bear_69cuda
Commander
- Joined
- Oct 10, 2008
- Messages
- 2,109
Hey Gang,
I wanted to start yet another thread about 4 blade propellers. I?ve been reading in the prop forum regarding 3 to 4 blade conversion, and folk?s performance reviews between different prop manufactures.
Presently, I?m very impressed with the overall performance of my stainless 3 blade, with normal load (30-50 gal of fuel, gear myself and the sheriff) I get good hole-shot, mid and nice top end performance. My issues are when I have a heavy load 4-6 on-board, with all the gear and such, I?d like more of an improvement with hole-shot, mid-range, and rough water performance.
I've been looking at 5 props ( all 4-blade stainless ) listed below, in hopes that the advice and comments posted, will help me make my selection.
So I?ll start with my boats current data.
Boat: 2008 Hurricane 202 Deck Boat
Length: 20?
Beam: 102"
Hull: Modified V hull
SS Smart Tabs 60 lb actuators. (~ 100 rpm drop @ WOT when I installed tabs, all data below is with tabs.)
Weight wet: ~ 3500 lbs.
Weight with load: 4 adults, all gear ~ 4400 lbs.
Engine: 2008 Yamaha F150TXR 2.0:1 (28/14) gear ratio
Prop: Yamaha Reliance 14.25 x 17"P (non vented)
Yamaha Command Link digital Tachometer.
WOT-RPM?s: 58-5900 ~ 95% trimmed up. (If heavy load 56-5700) If the trim gauge is 100% correct, the prop seems to start ventilating and loosing speed after 95% trim up? My gut tells me the gauge/trim sender could be slightly off? Like 5%
Top speed: 42.5 mph GPS
Boat can stay on plane between 15-17 mph.
Anti-cavitation plate: See pictures below of my Hull. It seems to be ~ 1" or possibly 1.5" lower than the keel. My deck boats modified V hull doesn?t have much of a true V keel? Kinda flat (seen in pics)? It's also possible due to this design of hull, that the engine is mounted at the correct height, I'm just not sure... Nothing on Hurricane web-site or owners manual notes mounting height for this hull. My Yamaha factory service manual states "the anti-cavitation plate should be even with bottom of the boat" So should I move the engine up with 4 blade? Less resistance correct? Curious why the dealer rigged it this way???
These are the props I'm looking at. ( I believe 14.25" diameter is the largest the F150 can handle, please correct me if that's not the case... )
Stiletto Bay-Pro II and III
Solas HR Titan 4
Turbo Ultima 4
and PowerTech SkiMax (MQS4)
If I chose a 17"P 4-blade I should drop ~ 100 rpm = ~ 5700 rpm, Then if I subtract 2"P I'll gain ~ 3-400 rpm, so in theory a 14.25 x 15"P should put my F150 in the 58-6000 rpm @ WOT range. Now I get lost with the rpm effects of slip, cup, and rake.... I'm hoping the experts can help me...
Am I on the right path?
I wanted to start yet another thread about 4 blade propellers. I?ve been reading in the prop forum regarding 3 to 4 blade conversion, and folk?s performance reviews between different prop manufactures.
Presently, I?m very impressed with the overall performance of my stainless 3 blade, with normal load (30-50 gal of fuel, gear myself and the sheriff) I get good hole-shot, mid and nice top end performance. My issues are when I have a heavy load 4-6 on-board, with all the gear and such, I?d like more of an improvement with hole-shot, mid-range, and rough water performance.
I've been looking at 5 props ( all 4-blade stainless ) listed below, in hopes that the advice and comments posted, will help me make my selection.
So I?ll start with my boats current data.
Boat: 2008 Hurricane 202 Deck Boat
Length: 20?
Beam: 102"
Hull: Modified V hull
SS Smart Tabs 60 lb actuators. (~ 100 rpm drop @ WOT when I installed tabs, all data below is with tabs.)
Weight wet: ~ 3500 lbs.
Weight with load: 4 adults, all gear ~ 4400 lbs.
Engine: 2008 Yamaha F150TXR 2.0:1 (28/14) gear ratio
Prop: Yamaha Reliance 14.25 x 17"P (non vented)
Yamaha Command Link digital Tachometer.
WOT-RPM?s: 58-5900 ~ 95% trimmed up. (If heavy load 56-5700) If the trim gauge is 100% correct, the prop seems to start ventilating and loosing speed after 95% trim up? My gut tells me the gauge/trim sender could be slightly off? Like 5%
Top speed: 42.5 mph GPS
Boat can stay on plane between 15-17 mph.
Anti-cavitation plate: See pictures below of my Hull. It seems to be ~ 1" or possibly 1.5" lower than the keel. My deck boats modified V hull doesn?t have much of a true V keel? Kinda flat (seen in pics)? It's also possible due to this design of hull, that the engine is mounted at the correct height, I'm just not sure... Nothing on Hurricane web-site or owners manual notes mounting height for this hull. My Yamaha factory service manual states "the anti-cavitation plate should be even with bottom of the boat" So should I move the engine up with 4 blade? Less resistance correct? Curious why the dealer rigged it this way???
These are the props I'm looking at. ( I believe 14.25" diameter is the largest the F150 can handle, please correct me if that's not the case... )
Stiletto Bay-Pro II and III
Solas HR Titan 4
Turbo Ultima 4
and PowerTech SkiMax (MQS4)
If I chose a 17"P 4-blade I should drop ~ 100 rpm = ~ 5700 rpm, Then if I subtract 2"P I'll gain ~ 3-400 rpm, so in theory a 14.25 x 15"P should put my F150 in the 58-6000 rpm @ WOT range. Now I get lost with the rpm effects of slip, cup, and rake.... I'm hoping the experts can help me...
Am I on the right path?