Looking for original prop size on a Carver

[Shamfarlango]

Boat is a 1995 Carver 310 Santego with 5.0L Mercs and Alpha sterndrives (counter rotating). Does anyone know what these boats came with for props originally by chance?

TIA

 

[Bondo]

Ayuh,.... Generally speakin', boats don't come with props, but are added at the prep dealer,....

What size props ya got now,..??
How do the motors handle those props,..??
What do you wanta change about the props on it now,..??

 

[porscheguy]

The only possible source of that info is going to be carver or another owner who bought one new. Even then, there’s no guarantees because some of them may have been fitted with one prop and others got different ones.

I did did some searching and found an old carver spec page from a brochure. It put the top speed at 41mph @ 4400rpm.

Having had a similar sized bayliner from that era, I know there was a lot of compromises with regard to props and performance. They wanted fast cruising speeds (which requires more pitch) and wound up sacrificing a lot of rpm to get it. This is why the data above shows the top end at the lowest recommended RPM.

Carver’s at this time were genmar price point boats and I’m betting they were fitted with aluminum props. If the chart I saw was accurate, the boat was most likely equipped with 14.5X19 pitch props when they got that data. In that size, those performance numbers were attainable with 16% slip. This is reasonable slip for a 6 ton boat that’s 31’ long with aluminum props.

What are you trying to accomplish?

 

[QBhoy]

No idea for sure, but I know similar boats and engine set ups come with either 17” or 19” ally props.
i also know that most people I know with these boat/engine combos have now changed to the big 16x16 props. Loose a mph or two top end, but my god what a difference to all round usability. Rocket up out the hole now too.

 

[Shamfarlango]

I'm going to assume that someone threw a set of props they had laying around originally. I made some prop adjustments to a 15 x 17 4 blade which improved my hole shot but my WOT is 33-3500 RPM and 28 MPH. Drive specs say I should be 44-4500 RPM @ WOT as Porscheguy also mentioned. 15 x 15 would pop me up ~ 400 RPM which is still a stretch to the 4400 I should be getting. Someone suggested 14.5 x 17 but I'm now sure how a 1/2 inch of diameter would make such a difference; does that seem feasible that a 1/2" would give me about 1000 RPM?

 

[porscheguy]

I don’t know how much you want to spend on this. Not to burst your bubble but I had a bayliner 2958 command bridge with a pair of 5.7 OMC cobras. I want to say that it maxed out at 40 or so and at 4200-4400. This boat was a bit smaller and lighter than yours. Cruise was around 24-26mph.

Your performance data sounds about right for your boat/engine combo. 440HP just isn’t gonna move 6 tons very fast.

Assuming your engines are running well, you’re overpropped quite a bit.

Pitch gives you speed and acceleration. Diameter allows you to move mass. There’s a reason why a boat 2x larger than yours may use props 2’-3’ in diameter. Diameter increases blade surface area which moves more water. Diameter doesn’t have a lot of impact on RPM. Pitch does.

For maximum performance, I’d go with a set of mirage+ props. They’re also sold as the Quicksilver thunderbolt. They’re available as 15.75”X15”P. They have PVS which can allow you to add slip to increase rpm. They’re about the largest diameter you can run on the alpha drive. Thunderbolts can be had for under $400 each, new. If you search craigslist, you can probably find a used set for less than $400. Low pitch mirage props are frequently sold as pairs on CL.

 

[Scott Danforth]

call carver's customer service line.

I agree that 15's were what was probably on there.

 

[Bondo]

which improved my hole shot but my WOT is 33-3500 RPM and 28 MPH. Drive specs say I should be 44-4500 RPM @ WOT

Ayuh,...... Don't run it like that,.... You'll burn holes through the pistons,.....

The 44-4500 rpms is a Dead Minimum rpms,....

Those motors will be Much Happier at 4800 rpms, Wot,.....