Pressed in verus Floating wrist pins

Thread Tools
 
Search this Thread
 
  #1  
Old 03-22-2012, 08:59 AM
85bobtail's Avatar
85bobtail
85bobtail is offline
Senior User
Thread Starter
Join Date: Aug 2010
Location: Coastal-SC
Posts: 111
Likes: 0
Received 0 Likes on 0 Posts
Pressed in verus Floating wrist pins

Needs some advise on couple of wrist pin issues:

1-Is there an advantage of a floating wrist pin over the pressed in. I have noticed that the floating or bushed type are a few $ more and that they have larger bolts-7/16 instead of 3/8 (Eagle SIR 5956 FB rods)

2-I have a new set of Sealed Power pistons (H336CP) for my 351 W and the spec say pressed wrist pin. Can you use a bushed connecting rod with these pistons?

Thanks for the help!
 
  #2  
Old 03-22-2012, 09:44 PM
baddad457's Avatar
baddad457
baddad457 is offline
Post Fiend
Join Date: May 2003
Location: south louisiana
Posts: 11,122
Likes: 0
Received 14 Likes on 14 Posts
Those pistons lack the grooves in the wrist pin bores to install either lock rings or spirolocs to retain the pins in the bores. And unless you're building an engine for dedicated racing only, pressed pins are fine. Floating pins are nice to have, but hardly necessary for 99% of applications. They're also nice in that you can mount the pistons on the rods yourself instead of having to pay a machineshop to do it for you.
 
  #3  
Old 03-22-2012, 11:38 PM
jimbbski's Avatar
jimbbski
jimbbski is offline
Elder User
Join Date: Nov 2009
Location: Chicago area
Posts: 666
Likes: 0
Received 0 Likes on 0 Posts
What he said.

I have rebuilt a number of engines that either came stock with floating pins or were rebuilt with that type of piston and being able to assemble your own piston/rod combo instead of paying a shop to do it is nice. My last build for someone else was a 4 cyl engine and it cost me $100 in labor to install the piston on the rod.
 
  #4  
Old 03-30-2012, 07:17 AM
85bobtail's Avatar
85bobtail
85bobtail is offline
Senior User
Thread Starter
Join Date: Aug 2010
Location: Coastal-SC
Posts: 111
Likes: 0
Received 0 Likes on 0 Posts
Thanks
My research shows that if the piston isn't listed for a floating pin, then you need to use the pressed in pins. If I every build another engine, I will go with floating pin pistons (since the bolts are bigger-7/16 vs. 3/8). I guess the cash cow will get bigger as I shell out to get the rods pressed on the pistons
 
  #5  
Old 03-30-2012, 07:48 AM
baddad457's Avatar
baddad457
baddad457 is offline
Post Fiend
Join Date: May 2003
Location: south louisiana
Posts: 11,122
Likes: 0
Received 14 Likes on 14 Posts
Originally Posted by 85bobtail
Thanks
My research shows that if the piston isn't listed for a floating pin, then you need to use the pressed in pins. If I every build another engine, I will go with floating pin pistons (since the bolts are bigger-7/16 vs. 3/8). I guess the cash cow will get bigger as I shell out to get the rods pressed on the pistons
Rod bolt size has nothing to do with floating vs pressed pins. My 331 has floating pins and 3/8 bolts.
 
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
cfrazier77
1973 - 1979 F-100 & Larger F-Series Trucks
3
06-05-2010 12:53 AM
pud
Performance & General Engine Building
6
08-28-2006 11:14 AM
PyroBob
Performance & General Engine Building
5
04-06-2006 05:04 PM
sancochojoe
Small Block V8 (221, 260, 289, 5.0/302, 5.8/351W)
4
01-17-2005 05:44 AM
garysvan
Ford Inline Six, 200, 250, 4.9L / 300
1
03-14-2004 11:09 AM



Quick Reply: Pressed in verus Floating wrist pins



All times are GMT -5. The time now is 12:49 PM.