Forum Index
The Boater's Guide to Information, Education & Scuttlebutt...
 
 FAQFAQ   SearchSearch   MemberlistMemberlist   UsergroupsUsergroups   RegisterRegister 
 ProfileProfile   Log in to check your private messagesLog in to check your private messages   Log inLog in 

Tempest to Laser II

 
Post new topic   Reply to topic     Forum Index -> Props
View previous topic :: View next topic  
Author Message
silver_power



Joined: 22 Jun 2008
Posts: 3

PostPosted: Mon Jun 23, 2008 12:26 am    Post subject: Tempest to Laser II Reply with quote

I own a Wellcraft 202 Nova Spyder with 5.7L(350cid) 260hp Alpha one engine and i have a Tempest (14 5/8"" 21p) propeller.The boat reaches with full trim 4400rpm and gets 55mph.I think i have wrong propeller because of the large diameter and so the load is big because big is the diameter.I would prefer to have much load for the engine because of the pitch so to have better top speed and not because of the diameter.I believe that the proper propeller would be a laser II (13 3/4"" 23p).The rpm range of the engine is 4200-4600rpm.What do you think?
Back to top
View user's profile Send private message
MikeW
Senior Member


Joined: 01 May 2006
Posts: 680

PostPosted: Fri Jun 27, 2008 12:53 pm    Post subject: Tempest to Laser II Reply with quote

The prop sounds close. I would stay with the diameter and drop the pitch by an inch or two. Every inch of pitch smaller the engine will gain 200rpm's. This will also give the boat more bottom end and the engine won't work as hard.
Back to top
View user's profile Send private message Send e-mail
silver_power



Joined: 22 Jun 2008
Posts: 3

PostPosted: Mon Jun 30, 2008 1:52 am    Post subject: Reply with quote

Thank for your reply,but i have already increased the diameter of the factory propeller about 5/8''. I beleieve this is useless especially for a sportboat 20ft with 260hp sterndrive.I am going to buy an Enertia 22p 13 1/2''dia .I beleieve that decreasing prop diameter about 1 1/8'' i will gain at least 400rpm and increasing pitch by 1 i will loose about 200rpm....totaly i will gain about 200rpm than now and i will have 22p than 21...typically, if i have now about 54mph at 4400 with the tempest(14 5/8 21P) , with Enertia (13 1/2 22P) i will catch 4600rpm with about 59-60mph.The engine's wot range is 4200-4600rpm. I expect with this change to achieve better top end with less load especially at the middle range.
Back to top
View user's profile Send private message
silver_power



Joined: 22 Jun 2008
Posts: 3

PostPosted: Mon Jul 21, 2008 2:18 am    Post subject: Reply with quote

Well, i received the brand new Enertia 22p and i did a test...comparing the Tempest (14 5/8'' 21P) with the Enertia(13.5 22P), i have better planning time (even the Enertia is 22P) much better mid range acceleration, better cruising speed (36mph@3200 than 33@3200), 3mph differnce @same rpms!!) but the boat reached only about 4300rpm with 56mph (+2) than Tempest (54@4400rpm).To be honnest, i expected the enertia to reach about 4500-4600rpm because of the small diameter she has.iI expected that the 1.125'' diameter difference would be equal at least with a pitch inceasment, so i expected at least to reach the same rpms, not 100 less that happened... Sad ..What do you think?
Back to top
View user's profile Send private message
Display posts from previous:   
Post new topic   Reply to topic     Forum Index -> Props All times are GMT - 7 Hours
Page 1 of 1

 
Jump to:  
You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot vote in polls in this forum