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Thread: In search of 1970 Donzi 16 exhaust parts

  1. #1
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    In search of 1970 Donzi 16 exhaust parts

    I have a 1970 Donzi ski sporter 16 that came with a set of Holman Moody Manifolds to put on it. The previous owner said they were supposed to be the originals. They bolt right up to my Holman Moody 302 that is in the boat but the risers are definitely wrong for my application. They angle straight down and there is no chance of me being able to make any kind of bends to bring them around and connect them to the current exhaust ports in the hull there is just no space.

    Really all I need is if I unbolt the riser section and just run the pipe straight out it will perfectly meet up with the current exhaust ports in my hull.

    The boat will never sit in the water so I'm not concerned with not having a riser section but I'm not sure where I can find the part I need if anyone can guide me.

  2. #2
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    You are looking for the snails. They made two versions one was an end dump which came straight out the back and the they made a down dump which were angled down the angled down work in a true inboard or with wide low thru hulls I would imagine the thru hulls on your 70 are narrow and high

  3. #3
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    I think Holman Moody used glenwood marine exhaust with their logo on them

    Look thru their catalog should have what you need

    Make sure the old exhausts are in good shape don't want to ruin the motor
    It may also pay to look at new center risers

    http://www.glenwoodmarine.net/Catalo...T%20SYSTEM.pdf
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  4. #4
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    You need a riser of some sort the riser protects the engine from internal cooling water not the outside lake water the flapper protects you from that
    The riser mixes exhaust gas and Cooling water as far from the motor as possible to prevent reversion
    resonance reversion is what will destroy your engine
    When the sky is grey,look out to sea.
    When the waves are high and the light is dying,
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  5. #5
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    That glen wood link is great I will call them today and hopefully they will have what I need.

    The H&M exhaust I am putting on the boat is NOS so it's new and in great shape. I think that glen wood straight water cooled outlet will work for my application.

    Thank you again as always guys this site has been amazing help versus any other Google Search so far you guys are 2-0.

  6. #6
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    Quote Originally Posted by 70donzi16 View Post


    Thank you again as always guys this site has been amazing help versus any other Google Search so far you guys are 2-0.
    Matty knows all............
    1967 Ski Sporter (sold)
    2004 40th Anniversary Edition 18

  7. #7
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    I found these HM manifolds last year.... They are around but, you have to look and be patient. FWIW, they were not expensive either.
    Attached Images Attached Images
    Sean Conroy,
    1964 Formula Jr. (hull #2) project

    1972 Greavette Sunflash III
    1981 Kavalk Mistral project

    "A man can accomplish anything... as long as he doesn't care who gets the credit."

  8. #8
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    The other "almost" straight version look like this (pic below) and are for inboard engines.
    Attached Images Attached Images
    Sean Conroy,
    1964 Formula Jr. (hull #2) project

    1972 Greavette Sunflash III
    1981 Kavalk Mistral project

    "A man can accomplish anything... as long as he doesn't care who gets the credit."

  9. #9
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    While the p/o of your boat said that HM manifolds were original on Donzi 16's , perhaps they were not original on "your" Donzi 16. They are very cool and imho worth the effort to fit.

    However, you wouldn't be the first person to need to re-locate the through-hull exit tips. If you can't fit what you have and need to drill new holes there are covers/plugs that are made to cover the old holes if you don't want to glass/paint/repair the area. Maybe not the optimal solution but, an optional solution nevertheless.

    http://www.cpperformance.com/p-345-t...er-plates.aspx
    Sean Conroy,
    1964 Formula Jr. (hull #2) project

    1972 Greavette Sunflash III
    1981 Kavalk Mistral project

    "A man can accomplish anything... as long as he doesn't care who gets the credit."

  10. #10
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    My 16 had the snails like you are looking for they basically come straight back with a slight down angle after the hump in the riser I had about 3 inches of exhaust hose between the end of the riser and the thru hull fitting the end of the riser and the thru hull fitting almost touch like an inch apart
    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

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  11. #11
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    finally found a pic of what you need
    Attached Images Attached Images
    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

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