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470 RPMbs

E

ed sicoa

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"This question has probably be

"This question has probably been asked a hundred times but, what is the rpm range on a 470 merc. motor? My boat is a 22'2 Aquasport cuddy(heavy boat)with a 19" pitch prop. Boat would only turn around 3200rpm's.(motor was bogging down) went to a 15" pitch, and now turns 4200. Woke motor right up. I read somewhere that this motor is more of a torque motor then a higher rpm motor."
 
I can get 5000 out of mine at

I can get 5000 out of mine at WOT. Redline is 5100. But my boat is only weighs 2500 lbs. Yes read the label on the motor. Do you have a single or twins? That seems like a big boat for the motor. What speed do you get with the new prop at WOT?
 
It has just one motor. Top spe

It has just one motor. Top speed is only 22mphs. And your right about this motor being too small for this boat. It needs a v-8.
 
Put in a 220HP 4.3L V-6 and it

Put in a 220HP 4.3L V-6 and it will fly like a rocket. Install a 6.1L V-8 and she'll fly like the SR-71 Blackbird spyplane and put you in the poorhouse.
 
"My understanding is that the

"My understanding is that the 470 is made with off the shelf Ford 460 internals (pistons, rods). Think the cast iron head is right off a Ford 460. Based on that i would expect similar top end RPMs. Last one i had in a 19 foot boat was load limited to about 4800. I wouldn't want to turn em up any faster than that for any length of time. Not the most reputable motor for durability."
 
"[b]"I can get 5000 out of

""I can get 5000 out of mine at WOT. Redline is 5100."

Ayuh,....

You need a Bigger Prop, or you're going to Blow Up that motor...

The 470 shouldn't be spun more than 4600/ 4800rpms/ WOT...."
 
"Bondo: You're probably ri

"Bondo: You're probably right, it has a 4 blade SS that came on the boat when I got it. Don't what size or pitch it is. The guy I bought it from used the boat mainly for water skiing. That prop does give the boat a pretty good hole shot for that purpose.

I have only taken up to WOT twice since I've owned it just to clear the carbon out a little. I mainly cruise at 3400-3800 RPMs and 4000 when cruising fast. At those speeds I get a pretty respectable 3.5 - 4.0 GPH fuel useage, it's hard to give that up. I do have the OEM merc prop, I may put that on next year and see what WOT is. I've never worried about blowing up the motor because I am usually not a speed demon. I would rather cruise with a drink in my hand and enjoy the time on the water. Thanks for the heads up."
 
"Ayuh,....

Something else t

"Ayuh,....

Something else to ponder,...

If you go Up in pitch,....
Your cruising rpms will be Lower,...
Which should give you Better fuel economy,+ make your motor last longer, as the pistons travel a shorter distance to move the boat per mile.....
Especially since you're Not a speed demon,+ are Not water sking.....

Just don't Over-prop it,...
That leads to Detonation,+ Destroyed motors....
I'd shoot for 4400rpms @ WOT for your particular application...
Normal to light load,+ perfect water conditions of course..."
 
"Ayuh,... I don't know wha

"Ayuh,... I don't know what you've Got...

If it were Me,...
I'd buy a Prop with 4" More pitch,+ throw the 1 you've got down in the boat for a Spare...

Repitching is usually only good for an Inch,.. Not near enough for the Revs you're spinning..."
 
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