Twin 360's props

[balthaus]

I have seen a couple of 16x15 for sale and am wondering what type of performance I could expect from them.
Currently have 17x19's (on there when I bought her) and engines bog out at about 2800 rpm.
I started another thread a while ago and revisited that one.
I wanted to use Fastjeff's 17x16 4 blade but have not found any (used) yet.
I know stock props were 16x16...just wondering what 16x15's might do.

Thanks

[Joe]

On my 32 with 240 318 with a clean bottom will turn 4500. Max. Dirty and heavy load 4000 to 4200 you would be better off with the 16x15 than the 17s . you do not want the engines to "bog" That is the worst thing you can do!!! The engine should allways be able to turn 4000. If not you have to much prop!!!! To much prop will kill an engine ,before to small of prop. Joe

[jralbert]

My 1988 32' FBS had 16x15 props. Had performance similar to Joe's.

Engine manual calls for 4000-4400 rpms at max throttle. I think 17x19 is significantly overpropped causing engine to lug. Not good.

[balthaus]

Will the 20 xtra Hp make any difference?
360's / 260 Hp
Thanks for the replies.

[Joe]

The difference 16x16 and 16x15 would be about 200 to 300 rpm on the top end. Clean bottom,light load,strong engines, you might see 4600 to 4700 max would be a my guess.

[Fastjeff]

I used 17 x 15s on mine--not 17 x 19s. That's way too much pitch. My engines never saw over 3,900 rpm with them.

Using 16 x 15s will waste gas and wear the engines unnecessarily. (Stock was 16 x 16 three blades.) Using 16 x 15 FOUR bladers would work okay.

Rule of the thumb says a four blade prop equals a three blader with one inch more pitch (ie: a 16 x 15 four blader = a 16 x 16 three blader).

Jeff

PS: At one time, I had a 16 x 16 'normal cup' prop on one side and a 16 x 15 heavy cup on the other side. Performance of both was identical.

[balthaus]

Fastjeff
Thanks for the reply.

[balthaus]

Not trying to beat a dead horse... But...
Used props are proving difficult, if not impossible, to find in my area.
To recap....
Current props....17x19 (see signature for boat)
I know those props are just plain NOT right for our boat.
I am going to pull the trigger and buy a pair of Michigan Wheel props.
Anyone with experience on the Ohio River, Louisville area have some advice?
Economy vs Performance?
Is stock configuration just simply the best place to start?
I am concerned with real world info....we do not pull the boat during the winter....bottom paint is 1 year old(obviously will be observed during prop swop).
Thanks in advance

[balthaus]

Not trying to beat a dead horse... But...
Used props are proving difficult, if not impossible, to find in my area.
To recap....
Current props....17x19 (see signature for boat)
I know those props are just plain NOT right for our boat.
I am going to pull the trigger and buy a pair of Michigan Wheel props.
Anyone with experience on the Ohio River, Louisville area have some advice?
Economy vs Performance?
Is stock configuration just simply the best place to start?
I am concerned with real world info....we do not pull the boat during the winter....bottom paint is 1 year old(obviously will be observed during prop swop).
Thanks in advance