23' & 26' Hourston Project Commenced...

Discussion in 'Boats, Motors, Trailers and Towing Rigs Forum' started by Robert Snyder, Sep 4, 2019.

  1. Captain PartyMarty

    Captain PartyMarty Well-Known Member

    Hey Rob,

    After the discussion about the fuel shut offs I did some research in the Code. Here is what it says

    Fuel distribution and return systems shall be provided with anti-siphon protection by at least one of the following:
    Keeping all parts of fuel distribution and return lines above the level of the tank top from the tank to the carburetor inlet or a location where fuel leakage cannot enter the boat when the boat is in its static floating position.
    Installing an anti-siphon device at the tank withdrawal fitting or along the line, with a rated siphon protection head and flow rate greater than required for the installation
    Installing an electrically operated valve at the tank withdrawal fitting or along the line connected to be energized open only when the engine ignition switch is on and the engine is runing A momentary type override is acceptable for starting
    Installing a manual shut-off valve directly at the fuel tank connection arranged to be readily accessible for operation from outside the compartment if the fuel tank top is located below the level of the carburetor inlet and the fuel line is rigid metal or USCG Type Al hose. If the length of fuel line from the tank outlet to the engine inlet is greater than 12 feet, a second manual shut-off valve shall be installed at the fuel inlet connection to the engine.

    So looks like Wolf is correct with a Shut-Off valve. I think I am going to put an Anti Siphon valve on my fuel outlets because I think if you have a fire, or a leak it will stop the flow automatically rater than having to find a valve (If the boats on fire I will be more focused on getting the hell off it...)

    With further reading in the Canadian Code it adds this note. Wolf's Surveyor was correct but it could have also been handled by any of the other 3 options

    Information Note:

    “Readily accessible for operation from outside the compartment” may be achieved by a shut-off valve installed at the tank, close to, and directly below, a quick-acting access port in the deck through which the valve can be operated. The access port shall be clearly and permanently labeled.

    I am going to install: http://www.moellermarine.com/moelle...anti-siphon-valve-38-npt-x-38-barb-033808-10/

    Since you have an aluminium tank you will want the Aluminium version if you decide go in that direction.

    Here is the ABYC Fuel System Code (Gasoline), It a good read!


    Also Here is Canadian Code

    Last edited: Feb 13, 2020 at 5:04 PM
  2. Robert Snyder

    Robert Snyder Crew Member

    Thank you so much for this info, I believe I will be placing shut-off valves at the siphons since I will deck access ...

    Things are going to get a bit slow with the build as I started back to work Monday,I am hoping to be flat out until at least June... money first! :)
    Last edited: Feb 13, 2020 at 7:11 PM
  3. trophywife

    trophywife Crew Member

    pretty easy to put a stop cock inline instead of way down at the filter.
  4. Sir Reel

    Sir Reel Well-Known Member

    Hey Rob, Don't mean to hijack your thread but thought you might be interested in this.
    Had to drill a 3 .5" hole in the bottom of my Commander 30 for a new through hull transducer.
    This was just in front of the engines dead center. No wood and over 1.5" thick. We had already ground it flat on the underside so took off an 1/8" already.
    Is why the Commanders are well respected west coast boats.

    Core (Medium).jpg
  5. wolf

    wolf Well-Known Member

    Funny you say that as when I took all the courses this exact topic came up .I said in no way means if flames are shooting out im telling my people to get off boat and swim away, its just a boat and a piece of equipment its replaceable peoples lives are not. and believe it or not people thought i was crazy for saying it as they would try and fight it..... I know a full tank of gas is a ticking time bomb if there is a fire and personally I dont want to be anywhere near it...
    casper5280 likes this.
  6. Kildonan

    Kildonan Well-Known Member

    Rob, you're either crazy, ruthlessly ambitious or both to tackle two boat builds and a home reno all at the same time. My hat's off to you for tackling all that. Do you have time to sleep? LOL

    Enjoying this thread and your progress.
  7. Robert Snyder

    Robert Snyder Crew Member

    Thx bro appreciate it :) You are correct, I have moments of being either or, or both... "crazy, ruthlessly ambitious" LOL
    Last edited: Feb 15, 2020 at 4:08 PM
    Kildonan likes this.
  8. Robert Snyder

    Robert Snyder Crew Member

    Hey, for those that are interested in buying this boat in a few years, let it be known, just for you fellas, I installed 2 siphon's and one aux port... :p

    2 x coats of coal tar epoxy for extreme protection! :eek:

    Attached Files:

    Oly1 likes this.
  9. Robert Snyder

    Robert Snyder Crew Member

    Hey guys, let's revisit the power options again for the 26'er, I have a couple of questions? I know everyone thinks latest and biggest is best but is this actual or just a wish list based on assuming I have an unlimited expense account? :rolleyes: I really like the twin idea...

    How accurate is this statement? - "The rule of thumb is based on weight alone, and says you should have between 40 and 25 pounds of weight for each horsepower. For example, a 5,000-pound boat could have an engine with between 125 and 200 horsepower."

    Based on the boat being #8000 - a motor sized between 200hp and 320hp, so according to this, I could possible get away with twin 115's? (115 are light and readily available for parts/replacement)

    - min twins to get on plane and sustain a comfortable cruise speed?
    - min single to get on plane and sustain a comfortable cruise speed?
    Last edited: Feb 16, 2020 at 8:57 AM
  10. Aces

    Aces Well-Known Member

    I think twin 115’s are 2 small. I have counter rotating 4 stroke 150’s which were an improvement over twin 135 Optimax 2 strokes. No experience with singles so won’t comment
  11. Robert Snyder

    Robert Snyder Crew Member

    Is there a more accurate formula or has it been the "neanderthal" method of trial and error over the years? :confused:
    Last edited: Feb 16, 2020 at 7:23 PM
  12. Robert Snyder

    Robert Snyder Crew Member

    I really like the commander as well, GREAT boats, thank you for posting your findings...
    Sir Reel likes this.
  13. BCI

    BCI Crew Member

    Try this. Couch's Calculator. I usually use 200 as my constant in the formula. You can do a better job determine the Constant if you already have some performance data for the hull, weight, and WOT speed from previous configuration. If you have that you can calculate your Constant and then with the determined constant you can then leave that the same and input your new weight, horsepower, to calculate your top speed. Top speed should give you a good idea of how she'll get out of the hole and run WOT.


    (For my 2018 Whaler 315 Conquest my C value is 200 when fully fully loaded)
    Robert Snyder likes this.
  14. Robert Snyder

    Robert Snyder Crew Member

    Thank you... is speed in knts or mph?

    Screen Shot 2020-02-16 at 9.41.29 AM.png
  15. BCI

    BCI Crew Member

    @Robert Snyder for me it was MPH, because I inputted my value for for speed in MPH in my calculation to find my Constant value.

    If you have any past data for your hull, with the original power and the original weight and the original WOT speed in MPH, you can calculate the C value.. then knowing the C value (in that case it will be MPH since you generated C value using MPH) you can input your new expected Weight, and Horsepower to calculate the new expected speed in MPH.

    If you calculate your Constant using KNOTS in your original calculation then you would get KNOTS out at the end of the new calculation.

    In the case of my Whaler, it's MPH. I calculated mine with full fuel, full water, four pax, and all my gear on board. With light load and no bottom paint the C value would be higher (I see 46mph WOT loaded and 50 unloaded).
    Robert Snyder likes this.
  16. Robert Snyder

    Robert Snyder Crew Member


    Can you help me out to populate this calculation as I have no past data for this hull?
  17. BCI

    BCI Crew Member

    Is this for your 26 or your 23?

    From WOLF on his 26 Hourston Sedan;

    26 Sedan/Sportfisher, 7100 pounds dry w/ 383 Stroker, WOT 45mph (I'm assuming he has some fuel on board for that test and some passengers so try 100% fuel and no passengers for your weight calculations). Adjust removal of 383 stroke and leg and add your pod and outboards on.


    You really dont need to go big block unless you want to carry a fuel station behind you LOL
    my boat which is the sportfisher weighs in at 7100 lb dry with the 383 and 425 hp with the volvo duo prop it has more than enough snot to pull it out. I get on plane on about 30 ft run at 3200 rpm at 25 kts no problem WOT is about 4400 rpm at 45 mph WAY faster then i ever want to go. best part about the 383 is its basically a 350 chev and parts are VERY easy to get etc.....



    Just for fun I ran it with 7500 pounds, 425hp, 45mph WOT and got a Constant of 189.

    Then I ran it with 380hp (knocked of 10% for driveline loss) and 45mph WOT and got a constant of 200.

    My suggestion is just run a constant of 190 and again at 200 and expect your figures to be somewhere in there.
    Last edited: Feb 16, 2020 at 10:13 AM
    Robert Snyder likes this.
  18. casper5280

    casper5280 Well-Known Member

    Believe the 23' dry wt is 5100 lbs-5300lbs depending on which brochures you look at. The 26' Dry wt 5500lbs and 5900lbs w/flybridge.
  19. Sir Reel

    Sir Reel Well-Known Member

    I would be very interested in the single Suzuki 350 duo prop.
    Cousin has a 23’ Campion Explorer. It’s 3600 pounds dry and maybe 5000+ fully loaded
    he does 54mph wot with his 300 Yamaha. Could have got a 250 HP but the 300 actually runs at lower rpm and better fuel mileage.
    Personally I think twin 115 is way to light.
    Your going to have a command bridge too.
    MadJigga likes this.
  20. MadJigga

    MadJigga Crew Member

    I love that motor. Or twin 200’s
    Sir Reel likes this.

Share This Page