question about prop pitch as it deals qwith speed of boat

rookie to boats, im wondering if theres anyone out there that can other give me some info or lead me in the right direction to learn about increasing the overall speed of my boat. i heard that proper pitch on the prop for the boat is important.. all help/ advice is appreciated, thank you

Read this. http://www.boatfix.com/how/props.html

For the most part, the prop is the only economical means of matching the engine to the load presented by the hull. Proper pitch is usually the one that allows the engine to operate in the WOT band provided by the engine maker.

You'll notice "speed" rarely, if ever, occurs in those discussions. That is usually limited by the hull. for a smaller hull, probably more by the way you load it.

The short version - if the prop is pitched to provide proper WOT for the engine and the speed isn't enough, it is time for a new boat. If it's close to being fast enough, there are several 'adjustments' you can make that will help getting to 'enough', the prop's pitch being but one of them.

thanx ibnfshn.

mako, i think i understand what youre saying,lol. i realize the hull speed is what im going to get but i was wondering if what i have was as good as i can nget, perhaps with a little more info you could help?

i have a 22ft deep v-hull cabin cruiser, fibreglass, she is just under 8 ft wide, not sure of the weight.

at the moment theres a md-17 36hp volvo in her, i found some numbers on the prop,, guess theyre the make and pitch of the prop..????

H&S 86 (which im guessing is the make)

18L-H 15 (is im guessing the pitch)

not sure if can help me out with this info or if its enough,, any help ill be greatful for..

there is a flybridge on the boat, but im taking it off this spring as well as giving her more deck space by taking out the bunk, stove and fridge to make a smaller house,, so this will make the boat alot lighter im sure, thanks in advance. i could get more pics if youd like..

I'd guess what you have is an 18" dia with 15" of pitch; a search on the www may show more details.

I'd start by getting the prop dialed in with a clean bottom to make sure you get to WOT. If you are gonna do the mods listed, do them first as the engine should rev more with less load. A prop shop that has "propscan" equipment is highly recommended. Been there, spent the money, and has zero regrets.

Most boats will get to max speed by being slightly overpropped - where you just make it to the bottom of the WOT range. The trade is you put a bit more load on the engine so you are trading speed for longevity. I've had one where the max speed occurred silghtly under-propped. Wound up 300 rpm over max recommended.

Another item to discuss with the prop shop is what RPM you want max speed. If the hull planes, most want it at the cruise speed, which infers an over prop. You also need to consider where you boat and the conditions you can see. I wouldn't want an overpropped setup fishing in the ocean where a storm can stack up the breakers in the inlet...

thank you,, ill look for a shop over the winter.. as for conditions,, im on the atlantic, and will be using it in rough water,, i love it in a storm,lol.. so ill do the renoes first, then find a shop to help me while im at that,, hopfully there is one in atlantic canada,, thanks again makomark.....