Results 1 to 7 of 7

Thread: Wes Farmer's Trumpet

  1. #1
    Join Date
    Jul 2007
    Location
    Charleston, SC
    Posts
    336

    Default Wes Farmer's Trumpet

    Who wouldn't like to have a more fuel efficient boat that doesn't plow before it planes? I have often wondered how it could be done and wondered if I had discovered a kind of lost solution when I read Farmer's description of his Trumpet design. (And I am familiar with Tom Lathrop's interpretation of Farmer's lines and this concept in his "Bluejacket" boats/design.

    One of the questions I offer up for thought and discussion here pertains to outboard size and weight. His plans call for a 40 hp engine. Now my first thought about that was that those old engines must have weighed much more than our much improved modern ones. Wrong. His notes say 130 lb engine. A 40 hp Yamaha today is 214!!! OK you might think that difference is 2 stroke vs 4 stroke so I checked that out and a 40 Etec is 240 lb !!!! (head exploding emoji). So am I right in thinking that ol Wes would not approve of the additional 80-110 lbs on the transom since he wrote on the plans " don't fiberglass- it'll be too heavy"?

    I bought the plans on Duckworks (and I'm generally a fan) but I feel like I got burned a lil since they look like they just xeroxed them from Farmer's book that I already have - for $70 I was hoping for a little more quality and information.

    So in the absence of a 1960 Johnson 40 what could a guy do?

    Thanks for your time and consideration.

  2. #2
    Join Date
    Apr 2017
    Location
    Kailua, HI
    Posts
    341

    Default Re: Wes Farmer's Trumpet

    The two stroke OMC 40's were around 130lb iirc, and they made quite a few. Up to early '90's, I'd say.

  3. #3
    Join Date
    Jul 2010
    Location
    northeast Ohio
    Posts
    2,657

    Default Re: Wes Farmer's Trumpet

    Provided you're not stuck on a Trumpet, I suggest you look a Atkin's Ninigret.
    I have just completed one and can tell you it runs along great on a 25hp Suzuki 4 stroke.

  4. #4
    Join Date
    Nov 2014
    Location
    Seattle, WA
    Posts
    5,313

    Default Re: Wes Farmer's Trumpet

    You might want to reach out to forum member Graham Taylor (http://forum.woodenboat.com/member.p...-Graham-Taylor) who was building a Trumpet in NZ. I believe he was planning on using a 50hp four stroke Honda despite the increased weight. I don't know if they have launched the boat yet but if so he may have useful feedback.

    I also note that there is a significant weight jump between current 30hp motors and 40hp motors. Which leads me to assume that current 40hp motors are detuned from 50hp or 60hp units and carry a weight penalty. In the 1950s/1960s the weight of a 30hp/35hp was essentially the same as the 40hp. So likely the old 1960s Johnson 40hp was a 30hp/35hp motor bored out for the increased power rather than a detuned larger motor, hence the lighter weight. So a current 30hp motor might be a better fit than the larger and heavier 40hp motor.
    - Chris

    Any single boat project will always expand to encompass the set of all possible boat projects.

    Life is short. Go boating now!

  5. #5
    Join Date
    Jul 2007
    Location
    Charleston, SC
    Posts
    336

    Default Re: Wes Farmer's Trumpet

    Timo - thanks and I have been fully tuned to your build. Nice job!

    Cat - agree with you. I sent a message to Taylor last week. His pics disappeared from his thread...

    I built a Cackler in 99. Still going strong but I repowered from a 2 stroke suzuki 25 (died unfortunately) to a 4 stroke Too-hot-sue 30. Big disappointment in both power and top speed.

  6. #6
    Join Date
    Mar 2021
    Location
    Oriental, NC ,usa
    Posts
    182

    Default Re: Wes Farmer's Trumpet

    A few notes about outboard weight. Four strokes are generally heavier than two strokes of the same power rating. cstevens is a bit off the mark about how the different power ratings came about for engines of the same or nearly the same displacement in a manufacturers line though. Most always the lower power engine is marketed first and the the others come along later. In my experience, most or nearly all the performance increase is at the upper RPM range and all will have nearly equal thrust at the low end. Some differences in this bald statement allow for changes in timing to add more power at either end of the RPM ranges. The engine of my most experience is the Yamaha 50, 60 and 70 HP. Looking at he specs we see that the powerblock displacement is the same or nearly so for all three so any increase in power has to come from changes in breathing, exhaust, timing, etc which are external to the engine block. There is usually some penalty for having the extra speed available though in higher fuel use.

    I started with a high thrust 50 for the first Bluejacket, mostly because local experts said the boat would not even plane with a regular 50 HP. Wrong, wrong, as typical top speed is 23 to 24mph and planing begins at about 10mph with a light load and is going well by 12mph which where I cruised much of the time. They had this logical opinion probably because they were only experienced with heavier boats with smaller bottom footprints than optimum for a lower speed range between the planing hump and a full plane. Since Bluejackets don't even have anything like a noticeable planing hump you just go at any speed above 10mph and you're clear. A normal gear ratio (with a smaller and lower drag lower unit) works just a good as the higher thrust engine in a boat like any of mine.

    In any case, I suspect Trumpet would run well with a 25 four stroke. Maybe have the battery and fuel tank located further forward than normal though. While Ninigret looks to be fine boat, there is a lot to be said for looking even a bit outside the usual lines. Lapstrake boats take a bit more effort in building but pay it back in pleasing lines you can be proud of in a boat as nice as Trumpet. In any planing boat, pay close attention to any irregularity in the aft bottom lines or a good boat can become something less than good boat.
    Last edited by Sandlapper; 10-28-2021 at 02:28 PM.

  7. #7
    Join Date
    Jul 2007
    Location
    Charleston, SC
    Posts
    336

    Default Re: Wes Farmer's Trumpet

    Sandlapper or Mr Lathrop, if that's you - thanks for detailed response! I love the story of your boats and design!
    I guess I'm scared of being underpowered with a four stroke that's too small but too heavy at same time - someone once told me when switching from a 2 stroke to a 4 stroke you need to add 10 hp. So I was thinking of putting a 50 on Trumpet. The other thoughts are in the scary column... adding pods to transom or increasing beam (I know big cringe there as I typed that last one) A bracket might look awful with lapstrake... The other option might be to extend the transom and put engine in a well like Timo's Ninigret.

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •