How many RPMs 89 2001 with 1.23:1
Printed From: CorrectCraftFan.com
Category: Repairs and Maintenance
Forum Name: Boat Maintenance
Forum Discription: Discuss maintenance of your Correct Craft
URL: http://www.CorrectCraftFan.com/forum/forum_posts.asp?TID=14471
Printed Date: November-17-2024 at 8:47pm
Topic: How many RPMs 89 2001 with 1.23:1
Posted By: hunterdan
Subject: How many RPMs 89 2001 with 1.23:1
Date Posted: July-15-2009 at 10:42am
Hello
I just installed my new Acme 470 last night and it seems I can run a lot more RPMs now. According to the tach in the boat I am close to 5000 a WOT. Is this normal?? Is this ok for the motor and trans?? Is the tach in the boat normally pretty accurate??
Other than that, the first test drive was GREAT! What a difference, I need to get the GPS out and see what the top end speed is now. I was aat about 41-42, so it will be interesting to see what it goes to. the motor seems to rev way faster, and over all the boat is much smoother!
Thanks for all the great posts on this prop!
Dan
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Dan
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Replies:
Posted By: azeus17
Date Posted: July-15-2009 at 12:08pm
5000 RPMs should be fine
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Boats:
Current: 02 SANTE
Sold: 89 Sport Nautique
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Posted By: TRBenj
Date Posted: July-15-2009 at 3:02pm
5k RPM's wont hurt the bottom end- the 351w is strong (I turn mine 5200+)... but its not ideal since your peak power is still around 4400. Im surprised youre turning that many revs- I only got 4600 with my 470 on the stock motor (with the DUI ignition)... about 200 RPM more than the 4-blade OJ 13x16. Now its possible that your '89 has a much faster hull than mine (which is very slow) and may be turning a few extra revs, but 400 is a lot! Get a GPS on the boat and that will tell us if your tach is accurate. My 4600 RPM translated to 43mph, so I would expect you to be in the 46-47 mph range if youre actually getting a true 5k.
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Posted By: Luchog
Date Posted: July-15-2009 at 3:36pm
Tr, what prop would turn 2800-3200rpms in a heavy loaded 93SN hull with a GM 290hp and 1.23:1 at 22mph?
1458 13x14 .135c????
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http://www.correctcraftfan.com/diaries/details.asp?ID=2095" rel="nofollow - 1980 Ski Nautique
Commander 351W
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Posted By: TRBenj
Date Posted: July-15-2009 at 3:41pm
Luch, that BFN prop might get you close- but thats just a guess. Too many variables to say for sure, as I dont load my boat up and Ive got a Ford with a few more ponies. I overturn by 200 or so at skiing speeds (30-36) with the 1442, but the slip at 22 may be greater.
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Posted By: Luchog
Date Posted: July-15-2009 at 3:49pm
first of all thanks for your help always.
The 1598 might even turn a few more rpms since it has less cup.
I'm actually selling ACME props down here, the problems are they are a bit expensive for us so clients want to get the right one the first time, and there's no standarized production on boats so every one is different from the other. Most want them for wakeboard on heavy loads so I always try to put boarding speed on the best torque range for the engine while watching for wot range.
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http://www.correctcraftfan.com/diaries/details.asp?ID=2095" rel="nofollow - 1980 Ski Nautique
Commander 351W
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Posted By: kapla
Date Posted: July-15-2009 at 7:01pm
lucho mmmm sn with a bowtie, ...sounds like a victoria!!! at least they put some decent power and not the Y ford!!!
LOL
on the other thing was that engine finally a C?
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<a href="">1992 ski nautique
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Posted By: Luchog
Date Posted: July-15-2009 at 9:12pm
Kapla, never found out about that engine, my bet is it was not, I dont know if the PCM exhaust manifolds would fit a Cleveland.
This guy asked for a wakeboarding prop for a Victoria, nice thing he got the PCM reduction gear, it allows for much more pull.
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http://www.correctcraftfan.com/diaries/details.asp?ID=2095" rel="nofollow - 1980 Ski Nautique
Commander 351W
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Posted By: SNobsessed
Date Posted: July-15-2009 at 10:07pm
Dan - I had a 470 on my '89 & the RPMs were much the same as yours.
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“Beer is proof that God loves us and wants us to be happy.”
Ben Franklin
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Posted By: kapla
Date Posted: July-16-2009 at 12:32am
lucho
choice would be the 1442....almost same config as my boat...
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<a href="">1992 ski nautique
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Posted By: SNobsessed
Date Posted: July-16-2009 at 10:52am
Kapla - That is what I just bought last week - brought the RPM down (at 23 MPH) by 200 RPM. I think this will save gas.
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“Beer is proof that God loves us and wants us to be happy.”
Ben Franklin
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Posted By: hunterdan
Date Posted: July-16-2009 at 11:02am
I put the GPS in last night, it showed around 45mph. The tach is just under 5K so I guess I am ok. Thank you for all your input, I was just shocked to see it up that high, I was at around 4500 with the old prop.
Thanks again for all the help, and thanks to TRBenj for all his great threads on Acme props, it helped me to make a difficult decision!
Dan
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Dan
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