mickeymcclgn

iTrader: (1)

I will also add that when I lowered the box (has a 3 hole 1" incriment adjustment) and planing ability from .5 to 1.5 below didn't change. The boat planed the same. I want to try raising it to .5 above the bottom
But haven't had a chance. I think if it can be raised enough and still get on plane it will eliminate some of the bow lift from the prop and maybe run alittle more flat (or trying a q4 straight ear prop which I will be doing soon)

Bajajay98

I run a bblades p5 33 cleaver 5blade and I don't have any problems getting on plane and I'm completely level with the bottom of my hull.

TxHawk

iTrader: (2)

TTT.
I have a little more power now. Running a 28 B1 LH I can turn 5200-5300 with neutral trim @83MPH. I tried to go up to a 30P B1 LH and I have to trim to get the RPM. With the high X, the trim doesn't leverage the bow enough to let the 30P get and gains. Speed is no better, so the slip is obviously better with the 28. I also haven't leaned on it for a long period to play with all changes.

My feel is that I need some bow lift. Before I move the drive town .5-1", any input on a 29P 4 blade hydromotive or any 5 blades? My goal is really 60MPH cruise but I know the boat has high 80's in it with a good all around prop. Making 650HP now.

ToMorrow44

A hydro P-5X and Maximus are both good bow lifting 5 blades and will definitely increase cruise speed. On my boat, both those props were ~5mph faster in the midrange cruise speed, just a tad slower on the top end. You'll need to drop down a pitch or two going to a 5 blade, like a 26P. For the Maximus, get the diffuser ring cut off, that helps increase bow lift. The Hydromotive Q-IV-X is very similar to the Bravo 1, maybe a couple mph faster midrange. I have a stock Hydro Q-IV-X 28P that performs very similarly to a 30 lab Bravo.

I would say no need to space the drive down unless you have a problem getting on plane. With the drive any lower, its going to scrub speed with more drag.

TxHawk

iTrader: (2)

No problem getting on plane but also very little leverage. I need to get some good shots of it running to see what the wetted surface looks like.

johnmiffco

I wouldn't lower the x
the 27 Excalibur was a 6' wide 24 deg bottom boat
has very fat lifting strakes lower is only 3" from bottom of vee and goes out the rear of the hull
this was 1 of the fastest planning 27s of its day,,,,,mid 70s design because of the strakes
the hull will planes well with high x dimension
I have o/bs on mine @ 1 3/4" above bottom and rockets on plane
your bow is heavier than the welcraft version because it had a cabin up front
and the lower stake has a little hook in it to help hold transom up to plane faster ,ride higher in the rough and to pull bow down some from the skinny high riding hull,,,,
I blueprinted my bottom from lower strake to vee from bow to transom and it picked up mph
getting into the 80s with ur set up is good if want little more just have prop labbed for the hull
shelf prop gives u shelf results if want more bow lift have it put in
these were skinny wave crushers not high speed hulls
if u decide to take out the little hook in the strake u may not like it ,,tail wants to walk more at higher speeds from strake so low to bottom and no hull is gripping
so ur doing very well with it and resto turned out nice
to gain just a few mph its all in prop work,,,,,

TxHawk

iTrader: (2)

Thanks John. You've been helpful with this little boat.

johnmiffco

no problem,,,,,
I had an I/o version back in the mid 80s that I raced with a #3 drive that was 1" below bottom
now the 85 model with the trips and this 1 passes speeds the hull can handle
so have learned the good and bad with these hulls
as stated if ur bravo has the diffuser ring have it cut off and blades tweaked/cut
to get more bow lift and speed,,,,,
30 is kinda big for the hp and hull like u said had to trim out to rpm which just blows water in the air no speed gains
ur real close where ur at 80-90 with single I/o is good #s on a bravo drive
since ur running lefty harder to find single blades of different brands
bravo and hydro are good all around props to find cheap and have tweaked on
the 28 is loading motor if cannot get over 5300
but that all depends on what max rpm motor was built for
if u can have prop labbed for hull and get to 5600-5800
u will hit ur high 80s
but also will loose some holeshot/mid,,,,
hard to find both worlds big cruise #s and big mph on same wheel
as suggested a 26 5 blade maxum for full load of people and fuel for cruise
and a built 4 blade for speed

TxHawk

iTrader: (2)

Went back to the stock B1 28 LH. Got the break in oil out and let it eat. Turning 5400 with half tank and 2 guys running 86-87. I can't stare at the MPH while running and no tattletale, but I glanced down and was working closer to 90 than 80. I didn't get to aggressive on the trim and it kept the walk down. Chop on the water helped to. Felt great! Take a look. Still has the bow in the water in my opinion. Runs very flat.

TxHawk

iTrader: (2)

I forgot about this thread. The old 27' is up to 91mph with a labbed 30p LH. Big headers woke it up. Now turning 5600 RPM.