Carb Comparo Thrash

Discussion in ''Da Nailhead' started by Bigpig455, Aug 31, 2012.

  1. hjsonnie

    hjsonnie '51 Henry J '72 Skylark

    I wish I did not have my Henry j all wrapped up to paint it. I would give you my 800 cfm Holley spreadbore to try. It works great out of the whole on my 425, but still needs tweeking or maybe just another good Q-jet( right Ken?).:Brow: Man, I hope I can get over to the valley on Friday somehow.:pray:
    Don
     
  2. Bigpig455

    Bigpig455 Fastest of the slow....

    I'd love to see the J - get your gun out and spray! We can buff it out between runs!

    If your interested in another Q-Jet, I'll probably sell the 800 after this.. I'm still going to run the 750 either way. it's set up for a
    nailhead/ST trans but has no choke components (I do have all the parts for a 67 divorced set up) . It might need some dialing in on the primary side (for my motor anyway), it has 73 jets and 44 rods but the secondary circuit hits strong. I think it's probably just float level trial and error

    I could drop it off with Ken when I return the Holley if your interested - I've maybe got 200.00 into it, and it really shouldnt need anything except Ken's blessing

    PM me for the full specs if your interested.
    .
     

    Attached Files:

  3. 66gsconv

    66gsconv nailhead apprentice

    Hey Rhett,This is getting better every day. Sounds like fun, wish I could help. To bad I am not closer,I have a EELCO 2x4 with carbs and linkage ready to bolt on sitting on the shelf. I thought I seen GSGTX was going to take the 340 "out for a spin" on friday. Keep your eyes open:laugh::beer
     
    Last edited: Sep 3, 2012
  4. gsgtx

    gsgtx Silver Level contributor

    were all buick brothers here, going run down some chevys, there held together by bolts, 4 bolt this and 12 bolt that. lol
     
    Last edited: Sep 3, 2012
  5. telriv

    telriv Founders Club Member

    As far as I'm concerned a 950/1050 three barrel will be too much for the combo your running. I've had the same combo on my Riv. for 35+ years. An old 750 dp which I converted to electric choke. On a good day & flat run with 3.08's I've gotten as much as 20.3MPG. Average is 15-16.5. Has MY square bore mod. Is dialed in for my 425. Has the adapter plate on it, port matched all around. The fuel hose is for the stock 3/8ths. fuel filter. An easy unbolt for me & bolt onto your engine would take at most 30 minutes. Let me know if interested & will pull the "Assembly" off & you could pick it up at my shop. You must supply new steel gaskets for me to replace. I will port match them myself. I'm at home now. Give me a shout.

    Tom T.
     
  6. Bigpig455

    Bigpig455 Fastest of the slow....

    Tom - Thats a great offer! I'll call you at the shop today.
     
  7. 6WildCat5

    6WildCat5 Great Dale House Car

    Sounds like you've got your hands full of choices here.. and with 5 hours give or take of track time... Your gunna be busy.. :TU: If you don't already have a stock spread bore intake to test against your modded intake. I could pull mine with a late '67 qjet to test against... Same deal as Tom, new steel gaskets...

    Photo1063.jpg Photo1068.jpg Photo1067.jpg
     
  8. Bigpig455

    Bigpig455 Fastest of the slow....

    Just spoke with Tom, I'm gonna try to pick up his set up Wednesday AM ( and talked about rockers too - maybe 10/1)

    I bought stock in Felpro and got 4 sets of gaskets -hopefully they're in by Thursday. Tom also suggested using Loctite gasket eliminator for additional sealing.

    6Wildcat5, great offer and I may take you up on it someday, but I think my dance card is full for this round. I'n addition to all the carb/intake swaps, I'm also trying to sort out the distributor timing curve (all in at 2500 vs. 3000), manual switch pitch control vs. Roe controller and my ongoing quest for weight transfer and traction ( i have another thread in "whoa and sway" about all the suspension mods I've done)


    I will say this - I put the 800 Q-Jet on the car as I took some weight transfer pictures and did some burnouts - it still needs calibration at idle but it makes OMG power at full throttle and has great throttle response.. I might just keep that carb after all!
     
  9. 6WildCat5

    6WildCat5 Great Dale House Car

    No worries, Easier for me to leave it in place... :beers2: Looking forward to reviewing your test results... Have fun.. :3gears:
     
  10. doc

    doc Well-Known Member

    I dont think that a 3 barrel would be too much at all.... the biggest ones were 1050 cfm and had a vac operated secondary.... the front barrels were about 450 cfm.... and that is what you are running on untill the engine demands that the back barrel comes in... by then the rpms are high enough to take it.....
    lower diff gears do make them come in quicker and stronger..... i was running a 950 on a 401 with a 091 cam, headers, and a single intake, completely stock, not even portmatched,, and it ran very strong......
     
  11. CameoInvicta

    CameoInvicta Well-Known Member

    Looking forward to the comparison! I've been running a Holley 850 DP for the last few years on a "doc dual plane". Always been really happy with it. It's been a little challenging to tune since the cam swap, but otherwise has always run really strong.
     
  12. 66gsconv

    66gsconv nailhead apprentice

    Rhett. have you thought about a video or two. That would be:cool:
     
  13. doc

    doc Well-Known Member

    What you need on the back is a good set of 10 inch slicks.....:Brow:
     
  14. Bigpig455

    Bigpig455 Fastest of the slow....

    I can video the runs, or at least a few. i dont know how exciting that'll be, as this is just a test and tune day and I'm willing to bet most of the cars I line up against will be faster than me.

    Although the last track rental day I was at, I teamed up with a guy in a 2010 Subaru Legacy Turbo Wagon that he had laptopped into the engine management for more boost - we we're both running 14.9 - 15.0 all day and the starter at the track said that we were the only ones really racing that whole day. I'd 60 ft him, and he'd generally catch me 3/4 track unless he bogged it or missed a shift. I felt kinda bad when he blew his clutch and I drove home. Those cars arent made to launch like that!

    Doc - You're right of course on the slicks, but the masochist within me wants to do it all on street tires....and so far so good. It launched pretty good before, and I could get into the throttle 10-20 feet out and be ok, and I'm getting pretty good at working the converter - I think I got the front end to come up enough to transfer even more weight now, and that should help. No better feeling than 60fting a guy with drag radials and 3.73's in an essentially box stock car on skinny little tires.
     
  15. Bigpig455

    Bigpig455 Fastest of the slow....

    Tom -

    still planning on coming down tomorrow, but I have to meet you as early as possible so I can get back up here to work at a reasonable time. I tried the shop and got your machine. Can you call my cell tonight to coordinate?
     
  16. techg8

    techg8 The BS GS

    eagerly awaiting results...inquiring minds want to know
     
  17. doc

    doc Well-Known Member

    Dang,,,,, I wish I was there,,, I am positive that me, Rhett, and Tom could stir up some major proverbial stuff......:rolleyes::laugh::laugh:
     
  18. Bigpig455

    Bigpig455 Fastest of the slow....

    The good news is: I drove it home (anytime you can drive home from the track means you had a good day...!!!)

    Bad news is I couldnt make any complete runs - I had my same old problem where it falls on it's face at 4500 rpm or so..

    I'll start another post on that, I had always attributed it to float level but now I think it's electrical

    The other good news....the car 60fted like mad, I even 60fted a big block 68 Vette on drag radials. My average 60 ft to now was 2.22 - 2.20, this time I snapped off a string of 2.17s. I had pulled a 2.17 before on a fluke run last year, but that was in much better air and was never able to back it up (2000 ft DA yesterday). Take a look at the chart below of folks who ran consistant 2.17's at the 2011 Pure Stock race..thats legit supercar territory (but doesn't mean I'll be running 13's any time soon) [TABLE="width: 421"]
    <TBODY>[TR]
    [TD="class: xl22, width: 84, bgcolor: white"]1966
    [/TD]
    [TD="class: xl22, width: 89, bgcolor: white"]Chevrolet
    [/TD]
    [TD="class: xl22, width: 112, bgcolor: white"]Chevy II
    [/TD]
    [TD="class: xl22, width: 84, bgcolor: white"]327/350
    [/TD]
    [TD="class: xl23, width: 64, bgcolor: white, align: right"]2.179
    [/TD]
    [TD="class: xl23, width: 64, bgcolor: white, align: right"]14.051
    [/TD]
    [TD="class: xl24, width: 64, bgcolor: white, align: right"]100.84
    [/TD]
    [/TR]
    [TR]
    [TD="class: xl25, bgcolor: transparent"]1968
    [/TD]
    [TD="class: xl25, bgcolor: transparent"]Pontiac
    [/TD]
    [TD="class: xl25, bgcolor: transparent"]GTO
    [/TD]
    [TD="class: xl25, bgcolor: transparent"]400/350
    [/TD]
    [TD="class: xl23, bgcolor: white, align: right"]2.177
    [/TD]
    [TD="class: xl26, bgcolor: transparent, align: right"]14.140
    [/TD]
    [TD="class: xl27, bgcolor: transparent, align: right"]99.12
    [/TD]
    [/TR]
    [TR]
    [TD="class: xl22, bgcolor: white"]1973
    [/TD]
    [TD="class: xl22, bgcolor: white"]Plymouth
    [/TD]
    [TD="class: xl22, bgcolor: white"]Duster 340
    [/TD]
    [TD="class: xl22, bgcolor: white"]340/240
    [/TD]
    [TD="class: xl28, bgcolor: white, align: right"]2.177
    [/TD]
    [TD="class: xl29, bgcolor: transparent, align: right"]14.275
    [/TD]
    [TD="class: xl30, bgcolor: transparent, align: right"]98.81
    [/TD]
    [/TR]
    [TR]
    [TD="class: xl22, bgcolor: white"]1967
    [/TD]
    [TD="class: xl22, bgcolor: white"]Chevrolet
    [/TD]
    [TD="class: xl22, bgcolor: white"]Chevelle SS 396
    [/TD]
    [TD="class: xl22, bgcolor: white"]396/375
    [/TD]
    [TD="class: xl29, bgcolor: transparent, align: right"]2.176
    [/TD]
    [TD="class: xl29, bgcolor: transparent, align: right"]13.250
    [/TD]
    [TD="class: xl30, bgcolor: transparent, align: right"]107.68
    [/TD]
    [/TR]
    [TR]
    [TD="class: xl22, bgcolor: white"]1963
    [/TD]
    [TD="class: xl22, bgcolor: white"]Studebaker
    [/TD]
    [TD="class: xl22, bgcolor: white"]Avanti R2
    [/TD]
    [TD="class: xl22, bgcolor: white"]289/289
    [/TD]
    [TD="class: xl23, bgcolor: white, align: right"]2.176
    [/TD]
    [TD="class: xl23, bgcolor: white, align: right"]14.018
    [/TD]
    [TD="class: xl24, bgcolor: white, align: right"]101.10
    [/TD]
    [/TR]
    [TR]
    [TD="class: xl22, bgcolor: white"]1968
    [/TD]
    [TD="class: xl22, bgcolor: white"]Chevrolet
    [/TD]
    [TD="class: xl22, bgcolor: white"]Camaro Z-28
    [/TD]
    [TD="class: xl22, bgcolor: white"]302/290
    [/TD]
    [TD="class: xl26, bgcolor: transparent, align: right"]2.175
    [/TD]
    [TD="class: xl26, bgcolor: transparent, align: right"]13.520
    [/TD]
    [TD="class: xl27, bgcolor: transparent, align: right"]106.57
    [/TD]
    [/TR]
    [TR]
    [TD="class: xl22, bgcolor: white"]1969
    [/TD]
    [TD="class: xl22, bgcolor: white"]Mercury
    [/TD]
    [TD="class: xl22, bgcolor: white"]Cougar Eliminator
    [/TD]
    [TD="class: xl22, bgcolor: white"]351/290
    [/TD]
    [TD="class: xl26, bgcolor: transparent, align: right"]2.175
    [/TD]
    [TD="class: xl26, bgcolor: transparent, align: right"]15.234
    [/TD]
    [TD="class: xl27, bgcolor: transparent, align: right"]90.77
    [/TD]
    [/TR]
    [TR]
    [TD="class: xl25, bgcolor: transparent"]1963
    [/TD]
    [TD="class: xl25, bgcolor: transparent"]Studebaker
    [/TD]
    [TD="class: xl25, bgcolor: transparent"]Avanti R2
    [/TD]
    [TD="class: xl25, bgcolor: transparent"]289/289
    [/TD]
    [TD="class: xl29, bgcolor: transparent, align: right"]2.171
    [/TD]
    [TD="class: xl29, bgcolor: transparent, align: right"]14.148
    [/TD]
    [TD="class: xl30, bgcolor: transparent, align: right"]99.78
    [/TD]
    [/TR]
    </TBODY>[/TABLE]

    So the Q-Jet/ 2.5 exhaust combo is working.

    So did the front end work to help weight transfer. It doesnt feel like it in the car, but pictures show the nose really is loose now and comes up well. I dont go through the waterbox or do big burnouts, just a quick dry spin to clean the tires and a couple times it would even spin, it just nosed up and launched...right past the staging line - Kinda embarrasing! If I can get the video up I'lll link it here, it's pretty - the nose comes up quick but controlled in a nice arc, and stays up well with the 90/10s - I'm no Gessler, but it's still good action.


    Back to the carbs - I did swap carbs a bit trying to track down the issue, and judging again by 60 ft times the carbs stack up like you'd think

    AFB (doc mod) - 2.30 - 2.35
    750 Q-Jet (doc mod)- 2.20-2.22
    8000 Q-Jet (doc mod)- 2.17 - 2.18

    The same AFB has run 2.17 in better air, but this is how they stacked up on the same day....and that 800 is such a drivability pig (disclaimer: Ken didnt build it, I did..) , It really surprised me, it makes big power at WOT!

    I only had time to make one manifold swap, and I chose the AFB over Tom's Holley becuse that was the carb I'd be driving home on...Both Tom and I made so much effort to line up that swap so I'm extremely bummed I couldnt make it all work.

    Good news is it's doing it pretty regular and should be easier to track now. I'll start another thread.


    Thanks to everyone who was interested in this....
     

    Attached Files:

Share This Page