Did Anyone Cup their Props on a Carver?

Have you worked out how much slippage you have now? There's a formula for it that takes into equation prop size, rpm, gear reduction = speed.......Cupping the props and cutting pitch might not give you anything, or it might be slightly beneficial depending on how much slippage you have now.

Can you fill us in a little better; What reduction, 3 / 4 blade, wot rpm, cruising rpm you run at now, how much more weight will you be adding to the ship? Trim tabs required?
I'm assuming LBC 454 or 502's.

Capt J has important thoughts also, wheel slippage. A cup reduces some at higher rpm. You may need to check/determine these values before any adjustments are made. A better prop shop can be helpful here also.

Keep us up on what you find.

Speed at 3200,3400, WOT rpm and speed?

4400 may be just a lil short already. Could you already have a cup in the wheels?

Well excuse me,, if it was running per Carver and Merc per that vessel- Why are you asking us anything?

Cupping is reserved more for high performance boats that need a good hole shot. Cupping a prop doesn't come into play until you are spinning up the rpm's. Me, nor anyone I know are interested in running their boat at 4,000 rpm's. Those 4 barrel carbs suck enough fuel through that 454 at 2,000 rpm's, much less doubling the r's.

I've owned a parking lot full of 454 trucks, and I can tell you for a fact; they were never designed to run at 4,000 for very long. You can get away with almost anything on a 350, but not a 454.

So do the math and see how much slippage you have.

google it (prop slip calculator). 4300rpm's, 26mph, 2.46:1 reduction= 28.60% slippage, if speed was 30 mph, you'd be at 17.6% slippage
3200 rpms and 19mph is 29.89% slippage. If speed was 22mph, you'd be at 18.82% slippage

NOW, have you used the trim tabs and put the bow down to increase the speed? Because on a boat like yours, putting the trim tabs down usually nets a 3-5mph gain in speed. If that is the case, you'd probably benefit from keeping your old props as spares and putting 4 blades on, to give you more stern lift.

I think you need to talk to a good propellor shop. You might be well served by buying a new set with a modern blade profile.....they would be able to best help you. Although I had a customer with a 1999 45' searay about 5 years ago talk to S+S propellor in Stuart,FL and they were able to get him over 3 knots reworking his existing set with the same top rpm's.

Aimhil
I have a 1999 Carver 404. The vessel is not fast and I'm not sure that cupping would be the answer.

With the way my 454 gas enjoins suck up fuel, I effored the maximum knots for the lowest RPM range. I had my props reshaped by Wilimington Prop Service (800-438-3792), the managers name was Tom.
They will want to know the following:
What are your engines rated? (this information was in my owners manual)
Full throttle speed & RPM's at that speed
Then bring down the vessel 500 RPM's at a time (4,ooo, 3500, 3000, etc) and note the speed for each stair step, all the way down to 1500 RPM's.

Once you have this information, give them a call, tell them what performance you are looking for and they will tell you your options. The boat owners in So Cal call these guys the "Prop Whispers"

They turned my 4 bladed props around in 2 days and it cost me a total 1800. When I was at their shop, I was surprised to see props from all around the world that they were working on and shipping back to places like Thailand, Japan, China, England and France.

The final result is that I gained about 6 knots at 2300 RPM and now cruise to Catalina Island at about 14 knots, and use about 60 gallons of fuel, rather than 10 knots at 2800 RPM more than 100 gallons that it use to take. (the props on the vessel were way oversized when I bought it).
My top speed is about 24 knots now.

I hope this helps.

All the best,
Jimmy

Aimhii,

Unfortunately, I do not have the before and after information on the props.

Sorry about that

-Jimmy