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Flathead aluminum heads choices

Discussion in 'The Hokey Ass Message Board' started by Saxon, Sep 25, 2008.

  1. Saxon
    Joined: Aug 9, 2008
    Posts: 2,157

    Saxon
    Member
    from MN

    I have a 59a that I want to put aluminum heads on. What compression ratio is to much (is there such a thing) Running a stock stroke and bore, 3 3/16 x 3 3/4. Single carb for now, putting fenton exhaust headers on.

    8:1 looks like it will work well with a stock motor but what about 9:1. Will there be any clearance problems. Edelbrock has a set up for stock engine
    (boring???) off's has a 9:1 and cyclone has serious promise but unclear of any potential problems. Going to call them tomorrow.

    Little flathead head 101 is in order for me.
     
  2. Flat Ernie
    Joined: Jun 5, 2002
    Posts: 8,406

    Flat Ernie
    Tech Editor

    Much beyond about 8.5:1 you start restricting breathing. Seat of the pants-wise, you'll never tell the difference between 8:1 and 9:1...
     
  3. Saxon
    Joined: Aug 9, 2008
    Posts: 2,157

    Saxon
    Member
    from MN

    yeah I know that without roddin' out the cam's, pistons, crank.... I won't be making a speed demon.:rolleyes:

    Question is will there be any problems with clearance? Cyclones look great at 8.75 to 1. I may rebuild someday with cam's down the road, but I just rebuilt a 21bolt and funds are not in the cards for the 59a at this time.
     
  4. Check with cyclne Kevin on here
     

  5. Lots of good heads out there - kind of depends on what you're partial to and how much you want to spend. If you have the cash, it is almost always better to buy a new set of heads, than screw around with a more than well used set of vintage ones.

    I love the Navarro stuff (from H&H Flatheads) - but they'll probably run $200 or so more than the typical Offy or Edelbrock heads. Others that I wouldn't hesitate to run are Sharp from Wilcap or Cyclone . . .

    You should probably shoot for somewhere between 8:1 to 9:1 . . you should have no problems with a stock engine as far as piston or valve issues.

    If you're going through the trouble of putting on new heads . . . REALLY think about dropping in a new cam at the same time. A cam will make make more of a difference than heads . . . any day of the week. Of course, once you start down the performance path . . . then you'll need two carbs, a better ignition, headers . . . a stroker crank . . . a blower . . . the list goes on. Once you have the "flathead sickness" . . . it only gets worse!
     
    Texas Webb likes this.
  6. CNC-Dude
    Joined: Nov 23, 2007
    Posts: 1,031

    CNC-Dude
    Member

     
  7. busyhornet
    Joined: Aug 7, 2013
    Posts: 38

    busyhornet

    I got a set of used vintage Edelbrock heads at a swap. Is it risky to run them. Looks like a little corrosion on one chamber.
     
  8. tubman
    Joined: May 16, 2007
    Posts: 6,916

    tubman
    ALLIANCE MEMBER

    So far, I see no one has gotten into the subject of piston clearance and "squish" (optimizing the combustion chamber "quench" characteristics). In my opinion, it is THE most important factor to be considered when installing a set of heads (stock or aftermarket) on a flathead Ford. If you are truly interested, let me know and I can put you onto some threads, both here and on "The Ford Barn" that I believe will be very helpful for you. Here is an example : https://www.jalopyjournal.com/forum/threads/v8-engine.1105458/page-4#post-12545746.
     
    Saxon likes this.
  9. tubman
    Joined: May 16, 2007
    Posts: 6,916

    tubman
    ALLIANCE MEMBER

    If the heads appear to be in good shape they will probably be OK ("a little corrosion in one chamber" is about as good as it gets with used heads). They should be checked for flatness and clearances before you bolt them on for good. There is a procedure using little balls of rolled-up aluminum foil stuck to the piston tops with grease and turning over the engine, removing the heads and then checking the thickness of the squished balls that will tell you what clearance you have. Anything less than .040" (measured with used gaskets) means the heads have probably been resurfaced and may be unusable. If they are close, you can probably relief the combustion chambers to obtain the clearance you need. If the clearance is above .060", you have too much clearance and will not have proper quench in the combustion chambers. In this case, the heads should be milled to bring the clearances down to .040" to .060". This will provide the proper squish that will improve both performance and fuel economy. For example. if the average clearance over the pistons is.090", the heads should be milled .040" to bring them down to where they need be. This will also ensure that they are perfectly flat. As I mentioned above, this procedure is a very important step in getting a good running well performing flathead. There is more to this than just a "measure and mill" as I have described here, but there are tons of threads both here and on "The Ford Barn" that go into this in detail. The "Search" function is your friend.
     
  10. F1106077-8125-4CF6-95D2-1C434BF24216.jpeg The more you mill the head, the less chance you have to make a “big cam” work. I don’t buy any cams with less than 350-380 lift. You start milling the head and a “big cam” will hit the spark plug on the exhaust and close the gap or worse shatter the plug into smaller “schmegma” that is now bouncing around within the confines of your cylinder. Joe Abbin of Albuquerque has flowed many heads and made the determination the best flowing heads only make 3-5 h.p. Over Henry’s cast iron head. He makes 335 h.p. On the dyno with a b&m blower and a set of Henry cast iron heads.
     
    hrm2k and UNCLECHET like this.
  11. dirty old man
    Joined: Feb 2, 2008
    Posts: 8,910

    dirty old man
    Member Emeritus

    FlatheadJohn47's comments about stock Henry heads make a lot of sense. Back in the 50s here in GA which at the time was the hot spot for oval racing and flatheads still competitive with the OHV V8s, many of the fastest flatheads still had cast iron heads. But we also had old timers who had been building these engines for decades, both for racing and hauling shine. The milling, filling, flycutting, etc. that couldn't be seen from the topside was as closely guarded a secret as the"Manhattan Project"s development of the atomic bomb:D
    But almost all of them started with the scarce as hen's teeth 81SB "Denver" heads.
     
  12. tubman
    Joined: May 16, 2007
    Posts: 6,916

    tubman
    ALLIANCE MEMBER

    You're right about that. The thing is, that all of those operations are quicker and easier with aluminum rather than iron. Plus the fins just plain look cool, and we don't have to worry about conforming to some racing association's rules or foolin' the feds.
     
  13. Saxon
    Joined: Aug 9, 2008
    Posts: 2,157

    Saxon
    Member
    from MN

    Tubman you know this thread is over 12 yrs old right? I've moved on. Just kidding.
     
    Last edited: Aug 30, 2018
  14. Saxon
    Joined: Aug 9, 2008
    Posts: 2,157

    Saxon
    Member
    from MN

    Racing for flathead and others had rules. Stockish. A nice set of cheater "denver" heads tricked some. Early 24stud Canadian aluminum heads too.
     
  15. tubman
    Joined: May 16, 2007
    Posts: 6,916

    tubman
    ALLIANCE MEMBER

    I wasn't the one that brought it back up to the top; I was just answering a current, relevant question.
     
  16. Saxon
    Joined: Aug 9, 2008
    Posts: 2,157

    Saxon
    Member
    from MN

    hey you can quote yourself! :)
     

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