Prop Size Trouble
 

Does anyone know who I need to talk to about the right size prop for my boat. The boat is approx. 12000 lbs. 40' Scarab twin 550hp, TRS drives.. I can not get over 42-4300 rpm. Top speed is low. and fuel economy is poor. (not really caring about that),
I was hoping someone can lead me in the right direction. I just don't want to start buying props.

Currently running ?? prop

I have 15.5 X 23 4 Blade

Assuming the engines are running correctly, you're over propped. 550hp engines at what rpm??? At 4300 rpms, they are prob only making 400hp.
Every 1" drop in pitch equals about a 200 rpm gain at WOT.

I'd guess it came new with something like these.
https://austin.craigslist.org/boa/5872993139.html

Is that the 38 with a swimstep ? because that boat with TRS drives should run a 23 Bravo 1 3 blade. But if you have the generator and A/C it might drop down to a 21 3 blade

Scarab 400
 

It is the 400, Basically the 38' hull with the swim step as part of the hull , has the reverse arch. Does not have a generator. Motors run fine just trying to find out what size prop to go to since I feel what I have now is not correct.

Prop
 

Call Dough at spinellie bros. He knows his stuff. I have a custom prop from him and it works great

Jj

Prop help
 

Give Doug at spinellie brothers a call he was very helpful when I bought a prop from him. He made the correct prop for my boat

Jj

post #4, and the price is right. (thread is for 25's but post 4 has a pair of 23's)
http://www.offshoreonly.com/forums/w...5p-3blade.html

i might be wrong but, trs typical depth is like 7 1/4 inches and i think the bravo 1, 4 blade does not like to be that deep

FYI
I ran 21 pitch with 330's boat topped out at 53 mph @ 5100 rpm
700 hp a side with 26 pitch 68 mph @5200 rpm

mine was an 86' 400 Scarab ,, they are not meant for speed or big water...

conneroutlaw.

You seem to post the same response to every question. Are you on the Spinelli payroll? I see your from NY. Any chance it is Rochester?
Advertising on this forum actually cost money. There is plenty of room for your guys to step up and advertise while answering technical questions on this forum.

Brett

chuckm,

First thing we need to know is the engine builders desired WOT operating range. From there we can discuss the options you have from 3-4 blades as well as pitch and rotation. We have a test program and can get you set up with test props without having to buy them.

Thank you,
Brett

No not on the payroll, just friends with the owner. I use his products and they work well on my boat. He has a great product and great customer service. Everyone else tells people to go certain places for service, are they doing the same thing I am. Should they pay for advertising when they refer someone some place. I guess there is no such thing as a free lunch.

I called him out on this before - I guess he doesnt understand that people post questions to get answers - if they wanted to call someone they would have done that. His response is identical to other posts, he must have cut and pasted it.

[QUOTE=dcb;4549860]I called him out on this before - I guess he doesnt understand that people post questions to get answers - if they wanted to call someone they would have done that. His response is identical to other posts, he must have cut and pasted it.[/QUOT


Thanks for the support dcb,
I'm not looking to open a can of worms just venting a little. People have the right to post here. I just get a little frustrated when I have given almost 15 years of free advice on this forum and semi knowledgeable people just throw canned statements out there to redirect people.... I have been in the industry professionally for over 25 years and have been a boater for over 50. It takes time effort and knowledge to answer questions and spend time doing that. And of course a love for the sport of boating is essential.
I happen to pretty much know all my main competitors backgrounds and let's just say there isn't always a boating and boat set up knowledge base to begin with. I never release information about folks backgrounds because it would be unprofessional and wrong to do so. But guys who have been in the industry for a long time talk to each other. Foundries talk to each other and other manufacturers talk to each other and prop guys talk to each other, Anybody can sell anything but I value history and experience. It's interesting how people become gurus over night. I wish all prop shops success. Because, there is room for all. I just find it cheesy when people not within the actual company and without basis offer non constructive comments. I find it professional when the so-called professional shows their true colors by participating in actual dialing in conversations.

Ok, I'm down from the soap box.
Thank you to all BBLADES long standing clients.

Brett

Have a snicker Brett, you'll feel better....:D........I get what your saying, guess its no different when someone tells people to go to a certain engine or drive builder because of their experience, several of my Baja bud's run your labbed props with great success because your mod's are spot on, keep up the good work,..:drink:

LOL, thanks F-2 Speedy. I love snickers and I do feel better.

Hey Brett - the fact that you come on here to help FREE, means a lot. It irks me when someone
constantly plugs a non-supporting business with a cut and paste.