hemi vs wedge head motor

Discussion in 'Manton Push Rods Top Alcohol Tech Questions' started by hines, Sep 27, 2010.

  1. hines

    hines Member

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    Can anyone tell me what are the biggest reason why most blown engines are hemi instead of wedge heads? The flow numbers on some wedge heads are just as good.
     
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  2. Ken Sitko

    Ken Sitko Super Comp

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    Because the hemi motors are more durable and are built for big horsepower.
     
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  3. JustinatAce

    JustinatAce Member

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    I think it's also a matter of fuel volumes, available compression and the way the mixture burns in a Hemi. Not to say that it can't be done.. I know Rob Atchison uses the AJ481X wedge setup with a block that uses chevy mains and made really good power with the roots setup. The block is what impressed me, I asked sometime back if they ever smoked the rear main, his guy Dennis at the shop just says "Blackened rear main? What's that?"
     
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  4. SoDak

    SoDak Active Member

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    I think it also has something to do with used part availibility.

    Also that the more people use the hemi in blown situations means for manufacturing reasons they can get cheaper.

    Technology trickles down,,,
    Can you legally even run a wedge head in a fuel car?
     
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  5. Moparious Maximus

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    wedge motors

    There are a few of us wedge guys out there, I think the main reason people always lean toward the hemi is the simple fact that more of them have been built more people are comfortable building and tuning the hemi motor.

    The parts selection is poor with a wedge expecially heads, you have the big Indy's or the B1, pretty much it. Pistons are a special order thing for us, you could build around some shelf pistons maybe.....maybe.

    Im really impressed with our combo, granted its no HH 14-71 motor making 48lbs of boost, but we put down a good number for an old 8-71 at only 28% over.
     
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  6. TWD

    TWD Blown alky

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    Hemi v wedge

    We switched from a wedge to a hemi. I think you can probably get the same power from a wedge, but it's easier (you can buy it) with a hemi setup and in the end costs will probably be the same to be competitive. I think costs for parts and maintenance will depend on the amount of HP rather than the head style.
    I personally like ease of maintenance on the hemi engine and the valve train setup. We ran a jesel setup on the wedge, but still the hemi shaft rockers are much easier to work on and more rigid.

    Just my 2cts
     
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  7. tafccrewguy

    tafccrewguy New Member

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    Ease of changing and checking spark plugs is reason enough on most cars.Plus look at the valve angle,hard to get that on any wedge.
     
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  8. WANNABE

    WANNABE New Member

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    No. You cannot run a wedge on a fuel car. (NHRA and IHRA top fuel/funny car.)
    You can, and lots do on nostalgia front engine and stuff, where the rules are not limited.
     
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  9. overkill69

    overkill69 Member

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    wedge

    the 481X is the most advanced wedge engine. They can make serious power and are easier to maintain in some ways. We run a 14 degree big chief that makes comparable power but it's cast block/heads.
    Most of the hemi programs seem like monkey see monkey do. A wedge can easily run with fuel headed hemis on alcohol.
    A max effort billet hemi with a screwcharger seems to pull away from even a 481X.I've been told that only the hemis can breathe well and live at 10000 rpm plus that the screw blowers like.
    The MBR/Fontana/Arias uses a Chevy crank and bottom end with the hemi top end. They make huge durable power but they are rare so they will never be as cheap as a BAE or Veney setup.
     
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  10. Mike Canter

    Mike Canter Top Dragster

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    Overkill, I am not sure that I agree with some of your observations on wedges and hemis. The monkey see monkey do is totally wrong. Not all those hemis are the same. They may look the same from the outside but inside they are different. If one keeps trying to make more power and you try different things then yes I do agree that sooner or later the motors are all going to be close to similiar and the same applies to wedge motors. Same thing has happened in the design of jet fighters. When you use software to design a supersonic fighter then all the fighters are going to look similiar. Also I am not sure that I believe that it is easy to make the same power with a wedge as with a hemi. You can have ten guys with ten hemi motors and some will be faster than others. The same with a wedge motor you have fast motors and faster motors. Same when comparing a wedge against a hemi but there are too many varibles to contend with. Some wedge motors have the right combination and a great tuner and are fast but the majority of the winning motors are still hemi motors.

    In blown alcohol and nitro applications the hemispherical combustion chambers are a better match for the flame propagation from around the tip of the spark plug. When under load the flame propagation looks like a doughnut around the plug and it expands evenly in all directions out from there and with a hemi head it hits the spherical top of the head evenly and pushes back down evenly against the piston without multiple flame fronts so detonation is kept to a minimum. That is not so with a wedge. Also the swirl pattern of the gases is better in a hemi both for the gases coming in and the spent gases going out.


    The big shortfall of the current hemi for racing is the geometry of the valve train because of the position of the sparkplug and the valves. In our cars for family use the wedge head is slowly being pushed out by the more efficient hemi head because the overhead camshaft got rid of the bad valve train geometry.
     
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  11. jody stroud

    jody stroud ZOMBIE Top Dragster

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    I switched to a MBR Fontana Hemi from an 18deg big chief chevy and couldn't be more pleased. Price was same as or cheaper than a Brad, AJ or 481X. LOVE my Bob Miner Hemi. Plus it's faster than my chevy was.
     
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  12. Kalamahoon

    Kalamahoon Member

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    Walt Austin

    It would be tough to discount the fact that Walt ran the A.J. for years. 5.56 or 5.58 was his personal best with the wedge engine at 92% over. There are many, many hemi engines out there that wish that they could say the same.

    Regards
    Kyle Harris
     
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  13. Mike Canter

    Mike Canter Top Dragster

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    Gosh let me see........Manzo maybe. There will always be guys that can make and engine perform but how many Walt Austins do you see running at a race. Same as how many Ace Manzo's are out there. These are not a fair examples to use for comparison for the regular racer.
     
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  14. blown375

    blown375 New Member

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    You are %100 correct Mike and a prime example of this was Rick Santos with his wedge headed smallblock Chevy's , he was so fast against the Hemis that they ruled him out of the class. Then he came back with a Hemi and continued to cut throats !
     
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  15. overkill69

    overkill69 Member

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    Mike C I'll stand by my monkey see statement. There are at least 3 serious wedge programs in ADRL PX. Lower dollar teams without any Manzo talent that run hard. As far as new head designs and such the wedge stuff development is stagnant yet they are still competitive.
    I see a combination that was killed by a lack of popularity. On the used market,you can't give a wedge combo away.
    Our Big Chief Olds makes 2500 plus hp and wouldn't bring 20k on the open market hat to pan. Add 10k if it said "hemi" in the add because all the monkeys need hemis to run fast.

    Mike
     
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  16. Mike Canter

    Mike Canter Top Dragster

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    Well that is a major problem. Why should a racer put out a lot of money for a motor that is going to be hard to make competative. We all go to the race with the intention or dream of winning or we wouldn't be doing it.
     
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  17. ansleev

    ansleev Member

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    10-4 to that one







     
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  18. badbird

    badbird New Member

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    so Manzo,Taylor,Hernandez Stott Burgess/Billes and more than a few dozen more are monkeys? I think they use a hemi cause they know from experience what makes more power, sure 481x is a very good piece no argument, but its not a hemi, the parts are not so available or cheap, there is not so much info available,
    big chief is old cast stuff, you expect the same money as billet hemi stuff?
    sorry im firmly with mike on this one apples and oranges
     
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  19. shawn davis

    shawn davis Member

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    Myself I like the 481x because it's so easy to work on, everything fits when you buy it,and has no valvetrain-rocker-pushrod problems. It may be a little down on power compared to some Hemi's, but works pretty good for a one man operation
    You couldnt give me another Big Chief deal, those are like fabricating an engine from scratch.
     
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    Last edited: Sep 30, 2010
  20. Mike Canter

    Mike Canter Top Dragster

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    Let me add this. Comparing cars and motors that run only in ADRL is a hard thing to do because of the no rules. There are expensive traction control devices, expensive modified superchargers, different fuels and a host of other secret or trick things. Don't get me wrong because I think that is all great. The best comparison of one motor against another would be in NHRA or the European FIA where there are strict rules and everybody has to run the same overdrive on the blowers, the fuel is all the same and no traction devices allowed. Now we are getting to more of a motor to motor comparison.
     
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