SaltyCajun.com

SaltyCajun.com (http://www.saltycajun.com/forum/index.php)
-   Boating Talk (http://www.saltycajun.com/forum/forumdisplay.php?f=28)
-   -   Prop advice (http://www.saltycajun.com/forum/showthread.php?t=33632)

j.e.hagen 07-10-2012 01:39 AM

Prop advice
 
I have a 18x44 tunnel hull with 2000 model 40 mariner the prop I'm running is stainless 14 pitch, it seems like my motor is running up to many RPM any advice?

CajunChristian 07-10-2012 06:07 AM

Quote:

Originally Posted by j.e.hagen (Post 459761)
I have a 18x44 tunnel hull with 2000 model 40 mariner the prop I'm running is stainless 14 pitch, it seems like my motor is running up to many RPM any advice?

Have the prop cupped to run on a tunnel. It's called cavitation:D
D

ml2oo3 07-10-2012 03:12 PM

x2 What type of prop are u running on the tunnel a round ear blade or semi cleaver?

j.e.hagen 07-10-2012 09:44 PM

Round ear, it has some cup in it already you saying I need more Cajun Christian?

CajunChristian 07-11-2012 06:57 AM

Quote:

Originally Posted by j.e.hagen (Post 460319)
Round ear, it has some cup in it already you saying I need more Cajun Christian?


How many rpm's and mph? That will tell you how much slip. You can then reduce slip with cup. Tunnel boat props require a ton more cup than flatbottoms.
D

cmcnabb 07-11-2012 09:48 AM

Hagen bring that prop to Doug. He said he used to cup props for fun on his hitch with a ball peen hammer

jchief 07-11-2012 10:40 AM

What would make a tunnel pull hard to one side? Prop is fairly new and it has been worked on

Raymond 07-11-2012 11:14 AM

Quote:

Originally Posted by jchief (Post 460525)
What would make a tunnel pull hard to one side? Prop is fairly new and it has been worked on

Tab not set properly, too much prop out of the water wide open. Mines pulls a bit at top end even with tab turned all the way to the opposite side but not unmanageble. You'll loose it if the tab ever comes off (don't ask).

Any advantage of running a clever prop on a tunnel hull rig??

jchief 07-11-2012 11:18 AM

Had the tab all the way over and it still pulled. Going to put a torque tamer on it. Just looking for ideas.

Shawn said his fell of and it quit pulling at all.

Thanks.

j.e.hagen 07-12-2012 01:20 AM

I got my prop turned up to 15 pitch, recupped, and repolished it seemed to run great. The only thing I noticed is that it runs much better when whoever is with me is in the back, when someone is in the front it doesn't bite, but I'm happy with that.

ml2oo3 07-12-2012 08:27 PM

Quote:

Originally Posted by Raymond (Post 460559)
Tab not set properly, too much prop out of the water wide open. Mines pulls a bit at top end even with tab turned all the way to the opposite side but not unmanageble. You'll loose it if the tab ever comes off (don't ask).

Any advantage of running a clever prop on a tunnel hull rig??

Semi cleaver props have alot better bite at higher trim settings than a round ear blade all I run on tunnel boats. Four blade semi cleavers work very well on tunnels also.


All times are GMT -5. The time now is 03:21 PM.

Powered by vBulletin®
Copyright ©2000 - [ARG:3 UNDEFINED], Jelsoft Enterprises Ltd.
vB.Sponsors
All content, images, designs, and logos are Copyright © 2009-2012,
Salty Cajun, LLC
No unathorized use is permitted