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Thread: Gearhead Question

  1. #1
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    Gearhead Question

    Hi All As I wait for my 69 barrel back I have been thinking about the engine thats in it, a 302 ford and talking with a good friend of mine who owns a Mustang, Cobra performance shop here in California. He has offered to help me build a new engine mostly out of what he has off the shelve and could use some advice. First off I'm not looking for more than 300HP or to over tax the existing Volvo 250. He has a newly machined 302 block, conrods, pistons, roller set up and crank. What sort of cam should I be looking for? Carb? Distributer? Manifold? He has some Iron heads that we would like to use. What else am I missing? I have never built an engine and appreciate any help in this matter. My buddy builds some of the nicest performance engines out there but is new to marine engines. We know about brass freeze plugs being mandatory and the fact that we need torq early but don't know what is the best approach. Cheers Brian

  2. #2
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    GT40 heads if available as a start
    Scars are tatoo's of the fearless

  3. #3
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    not sure what type of ignition you are going with but it should be Marine grade I used a Mallory Marine electronic breakerless dist. and a marine grade starter usually they have different spark arrestor than auto stuff fuel pumps and carbs too again due to fire hazzards in a closed bilge.


    I seem to recall a marine head has additional water passage thru it? or something like that one of the guys may have more info


    don't worry about the 250 she'll take what ya give her up to about 400 hp or so.


    and I think you need torque thru out the entire rpm range there's no coasting on the water
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  4. #4
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    I WORKED WITH THE ENGINEER that was in charge of designing the gt40 heads. they were for marine use initially guessing for OMC as they were about the last to use SBFs. Porting them would be the best for a SBF in a boat or most automotive apps. only issue i know of about moding for coolant holes is if the block is a Siamesed block such as some of the newer ford motor sport boss blocks.
    As stated anything electrical should be marine / coast guard approved same with hoses.
    Are

    INTAKE would depend on heads as well as cam
    cam also depends on if its hyd flat tappet of a hyd roller
    Scars are tatoo's of the fearless

  5. #5
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    Turbo

    yeah I think OMC with their cobra motors , PCM also used the ford motors by 1996 OMC was done but PCM was still using the Ford in skiboats

    they made a 5.8 ho pro boss and a GT 40 motor i think at one point they were getting close to 330 hp out of the 351 I guess that would be a good benchmark if you found the specs for that motor they also made a 5.0 too the only big difference I see on those motors is the PCM center risers have a steep long down angle for the exhaust exits under water that may let them use a hotter cam without worry about reversion.
    When the sky is grey,look out to sea.
    When the waves are high and the light is dying,
    well raise a glass and think of me...
    When I'm home again,
    boys, I'll be buying!

    My Ride

    Come Join Us on The Queen Of American Lakes



    Contact Us

    www.lgdonziclassic.com

  6. #6
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    GUY HERE IN TOWN that had one of the better marine repair shops had a SFI 302 OMC tried to purchase it a couple times. Last i knew it is sitting in a corner in the field were his shop was it has the GT40 heads mustang looks like a cobra mustang engine was a stock omc pulled from a boat. guessing has a different cam.
    Scars are tatoo's of the fearless

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