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Lake Headers For Neophytes

Discussion in 'The Hokey Ass Message Board' started by D-Russ, Mar 14, 2011.

  1. There are a number of companies manufacturing lake headers out there and I'm certain they're all top notch. But they all cost more that I wanted to spend because I'm not sure whether I'm going to run them or a set of stock ram's horn manifolds in the end. This post is specifically for a small block Chevy, but the process would be basically the same for any make of engine.

    Anyway, HAMBer old bone asked me to do a tech thread to document the headers I built, so here goes.

    First of all, I started with the Speedway four inch cone kit. For $164, it comes with everything you see here:


    I bought a pair of 4 inch turn outs from Jeg's for $40, like these but in raw steel, not polished stainless:


    I picked up four round junction box covers at the hardware store for about $10. I brought the cones from the header kit with me to pick the best two sizes to slide into the cones – two 4 inch diameter and two smaller – a bit over 2 inches.


    And finally, I ordered two louvered tubes from Cone Engineering at $26 for the pair:


    Building the headers is pretty straight forward. With the engine installed in the car, I bolted the flange onto the head and started fitting the front bend. When I was satisfied with the angles, I cut the first bend to length. From the side, I ran the cone parallel with the angle of the head and the inside edge of the cone runs parallel with the cowl when viewed from the top. Then I welded the front bend to the cone. I didn't weld the front bend to the flange at this point to maintain adjustability up and down from the side when fitting the other primary tubes.


    Next I started fitting the back tube. I wanted the primary tubes to curve smoothly into the cones so I aligned, measured, looked at it from every angle and then committed to the cuts. With a cut off wheel on an angle grinder, I cut the bend first so that it fit snugly onto the cone. I fine tuned the shape of the the tube with a flapper wheel and various files.



    Then I traced around the bend onto the cone to mark where the hole would go. Then with a cut off wheel, flapper wheel and various files, I cut and shaped the hole in the cone, then tacked the tube to the cone.



    I followed the same process for the two middle tubes, but because they're close together, the cuts for the tube second from the front would be a little different. Starting with the tube third from the front, to maintain the sweeping curve into the cone, I repeated the procedure I used for the rear tube. Once that tube was fitted, I taped it in place so I could fit the last tube for that side. Because it runs close to the third tube, the shape of the end and the opening in the cone would be different.


    Next, I taped the two center tubes together and then welded them together on the inside where they touch as they enter the cone. If this isn't welded before you weld the tubes onto the cone, you won't be able to access it later for final welding. Sorry, no pic.

    Then, I welded the attached center tubes onto the cone.



    After all the primary tubes were welded to the cones, I removed the primary/cone assembly and unbolted the flange from the head. Then, with the primary tubes positioned squarely into the flanges, I welded the tubes to the flange from the inside. I ground the flange welds and then filed them flat. I followed basically the same procedure for the other side.

    For the baffles, I started by grinding off the galvanized coating on the junction box covers and then welding up all the holes and perforations. Then I marked the centers and cut a hole in each of the four for the perforated/louvered baffle tubes. I drilled a series of holes around the larger center holes to allow the exhaust to flow in and out. I then welded the tubes to the junction box covers – a big one and little one on each. Next, I cut down the length of the turn outs and recut the outlet closer to the turn. Then I butt welded the turnouts to the big end of the baffle. The baffles are held in place with a bolt and lock nut at the bottom. Sorry, no fab pictures, just the finished product.


    The last thing I did was finish the welds to prep them for coating. This was done as much as I could with a small angle grinder, but mostly with various files and a lot of hand sanding. Hope this helps someone.





    Last edited: Sep 25, 2017
  2. chaddilac
    Joined: Mar 21, 2006
    Posts: 13,795


    Nice!!! Looks good Dave... I'll probably be adding muffles to mine too once I drive it!!
  3. Frank
    Joined: Jul 30, 2004
    Posts: 2,321


    I just got done with the same kit on a SBF. I have them tacked together and getting ready to finish out but was undecided on the muffler design. I really like this idea.
  4. Ole don
    Joined: Dec 16, 2005
    Posts: 2,915

    Ole don

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  5. Von Rigg Fink
    Joined: Jun 11, 2007
    Posts: 13,429

    Von Rigg Fink
    from Garage

    Thanks for the tech. I like the baffles, and will probably need to make a set for my Lakes.
    I wonder if you kept cutting back the length of the waffle tube until the tone would improve or be more of a note you would care for? or if you went to a larger diameter waffle tube..and or didnt cover it with anything...
  6. Von Rigg Fink
    Joined: Jun 11, 2007
    Posts: 13,429

    Von Rigg Fink
    from Garage

    I had made a custom baffle for my Harley with 2-1/6" Dia. pipes that went about 4" past the rear wheel.. I played with the length of baffle pipe, and wrapped it with ceramic fiber tape..I kept playing with the length of baffle and amout of ceramic fiber woven tape until i reached a sweet note..took a little while, but well worth it, note..: i used stainless wire to tie the Ceramic Fiber weave to the baffle pipe
    Last edited: Mar 15, 2011
  7. Very nice. Nice job of blending welds into the cone. What are you using to permanently hold the baffle/ turnout in place on the cone?

    i made a similar set with 4" cones for breaking in my hemi on the engine stand. it was too loud to think without any muffling! I will have to follow your lead when I rebuild my next one, in order to quiet it down.
  8. Sorry for the down time.
    All linked images in this thread originally hosted by PhotoSuckIt have been relinked to the HAMB servers.
    kidcampbell71 likes this.
  9. Bugguts
    Joined: Aug 13, 2011
    Posts: 541


    I'm glad you brought that back up, vey ingenious with the junction boxes!
  10. Atwater Mike
    Joined: May 31, 2002
    Posts: 9,216

    Atwater Mike

    Junction boxes! Brilliant! (otherwise, one would be tied up plasma cutting flat iron...)

    Just go to the Big Box Store. Look around in Electric, Plumbing, and.....
  11. Ebbsspeed
    Joined: Nov 11, 2005
    Posts: 4,544


    Nice work, looks good. One question, are the "scoops" in the baffle directional, or doesn't it matter which way they are in relation to the exhaust flow?

  12. Really good and informative.Thank you.
    D-Russ likes this.
  13. Atwater Mike
    Joined: May 31, 2002
    Posts: 9,216

    Atwater Mike

    It does make a difference, somewhere in the decibel range of 'loud' and 'louder'.
    Actually, if they were turned around backwards, they quiet more; but the tumultuous effect in the pipe robs a little horsepower.
    D-Russ likes this.
  14. Yes, the scoops are directional. If the scoops face the engine, more of the noise will be forced through the packing, be it steel wool or fiberglass and the exhaust should be quieter (until the packing burns out). If the scoops face the outlet of the header, the exhaust noise will be louder.
  15. rhtfo
    Joined: Jun 12, 2016
    Posts: 36


    D-Russ, what did you think of the quality of the Speedway kit ? Friend of mine bought that kit and had trouble with the header flanges. He went and bought another set of flanges from a shop in Chicago and those looked to be half again as thick as the Speedway flanges. All the other pieces in the kit were fine.

    Sent from my SM-N910V using The H.A.M.B. mobile app
  16. The flanges were 3/8 thick I think, but I don't remember. I never had any trouble with them leaking with single header gaskets.

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