Go Back  Offshoreonly.com > Technical > Do It Yourself, Boating on a Budget
8.1 liter forged rods and pistons >

8.1 liter forged rods and pistons

Notices

8.1 liter forged rods and pistons

Thread Tools
 
Old 11-18-2013 | 02:19 PM
  #21  
MER Performance's Avatar
Platinum Member
 
Joined: Jul 2008
Posts: 931
Likes: 0
From: Little River SC
Default

Originally Posted by fastestonehere
Anybody have a torque honing plate for rental. My engine shop does not have one for this motor
Before I buy one I thought I would see if anybody help a brother out. I have one on hold for a few days just incase
Sorry, no; about the only one I don't have a alum or steel plate for. The deck and cylinders are pretty thick, so hardly any deflection.
MER Performance is offline  
Reply
Old 11-18-2013 | 05:03 PM
  #22  
Thread Starter
Registered
 
Joined: Dec 2010
Posts: 149
Likes: 0
Default

Originally Posted by MER Performance
Sorry, no; about the only one I don't have a alum or steel plate for. The deck and cylinders are pretty thick, so hardly any deflection.
Are you saying it should be safe to NOT use one. Also can anybody tell me if the marine heads use different valves than GM 8.1 trucks? If not the same anybody have the valve replacement part numbers for SS and Inconel. And maybe a few venders with them in stock as well.

Thank you all for the help I'm not trying to be cheap just cheaper than new drop in's or 525's
fastestonehere is offline  
Reply
Old 11-19-2013 | 05:32 PM
  #23  
Thread Starter
Registered
 
Joined: Dec 2010
Posts: 149
Likes: 0
Default

Originally Posted by fastestonehere
Are you saying it should be safe to NOT use one. Also can anybody tell me if the marine heads use different valves than GM 8.1 trucks? If not the same anybody have the valve replacement part numbers for SS and Inconel. And maybe a few venders with them in stock as well.

Thank you all for the help I'm not trying to be cheap just cheaper than new drop in's or 525's
1 last thing what is the hp potential of factory crank. I'm sure I will not be close to it just checking
fastestonehere is offline  
Reply
Old 11-20-2013 | 08:19 AM
  #24  
Registered
 
Joined: Jul 2011
Posts: 821
Likes: 0
From: mirabel,qc
Default

I asked Ray at Raylar (2 years ago) about the crank...I was told 750-800hp; he told me not to worry, at my power level (625-650hp)
pqjack is offline  
Reply
Old 11-20-2013 | 08:21 AM
  #25  
Gold Member
15 Year Member
Gold Member
 
Joined: Jul 2008
Posts: 3,748
Likes: 869
From: Delray Beach, FL
Default

Originally Posted by pqjack
I asked Ray at Raylar (2 years ago) about the crank...I was told 750-800hp; he told me not to worry, at my power level (625-650hp)
Thats what I heard from Dustin too.
Keith Atlanta is offline  
Reply
Old 11-20-2013 | 02:55 PM
  #26  
MER Performance's Avatar
Platinum Member
 
Joined: Jul 2008
Posts: 931
Likes: 0
From: Little River SC
Default

Get above the 800 with the stock nodular will break. Raylar, tried to tell me the stock would break at the snout where the pin is that indexes the timing gear. Found out from my crank expert all the diesel cranks are drilled the same way for round pin. They are drilled preventing stress risers, with a step. The diesel guys weld the gear to prevent shearing the pin in high HP applications.
MER Performance is offline  
Reply
Old 11-20-2013 | 08:59 PM
  #27  
Thread Starter
Registered
 
Joined: Dec 2010
Posts: 149
Likes: 0
Default

Originally Posted by MER Performance
Get above the 800 with the stock nodular will break. Raylar, tried to tell me the stock would break at the snout where the pin is that indexes the timing gear. Found out from my crank expert all the diesel cranks are drilled the same way for round pin. They are drilled preventing stress risers, with a step. The diesel guys weld the gear to prevent shearing the pin in high HP applications.
Thanks MER performance very helpful lead you gave me
fastestonehere is offline  
Reply
Old 08-03-2020 | 03:39 PM
  #28  
Registered
 
Joined: Aug 2020
Posts: 2
Likes: 0
Default

Would there be any disadvantage, or any reason that you couldn't use 6.385 lenght rods and the correct bore BBC pistons with the correct compression height for the block to build an 8.1 and overcome the top ring land weakness of the factory style piston, and forged versions that are set up the same way?
wjbeasleyjr is offline  
Reply
Old 08-06-2020 | 12:40 PM
  #29  
Registered
5 Year Member
 
Joined: Dec 2016
Posts: 587
Likes: 366
From: Portland OR
Default

I recently purchased the off the shelf Wiseco pistons for the 8.1 and discovered they made the top ring land thicker than the factory pistons. I'ts .300" thick in the Wiseco. The stock pistons are .200" on the top land. Both pistons have the same .180" on the second land.


Last edited by 87MirageIntruder; 08-06-2020 at 01:01 PM.
87MirageIntruder is offline  
Reply
Old 08-07-2020 | 10:22 PM
  #30  
Registered
 
Joined: Aug 2020
Posts: 2
Likes: 0
Default

Good to know. Thanks.
wjbeasleyjr is offline  
Reply

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.