Albers
Cadet
- Joined
- Apr 8, 2012
- Messages
- 12
I bought a 26' Excel cruiser with a VP 5.7 with an SP-C drive about 2 years ago and it had a 15.5 x 15 prop which I used on the first few ocean runs to Catalina averaging 2.3 mpg. At the time I was new to it all and after a few trips I switched to the spare prop the boat came with - it too was a 3 blade but was 16" dia but had huge blades - looking at the prop from the back you could hardly see between the blades - someone told me they were called Elephant Ear props and I averaged 3 mpg which I think is good for this size boat. I used that prop for about a year til it finally broke - I didn't hit anything it was just a pitted, old, spare blade when I started using it. I tried to find another one just like it but couldn't so I bought a 15.5 x 17 Solas prop next and still using it but average around 2mpg with this one.
Can anyone tell me the correct name for the "elephant" props? I never see them - is there a reason why? What are the cons?
Summary:
First couple of trips with the 15.5 x 15 - could tach out but cruised at prox 5000 rpm always hitting 22-23 mph - prox 2.3 mpg
The next 3 trips with the 16.0 x Elephant (no readable pitch mark but looks around 15) - max rpm I could hit was 5100 and would cruise at 5000 rpm at 22-23 mph too - about the same but mileage was much better - prox 3 mpg
Currently I used the 15.5 x 17 - max rpm I can hit is still around 5100 but now cruise there at around 4400 hitting 25 mph but it's sucking gas quicker. Lower rpm and higher speed should be better mpg shouldn't it?
PS - planning speed is around 17
- WHAT SHOULD I DO?
Can anyone tell me the correct name for the "elephant" props? I never see them - is there a reason why? What are the cons?
Summary:
First couple of trips with the 15.5 x 15 - could tach out but cruised at prox 5000 rpm always hitting 22-23 mph - prox 2.3 mpg
The next 3 trips with the 16.0 x Elephant (no readable pitch mark but looks around 15) - max rpm I could hit was 5100 and would cruise at 5000 rpm at 22-23 mph too - about the same but mileage was much better - prox 3 mpg
Currently I used the 15.5 x 17 - max rpm I can hit is still around 5100 but now cruise there at around 4400 hitting 25 mph but it's sucking gas quicker. Lower rpm and higher speed should be better mpg shouldn't it?
PS - planning speed is around 17
- WHAT SHOULD I DO?
