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Thread: Engine Weight and Performance

  1. #1
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    Engine Weight and Performance

    Hi all,
    I have a 20' Cigarette that I'm considering repowering. I have seen that there is a wide variety of power plants in many of the 22 classics on this site and could use the breadth of experience that this forum provides.
    I was wondering, as the speed moves into the 80s and 90s, how important engine weight is from a ride perspective? More specifically, do the 200-250lb weight reduction offered by an Ilmor motor or steroid small block or 400lb reduction offered by an LS motor (vs BBC) really improve how the boat handles at speed? I run with an ITS/XR/Shorty combo so the boat already has extra weight right at the back. Any thoughts would be appreciated.
    Many thanks,
    Yoryi

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    I think the Cig 20 is a significantly different hull w/a lot of additional reserve buoyancy in the stern so that BBC's work well w/that hull.
    I don't think that you can really compare the Cig 20 to a Donzi 22C.
    I do know that 22C's do work well w/less weight in the stern.
    George Carter
    Central Florida
    gcarter763@aol.com
    http://kineticocentralfl.com/


    “If you have to argue your science by using fraud, your science is not valid"
    Professor Ian Plimer, Adilaide and Melbourne Universities

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    If it is to light aft it will run to flat having too much wetted surface that will steal speed, yes you can compensate some with trim. You can also dial it in with ballast, you need to keep wetted surface to a minimum without over trimming.
    No matter what your beliefs are "GOD BLESS AMERICA"

    Semi retired marine tech over 50 years in the biz.

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    I have a few different early Cig 20's in our shop that we are redoing.

    The hulls are kind of like a heavy cross between an 18c & 22c, but they are definitely their own hull and set up. The hulls are laid up quite heavily too.. They too have gone thur a few different generations of cig 20, but overall they still all have the same essence..

    Bigger power is cool in them. Weight reduction is usually always a good thing. The were some small blocks that made it into some of them, but they do usually respond better bigger power & torque.. Enter the BBC... The 2 in my shop are going to be running bib blocks. 1 is getting a 540 put in that we just dyno'ed @ 650+hp / 660+tq.... The other cig 20 will be getting a big block as well, we just have not nailed down what flavor BBC is going in (502/509/540/572) and exactly what power level other than it will be at least 5-600hp..

    We did look at possibly putting in a high HP SBC, but to put a big hp & tq sbc is still more costly than the BBC at this point to do right.. However there was one done recently that worked out pretty well, but it didnt yeild any huge speed #'s.. It was in the 70's somewhere if I remember correctly. Most of the Cig 20 guys want to see 80's or 90 if possible on a good day.. There have also been a couple that have crossed the 100 mark too.. That though IMO is a bit much in a 20' boat..

    Jamie / Lakeside Restorations.

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    I haven't seen a lot of Cig 20's, but when viewed next to a Donzi, they are really different!!!!!!
    If you look at a 22C or a Minx, the widest part of the bottom is at about station 7 or 8, then it narrows a bit.
    On a Cig 20, the widest part of the bottom is at station 10, right at the transom. This is to allow the 20 to have the buoyancy to support the weight of a BBC w/o the stern squat of an 18C w/a BBC.
    To me, it seemed as though Cig took a 24' mold and put a 4' plug in the stern.
    Who knows?
    Maybe they did!
    George Carter
    Central Florida
    gcarter763@aol.com
    http://kineticocentralfl.com/


    “If you have to argue your science by using fraud, your science is not valid"
    Professor Ian Plimer, Adilaide and Melbourne Universities

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    Yes, indeed they are not the same as a classic.. They just share in the same Aronow family design heritage..

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    there have been a few modifications on the 20 cig over the years. the early ones were setup for small block power and had larger cockpit areas. Then they moved the rear seat forward and made the bilge area bigger for big block power. The next modification was adding a pad to the later ones.


    There is a video( floating somewhere on the web) of a pad bottom 20 cig running at 100 mph it is rock solid and running on rails. whatever that setup is I would say would be " perfect".

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    That 101mph 20 is scary... these boats originally went about 50mph before the advent of the big block! Also, I believe it's a round bottom boat with a properly setup Blackhawk and a Zul 750 (see attached photo).
    I also understand that the second boat shown runs near that speed with a supercharged small block and a Blackhawk. It's also a round bottom boat.
    Great info from all... especially gcarter and the hull shape... I'm learning.
    Love the Ilmor idea, but for the money you can't beat a BBC. I'm still thinking.
    Thanks to all,
    Yoryi

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    Ilmor 7/10
    Please keep in mind I don't know anything......
    any information I have is made up.....
    and generally I am part of the problem
    VICE President-Weller's Bay DONZI Association

    OFFICIAL LAKE GEORGE POKER RUN CHAMPION

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    The Cigs with Big Blocks still run very flat. They don't have the same attitude whatsoever of a 22 Classic which runs bow high. It seems as speed increases on a 22 you see more of the hull come out of the water measured front to back. On a 20 Cig it seems to rise up out of the water so to measure the wetted area you would view from the front or back and measure how wide of an area it is touching.

    With all that said, I imagine a lightening the load in the stern could make for a bow heavy experience that could really be unfavorable.

    I have heard the Phil Lipshutz (sp?) is a great guy, willing to chat on the phone... he owns Lipship down in miami... done quite a few 20's that were all high ticket items. He might know what's what with the balance of these things more than anyone else.

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    Quote Originally Posted by ykoutsaris View Post
    That 101mph 20 is scary... these boats originally went about 50mph before the advent of the big block! Also, I believe it's a round bottom boat with a properly setup Blackhawk and a Zul 750 (see attached photo).
    I also understand that the second boat shown runs near that speed with a supercharged small block and a Blackhawk. It's also a round bottom boat.
    Great info from all... especially gcarter and the hull shape... I'm learning.
    Love the Ilmor idea, but for the money you can't beat a BBC. I'm still thinking.
    Thanks to all,
    Yoryi
    Yoryi Here are some photos of the SB 20 Cig with a 22 BH donzi at AOTH X you can see the two hulls running about 60 mph
    last photo is cig's that run well red /white with a big block & Lil Max with a Small block. They both run on rails & handle the same at all speeds.
    It is all in the set up Small Block or Big Block
    Rick
    Little Max

    Run Hard Or Stay At The Dock

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    Nice shots Rick!

    Got any more?

    One qualifier on comparing the BH LE Donzi to the Cig 20 BH. The BH-specific hull runs very high in the nose due to the rocker on the aft end.

    The typical 22 Classic with a surfacing drive like the IMCO shortie or even the Blackhawk drive mounted up in place of a typical Bravo run very flat, not nose high, just like the 20 Cigs. It takes a lot of power to lift these boats out of the water, just like the Cigs. I will say that the 22 tends to run up front, when the water gets snotty, from my experience, so that little bit of extra length does count for something!

    I second talking to Phil. There are several generations of this boat and weight seems to differ dramatically between them, which I am sure makes a big difference on set-up. Peanut's last generation Imco 20 Cig runs pretty good with a 496HO, so that is the boat I would want to talk about.

    And my choice for power? 540 EFI NA.

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    Quote Originally Posted by Sweet little 16 View Post
    There is a video( floating somewhere on the web) of a pad bottom 20 cig running at 100 mph it is rock solid and running on rails. whatever that setup is I would say would be " perfect".
    [media]http://www.youtube.com/watch?v=UEbO6tra5to[/media]
    “Oh right, because you walked into strippers discount warehouse and said ‘Help me showcase my intellect.’” - Archer

    Bill
    Grand Rapids, Michigan
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    Quote Originally Posted by ykoutsaris View Post
    That 101mph 20 is scary... these boats originally went about 50mph before the advent of the big block! Also, I believe it's a round bottom boat with a properly setup Blackhawk and a Zul 750 (see attached photo).
    I also understand that the second boat shown runs near that speed with a supercharged small block and a Blackhawk. It's also a round bottom boat.
    Great info from all... especially gcarter and the hull shape... I'm learning.
    Love the Ilmor idea, but for the money you can't beat a BBC. I'm still thinking.
    Thanks to all,
    Yoryi
    I think it was actually like 105, but who's counting at that point. The same shop on LI did both cigs. Another difference between the cig 20 and 22 donzi is these blackhawk 20's run 1.36 gearing I'm pretty sure which the 22 is not supposed to like (I've never tried it) Between the hp, running over 5000rpm and the 1.36 gears I would think those drives would be ticking bombs.
    1978 Magnum Starfire "MAYHEM"
    1994 Donzi 22 Classic 540/Blackhawk - Sold
    1982 Midnight Express 32 SS

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    20 Cig
    [media]http://www.youtube.com/watch?v=164dvuA84fA[/media]

    20 Minx
    [media]http://www.youtube.com/watch?v=lG9h68qPFP8[/media]



    Obviously my Minx has know where the power of the Cig.
    but serves a better comparison than a 22C. Note that because this is a Window's media file, it fattens up the true scale of the Minx.
    machinist ,bore it deeper,ream it bigger, and lap it to a fine finish



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