Notices

5000 on 7.4

Old 06-15-2005 | 07:21 PM
  #1  
mboger's Avatar
Thread Starter
Registered
 
Joined: Jun 2004
Posts: 247
Likes: 0
From: Lebanon OH
Default 5000 on 7.4

has anyone run a 7.4 at 5000 rpms and it held up decent
mboger is offline  
Reply
Old 06-15-2005 | 07:53 PM
  #2  
Hydrocruiser's Avatar
Gold Member
 
Joined: May 2004
Posts: 5,762
Likes: 1
Arrow Re: 5000 on 7.4

Originally Posted by mboger
has anyone run a 7.4 at 5000 rpms and it held up decent
I was told it does not have 4 bolt mains...and to keep it to 4800 RPM...but what's 200 RPM anyways right?
Hydrocruiser is offline  
Reply
Old 06-15-2005 | 10:50 PM
  #3  
Registered
 
Joined: Apr 2004
Posts: 123
Likes: 0
Re: 5000 on 7.4

200 more rpm could lead to a bucket full of piston fragments.
HOTTZU98 is offline  
Reply
Old 06-16-2005 | 02:04 AM
  #4  
tomas_wallin's Avatar
Registered
 
Joined: Jul 2004
Posts: 1,229
Likes: 0
From: Stockholm, Sweden
Default Re: 5000 on 7.4

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...
tomas_wallin is offline  
Reply
Old 06-16-2005 | 08:41 AM
  #5  
Registered
 
Joined: Mar 2005
Posts: 489
Likes: 0
From: Cape Cod, MA
Default Re: 5000 on 7.4

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.
tpenfield is offline  
Reply
Old 06-16-2005 | 05:03 PM
  #6  
Airpacker's Avatar
Registered
 
Joined: Aug 2001
Posts: 4,008
Likes: 3
From: Aurora Ontario
Default Re: 5000 on 7.4

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.
Airpacker is offline  
Reply
Old 06-16-2005 | 06:25 PM
  #7  
tomas_wallin's Avatar
Registered
 
Joined: Jul 2004
Posts: 1,229
Likes: 0
From: Stockholm, Sweden
Default Re: 5000 on 7.4

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
I assume that mboger is going to change something in the engine - cam etc. Otherwise - with a std 7,4 it won't do much of anything besides making the engine much more unreliable...

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.
tomas_wallin is offline  
Reply
Old 06-16-2005 | 08:20 PM
  #8  
mboger's Avatar
Thread Starter
Registered
 
Joined: Jun 2004
Posts: 247
Likes: 0
From: Lebanon OH
Default Re: 5000 on 7.4

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
mboger is offline  
Reply
Old 06-17-2005 | 03:51 AM
  #9  
tomas_wallin's Avatar
Registered
 
Joined: Jul 2004
Posts: 1,229
Likes: 0
From: Stockholm, Sweden
Default Re: 5000 on 7.4

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
Do you have cast or forged rods and pistons? If you have cast ones I read somewhere that 5psi boost is the maximum it will take.

Last edited by tomas_wallin; 06-17-2005 at 03:54 AM.
tomas_wallin is offline  
Reply
Old 06-17-2005 | 09:47 PM
  #10  
mboger's Avatar
Thread Starter
Registered
 
Joined: Jun 2004
Posts: 247
Likes: 0
From: Lebanon OH
Default Re: 5000 on 7.4

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
mboger is offline  
Reply
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
t500hps
General Boating Discussion
13
10-28-2008 04:15 PM
open87
General Boating Discussion
3
05-06-2008 11:02 AM
LapseofReason
Nor-Tech
4
09-07-2005 12:15 AM
OldSchool
General Boating Discussion
24
08-04-2005 07:37 AM

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On


Contact Us - Archive - Advertising - Cookie Policy - Privacy Statement - Terms of Service

Copyright © 2026 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.