i would like some opinions pleasel

[swaycleveland]

facts
1985 4winns santara 217 fisherman
22 ft
4000lbs ?? guessing
3.8 l v6 producing a whopping 185hp 300 hours
perfectly tuned ( i'm so anal about this)
rpm range 4200- 4600 max
omc stringer
final gear ratio 1.71
current prop 14.5 x 19 stainless unknown brand original
bottom smooth as a baby's bottom
prop condition very nice
hull is not water logged
Bennett trim tabs

now that I've given you the skinny on the boat here's what i'm looking for. I now have a convertible top on it ( canvass attached to the windshield and going back only 5 ft) I have now lost some speed and rpms due to the drag from the new top. Previously i was right where you'd like to be as far as rpms, whole shot and top speed were concerned. she would spin up nice and i could reach 4600 and somewhere around 38 mph (gps) depending on the conditions. I now come in with an average of 4300 rpms and 35 mph. Not really a big deal but i have noticed that mid range is a bit lower then i would like I generally cruise to fishing spots and to and from the slip at about 3000 rpms and run about 23 mph.

I would like a new prop to use regularly and use the old as a spare. the new prop i would like to be a aluminum prop. 4 blades
I picked this combo because i would like to cruise at 2800 while maintaining the 23 mph. To achieve this i'm thinking something like a solas brand 4 blade in the 15 or 17 pitch I'm leaning toward the 15 for many reasons. The general rule of stainless to aluminium ( rpm lose) and the 3 blade to 4 blade ( rpm lose) and the fact i'm down a touch on my max rpm specs.
I dont run up at the higher rpms and speed but the extra power would come in handy on lake Erie to over come rolling waves and heavier loads

if you all wouldn't mind weighting in on 15 or 17 or anything else you'd like to add
thanks

 

[Maclin]

If you want lower RPM;s yet generate the same speed then you need a higher pitched prop. Right now you said you cruise at 23mph and 3000 rpm. If you go to a 17 or 15 the rpm's will be higher and attainable top speed will be less.

Since you are in the right RPM range at WOT right now (4300rpm) you are propped correctly. If you go to a 17 you will get better takeoff but less speed for any given RPM. A 15 would be even farther in the wrong direction in my opinion.

 

[swaycleveland]

the reason i am considering a lower pitch (15 or 17) is because i am considering switching to a 4 blade aluminum prop FROM a 3 blade stainless (19 pitch). With that comes a reduction in rpm's. If the base is 14.5x19 3 blade stainless = 3000 @23 then a 14.5x17 4 blade aluminum might 2800 and a 14.5x15 4 blade aluminum might be 3200? If i could find some people that converted to solas 4 blade aluminum and get a feel for the rpm drop i could make a better guess. I lean more toward getting a 15 because lets face it... I control the throttle and i dont HAVE to pin it to the floor. But if I need more and its not available then it cant be used

 

[steelespike]

I think I like the 17 4 blade .4 blades should grip well in the swells.
Should maintain plane better at reduced rpm should be able to maintain boat attitude in the swells.
may seem smoother and may respond better around the dock.Top end will be less though it seems you usually don't have much use for top speed.

 

[Maclin]

I am with steelespike on the 17p then in a 4 blade. A 15 would be dicey even with you keenly aware of the RPM's, but would be pretty racy out of the hole I bet :eyebrows: