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  1. #1

    aftermarket head?

    Hey guys i'm gettin ready to invest in a new aftermarket head. Would like some guys input on the best for rec ridin, but help with a little boost on a rec engine. thanx guys


  2. #2
    96XPSS's Avatar
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    R&D 43cc head.

  3. #3
    SURFnTURF's Avatar
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    Im assuming 947 application here.

    The stock head is as good as a miller head.And the miller head is the best of the aftermarket heads. Have used both in the rec and racing set up and the only difference is the miller head doesn't use an expensive head gasket to seal it uses O/rings.Which reduces cost's every time you want to remove the head.

    Me I would have the stock head machined down to reduce the c/cs and the squish angle recut because the stock head flows so much water across the domes .Its cooling abilities are not exceeded by any other head.

    Aftermarket heads usually have more quantity of water around the domes but dont flow as well across the head to remove heat.This alone helps with detonation which these engines can suffer with. It would be cheaper as well.Other guys swear aftermarket but on a rec set up not really required.

  4. #4
    Would anybody happen to know how much is supposed to be milled away on the stock head?
    Are their any threads on this which could guide me in this process?

  5. #5

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    [quote=SURFnTURF;1165852]Im assuming 947 application here.

    The stock head is as good as a miller head.And the miller head is the best of the aftermarket heads. Have used both in the rec and racing set up and the only difference is the miller head doesn't use an expensive head gasket to seal it uses O/rings.Which reduces cost's every time you want to remove the head. quote]

    Miller did not use head gaskets on their older heads but the newer heads for the 951/1050 motors do use a head gasket.

    Dan (drb)

  6. #6
    96XPSS's Avatar
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    [quote=drb;1167924]
    Quote Originally Posted by SURFnTURF View Post
    Im assuming 947 application here.

    The stock head is as good as a miller head.And the miller head is the best of the aftermarket heads. Have used both in the rec and racing set up and the only difference is the miller head doesn't use an expensive head gasket to seal it uses O/rings.Which reduces cost's every time you want to remove the head. quote]

    Miller did not use head gaskets on their older heads but the newer heads for the 951/1050 motors do use a head gasket.

    Dan (drb)
    What was Mel's reason for going back to the gasket Dan?

  7. #7
    SURFnTURF's Avatar
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    Quote Originally Posted by drb;1167924
    [B
    Miller did not use head gaskets on their older heads but the newer heads for the 951/1050 motors do use a head gasket.[/b]

    Dan (drb)
    If miller uses head gaskets on his heads now then I see no real gain in using them. Why would you,if your application is a 1050 or larger bore set up then the stock head can be re machined to suit these anyway. Maybe its just aesthetics ??? Or to change compression but you still have to use a head gasket

    The only draw back from the stock head is sometimes depending on coolant pressure they can get a hot spot on the domes where air can be trapped up where it says bombardier on the head. This is easily overcome though as group k have done .

  8. #8

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    [quote=96XPSS;1167943]
    Quote Originally Posted by drb View Post

    What was Mel's reason for going back to the gasket Dan?

    I don't know for sure, but I would guess that he felt that a gasket would seal better than the o-ring's especially if the top of the cylinder and sleeves were not completely flat.

    Dan (drb)

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