This Hobby is Exhausting

Discussion in ''Da Nailhead' started by Dragdoc, Mar 13, 2020.

  1. Dragdoc

    Dragdoc Well-Known Member

    My 1960 364 had been wheezing through a 2bbl and single exhaust for 60 years. Now has a 4 bbl, st400, and am converting to true dual exhaust. I will be building the exhaust using a pile of assorted mandrel bends to avoid kinks.

    Question is, do you think 2.0” tube is enough? Some space restrictions as the system will be routed in the trans tunnel and next to the drive shaft like the factory. Original single exhaust pipe was 2.25” at best - I figure 2.0 is probably enough as duals.

    Share your thoughts!
     
    hrbekroenick likes this.
  2. jmos4

    jmos4 Well-Known Member

    Hi,

    If you got room I'd do 2-1/4", I ran that on a 330 Olds and factory size for 65-66 Gran Sport was 2-1/4" also

    My 401 nailhead I am running 2-1/2" in a 65 Skylark

    Regards,
     
    300sbb_overkill likes this.
  3. Lucy Fair

    Lucy Fair Nailheadlova

    Should be plenty, i have 2.25 in 425 Riv and its great, i also run 2.5" magnaflow biggest straight through mufflers in stock location and short glasspacks just before exit. Spumd is deep bit not annoying yet still it can trigger more sensitive autoalarms :p
    Peace,
    Kacper.
     
  4. Houmark

    Houmark Well-Known Member

    2x2" should be enough.. According to charts, 2x2" should support at least 100hp more than 1x2,25".. You have 5,5inch2 instead of 3,5inch2 pipe area, so you're way better of.. Speciel if you make a h pipe..
     
    gsgnnut likes this.
  5. 1972Mach1

    1972Mach1 Just some M.M.O.G. guy.....

    Finding a good performance muffler in 2" might be difficult. I'd go 2 1/4" for muffler selection and future upgrades. I had 2 1/2" on my Riv and it worked great.
     
    Last edited: Mar 14, 2020
  6. Bigpig455

    Bigpig455 Fastest of the slow....

    If you go standard exhaust shop crimped pipe, 2 1/4 is your best bet. It's an expensive jump to 2 1/2 mandrel, probably not necessary for a cruise night/car show car..
     
  7. Dragdoc

    Dragdoc Well-Known Member

    Truly was exhausting! I have a lot of hours in this job, not to mention the new suspension and trans.

    EF0A3C57-C7BB-4FE7-A964-B3B8E97AD42D.jpeg 14570C50-BAED-4CCF-ACB0-338A5D15577A.jpeg 52498C21-FC89-4BE5-963B-151F763E7242.jpeg
     
  8. Briz

    Briz Founders Club Member

    Nice work. It sucks having to lay on your back under the car doing stuff like this. Least ya had concrete to work on. Back in the day all I had was dirt / sand .
     
  9. Bigpig455

    Bigpig455 Fastest of the slow....

    Beautiful!
     
  10. 71stagegs

    71stagegs bpg member #1417

    Wow how much work was that to go to a t400 remove torque tube, rear end ,crossmembers My dad had a 60 must have been all worth it first time u punched it and no more Dynaflow
     
  11. Mr62Wildcat

    Mr62Wildcat Guest

    As an ASE Master tech, prior exhaust shop owner and now a mandrel bending facility (shut down the exhaust shop and auto repair) My 62 Wildcat and all dual exhaust systems in 62' I has seen from the factory has 2-1/4" front pipes and 1-7/8" tails. I ran 2-1/2" tubes with a supercharger and it was good as the blower did all the work. So this time after putting my original motor in, I went with 2-1/4" front tubes and 2" tails. I used 2 front mufflers like an impala and two resonators in the back like a Cadillac, but I put everything exactly where is was originally. Sounds nice and quiet, yet a little rumbly. LOTS of power.

    Most people assume that bigger is better, but unfortunately, that is not correct especially in today's vehicles. There was a reason why the factory went with specific sized tubes and you wouldn't understand that unless you have over 40 year auto repair/exhaust experience as a shop owner. 99% of guys and girls out there have no idea except what they learned from a few cars they owned and I am glad to offer any help out there.

    By removing your 2bbl, it literally would starve the engine of fuel and you actually would use more to get up to speed. As the first person to install a T400 in a pre dynaflow engine (was told it couldn't be done back in the 80's but after I posted pics, then it all went quiet) the fuel mileage went from 8-9 mpg to 18 mpg with a 3:42 set of gears.

    The best mileage I EVER recorded was 25 mpg with a .040 over 401, RV cam, factory dual quad intake with 2-2bbls with no progressive linkage and 3:23 gears and a T400. The guy who bought that car in 2001 told me when he got to Michigan from N. California where I was, never believed it until he drove the car home with a loaded uhaul full of parts. (blocks/heads, etc) He told me that when others were slowing down to go over the Rockies, he put a little more gas down and passed all of the new cars.

    Keep up the good work! Awesome that you got rid of the torque tube!
     
    Lucy Fair and 322bnh like this.

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