VENSURA Four-Blade on Larger Boats, Motors - Moderated Discussion Areas

  ContinuousWave
  Whaler
  Moderated Discussion Areas
  ContinuousWave: Whaler Performance
  VENSURA Four-Blade on Larger Boats, Motors

search | FAQ | profile | register | author help

Author Topic:   VENSURA Four-Blade on Larger Boats, Motors

jimh posted 01-19-2006 11:31 PM ET (US)
I could not help but notice that the United States Coast Guard has rigged their 25-foot SAFE boats with Mercury VENSURA four-blade propellers on twin 225-HP motors.
This gives me encouragement to try a VENSURA four-blade on my boat, a REVENGE 22 W-T WD with a single 225-HP.
Whaler owners using a VENSURA four-blade on boats with 200-HP or more are invited to share any comments about how the propeller performs for them. As always, details are appreciated.
handn posted 01-20-2006 10:57 AM ET (US)
What is the difference between this prop and the Revolution 4 series?
Tom W Clark posted 01-20-2006 12:14 PM ET (US)
The Offshore/Vensura propeller is a more conventionally bladed prop. It was designed as a great new four blade prop by Mercury but never really lived up to its expectations.
It continues to be produced but is said to be best suited to the smaller V-6 motors when installed at heights that keep the prop fully submerged. Offshore fishing boats especially twins often use these props.
The blades on the Offshore Vensura are small in blade area. They are not radically raked like the blades on the Revolution 4 are.
The Revolution 4 has highly raked blades with slightly greater surface area and much more aggressive cupping which not only covers the trailing edge of the blade but actually curls around the tip and begins to descend the leading edge just a bit. You see this same cupping style on the Mirage Plus.
Tom W Clark posted 01-20-2006 01:10 PM ET (US)
I wanted to add that the Vensura is nothing more than a large hub Trophy Plus.
LHG posted 01-20-2006 04:22 PM ET (US)
Jim - I noticed that in your photos also. The Safe boat I saw being re-rigged with 250 Verados had Revolution 4 props installed. Quite frankly, I think the USCG has the wrong props on that particular boat. It too should be using Rev-4's.
Here's the sum total of what I know about the Vensura prop (used to be called Offshore Performance). As you know JimG and Steve run these, on my recommendation, and I alternately use one on my classic 21 Outrage.
It is not known for flat-out top speed, but has excellent hole shot acceleration, strong mid-range speed (like all 4-blades), and tremendous bow lift, with pretty good offshore holding. That is why I recommended it to Steve and Jim, as both of their boats needed these attributes. And neither has enough power-to-weight ratio to make WOT top speed a major concern, nor to be able to turn a 17" Rev-4. On both boats, the improvements were DRAMATIC, I think, particularly in hull lift, and plane-off for Steve. They really like the prop, running medium sized vent plugs, and I think Jim gained top end over the conventional Yamaha SS prop.
Mercury recommends the prop for 135-175HP V-6's, and for single/dual Offshore use, 18-24' boats. Minimum pitch offered is 17", max 23". Compared to a same pitch Mercury 3 blade, in my case it holds RPM down about 100, but will turn about 300 RPM higher than same pitch Rev-4. Mercury says the Revolution-4 holds better offshore, and I can confirm that.
On my classic, it is about 1-1/2 to 2 MPH slower top end than a Laser II or Revoultion-4, but has rocket-like low and mid-range acceleration, and great mid-range cruising, at lower RPM. It did run 1 MPH faster, however, than a brand new Mercury aluminum Black Max (much to my surprise a quite good aluminum prop) I tried in same 19" pitch. In short, it is a solid performer, I like everything about it except top speed. Also, it offers MUCH better engine control for docking and reverse thrust operations.
I think on heavier hulls, relative to HP, that go less than 45 MPH, 135-175HP as Merc recommends, it could be a great propeller to use.
In my case, when I want to go fast, (and not suffer the humiliation of having other brand 150's go by me!) I install the Laser II on this lightweight classic hull. For load carrying and cruising, I use the Vensura. Incidentally, the Laser II holds better offshore, when run 1" elevated, than the Vensura, to my surprise.
Getting back to your rig, I think the Vensura might run quite well for you, inspite of Mercury not recommending it for 3.0 liter outboards. But the 17" minimum pitch could be a problem? I think the Revolution-4 is clearly a better propeller, using much newer technology and blade design, but the high weight of the prop causes some limitations with gearcases, on 2.5 liter engines, and other brands. They even rattle the clutches on my 200 EFI's at 600 RPM in gear, but it goes away as I approach 800 RPM.
From what I can tell, the Revolution-4 is the talk of the town these days in boating, except for the bass-flats crowd, which use the Tempest Plus. Everybody else wants them, all brands of engines, and I am seeing them used that way.

Hop to:

Contact Us | RETURN to ContinuousWave Top Page

Powered by: Ultimate Bulletin Board, Freeware Version 2000
Purchase our Licensed Version- which adds many more features!
© Infopop Corporation (formerly Madrona Park, Inc.), 1998 - 2000.

Author	Topic: VENSURA Four-Blade on Larger Boats, Motors
jimh	posted 01-19-2006 11:31 PM ET (US) I could not help but notice that the United States Coast Guard has rigged their 25-foot SAFE boats with Mercury VENSURA four-blade propellers on twin 225-HP motors. This gives me encouragement to try a VENSURA four-blade on my boat, a REVENGE 22 W-T WD with a single 225-HP. Whaler owners using a VENSURA four-blade on boats with 200-HP or more are invited to share any comments about how the propeller performs for them. As always, details are appreciated.
handn	posted 01-20-2006 10:57 AM ET (US) What is the difference between this prop and the Revolution 4 series?
Tom W Clark	posted 01-20-2006 12:14 PM ET (US) The Offshore/Vensura propeller is a more conventionally bladed prop. It was designed as a great new four blade prop by Mercury but never really lived up to its expectations. It continues to be produced but is said to be best suited to the smaller V-6 motors when installed at heights that keep the prop fully submerged. Offshore fishing boats especially twins often use these props. The blades on the Offshore Vensura are small in blade area. They are not radically raked like the blades on the Revolution 4 are. The Revolution 4 has highly raked blades with slightly greater surface area and much more aggressive cupping which not only covers the trailing edge of the blade but actually curls around the tip and begins to descend the leading edge just a bit. You see this same cupping style on the Mirage Plus.
Tom W Clark	posted 01-20-2006 01:10 PM ET (US) I wanted to add that the Vensura is nothing more than a large hub Trophy Plus.
LHG	posted 01-20-2006 04:22 PM ET (US) Jim - I noticed that in your photos also. The Safe boat I saw being re-rigged with 250 Verados had Revolution 4 props installed. Quite frankly, I think the USCG has the wrong props on that particular boat. It too should be using Rev-4's. Here's the sum total of what I know about the Vensura prop (used to be called Offshore Performance). As you know JimG and Steve run these, on my recommendation, and I alternately use one on my classic 21 Outrage. It is not known for flat-out top speed, but has excellent hole shot acceleration, strong mid-range speed (like all 4-blades), and tremendous bow lift, with pretty good offshore holding. That is why I recommended it to Steve and Jim, as both of their boats needed these attributes. And neither has enough power-to-weight ratio to make WOT top speed a major concern, nor to be able to turn a 17" Rev-4. On both boats, the improvements were DRAMATIC, I think, particularly in hull lift, and plane-off for Steve. They really like the prop, running medium sized vent plugs, and I think Jim gained top end over the conventional Yamaha SS prop. Mercury recommends the prop for 135-175HP V-6's, and for single/dual Offshore use, 18-24' boats. Minimum pitch offered is 17", max 23". Compared to a same pitch Mercury 3 blade, in my case it holds RPM down about 100, but will turn about 300 RPM higher than same pitch Rev-4. Mercury says the Revolution-4 holds better offshore, and I can confirm that. On my classic, it is about 1-1/2 to 2 MPH slower top end than a Laser II or Revoultion-4, but has rocket-like low and mid-range acceleration, and great mid-range cruising, at lower RPM. It did run 1 MPH faster, however, than a brand new Mercury aluminum Black Max (much to my surprise a quite good aluminum prop) I tried in same 19" pitch. In short, it is a solid performer, I like everything about it except top speed. Also, it offers MUCH better engine control for docking and reverse thrust operations. I think on heavier hulls, relative to HP, that go less than 45 MPH, 135-175HP as Merc recommends, it could be a great propeller to use. In my case, when I want to go fast, (and not suffer the humiliation of having other brand 150's go by me!) I install the Laser II on this lightweight classic hull. For load carrying and cruising, I use the Vensura. Incidentally, the Laser II holds better offshore, when run 1" elevated, than the Vensura, to my surprise. Getting back to your rig, I think the Vensura might run quite well for you, inspite of Mercury not recommending it for 3.0 liter outboards. But the 17" minimum pitch could be a problem? I think the Revolution-4 is clearly a better propeller, using much newer technology and blade design, but the high weight of the prop causes some limitations with gearcases, on 2.5 liter engines, and other brands. They even rattle the clutches on my 200 EFI's at 600 RPM in gear, but it goes away as I approach 800 RPM. From what I can tell, the Revolution-4 is the talk of the town these days in boating, except for the bass-flats crowd, which use the Tempest Plus. Everybody else wants them, all brands of engines, and I am seeing them used that way.