what is your top speed, prop setup for 272 owners
#31
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I heard of a guy with the fastest 272 sr1 here that he gained a lot of speed with shorties , do a search "fastest 272 " you will find him. He did like 103mph, lots of power though.
#32
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we ditched the twin big blocks,,glassed up the transom,installed a ssm#5a. on a box-2up..in front of that we installed a 632..best speed with a 28p 4 blade was 96mph @ 5800..that was years ago and a few computor crash's ago..since them i pulled the engine,sold the drive and still have some parts like the crank from the 632..stringers were weak in the front part of the boat so we put it through a tree grinder and blew it into a friends field on his farm..
#33
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I have an '84' 272 and I'm at 57mph at 4000rpm and can't get a single rpm over 4000 with 23p props 3/4 tank of fuel and 3 people motors were rebuilt 2 years ago and sound great!! Just can't get above 4000rpm
#35
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I think you are over propped. Try a pair of 21" Mirage Plus...you will break 60 and run closer to 4500. You may also have bad tachometers...it does happen....but 23's are a bit much for stock 260 horse engines....you aren't at peak power which will be at about 4500~4600.
#37
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I've only topped her out a couple of times since I have had her both times she has been almost full of gas!! Mostly she is a cruiser will the 21p hurt my cruising speed and will it hurt to leave the 23p on it?
#39
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With the 23's, 65mph at a little over 5000 is about 12% slip which is probably accurate for a twin engine boat.
With the 25's, 63mph at 4200 is 4.8% slip. Sorry but old convential hulls arent that good so somethings is off.
Are they worked to 27s or something?? 27s at that speed and rpm would put you back in the 12% slip range.
With the 25's, 63mph at 4200 is 4.8% slip. Sorry but old convential hulls arent that good so somethings is off.
Are they worked to 27s or something?? 27s at that speed and rpm would put you back in the 12% slip range.
#40
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Ask about props, I believe labbing them helps them to cut into the water easier allowing you to spin them faster. All the blades are also made the same so they all push the same as opposed to one doing the most work and another the least.
If it allows your motors to unload up to 4800 rpm, that would be 68mph at the same 11%. Big if, call someone that knows what the heck they are talking about if you are really interested. How fast are your 454's supposed to spin? Is 4800 or 5000 within reason?
Brian