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Thread: 19' Howard Project

  1. #181

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    Well, if the side saddle fuel tanks are within one foot of the transom, you could do it this way .

    Back of the prop hub @ 24" equals the back of the strut barrel @ 28" from the transom .

    This would then give you 24" of bottom surface behind the strakes and the prop lift, but remember to add in 9 more inches for the plates . (15" long overall, with 6" under the hull, and 9" hanging out the back)

    With a 7.5 shaft angle, starting at 6" (trailing barrel on center) deep, you would end up with about a 7' long prop shaft, depending on how high you mount the V-drive plate .

    As I said on the phone, "with a T-400 you want the motor's #1 and #2 cylinders behind the prop, with this low of a shaft angle" .

    This would place the "timing cover/motor plate" about 18" forward of the transom .

    With a theoretical 7.5 degree shaft angle, plus the remaining 2.5 degrees of gear box angle, you will have no problem with the oil pan contacting any reasonably designed strut mount, blocks, or strut bracing to the stringers .

    This should "skim" across the water with minimal "wetted surface area", while allowing maximum use of the power (pushing instead of lifting), and offering great control at all speeds .

    The single (plate) stainless turn fin should be mounted with it's leading edge under the V-drive plate, and it's rear edge under the prop shaft coupler .
    "there are old racers and there are bold racers, but there are no old bold racers"

  2. Default

    Tanks are within 12" of the transom. You can make out the rear tank bulkhead in the second pic below.





    Plates - Unfortunately I don't think we can do 6" under the hull (?). The recess as it came from Howard is only about 3.5" and if we were to lengthen the recess we'd be into the balsa floors. Isn't it taboo to mount hardware through the balsa?



    Back of prop hub at 24" from transom - Once we had discussed moving the prop forward two inches to 26" but that is far as we could go. Is 26" still a viable option without affecting handling? The extra 2" behind would be nice to have at the transom/gunnel lip for working on/around the engine.

    Attached Images

  3. #183

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    If you built the strut with at least 2" of barrel behind the web, you can always move the prop forward, if needed .

    But moving the motor/trans forward 2" is like moving the prop back 6" . One inch of motor movement = 2 inches of prop, and one inch of motor/T-400 movement = 3 inches of prop .

    You know, 18" at the top of the stringers is more like 20"/22" up where the water pump mounts . Your transom does have some angle to it . There is actually enough room to mount the tiller high and BEHIND the 1 1/8" rudder shaft in that hull .

    As long as your plates extend only 9" behind the hull, the recess will be OK .

    I would drill a second row of mounting bolts, staggered between that single row of holes (an inch or two farther in) . A single row of mounting holes in the plates acts like a "hinge", giving the plates little support, no dampening effect, allowing them to be more easily bent (at the front), and will always develop leaks because the plates are "pivoting" on the single row of bolts . Use full sized aluminum washers too (5/16" bolts).

    After all this, you are going to use that "hex stuff" ?
    "there are old racers and there are bold racers, but there are no old bold racers"

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    Thanks George.

    The strut has two plus inches behind the web so we'll be able to move the prop forward if need be.

    Engine at 18" sounds like the number. Are we supposed to measure 18" from the top of the stringer at the transom, or 18" from the bottom/middle of the V of the hull at the transom?

    Plates/second row of staggered bolts - copy.

    Hex stuff - no, gonna build new cav/transom hardware, just using the old plates for a rough template. We will build new plates out of stainless, I assume they should be 3/16" like the aluminum plates are?

  5. #185

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    You can get away with .120" stainless, I fear 3/16's would "tear" at those close rows of mounting bolt holes . (that stainless is stiff)

    18" is along the top of the stringers to the front motor plate . This should place (looking from the side of the boat profile), the prop directly under the engine block between the #1/#3 or #2/#4 cylinders ( one and two would be over/behind the prop center).

    Make the final plates first, drill and fit them to the boat . THEN, measure where the plate pad hold ACTUALLY ARE, make a diagram (with exact measurements) and then make the cross shaft . You want all the turnbuckles straight up and down . The levers should be 45 degrees up, and the main control arm should be 40 to 45 degrees out, behind the cross shaft .
    "there are old racers and there are bold racers, but there are no old bold racers"

  6. Default

    Copy, thanks George.

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