in need of some prop advice

[jjboor]

in need of some prop advice

I'm running a michigan wheel vortex prop on my 120HP V4 'Rude. The prop is a 12.75 x 21. The boat a 16 feet Glastron GT-160 New teleflex tacho set @ 6P<br /><br />i'm running 5000 rpms @ WOT. Load doesn't really seems to matter. (2 or 3 persons in the boat) I now need to order my new prop. should I go for a 19 or a 17 pitch? I need to get around 5800 rpms so I guess the 17? But unfort. I cant change the prop once I order it. So how sure am I that the 17 will get me the right rpms? <br /><br />THX again!

 

[DJ]

Re: in need of some prop advice

Re: in need of some prop advice

A general rule is that one inch of pitch is equal to about 200 RPM. You can go from there. Read this this excellent FAQ thread.<br /><br /> http://www.iboats.com/cgi-bin/ubb/ultimatebb.cgi?ubb=get_topic;f=36;t=000030;p=1#000000

 

[jjboor]

Re: in need of some prop advice

Re: in need of some prop advice

O.K. so 21 minus 17 is still 4. 4 times 200 is 800 so I'd be hitting the "sweet" spot with the 17 cupped vortex... Calling the dealer now.<br />here we go!

 

[Dhadley]

Re: in need of some prop advice

Re: in need of some prop advice

Every GT-160 we ever rigged, even with V4 crossflows, used a 19 or 21. I would expected to use at least a 21 with the torque monster you have.<br /><br />Are you sure the motors running right?