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HOW Many HP's can you realistically get out of a Flattie

Discussion in 'The Hokey Ass Message Board' started by MattStrube, May 3, 2004.

  1. A Chopped Coupe
    Joined: Mar 2, 2004
    Posts: 1,133

    A Chopped Coupe

    I think the flathead experts have said it all, you can easily make 150/170HP by picking the right parts, but making it "reliable for long trips" is another question.
    Kind of like Joe Abbin's 34 Ford drag car with blown flathead............he runs in the low 13's and high 12's with a light car and fairly expensive motor. I believe the first motor he now has in a street car and has logged over 4k miles................which seems reliable to me especially after it came out of the drag car that had XXX many runs on it.
    To make over 250hp will require some bucks, special heads, blower setup, girdle, etc., etc.
    Here are some pictures of the motor I started..............and planned to make 300HP at the crank.......................and I spent around $ I am building a new motor for my Ole 1970 B/SM Maverick..........last year it did 9.901 @133 in the quarter.....and the car with me weighs 3325lbs...................for about the same price as the flathead motor I plan on getting into the mid 9's...................The flathead motor is truly a labor of love, and the old saying that has held true for the 30+ years I have been in drag racing is still true, "How fast you want to go is directly related to the amount of $$$ you spend". Oh, one more thing, you need to pay extreme attention to detail, like the crank which is 4.125 Merc stroker that has been nitrid'd, shot peened, and index'd, not to mention the SCAT I beam rods that were resized right out of the brand new box..............and the Ross pistons that were lighten and have lightweight tool steel pins.............I still have the short block and when the Maverick is finished I will put this motor in a little short wheel base drag frame and will turn in the 12's with carb's....................I hope.

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  2. Jimmy2car
    Joined: Nov 26, 2003
    Posts: 1,707

    from No. Cal

    I've debated a lot on whether to post this or not, but decided to go ahead.
    One day Bruce is going to give up the REAL secrets of Ford Flathead power. But today, I'm going to tell you all a story that should make some of you real believers in the flatheads ability to produce horse power. Just keep this in prospective. It is a flathead. It has it's limitations.
    In 1990, Ken Kloth upped the existing XFPRO speed by 13 MPH. Ken was protested. The biggest problem with the protest was keeping the prying eyes of his competitors away. Everything was legal. In 1991 he set the current record of 140.5 mph. The car has gone faster. Much faster.
    The car, a 50 Merc, weighed 4350# with Ken in it. A fully legal roll cage, etc.
    Now, the engine in this car still looks like a flathead. No extra exhaust pipes out of the top of the engine. Just a little flathead: It was the same engine that came in the car when Ken bought it.
    267 CI
    BIG roller cam
    1.6 Intake valves, stock exhaust
    stock Merc crank, stock rods
    Ross pistons
    No crank girdle, just a center main support
    Custom Offenhauser heads
    Single Holley 600 carb
    Electronic ignition (HEI and also coil to plug)
    Tube exhaust tried and 180 headers tried.
    The engine is LOUD. Loud like an engine of much greater displacement. When Ken would start it people would literally run to see the thing.
    Remember this is 1991, 20 years ago.
    Now, we'll go back to 1955, with the debut of the Chrysler 300. Remember that? Well, Chrysler brought that to see how fast it would go. It went pretty good. How good? 127mph. How much HP did it have? It was supposed to have 300. It must have had at least that because no factory was going to bring a car with less than it had advertised. They brought a team with the car.
    Reason I bring this up is that both the Merc and Chrysler have about the same frontal area, and weigh about the same, although weight isn't really an issue on the salt. It wasn't until 1956 that Chrysler was able to hit 140 mph with the higher powered 300B model.
    So to go 140 mph is no mean feat. It takes power to do it, and lots of it.
    Next people say "Well, it's almost impossible to determine HP from speed, because there are so many factors". Wind, temp, track conditions, etc. AND, that's pretty much true. Sooo, the HP necessary for a particular speed is difficult to determine. BUT, known to only a very very few, the Kloth flathead was raced: Drag-Raced once. Three passes, using a borrowed 9" center section with less than optimum gears. 3.5 as I recall.
    No ET records kept., Best speed was 93 mph. Would have been better had the gearing been correct, because the engine was over revving in 3rd and under in 4th. Several hundred rpm away from the normal 6000/6200 shift points.
    Car was also driven to the local cruise nights. Don't know if it qualifies as streetable, because the idle speed was about 1600 rpm. But
    I think you will find by doing the math (HP calcs), in excess of 275 Hp from 267 CI. Little engine showed 109% VE.
    Point is, it can be done. Remember- no blower, no nitrous, no fuel. 87-89 octane gas
    No secrets here. Everything I've posted has been published somewhere, sometime.
    Engine was sold some years ago and hasn't surfaced since, although there have been rumors about it. I think Bruce has it, cuz it's in his state. He's hiding it, ha ha

    Forgot to add: No big ports like we've all seen in articles and posts, and Compression of Less than 6:1 static
    Last edited: Nov 12, 2011
  3. nefareous
    Joined: Nov 21, 2008
    Posts: 361

    from maryland

    i`m surprised no ones mentioned this mill

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  4. Henry Floored
    Joined: Sep 18, 2004
    Posts: 1,370

    Henry Floored

    Thanks Jimmy. The Kenny Kloth story is a fascinating one. I remember a couple things from an article I read in a book about him and that little Merc Flathead. The first corresponds with the 6:1 compression ratio that you mentioned. The article stated that Kloth found that the balance between intake flow and compression in a Flathead worked best when flow was maximized. I am assuming that the camshaft was designed in such a way as to improve the dynamic compression of the engine to help the somewhat low mechanical compression ratio needed in this engine to make way for a free flowing intake charge.
    The second thing I remember was a unique experimental head design that had an intake port above the intake valve to turn and carry the charge to the center of the cylinder like in a typical OHV engine. The article explained that this method did not work. If I could place a bet I would put my money on Kloth found a different way to do that.
  5. Jimmy2car
    Joined: Nov 26, 2003
    Posts: 1,707

    from No. Cal

    You'd win that bet.
    Most folks think that there is some magic item that made the engine powerful. Like many things it's all in the combination. I remember Kenny loaning his special heads to another competitor. Guess what? No improvement

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