Go Back  Offshoreonly.com > General Discussion > General Boating Discussion
What would you do - swap or rebuild? >

What would you do - swap or rebuild?

Notices
General Boating Discussion

What would you do - swap or rebuild?

Thread Tools
 
Old 08-13-2007 | 04:15 PM
  #1  
Thread Starter
Registered
20 Year Member
 
Joined: Aug 2005
Posts: 705
Likes: 88
From: South FL
Default What would you do - swap or rebuild?

Those of you who have followed the Swampy saga know that my carbed 502s (one counter rotating) were built by Bills Marine in FLL and have never worked right - couple of booms later and a few years of unreliable hassle, my port motor locked up while sitting at the dock for 10 days - no aparent reason.....I've had it.

So my thought process is as follows:

1) Pull both motors (since I don't trust them or know what is in them) and swap the for 540 or 572 long blocks and change out the borg warners 1.5:1 transmissions for 72Cs at 2:1 (so that there is more ratio and so I can run two normal rotation motors). This would cost $16k plus transmissions and I'd have to buy regular rotation alternator, starters etc.

2) Find a reliable local engine builder and have them take my existing motors, add cubes, go through everything and dyno them ... put them back in the boat and hope more HP/Torque will work with existing trans ratios. For a pair of 500hps - this would cost me about $12k plus transmissions if I change them out. I'd prefer more HP/Tq but not sure what that would run yet.

Your thoughts?
Swamplizard is offline  
Reply
Old 08-13-2007 | 04:29 PM
  #2  
pkspx's Avatar
Gold Member
 
Joined: Sep 2003
Posts: 1,225
Likes: 2
From: Fort Lauderdale, FL
Default

Originally Posted by Swamplizard
Those of you who have followed the Swampy saga know that my carbed 502s (one counter rotating) were built by Bills Marine in FLL and have never worked right - couple of booms later and a few years of unreliable hassle, my port motor locked up while sitting at the dock for 10 days - no aparent reason.....I've had it.

So my thought process is as follows:

1) Pull both motors (since I don't trust them or know what is in them) and swap the for 540 or 572 long blocks and change out the borg warners 1.5:1 transmissions for 72Cs at 2:1 (so that there is more ratio and so I can run two normal rotation motors). This would cost $16k plus transmissions and I'd have to buy regular rotation alternator, starters etc.

2) Find a reliable local engine builder and have them take my existing motors, add cubes, go through everything and dyno them ... put them back in the boat and hope more HP/Torque will work with existing trans ratios. For a pair of 500hps - this would cost me about $12k plus transmissions if I change them out. I'd prefer more HP/Tq but not sure what that would run yet.

Your thoughts?
Get them rebuilt since you already have the engines. Dean Gellner of Gellner Engineering can help you sort it out and get it up and running again. He will tare them apart, inspect them and quote you what you need to make them reliable again. Not only can he rebuild them, He can mod them to whatever setup you want to run. They do all of their machining in house. Dean also has a dyno shop so that wouldn't be a problem at all, one stop shop. Call him at his shop 216-398-8500.

Last edited by pkspx; 08-13-2007 at 04:31 PM.
pkspx is offline  
Reply
Old 08-19-2007 | 09:26 AM
  #3  
Thread Starter
Registered
20 Year Member
 
Joined: Aug 2005
Posts: 705
Likes: 88
From: South FL
Default

Thanks for the lead. I have a good guy here locally that I trust and does good work - the new questions is:

Do I have him rebuild them and get me 510 cubes and 500 hp or do I buy a pair of 540 or 572 short blocks and have him move all my stuff over, dyno and tune? I could then sell the existing blocks or keep them as spares?

Decent short blocks would be around $4k, labor and dyno would add ?????? compared to $5500 each to rebuild and dyno what I already have.

What makes the most sense for a heavy cruiser?

What
Swamplizard is offline  
Reply
Old 08-19-2007 | 09:35 AM
  #4  
Registered
 
Joined: Feb 2001
Posts: 62
Likes: 0
From: houston texas
Default

I would work with what you have now and not have to
move things around. That will give you some decent
power for that big ol Harley...........nice riding boats
captdave is offline  
Reply
Old 08-19-2007 | 10:41 AM
  #5  
cuda's Avatar
Banned
 
Joined: Sep 2001
Posts: 25,191
Likes: 0
From: Deland, Florida
Default

I'd rebuild what I have with a GOOD builder, or I'd do it myself.
cuda is offline  
Reply
Old 08-19-2007 | 11:37 AM
  #6  
Registered
 
Joined: Mar 2004
Posts: 726
Likes: 10
From: Miami, FL
Default

I would say before you took the final decision have your engines disassembled and inspect all your components such as the block heads and hard components to make sure they are worhty of a good build without any weekness such as heavy corrosion in the water jackets in the blocks or the heads and no cracks from previous damage.This will not be too costly and may save you trouble later . Best of luck to you I know you've been contemplating this for a while.Sincerely Laz
MESABALANCING is offline  
Reply
Old 08-19-2007 | 11:44 AM
  #7  
cuda's Avatar
Banned
 
Joined: Sep 2001
Posts: 25,191
Likes: 0
From: Deland, Florida
Default

Originally Posted by MESABALANCING
I would say before you took the final decision have your engines disassembled and inspect all your components such as the block heads and hard components to make sure they are worhty of a good build without any weekness such as heavy corrosion in the water jackets in the blocks or the heads and no cracks from previous damage.This will not be too costly and may save you trouble later . Best of luck to you I know you've been contemplating this for a while.Sincerely Laz
That is very sound advice.
cuda is offline  
Reply
Old 08-20-2007 | 07:08 AM
  #8  
Thread Starter
Registered
20 Year Member
 
Joined: Aug 2005
Posts: 705
Likes: 88
From: South FL
Default

thanks guys - that is the plan
Swamplizard is offline  
Reply
Old 08-20-2007 | 08:48 AM
  #9  
Registered
15 Year Member
 
Joined: Jan 2007
Posts: 6,473
Likes: 357
From: Mansfield, TX
Default

I think that replacing the engines would be better for resale.
TexomaPowerboater is offline  
Reply
Old 05-31-2009 | 01:05 PM
  #10  
Thread Starter
Registered
20 Year Member
 
Joined: Aug 2005
Posts: 705
Likes: 88
From: South FL
Default

diesels would be best for resale but ....... $$$CHAching$$$$
Swamplizard is offline  
Reply
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
fast22
Drives and Lower Units
7
06-04-2008 01:05 PM
Cigaretteman
General Q & A
3
04-12-2004 08:53 AM
Ailina
General Q & A
0
01-21-2004 12:12 PM
traviss
General Q & A
9
11-21-2003 06:16 PM
mikev
General Q & A
10
12-13-2002 09:10 PM

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.