LT1 Based Engine Tech 1993-1997 LT1/LT4 Engine Related

5.7 or 6 inch rods??

Thread Tools
 
Search this Thread
 
Old May 27, 2004 | 05:04 PM
  #1  
97SS0594's Avatar
Thread Starter
Registered User
 
Joined: Jul 2002
Posts: 1,651
From: baycity, mi
5.7 or 6 inch rods??

ive been searching but i cant get a exact answer.. im about to order my forged 383stroker kit, and i plan on juicin a 200 shot or so, but the question is, which rods are going to better suit my project?? im burrying alot of money into this, so i want it done right so i have no regrets. thanks in advance!!
Old May 27, 2004 | 05:10 PM
  #2  
simple's Avatar
Registered User
 
Joined: Apr 2001
Posts: 2,195
From: Springfield, IL
<--(n00b)..

5.85".......$$$ but best of both worlds

from what i gather a longer rod moves the pin farther up in the piston decreasing the ringland area which can lead to a weaker combination (especially under boost or juice) and can create more cylinder wall side loading

a shorter rod is the opposite of that but doesnt get the piston speed up as high as the 6" rod does


i think thats how i understood it anyway
if i understand right i would go with a shorter rod and a beefy piston combo so i could torture it with all kinds of juice
Old May 27, 2004 | 05:41 PM
  #3  
mebanditws6's Avatar
Registered User
 
Joined: May 2002
Posts: 622
From: Nashville, TN
A longer rod decreases cylinder side loads from a smaller angle from rod to piston. A longer rod also causes slower piston speeds, putting less stress on the bearings at higher rpms. This is the reason the LS1 uses longer rods, to create a larger rod/stroke ratio.


Jason
Old May 27, 2004 | 05:42 PM
  #4  
simple's Avatar
Registered User
 
Joined: Apr 2001
Posts: 2,195
From: Springfield, IL
gatcha
i had a feeling i was misstating something
Old May 27, 2004 | 05:44 PM
  #5  
gb95zconv's Avatar
Registered User
 
Joined: Jul 2000
Posts: 1,428
From: Woodstock,Georgia
Originally posted by simple
<--(n00b)..

5.85".......$$$ but best of both worlds

Thats what I did...

The prices of the 3 sizes was the same on the Eagle H-beams.

Last edited by gb95zconv; May 27, 2004 at 05:47 PM.
Old May 27, 2004 | 06:51 PM
  #6  
96capricemgr's Avatar
Registered User
 
Joined: Feb 2004
Posts: 4,800
If you only plan on a 200 shot all forged is overkill, guys are spraying that and more on stock bottomends. I agree on the 5.85" recommendation.
Old May 27, 2004 | 07:47 PM
  #7  
ABA383's Avatar
Registered User
 
Joined: Jan 2004
Posts: 1,903
From: Littlestown, PA
Oliver 5.85"
Old May 27, 2004 | 10:47 PM
  #8  
SS MPSTR's Avatar
Registered User
 
Joined: Oct 2001
Posts: 2,525
From: SoCal
Originally posted by ABA383
Oliver 5.85"
Yeah, I agree, but you should be bowing to the bank - those are pricey mothers.

I went with 6" forged Scat h-beams.
Old May 28, 2004 | 07:54 AM
  #9  
97SS0594's Avatar
Thread Starter
Registered User
 
Joined: Jul 2002
Posts: 1,651
From: baycity, mi
is there gonna be a big N/A hp diff??
Old May 28, 2004 | 09:59 AM
  #10  
Eff's Avatar
Eff
Registered User
 
Joined: Mar 2004
Posts: 643
From: St. Charles, IL
More rod angle gives more torque. to a maximum point (1.62 or somthing) Piston speed isnt all bad either. It does cause more wear but the faster the piston goes down on your intake stroke the better you fill your cyl. I agree 5.85 is probibly the closest to ideal rod raito but its usually more $$$.
Old May 28, 2004 | 10:37 AM
  #11  
Injuneer's Avatar
Administrator
 
Joined: Nov 1998
Posts: 71,121
From: Hell was full so they sent me to NJ
You might want to do a "search" on the Advanced Tech board regarding the affect of rod/stroke ratio..... the general consensus among the experienced engine builders seems to be that it isn't worth worrying about when it comes to street engines. NASCAR engine... yes its important.

I also opted for the 5.85" rod length on my 381, in order to get the ring pack spacing I wanted (get the top ring away from the heat), keep the wrist pin from going too far into the bottom ring, and allow for strength in the top of the piston to handle a 300-shot. So far its worked fine.
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
secbase8
Parts Wanted
3
Sep 8, 2015 07:11 PM
colts0455
LT1 Based Engine Tech
22
Jul 24, 2015 04:51 PM
Noct
General 1967-2002 F-Body Tech
2
Jul 14, 2015 01:18 AM
mrwz28
Cars For Sale
0
Jul 8, 2015 09:11 PM




All times are GMT -5. The time now is 04:51 PM.