2014 Crownline 330 CR - Stern Drive & Prop

[TimJFlorida]

Hi All,
I have a 2014 Crownline 330 CR, I bought it used. Was told that the stern drives had been replaced by previous owner. The current boat is slow to get up on plane. It has twin Mercruiser Seacore 350 Mag engines (2A176425 & 2A054368) with Bravo3 stern drives. 600 hp @ 4800 RPMs. It is ~34' and weighs in dry at 15,300. I would like to know what gear ratio and prop offset came standard from the factory for this boat or if not known what it should be to get up on plane with more assertiveness.

Thank you in advance.

 

[alldodge]

Welcome
Member @Fun Times might be able to look what came from the factory

A boat that size should have at the highest a 2.0 ratio, but most likely have a 2.2 ratio

What is the max RPM you get at WOT ?
What is the max Speed ?

 

[Fun Times]

Sometimes there ought to be a secondary sticker on/near the engine plastic cover that has the stern drive and transom serial numbers as well as the engine serial numbers... Any chances of looking inside the boat for the stern drive seral number...With that, it would help know what gear ratio the drives were from new.

To know what props came on the boat from new, typically you could reach out to the manufacturer with the hull id number say via email or phone and they'd ought to be able to tell you what props where sent that worked well from new usually.

 

[TimJFlorida]

Welcome
Member @Fun Times might be able to look what came from the factory

A boat that size should have at the highest a 2.0 ratio, but most likely have a 2.2 ratio

What is the max RPM you get at WOT ?
What is the max Speed ?

Thank you for your reply.
WOT RPM is 4800-5000
Cruising speed 37 knots, max speed 41 knots

 

[TimJFlorida]

Sometimes there ought to be a secondary sticker on/near the engine plastic cover that has the stern drive and transom serial numbers as well as the engine serial numbers... Any chances of looking inside the boat for the stern drive seral number...With that, it would help know what gear ratio the drives were from new.

To know what props came on the boat from new, typically you could reach out to the manufacturer with the hull id number say via email or phone and they'd ought to be able to tell you what props where sent that worked well from new usually.

Thank you, very useful. Will look for the original numbers in the engine compartment.

 

[alldodge]

Thank you for your reply.
WOT RPM is 4800-5000
Cruising speed 37 knots, max speed 41 knots

Sounds like the boat is dialed in correctly.

The issue you have is not enough low end torque. Need torque to get something heavy moving. The 5.7 has the HP to keep it going once on plane but not enough to get it moving

If you have 6.2 motors you would get up faster because of longer stroke. Years ago they use to put 7.4 and 8.2 in the boats and they would get right up.

Could get up faster if the prop pitch was lowered but then have to watch so not to over rev, and would loose some top in speed

 

[Fun Times]

Thank you, very useful. Will look for the original numbers in the engine compartment.

I asked a friend to help look up your info and here is what the info pops up as far as Merc is concerned,

 

[Scott Danforth]

Your boat needs more torque to get the over 9 tons up on plane. Your wet weight is just over 18000# (assuming you do not have the coolers full of beer and ice, and you have no passengers)

Stock 350s are a fine motor, but your boat should have 502s at a minimum, or diesels to get it up on plane.

Longer trim tabs / k-planes would help the running surface to get it up on plane