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Opinions On This Exhaust Routing - '51 Mercury

Discussion in 'The Hokey Ass Message Board' started by Doctor Detroit, Jan 30, 2012.

  1. Doctor Detroit
    Joined: Aug 12, 2010
    Posts: 1,004

    Doctor Detroit

    I'm fabricating an exhaust for my 1951 Mercury. It has a Flathead with Red's Headers and a Mercomatic transmission. Mufflers are 12" Brockman Mellowtones just forward of the axle. Would anyone with more exhaust knowledge than I care to offer their opinion and/or suggestions for the routing on the drivers side? You'll see it's pretty tight. I've upgraded and relocated the master cylinder, which limits where I can pass through the X portion of the frame. Exhaust routing would continue where yellow lines are. Is this routing too close to the transmission and/or master cylinder, or would I be better off going under the frame?

    Attached Files:

  2. 34toddster
    Joined: Mar 28, 2006
    Posts: 1,469

    from Missouri

    If the car isn't too low I have always gone under the frame at front then thru the x-member in the back before going over the axel. If you use a connection at the header you will have a point to disconnect to pull the trans crossmember out. Nice looking work. Keep it up!
  3. 39 All Ford
    Joined: Sep 15, 2008
    Posts: 1,531

    39 All Ford
    from Benton AR

    IMO, you have plenty of room. I ran my exhaust between my trans and m/c on my 39, it is a lot closer to both of these than yours will be. I don't see where you will have any problem.

    Compared to my car, you have a freaking mile.
  4. V8 Bob
    Joined: Feb 6, 2007
    Posts: 2,523

    V8 Bob

    Keep in mind the flathead exhaust is cooler than most because it passes through water. You can also have the exhaust pipes (or all the pipes)ceramic coated (inside and out) to reduce the radiant temp about another 30%. This will not only reduce temperature but will make them last for a very long time. :)
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  5. Doctor Detroit
    Joined: Aug 12, 2010
    Posts: 1,004

    Doctor Detroit

    I was considering having them headers ceramic coated, or at least putting header wrap in that area....
  6. Doctor Detroit
    Joined: Aug 12, 2010
    Posts: 1,004

    Doctor Detroit

    Anyone else care to offer their suggestion?
  7. Member 'Showrod' has a Merc and is in Downers Grove, maybe we should all meet up sometime and check out the rides. I'm running a newer frame so I'm not of use to you on this topic.
  8. Fordtudor37
    Joined: Jan 5, 2011
    Posts: 273


    From a structural stand point you look good to cut thru the frame "X" there, I would just recommend you keep the new hole opening as small as possible.

    A good rule of thumb for clearances regarding heat transferrence is -
    * Non-Coated pipes - 1.00 inch, Ceramic Coated pipe - 0.50 *.

    Always try to plan for more space, but when things get tight I have found this is a good rule to follow.

    Can you add in a "bolted flange section" so that the piece you need to ceramic coat could be saller then the entire pipe, say just enough to get by your issue area ?
    You could then have that section ceramic coated inside and out which would allow you to get closer or just provide you with a little less worry(=stress=high blood pressure=??).
    Last edited: Feb 3, 2012
  9. 4tford
    Joined: Aug 27, 2005
    Posts: 1,600


    While mine is not a 51 merc I wrapped my 40 ford pipes with exhaust wrap at the pipes from the headers back to the H section no issues the past 7 years. My pipes are stainless steel also. I added some pics I also exited at the front of the rear wheels.

    Attached Files:

  10. 51 Leadsled
    Joined: Nov 23, 2007
    Posts: 953

    51 Leadsled
    from NC

    ImageUploadedByH.A.M.B.1409420840.969700.jpg ImageUploadedByH.A.M.B.1409420869.892366.jpg
    It tucks up nicely where attached to exhaust manifold!

    Posted using the Full Custom H.A.M.B. App!
  11. Mr48chev
    Joined: Dec 28, 2007
    Posts: 25,955


    Who ever put the duals on the 51 Merc I used to own cut windows in the X member to run the exhaust pipe through when they did it in the 50's. I remember thinking that the holes were cut pretty crudely the first time I had it on the hoist and got a good look at the bottom side.
  12. Slopok
    Joined: Jan 30, 2012
    Posts: 2,335


    I would not advise going under frame at all! My lake pipes are functional and they scrape all the time and they are under the frame at a high spot in the front where the frame kicks up. I am not on bags. Just noticed this is an old post. You probably have the exhaust done by now.
    Last edited: Aug 30, 2014
    DougO68 likes this.
  13. slddnmatt
    Joined: Mar 30, 2006
    Posts: 3,670


    Well for one I think your exhaust you have there is gonna melt .......;)Your clearance should be fine. Those damn master kits are right where the exhaust should route through the frame. You can run on the outside of frame but it can get real tricky by the rear leafs routing around them unless you have the rear linked. I did that on the last Merc and just had it dump out by the tire to avoid the issue.. On another I shoved the master to the side and made a swing set for the brake linkage to jive...
  14. DougO68
    Joined: Dec 13, 2008
    Posts: 185


    I ran my 50 Merc exhaust under the frame because I am running the same MC kit you have. If I had it to do again I would take the route you have now. I do not like seeing my exhaust pipes peaking out in every side view picture of my car. Another tip is you should run a skid plate over the master cylinder as it tends to hit the ground easy.
    My Two Cents...

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