Classic Parker Contest #1

[Megabyte]

In my best Maxwell Smart voice... "Missed it by that much!"

I thought that you'd do better than me with that fresh motor and clean bottom. That is why I guessed 36 kts.

Best I have ever seen in mine was 33 kts on a clean bottom and light on fuel. This time of year, with a dirty bottom, fuel fuel, full load of fishing and safety gear, and burning E10 fuel the best I can do at WOT is about 31 kts, and I'm only turning 5100 rpm.

I agree with your thought about the prop. I think my boat would benefit from a 15x15, but I wasn't able to locate one when I was shopping around and testing...

I believe the Mirage I'm running right now is the best of all the props that I've tested so far, but it's still a wee bit too much prop.

Interesting note... Are we seeing the "terminal velocity" of the MVSC hull here?
That is... you could hang more horsepower, but will it really give you much more speed that what we are seeing?

I'll volunteer to test this theory of someone would like to give me a new 300 hp motor to "long term test".

 

[DaleH]

Interesting note... Are we seeing the "terminal velocity" of the MVSC hull here? That is... you could hang more horsepower, but will it really give you much more speed that what we are seeing?

Very interesting and actually quite possible. Example, my old boat was an old '77 vintage Pro-Line 24' cuddy cabin, soft-V @ 10 degrees. Bought new, she wore an old 140hp flywheel-rated V4 OB. My family ran it like that for 20 years, getting a solid 20-22 mph cruise speed that was wicked fuel efficient.

When it became "mine" ... I desparately wanted more ponies, and I bought a 20" shaft 225hp on auction for < $3K that was mint. Hung it and drove it. Sure, my cruise now boosted to 25mph+, but, that hull could not handle nor use all of the available horsepower. Even thought the hull itself was rated to 235hp, I got negligable extra MPH once RPMs were above 5K.

I wonder if it was the same phenomenon, i.e., the hull is staying in the water, whereas the wetted surface stayed the same, I didn't get much boost when more HP was poured on. In contrast, with a deeper-V hull, the HP would continue to try and drive the hull up out of the water, thereby reducing the wetted surface area, which according to marine designers and naval architects, is the #1 drag component of a hull (that's why Formula uses those stepped hulls ... which ironically were designed in the era of steam engines, though they were too heavy to prove the design actually worked).

So ... I'll hang a 250hp without question, just to boost my cruise speed, but I highly doubt the WOT speed will increase much above low 40s. Hmmmmmmmmm ... maybe I can talk my local Suzi dealer into "donating" a 300hp 4-stroke for a Classic Parker "pilot" demo test !