a 1050 cfm style carb on the head and intake and it flowed 91% of the heads potential. Lots of things to consider. Then again, This is a nailhead we are talking about. I would love to get 225 cfm through the intrack tract and to the c.c.:3gears::laugh::laugh::laugh:
  18. gsgtx

    gsgtx Silver Level contributor

    to bad nobody will make a single 4 intake for the nailhead, then there would not be all that porting.:(
  19. Bigpig455

    Bigpig455 Fastest of the slow....

    Thanks guys - when I did my DDP on my spread bore manifold, I did not open the primary area up as much as Snake did. I was figuring I would try to preserve some velocity or intake charge guidance or something...I wonder if it makes a difference?

    Right or wrong, it still runs great with this set up.......

    Attached Files:

  20. 66gsconv

    66gsconv nailhead apprentice

    I know I posted one of these pictures somewhere but since we have a intake thread now, here is a couple of pics while I was working on it. I dont know how to make these pictures smaller, I drag them from photo buckett
    sqaure bore hoged out and the plenum still isnt as big as the q-jet. Its on my car right now with a 1/2 inch open spacer. I gotta say it runs pretty good. I hope to have a even better set up later in the year. I will have this intake off in a few weeks and plan to flow it and add it to the rest of the info.

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