5000 on 7.4
#1
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Join Date: Jun 2004
Location: Lebanon OH
My Boat: 1997 24convincer
Posts: 247

has anyone run a 7.4 at 5000 rpms and it held up decent
#2

Originally Posted by mboger
has anyone run a 7.4 at 5000 rpms and it held up decent

#3
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Join Date: Apr 2004
Posts: 123
Re: 5000 on 7.4
200 more rpm could lead to a bucket full of piston fragments.
#4

According to the feedback i have got it should not be any problem. I am going to rev my own rebuilt 7,4 Gen V (1995) to 5100rpm...
#5
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Join Date: Mar 2005
Location: Cape Cod, MA
My Boat: 1996 Formula 330SS, 1991 242SS
Posts: 476

Rev as high as you want, it is your engine.
Keep in mind that at that RPM range you are on the down side of the horsepower curve and that those extra revs generally come at the expense of torque.
Keep in mind that at that RPM range you are on the down side of the horsepower curve and that those extra revs generally come at the expense of torque.
#6
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Join Date: Aug 2001
Location: Aurora Ontario
My Boat: little cat...BIG MOTOR
Posts: 4,008

I ran my old 330 ( 7.4) to 5200 for 360 hrs intermittently after a cam and intake change before I rebuilt it. It has 4 bolt mains but it also has a cast crank and pistons and small rod bolts.
#7

Rev as high as you want, it is your engine.
Keep in mind that at that RPM range you are on the down side of the horsepower curve and that those extra revs generally come at the expense of torque.decent
Keep in mind that at that RPM range you are on the down side of the horsepower curve and that those extra revs generally come at the expense of torque.decent
The cam I put in my 454 has rpm range 1600-5800 and I will set the rpm limit to 5100 to make the engine last.
#8
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Join Date: Jun 2004
Location: Lebanon OH
My Boat: 1997 24convincer
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Im running the 7.4 with a stage one procharger on it now with a 28 labbed bravo prop and running 71 on gps at 4700 rpms and thinking about changing the pulley on blower to raise the boost from 5lbs to 7lbs and would like to put the rev limiter up to 5000
#9

Originally Posted by mboger
Im running the 7.4 with a stage one procharger on it now with a 28 labbed bravo prop and running 71 on gps at 4700 rpms and thinking about changing the pulley on blower to raise the boost from 5lbs to 7lbs and would like to put the rev limiter up to 5000
Last edited by tomas_wallin; 06-17-2005 at 04:54 AM.
#10
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Join Date: Jun 2004
Location: Lebanon OH
My Boat: 1997 24convincer
Posts: 247

I have cast so will probably leave it alone this year and put bigger power in it during the winter thanks everyone for all the info
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