New Duo Prop Propellers

[BarryTurano]

My Albemarle has a Duo Prop outdrive from 1999. The props have been reconditioned several times. I think that it is time to replace them (prop shop has agreed), I have D5 props. From what I can find out they are being replaced with "I" series props. These have a larger surface area and are thinner. Does any one have any experience with this model?

http://www.propshopinc.com/Volvo-Pen...ries-p684.html

 

[zell66]

not D5 but I have B5, they are hard to find and expensive. My main set has the most repairs to it. The forward most prop. repaired 5 time in last 2 summers. This set work just fine. Have a reserve set that has been repaired and are ready to go once main set fails. My personal opinion scower the craigslist adds and ask here. I purchased a set of great B5's from a person in these forms who lives in Florida.

 

[BarryTurano]

Both the Prop Shop in Wilmington N.C. and Albemarle confirmed that they are D5's. Even stamped on the inside of the hub. I would keep my current set as a back up. Just wondering about the new I series because what I now have is discontinued.

 

[Scott Danforth]

The J series is supposed to replace the A and B props, the I series the D props. Not sure I believe the J series literature with their replacements. then again the original VP A and B series props have a flaw on the table (ratios and speeds dont make sense (higher ratios are shown faster than lower ratios which is not mathematically possible)

B series props are about $500 - 550 a pair new if you keep your eyes out. the D series can be found on ebay for under $400 (a set of D6's is on there for $385)

 

[BarryTurano]

Would B series or D6 work on a 24 Albemarle CC with a 250hp 5.0? Not sure if my hp is still 250. I converted from Fuel Injected to Carbed. I don't think that I lost any HP but I am really not sure. I have no way of knowing because I could never get the boat to run with the injection system.

 

[Scott Danforth]

you most likely did loose some HP going to carb. your boat came with D series props. if you have D5's now, you would need a bit more HP to swing the D6's unless your banging against the rev limiter. the A, B, and C series are for the AQ drives

 

[BarryTurano]

Thanks for the info. My max rpm is 4250. But I have a painted bottom. Albemarle told me that when it was built and sea trialed they had 4900 rpms with 1/2 fuel. She is not a real go fast boat. But a very comfortable ride. I cruise at about 24 mph. At my age I will trade speed for not being beaten to death.

 

[Scott Danforth]

If your only hitting 4250, your rpms are a bit low. Has it always been low for you? May want to drop down to D4's

 

[BarryTurano]

Going to D4 or I4 will give me a higher rpm. What will that do for me performance wise? By the way THANK YOU for the help.

 

[Scott Danforth]

You will be faster out of the hole on a D4 vs your current D5's

 

[BarryTurano]

Basically I am over propped!?

 

[Fun Times]

Basically I am over propped!?

Yes if your not hitting within your recommended engine RPM range....Provided the engine is running 100% correctly and is capable of reaching preferably the top end of the RPM range.

There should be (or should have been before the fuel system swap) a sticker somewhere near the top of the engine that mentioned the RPM range.

Though you removed the EFI system due to it not running correctly, do you by chance recall any old top RPM's reached with the EFI system still installed?

Did switching to the Carb seem to help with the overall performance especially the top end speed & RPM?

 

[Scott Danforth]

your albemarle weights in at 3900# at 24'. not sure you could spin the D5's properly to full RPM with a 5.0. as Fun Times asked, what was the RPM prior to pulling the EFI?

 

[BarryTurano]

Not sure what top end RPM was. The boat was not running properly when I bought it. Could not get over 2200 RPM's. Spent a fortune with a "mechanic" that was really a parts changer then decided to scrap the injection system for the carb. Boat now runs well. Just thinking that 4250 to 4400 rpm's is low. And if my my props are worn should I go the next down, if I can get the D series or go to the I series. Would going from a 5 to a 4 increase my rpm's? Would it translate to more efficient running. In order for me to run at 24 mph I am turning about 3650 rpm's. To me that seems to high compared to the max I can get.

 

[BarryTurano]

Just found this. It is for a 270HP mine is 250. Look at the wheel it is turning.
242 Center Console Test Boat: Single Volvo Penta 5.0 Osi, 270 hp Swinging F-3 propellers through a 1.95 to 1 reduction RPM

KTS / MPH GPH Naut./ Stat. MPG Range Naut. / Stat. 1000 4.6 5.2 1.0 4.6 5.2 488 551 1500 6.6 7.5 1.2 5.5 6.3 583 668 2000 7.9 8.9 2.3 3.4 2.6 360 276 2500 11.2 12.7 5.9 1.9 2.2 201 233 3000 15.0 16.9 7.7 1.9 2.2 201 233 3500 22.3 25.2 9.2 2.4 2.7 254 286 4000 27.4 31.0 12.0 2.3 2.6 244 276 4500 32.7 36.9 14.1 2.3 2.6 244 276 5060 37.6 42.5 21.0 1.8 2.0 191 212 Boat equipped with factory t-top, 100 gallons of fuel, and 3 people. Weather was 65 degrees, light chop, light wind.
Range is based on 106 gallons, 90% of vessel’s fuel capacity.
**These numbers represent a Performance test in normal operating conditions by the engine manufacturer.
Due to a wide range of variables, Albemarle Boats can not guarantee exact duplication of these numbers.

 

[evantful]

If I recall correctly Barry had a Volvo Penta 5.0Gi PWTR engine. The recommended RPM range for the PWTR's was 4800-5000rpm I believe

 

[Scott Danforth]

The F series is similar to the D series (again, different hub)
With a carb, your motor most likely isn't making 250hp anymore. Probably about 230

 

[BarryTurano]

Below is performance data after conversion. Now I need to run about 3670 RPM"s to run about 24-25 mph burning 16.7 gph (on flo scan). Could it be that my props are so worn that I am losing performance? If I am now putting out 230hp, should I go to a D4 or I4 rather than the D5 series that I now have Boat performance 1/25/15. Ran on ICW myself with 115 gallons of fuel + 35 gallons of fresh water in stern fish well for added weight, light winds.
RPM's	MPH	GPH	MPG	Direction
3350	24	12	2	North
3400	24.5	12.3	1.99	North
3470	28.4	12.6	2.25	North
3490	27.8	12.7	2.18	North
3510	28.2	12.7	2.22	North
3550	28	13.1	2.14	North
3570	30.5	11.5	2.65	North
3600	30.3	13.5	2.24	North
RPMs	MPH	GPH	MPG	Direction
3350	24.2	11.5	2.1	South
3400	25.7	11.5	2.23	South
3470	25.8	12	2.15	South
3540	29.2	13.2	2.21	South
3550	26.9	14	1.92	South
3550	29.5	13.4	2.2	South
3580	27.4	13.8	1.98	South
Best RPM 3470
Speed average 27.1 MPH
GPH Average 12.3 GPH
MPG Average 2.2 MPG

 

[BarryTurano]

This is what I tried to post on #15 But it makes more sense looking at it this way. Same boat as mine with more horsepower F3 Props. I have D5 props.
[h=1]242 Center Console[/h] Test Boat: Single Volvo Penta 5.0 Osi, 270 hp
Swinging F-3 propellers through a 1.95 to 1 reduction [h=3][/h] [h=3][/h]

RPM	KTS / MPH	GPH	Naut. / Stat. MPG	Range Naut. / Stat.
1000	4.6	5.2	1.0	4.6	5.2	488	551
1500	6.6	7.5	1.2	5.5	6.3	583	668
2000	7.9	8.9	2.3	3.4	2.6	360	276
2500	11.2	12.7	5.9	1.9	2.2	201	233
3000	15.0	16.9	7.7	1.9	2.2	201	233
3500	22.3	25.2	9.2	2.4	2.7	254	286
4000	27.4	31.0	12.0	2.3	2.6	244	276
4500	32.7	36.9	14.1	2.3	2.6	244	276
5060	37.6	42.5	21.0	1.8	2.0	191	212

Boat equipped with factory t-top, 100 gallons of fuel, and 3 people. Weather was 65 degrees, light chop, light wind. Range is based on 106 gallons, 90% of vessel?s fuel capacity.



**These numbers represent a Performance test in normal operating conditions by the engine manufacturer. Due to a wide range of variables, Albemarle Boats can not guarantee exact duplication of these numbers.

 

[Scott Danforth]

I would drop down to d4s.