Go Back  Offshoreonly.com > Technical > General Q & A
454 To A 502? >

454 To A 502?

Notices

454 To A 502?

Thread Tools
 
Old 07-28-2006 | 08:06 AM
  #1  
DURANGOKID59's Avatar
Thread Starter
Registered
 
Joined: Apr 2006
Posts: 294
Likes: 0
From: Traverse City MI
Default 454 To A 502?

Well, its looking like Im going to have to bite the bullet and toss a new motor in the Outlaw. It currently has a stock 454 mag carb. Since I have to put a long block in it, I was thinking of maybe going to a 502 since the money difference is fairly close. I need some opinions on what to do? Benefits, negatives, problems with the switch? Ive also heard that I may need to switch the gear ratio in the outdrive to move to a 502. Is there a way to find out what ratio I have now, and what I would have to switch to? Let me know your opinions. Thanks guys.
DURANGOKID59 is offline  
Reply
Old 07-28-2006 | 08:17 AM
  #2  
mopower's Avatar
Toxic FORMULA
 
Joined: May 2002
Posts: 4,238
Likes: 1
From: pitman nj
Default Re: 454 To A 502?

You probably have a 1.5 ratio if you're running a Bravo with you 454. Since the money difference you're talking about is small , you must be talking about a mild 502. At worst , you'll have to change that prop to a higher pitch. Gear changes are only necessary with MAJOR horsepower gains.
Depending on what you're turning you 454 (say 4500) the 502 may turn 5000. You pick up a few rpms and a few mph and NO other changes.
I'd go for it
mopower is offline  
Reply
Old 07-28-2006 | 08:22 AM
  #3  
DURANGOKID59's Avatar
Thread Starter
Registered
 
Joined: Apr 2006
Posts: 294
Likes: 0
From: Traverse City MI
Default Re: 454 To A 502?

Thanks for the reply. Yeah, Im talking a stock 454 to a stock 502. What kind of horse power gains can I expect stock to stock? So basically instead of gear change just a reprop then. Any idea what to run for a prop, going with the 502? Its a 24 Outlaw, if that helps at all.
DURANGOKID59 is offline  
Reply
Old 07-28-2006 | 09:00 AM
  #4  
duksrule's Avatar
Registered User
 
Joined: Dec 2002
Posts: 151
Likes: 0
From: Virginia Beach, Va
Default Re: 454 To A 502?

Not sure about your 454 but my 502s are rated at 415 HP. If the money is close, I don't see a down side to going to the bigger motor. The wieght should be close to the same.
duksrule is offline  
Reply
Old 07-28-2006 | 09:05 AM
  #5  
DURANGOKID59's Avatar
Thread Starter
Registered
 
Joined: Apr 2006
Posts: 294
Likes: 0
From: Traverse City MI
Default Re: 454 To A 502?

Originally Posted by duksrule
Not sure about your 454 but my 502s are rated at 415 HP. If the money is close, I don't see a down side to going to the bigger motor. The wieght should be close to the same.
Are your 502's just stock 502 crate motors with that horsepower, or are they a built motor by an engine builder?
DURANGOKID59 is offline  
Reply
Old 07-28-2006 | 09:12 AM
  #6  
Registered
20 Year Member
 
Joined: Jun 2004
Posts: 1,949
Likes: 37
From: Omaha, Nebraska. Boat on the Mighty Mo! Longest river in the USA!
Default Re: 454 To A 502?

Whats wrong with the current engine?

It might be allot cheaper to use existing parts and stroke it to a 496, love mine it has allot of get up and go
1BIGJIM is offline  
Reply
Old 07-28-2006 | 09:30 AM
  #7  
DURANGOKID59's Avatar
Thread Starter
Registered
 
Joined: Apr 2006
Posts: 294
Likes: 0
From: Traverse City MI
Default Re: 454 To A 502?

Originally Posted by 1BIGJIM
Whats wrong with the current engine?

It might be allot cheaper to use existing parts and stroke it to a 496, love mine it has allot of get up and go
Basically long story short, I sucked water in to the #7 piston, and bent the valve, trashed a piston, and thats as far as I have gotten so far. I cant see a cracked block or anything, but Im guessing internals are trashed also. The other problem being is the guy I bought the boat from failed to tell me at initial purchase that it has a cam in it for a truck motor along with some other internals Im not so fond of, so using existing parts may not be an option. At this point Im just trying to get ideas as the best way to run with it.
DURANGOKID59 is offline  
Reply
Old 07-28-2006 | 11:20 AM
  #8  
duksrule's Avatar
Registered User
 
Joined: Dec 2002
Posts: 151
Likes: 0
From: Virginia Beach, Va
Default Re: 454 To A 502?

Originally Posted by DURANGOKID59
Are your 502's just stock 502 crate motors with that horsepower, or are they a built motor by an engine builder?
Stock motors.
duksrule is offline  
Reply
Old 07-28-2006 | 11:26 AM
  #9  
t500hps's Avatar
21 and 42 footers
20 Year Member
Platinum Member
Super Moderators
 
Joined: Sep 2004
Posts: 8,207
Likes: 146
From: Richmond VA
Default Re: 454 To A 502?

Look in the Swap Shop. Someone put a complete 502 mag up for $3,500.
t500hps is offline  
Reply
Old 07-28-2006 | 11:42 AM
  #10  
Registered
 
Joined: Mar 2006
Posts: 302
Likes: 1
From: upstae ny
Default Re: 454 To A 502?

well i'd stroke your engine to 496,good cylinder heads,should get 550 hp without a problem and be cheaper than 502
awsomethunder is offline  
Reply


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.