Rev 4 Prop Comparison
#1
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Location: Annapolis MD
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Rev 4 Prop Comparison
When I had the new motors installed last fall we installed the same 21 Rev 4's that I had been running on the old motors. They worked well but the max RPM was down from the mfg full throttle range a little (although the boat was 8 mph faster than with the old motors). This spring I got a set of 19 Rev 4's to bring up the max RPM. I was quite surprised (and disappointed) with the results, so last weekend I put the 21's back on. Speeds and mpg were back, but the river was too crowded to do a full throttle run so I only re-checked up to 5000 RPM.
Here are the comparison. Speeds are all GPS, but I didn't do two way runs so they can be off by +/- 1 mph based on the tide current speeds in my local river.
Economy cruise:
21" Rev 4000 RPM 38 mph 1.6 gph (from the Smartcraft)
19" Rev 4000 RPM 35 mph 1.4 gph
High Cruise:
21" Rev 5000 RPM 50 mph (didn't bother to look at mpg, but less than 1)
19" Rev 5000 RPM 45 mph
Max:
21" Rev 5800 RPM 58 mph
19" Rev 6000 RPM 51 mph
Boat: 32' Scorpion Racing (not a Chris Craft) Full fuel, about 8000 lbs
Motors: 250 Verado on 20" setback B-Bracket
-Greg
Here are the comparison. Speeds are all GPS, but I didn't do two way runs so they can be off by +/- 1 mph based on the tide current speeds in my local river.
Economy cruise:
21" Rev 4000 RPM 38 mph 1.6 gph (from the Smartcraft)
19" Rev 4000 RPM 35 mph 1.4 gph
High Cruise:
21" Rev 5000 RPM 50 mph (didn't bother to look at mpg, but less than 1)
19" Rev 5000 RPM 45 mph
Max:
21" Rev 5800 RPM 58 mph
19" Rev 6000 RPM 51 mph
Boat: 32' Scorpion Racing (not a Chris Craft) Full fuel, about 8000 lbs
Motors: 250 Verado on 20" setback B-Bracket
-Greg
#3
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Rick,
I'm very happy with the new motors. They are quiet, smooth and reliable. Recommended RPM is 5800-6400, so I'm technically in the range but many people recommended getting toward the top of the range so I thought I'd try the lower pitch prop. Just surprised at the major loss of speed across the board.
How's your boat running?
-Greg
I'm very happy with the new motors. They are quiet, smooth and reliable. Recommended RPM is 5800-6400, so I'm technically in the range but many people recommended getting toward the top of the range so I thought I'd try the lower pitch prop. Just surprised at the major loss of speed across the board.
How's your boat running?
-Greg
#4
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Rick,
I'm very happy with the new motors. They are quiet, smooth and reliable. Recommended RPM is 5800-6400, so I'm technically in the range but many people recommended getting toward the top of the range so I thought I'd try the lower pitch prop. Just surprised at the major loss of speed across the board.
How's your boat running?
-Greg
I'm very happy with the new motors. They are quiet, smooth and reliable. Recommended RPM is 5800-6400, so I'm technically in the range but many people recommended getting toward the top of the range so I thought I'd try the lower pitch prop. Just surprised at the major loss of speed across the board.
How's your boat running?
-Greg
#5
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Offshoreonly Advertiser
Bigger pitch almost always run better cruise speeds. The WOT numbers are strange. I expected 300-400 diference with a much closer speed.
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Brett Anderson / BBLADES Professional Propellers
920-295-4435 http://www.bblades.com/
[email protected]
Brett Anderson / BBLADES Professional Propellers
920-295-4435 http://www.bblades.com/
[email protected]