Register now to get rid of these ads!

Pennies in Heat Riser

Discussion in 'The Hokey Ass Message Board' started by qmdv, Oct 27, 2012.

  1. I bought this engine from an old hot rodder in 1978 for my dads 36 ford sedan. He sold the sedan and now I am finally using it in a 32 High Boy.

    59 block, Offy heads, two 97's, winfield cam, 4" crank and 3/16 over pistons. Tore it down a while back and am now reasembling it. Noticed the real speed secret, 1952 S pennies in the heat risers.
    [​IMG]

    Does anybody still do this.

    Tim
     
  2. sixpac
    Joined: Dec 15, 2002
    Posts: 553

    sixpac
    Member
    from Courtenay

    Looks like a dam good trick and the cost is managable
     
  3. AlbuqF-1
    Joined: Mar 2, 2006
    Posts: 909

    AlbuqF-1
    Member
    from NM

    I did it but with welch plugs, and in the intake manifold passage. I had trouble with cool weather running with it that way and drilled the plugs with a 1/4" drill. It's amazing how cold the carb gets even in 70 - 80 deg weather.
     
    Last edited: Oct 28, 2012
  4. bob3757
    Joined: Sep 26, 2008
    Posts: 167

    bob3757
    ALLIANCE MEMBER
    from Tigard, Or

    I did that on my 1946 Ford in about 1958, it sure made the pipes rap and crack! If I remember correctly, it earned me a " loud pipes" ticket. Bob
     

  5. We used to do that in our race car motors around 1960 as the heat riser passages weren't really needed.It does raise havoc with the running on a street engine in cool weather.
    We were running 1/4 mile(or thereabouts)ovals and used to try everything to keep the engine cool during the races.The biggest problems we had was the coolant not staying in the radiator long enough to actually cool.We tried using restrictors in place of thermostats;knocking off every other blade on the water pump impellers and drilling holes in the remaining ones and even running a smaller diameter crankshaft pulley and they STILL overheated!We ran straight alcohol in the radiator rather than anti freeze(this was long before the availability of special coolants).
    Being that virtually no modifications were allowed(save for the ones we thought we could get away with)it could be difficult.
     
  6. tommy
    Joined: Mar 3, 2001
    Posts: 14,757

    tommy
    Member Emeritus

    An older friend talked about slipping shim stock in under the flathead intake to make it more rappy. I got real excited and went to look at my 2 deuce intake and the old race car intake did not have the heat riser passage. I was heart broken.:) it was as rappy as it was going to get.
     
  7. flatheadpete
    Joined: Oct 29, 2003
    Posts: 10,479

    flatheadpete
    Member
    from Burton, MI

    You're supposed to use pennies from the same yr as the engine and have them heads up for luck. I had 2 1951 pennies on my stroker '51 Merc. V8.
     
  8. When I re-did a 59A block for a local guy about 15 years ago he told me it was out of his old High School car and the pennies were from the year he and his brother originaly put the engine together. Heads up 1951.
     
  9. This was a very old build done in Glendale-LA area on so cal. I am sure that it was built in 52. I will leave the pennies in cus I hate to let the Genie out.

    Tim
     
  10. We did this back in the early 50s to make our duals sound so much better..
     
  11. flat 39
    Joined: Dec 31, 2007
    Posts: 267

    flat 39
    Member

    I put pennies in my block when I built it five years ago. It gives the exhaust a rougher sound.
     
  12. 296 V8
    Joined: Sep 17, 2003
    Posts: 4,666

    296 V8
    BANNED
    from Nor~Cal

    Don’t use late model pennies …… they vanish / I think they melt.
     
  13. I had an old Edelbrock 2x2 high rise that had a pair of steel pennies in it.
     
  14. 57Custom300
    Joined: Aug 21, 2009
    Posts: 1,424

    57Custom300
    Member
    from Arizona

    I remember the old guys at work where I first started mentioning this when I was putting a Yblock together for my 56. Didn't have any square coins so I used a piece of sheet metal.
     
  15. Tuff Tin
    Joined: May 23, 2004
    Posts: 921

    Tuff Tin
    Member

    We did it in the early 50's. Made the duals rack a bit and of course gave us another 35 hp.
    lol
    Mike
     
  16. Bert Kollar
    Joined: Jan 10, 2007
    Posts: 1,232

    Bert Kollar
    Member

    Back in the day that was thought to make the Smittys sound better in addition to running better
     
  17. Max Grody
    Joined: Dec 15, 2005
    Posts: 94

    Max Grody
    Member
    from Ky

    Back in the day if a flathead had loud duals it was a given that the heat risers were plugged. And, pennies were the plug of choice.
     
  18. robber
    Joined: Nov 25, 2011
    Posts: 1,998

    robber
    Member


    Amen Brother! It makes good cents!:rolleyes: Resourceful hotrodders... makes a guy proud... making those kind of performance improvements for just pennies (literally)! I love what you found! ;):cool::D
     
  19. carlisle1926
    Joined: May 19, 2010
    Posts: 536

    carlisle1926
    Member

    Educate me on the purpose of blocking off that port and why in the world would blocking of a heat riser to the intake cause the exhaust to get louder? I'm completely unfamiliar with this.
     
  20. 60galaxieJJ
    Joined: Dec 24, 2009
    Posts: 1,525

    60galaxieJJ
    Member

    That's pretty kool!
     
  21. Johnunit
    Joined: Dec 31, 2010
    Posts: 93

    Johnunit
    Member
    from Toronto


    Count me in as someone who doesn't get the science behind the volume increase. I understand the power increase from a cooler intake charge, but louder exhaust?
     
  22. 87Heaven
    Joined: Dec 20, 2009
    Posts: 71

    87Heaven
    Member

    Its a pressure impulse thing. Think of it (the exahust riser port) as a crossover pipe that reduces the exaust pressure impulse of the four middle cylinders all sharing the same exhaust port. This lessons the direct impulses to each muffler.
    When you plug the riser you direct the note two either side thus making the muffler handle more impulses. I dont know if that makes cense but I understand it. I think the performance is increased by getting more of a scavaging effect. (or as much as you can from a flathead)
    I am sure someone else can explain it better.
     
  23. Randy in Oklahoma
    Joined: Sep 18, 2008
    Posts: 301

    Randy in Oklahoma
    Member
    from Oklahoma

    Would be my luck to pound in a pennie and then find out it was worth $10,000.
     
  24. 87Heaven
    Joined: Dec 20, 2009
    Posts: 71

    87Heaven
    Member

    Randy,
    I never thought of that!!! I am going out and check my pennies right now.
    Thanks
     
  25. Diavolo
    Joined: Apr 1, 2009
    Posts: 824

    Diavolo
    Member

    We used to just stick a piece of a beer can cut out with snips under the gasket. Does the same thing. I have some copper stock and a flathead I am assembling this winter. Hmm...
     
  26. tommyd
    Joined: Dec 10, 2010
    Posts: 11,948

    tommyd
    Member
    from South Indy

    Dang!...I love this kind of stuff. Thanks for the automotive history lesson.
     
  27. Johnunit
    Joined: Dec 31, 2010
    Posts: 93

    Johnunit
    Member
    from Toronto

    Makes sense to me. so it's sort of like eliminating the h-pipe in the actual exhaust tubing.
     
  28. Model T1
    Joined: May 11, 2012
    Posts: 3,309

    Model T1
    Member

    Keep this in mind, you must use only 1951 pennys with the heads up. Don't ask why. It's just the way it is. Look at the proof. That's why all pre 1951 flattys ran crappy. Those damned Indian Head pennys aimed down screwed up the flow. ;)
     
  29. Max Grody
    Joined: Dec 15, 2005
    Posts: 94

    Max Grody
    Member
    from Ky

    Precisely! Result is a much sharper exhaust rap and it starts rapping at a lower RPM. It might have given a couple of extra HP, but that's probably wishful thinking. I never noticed any negative effect other than a little stumbling until the engine warmed up.
     
  30. olscrounger
    Joined: Feb 23, 2008
    Posts: 4,770

    olscrounger
    ALLIANCE MEMBER

    I recall my cousins doing this to their flatheads in the early 50's. Said it made the exhaust louder as Max above mentioned
     

Share This Page

Register now to get rid of these ads!

Archive

Copyright © 1995-2021 The Jalopy Journal: Steal our stuff, we'll kick your teeth in. Terms of Service. Privacy Policy.

Atomic Industry
Forum software by XenForo™ ©2010-2014 XenForo Ltd.