Go Back   PowerStrokeArmy > Power Strokes > 7.3 Aftermarket

Reply
 
Thread Tools Display Modes
  #1  
Old 05-11-2018, 02:32 PM
Redrock2000's Avatar
Redrock2000 Redrock2000 is offline
Corporal
Member's Gallery
 
Join Date: Feb 2013
Location: Lubbock Texas
Posts: 59
Default Main cap walk/girdle ?

I was wondering at what point of hp or rpm have y'all actually seen main cap walk? Having built a few Ford big block gas engines I've saw main cap walk more associated with higher rpm and using even main studs increases main walk let alone a girdle doing anything but holding the broken parts together or at best absorbing harmonics. I know the differences in diesel and gas but Ive saw high compression 460 based 2 bolt main engines revving passed 6500 rpm on a regular basis making 800 hp or more with stock main bolts and 0 cap walk. The mains of a 7.3 block are twice what a 4 bolt big block are. Why the concern with cap walk with a 7.3 and at what point ? Thanks
  #2  
Old 05-11-2018, 03:02 PM
Arisley's Avatar
Arisley Arisley is offline
Mod Squad
Member's Gallery
 
Join Date: May 2011
Location: Arlington, Texas
Posts: 9,069
Default

A high compression gas engine would be a pretty low compression diesel engine. Not even considering throwing in 60 lbs. of boost of so.
__________________
E99 ECLB Dually, 2010 bed, 2005 headlights, smoked clearance lights, 2001 cup holder.
365,XXX miles. Pure stock, sorta.
SDRCM #478
PSA Conspirator # 22
  #3  
Old 05-11-2018, 05:11 PM
Redrock2000's Avatar
Redrock2000 Redrock2000 is offline
Corporal
Member's Gallery
 
Join Date: Feb 2013
Location: Lubbock Texas
Posts: 59
Default

So the higher cylinder pressure is the issue but at what point hp wise do you start to see cap walk? A 600 hp 7.3 doesn't see 60 psi of boost.
  #4  
Old 05-11-2018, 06:57 PM
DieselJpower's Avatar
DieselJpower DieselJpower is offline
Lieutenant
Member's Gallery
 
Join Date: Jun 2015
Location: Graham County NC
Posts: 723
Default

Quote:
Originally Posted by Redrock2000 View Post
A 600 hp 7.3 doesn't see 60 psi of boost.
Mine does
__________________
Josh
02 CCSB F350 4x4 -- GONE
04 Excursion 4x4 -- GONE
05 Excursion 4x4
19 CCSB F350 4x4
  #5  
Old 05-11-2018, 09:32 PM
ja_cain's Avatar
ja_cain ja_cain is offline
Colonel
Member's Gallery
 
Join Date: Aug 2013
Posts: 4,328
Default

You kind of need to stop thinking about it in terms of horspower. Instead you need to look at torque as an adjunct to cylinder pressure. Torque is going to directly correlate to cylinder pressures. Where as hp is a function of both torque and rpm.

Sent from my SM-G930V using Tapatalk
  #6  
Old 05-11-2018, 09:45 PM
m j m j is offline
Major
Member's Gallery
 
Join Date: Jan 2013
Location: BC Canada Eh!
Posts: 1,200
Default

fretting is not uncommon in diesel engines at stock power
__________________
Quote:
Originally Posted by Chvyrkr
BTS transmissions have the absolute top of the line hard parts and clutches, in every single one.....every once in a while that somebody like Mike O or Charles gets a different piece, because they've broken his normal piece.
  #7  
Old 05-11-2018, 10:05 PM
Redrock2000's Avatar
Redrock2000 Redrock2000 is offline
Corporal
Member's Gallery
 
Join Date: Feb 2013
Location: Lubbock Texas
Posts: 59
Default

Quote:
Originally Posted by m j View Post
fretting is not uncommon in diesel engines at stock power
That's something. How well do girdles prevent cap walk/fretting? My plan is to finish up my truck temporarily with a used forged engine while I build my original engine with Manley rods, block fill etc. My plan is to run 250/200 injector, either the up and coming KC s369 drop in or a T4 setup with a s467. And maybe some spray after while.
  #8  
Old 05-11-2018, 10:06 PM
Redrock2000's Avatar
Redrock2000 Redrock2000 is offline
Corporal
Member's Gallery
 
Join Date: Feb 2013
Location: Lubbock Texas
Posts: 59
Default

Quote:
Originally Posted by DieselJpower View Post
Mine does
Sorry didn't mean to sound like a know it all.
  #9  
Old 05-11-2018, 10:20 PM
ford_trck's Avatar
ford_trck ford_trck is offline
Sergeant
Member's Gallery
 
Join Date: May 2011
Location: Vail, AZ
Posts: 420
Default

I can make mine walk with a 6 speed and I'm only 400 HP. 4 high 3rd gear off the redline will shear a rib off the serpentine belt every time.
  #10  
Old 05-12-2018, 06:48 PM
Redrock2000's Avatar
Redrock2000 Redrock2000 is offline
Corporal
Member's Gallery
 
Join Date: Feb 2013
Location: Lubbock Texas
Posts: 59
Default

Quote:
Originally Posted by ford_trck View Post
I can make mine walk with a 6 speed and I'm only 400 HP. 4 high 3rd gear off the redline will shear a rib off the serpentine belt every time.
Wow I guess I am way off comparing to a gas motor. But how well does a girdle help?r
  #11  
Old 05-13-2018, 06:55 AM
ja_cain's Avatar
ja_cain ja_cain is offline
Colonel
Member's Gallery
 
Join Date: Aug 2013
Posts: 4,328
Default

Too bad you can't modify the block for splayed main caps. That along with some type of girdle qould probably be a pretty solid setup.

Sent from my SM-G930V using Tapatalk
  #12  
Old 05-13-2018, 09:58 AM
m j m j is offline
Major
Member's Gallery
 
Join Date: Jan 2013
Location: BC Canada Eh!
Posts: 1,200
Default

personally, even though I bought a girdle, I dont think they do anything.
IMO the block fill does more to help then a girdle.
__________________
Quote:
Originally Posted by Chvyrkr
BTS transmissions have the absolute top of the line hard parts and clutches, in every single one.....every once in a while that somebody like Mike O or Charles gets a different piece, because they've broken his normal piece.
  #13  
Old 05-13-2018, 12:56 PM
Magnum PD's Avatar
Magnum PD Magnum PD is offline
General
Member's Gallery
 
Join Date: May 2011
Location: VA
Posts: 8,486
Default

I’ll agree with that ^. Bedplate is far and beyond a girdle. Block fill for flex.
__________________
96 F-350 RC 4x4 Hypermax Rods, PIS 300/200s G head tunes, Garrett GT4294, Beans IDM, ARP head & main, girdle, half filled block, DI cam, Dual IPRs, ceramic coated bowls, anti-friction skirts, Haldex pump over Honey Badger Jr, Diesel site High volume lpop, Billet intake Plenums, Dual SD pumps, Fluidampner, beehive springs, cosmetic head gaskets, Inconel valves, hardend guides, Ported and polished heads by me, home made RR fuel, 5 speed tranny, with SB 3600 DxD. Snow water meth.
  #14  
Old 05-16-2018, 03:58 PM
Redrock2000's Avatar
Redrock2000 Redrock2000 is offline
Corporal
Member's Gallery
 
Join Date: Feb 2013
Location: Lubbock Texas
Posts: 59
Default

Thanks for the info y'all. I planned on doing a block fill but need to find a description on it that will upload pics. Anyone know of any?
  #15  
Old 05-16-2018, 08:08 PM
m j m j is offline
Major
Member's Gallery
 
Join Date: Jan 2013
Location: BC Canada Eh!
Posts: 1,200
Default

http://powerstrokearmy.com/forums/sh...ht=fill&page=2

mine are at the end of that thread
__________________
Quote:
Originally Posted by Chvyrkr
BTS transmissions have the absolute top of the line hard parts and clutches, in every single one.....every once in a while that somebody like Mike O or Charles gets a different piece, because they've broken his normal piece.
  #16  
Old 05-16-2018, 08:28 PM
Magnum PD's Avatar
Magnum PD Magnum PD is offline
General
Member's Gallery
 
Join Date: May 2011
Location: VA
Posts: 8,486
Default

For the record, I tow some and hadn’t had a problem yet with getting hot. But I don’t have a full fill. Just partial fill.
__________________
96 F-350 RC 4x4 Hypermax Rods, PIS 300/200s G head tunes, Garrett GT4294, Beans IDM, ARP head & main, girdle, half filled block, DI cam, Dual IPRs, ceramic coated bowls, anti-friction skirts, Haldex pump over Honey Badger Jr, Diesel site High volume lpop, Billet intake Plenums, Dual SD pumps, Fluidampner, beehive springs, cosmetic head gaskets, Inconel valves, hardend guides, Ported and polished heads by me, home made RR fuel, 5 speed tranny, with SB 3600 DxD. Snow water meth.
  #17  
Old 05-21-2018, 08:29 AM
DocBar's Avatar
DocBar DocBar is offline
Major
Member's Gallery
 
Join Date: May 2011
Location: Akron, Ohio
Posts: 1,329
Default

I've been running a high hp build for about 8-9 years with a girdle in it. I had no issues at all with main walk with a girdle. A cracked oil cooler and a wrist pin keeper, along with poor mechanic work, are the things that killed my truck. 1st time I've ever heard of a wrist pin keeper coming out and fragging a cylinder.
  #18  
Old 05-21-2018, 08:53 AM
Magnum PD's Avatar
Magnum PD Magnum PD is offline
General
Member's Gallery
 
Join Date: May 2011
Location: VA
Posts: 8,486
Default

Would have Swamp’s full circle wrist keeper pin helped in that situation?
__________________
96 F-350 RC 4x4 Hypermax Rods, PIS 300/200s G head tunes, Garrett GT4294, Beans IDM, ARP head & main, girdle, half filled block, DI cam, Dual IPRs, ceramic coated bowls, anti-friction skirts, Haldex pump over Honey Badger Jr, Diesel site High volume lpop, Billet intake Plenums, Dual SD pumps, Fluidampner, beehive springs, cosmetic head gaskets, Inconel valves, hardend guides, Ported and polished heads by me, home made RR fuel, 5 speed tranny, with SB 3600 DxD. Snow water meth.
  #19  
Old 05-22-2018, 03:03 PM
DocBar's Avatar
DocBar DocBar is offline
Major
Member's Gallery
 
Join Date: May 2011
Location: Akron, Ohio
Posts: 1,329
Default

Quote:
Originally Posted by Magnum PD View Post
Would have Swamp’s full circle wrist keeper pin helped in that situation?
I would assume so, but this is the 1st time I've encountered this. I never knew it could be an issue.
Reply

Thread Tools
Display Modes

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

Forum Jump


All times are GMT -6. The time now is 03:08 AM.

 

Powered by vBulletin®
Copyright ©2000 - 2018, vBulletin Solutions, Inc.

Designed by Military Ltd