Volvo 280 leg prop pitch?

[SteelyDan]

So it looks like I'm going to need to re-prop the 185 DE. We got it out for the first time and with the 305 we were running 3200rpm at only 23mph. Im trying to find any kind of stamped lettering on the prop but I cant see any markings anywhere on it. Anyone out there know where to look on a volvo prop for the pitch? I'm just guessing but it felt like it was a 15" pitch... I'm thinking it needs a 19 but again I am just guessing. Some experience from anyone with a similar hull design/motor/leg combo here would be awesome.

Thanks!

 

[Charlie415]

What was your WOT?

 

[SteelyDan]

WOT was 4500rpm and 28mph. Seems like I should have more speed than that? No?

 

[Charlie415]

I does seem a little odd. I'm not sure what your WOT is supposed to be. With my Merc 5.7 I am running a mirage plus 15p getting 4750 WOT with a recommended WOT of 4400-4800rpm. With the loads I run keeping it closer to WOT is best. You might want to consider a 4 blade. Without the numbers off your prop it is hard to know diameter and pitch. Without question you should be better than you are.

 

[wolf]

Volvo doesnt have a number system like merc/etc they are b1,b2,b3 all the way up to b7 for alum then you get into SS which is a deferent letter but same numbers, sorry dont know what it is cross referenced.w
A big pitched prop is going to slow your hole shot down most inboards run at 4300 to 48000 WOT need to find out where your is rated at phone a volvo dealer he will tell you then have fun experimenting with all the many props.

Wolf

 

[daddystoy]

First of all you don't prop your boat based on speed. You base it on getting the engine as close to WOT as possible according to what that 305 should be. Also the WOT should be attained with "AVERAGE" load conditions.
Saying that, I have a mid 70's 18' 6" Double Eagle with a 302 Ford and the 270 Volvo leg. My WOT for this motor is 4400 rpm. I run a 15"D 17"P prop. My average cruise speed is 20-23 ish knots from
3000ish rpm to 36/3800 rpm, all depends on weight, wind, current, etc. I keep thinking I should be able to go faster but it is what it is! I have an older 270 leg which takes the 15" diameter short hub prop. Later model Volvo legs took 16" diameter props which I would think would give you more speed.
You should be able to see some markings for diameter and pitch on the side of the hub or somewhere else on the prop. If not, the diameter is easy to figure out just by measuring the prop. To figure out the pitch you would need to go to a prop shop and they have a way of figuring out the pitch.
Now if you have a duo-prop leg, your on your own on that one! That is what Wolf is talking about with the lettered series props.

 

[daddystoy]

Yeah, you've got the identical boat as mine only with the 280 leg. Go for another cruise with a few buddies (for weight!) and see where the WOT comes in at. If it comes in where the specs say then I would say you have got the right prop.

 

[SteelyDan]

So after gutting and restoring the boat and removing hundreds of pounds of water logged foam WOT comes in at 4500rpm and 34mph with a few guys and some gear. I'm satisfied with the current prop but still need to find a spare!

 

[IMRINC]

The volvo props are stamped on the hub face underneath the prop cone.let me know if you can figure out what size it is i might have something kicking around.

 

[SteelyDan]

The volvo props are stamped on the hub face underneath the prop cone.let me know if you can figure out what size it is i might have something kicking around.

Will Do! Thanks

 

[trophywife]

HEY STEELY!! i have a SS 14 3/4 x 17 volvo penta prop, brand new... 150.00?

 

[SteelyDan]

Wow thats a nice prop. I'll get back to you if a 17 pitch prop is in specs for my boat.