115hp 16.5 lo-pro flat out

[cjames01]

re powerd my 16.5' campion lo-pro a few weeks ago, and finally got it broken in. went from a 1988 110 crossflow (blew a piston ring 47 hrs after fresh rebuild, shop gave me my money back at least) and now running a fresh rebuild (from another shop that i have heard great things about) 1996 115 looper with wiseco .020" o/b pistons. unbelievable low end and screams at the top end. turning with a 13x 19 omc ss prop that has had some work done to it before i bought the boat last year. either way running 53.5 mph at 5750 rpm but cant sustain due to inherent chine-walk these boats experience. anyways hear are some pictures, any advice on setup is welcome.




my to do list once i have a garage again is extend lower lifting strakes to transom and sharpen all edges on strakes and transom and a re gel of entire hull. (from what i have read its wat to much work for end product but it dose tend to stand up longer, and wont tend to blister at my bunks on my trailer) once again any comments are welcome trying to get as much out of her as possible with out compromising it as a slalom ski boat.

[David]

Your numbers don't compute in a prop calculator. Too fast for that rpm and pitch.

how low is your engine? Going up will help with chine wawalking be careful of water pressure, but you should be OK - it would surprise me if you needed enuf height to get in water pressure trouble

[cjames01]

the prop has been worked on before i got it with the old motor. i just know the speed was via my gps and my tach is bang on. the prop has 20p stamed on it but even at that the numbers dont add up. ass far as motor hight gose the ventalation plate is about 3/4'' higher than the bottom of the transom, i may try raising motor but my main problem with that is i do not want to loos any hole-shot/ pulling power for getting a skier out on one ski.( im 200lbs and a single ski aint much surface area to get up on)

[David]

You can go up and still use the boat for skiing with 4 blade props. At least that has worked for me with a 16 Baja. First a 100 GT Johnny, now a 115 HO Rude.

[David]

17 Stilletto ( sp?) for skiing works for me

[cjames01]

Ok I will try that. I finally got a chance the other day to give my 19p 4 blade solas aluminum a try for skiing and I got up ok. Maybe over the winter I will try going up to the last hole. I also would like to get the prop tuned a bit more to bring it down to the 5500 range which is the top recommended. Will that bring my speed down,up or keep it similar. Hole shot is Awesome as is but i would love so sacrifice some for more top end. What do you think?

[David]

John Tiger told me to keep my crossflow V4 to around 6000 rpm. I assume yours is a looper. No load solo, I still think 6000 is a good number. You might want to try a 4" manual jackplate. It makes adjusting height a lot easier and the setback might do you some good.

[cjames01]

I kinda figured as long as it stayed below 6000k id be ok. i am in the market for a jack plate, just waiting till after christmas and see if i can swing it by the wife. i did on the other had pic up a 13 1/2 x 24p raker on ebay the other day for 70$. so hoping i can swing it, using a slip calculator at 10% its telling me the prop im running is around 22p. once i recive the prop i will put up some numbers and continue adjusting setup.

[cjames01]

finally got the raker, it was is a bit rough shape when i got it but i put some time into and trued up the leading edge and cleand it all up on my polishing wheel and not it looks ok. took it out for a run yesterday flat calm 7 degrees Celsius out for air temperature. hit 5050 rpm or so at around 52 is mph with minimal trim because it started to walk. bow lift is awesome boat get right out of the water.

the things i now want to address

1. rpms. obviously are at the lower end of recommended so i want to see if through set up of blade i can gain some
2. engine high, as mentioned before jack plate i think i will go with a 3" setback manual which i hope to buy after Christmas, as of right now the cav-plate is basically even with the bottom of the hull.
3. once i have a jack plate and have that part of the set up dialed in begin balance possible reshape of blades, possibly reduce diameter by .5" to allow more rpm at a sacrifice of slip.

anyone have much luck with reshaping and blueprinting original rakers for the 41\4" gear case?