Difference between these two gen 4 rods ?
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Difference between these two gen 4 rods ? 
See both gen 4 rods. Why does one have a chamfer highlighted in yellow ?
is because the rod on the left is a gen 4 lq4 rod and the rod on the left of a ls2/3 rod? That is my guess....
will they both fit in a 1999 6.0 LS ok ? Let me know. I am using LS2 flat pistons
thanks !
I have both LQ9 and LS3 Rods here.
Just looked.
They all have the # 3847 on them.
The LS3 all have GKN on them.
I took that motor apart.
The LQ9 only has one that says GKN. I didn’t take that motor apart.
None have that relief in them.
Ron
Just looked.
They all have the # 3847 on them.
The LS3 all have GKN on them.
I took that motor apart.
The LQ9 only has one that says GKN. I didn’t take that motor apart.
None have that relief in them.
Ron
Clean the rod really good. Maybe hit that area that’s missing with a wire wheel and take a good close up pic. I’d like to see it clean. I don’t think that rod came that way from the factory.
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TECH Junkie
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From: Nitro Alley
That groove in the big end of the connecting rod is something commonly done in a machine shop to direct oil exiting at the rod bearing up towards the piston/ wrist pin for better lubrication/ cooling.
TECH Junkie
Joined: Jun 2008
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From: Nitro Alley
You need to clean and deburr the connecting rods as needed.
You need to check and measure the connecting rod bearing clearances, the wrist-pin clearances, and the side to side clearances.
I would recommend new wrist-pin wire-retainers and purchase a cheapo rod bolt stretch-gauge for torquing the connecting rods.
Have fun!
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From: Arizona
See both gen 4 rods. Why does one have a chamfer highlighted in yellow ?
is because the rod on the left is a gen 4 lq4 rod and the rod on the left of a ls2/3 rod? That is my guess....
will they both fit in a 1999 6.0 LS ok ? Let me know. I am using LS2 flat pistons
thanks !
I really like the idea of oil cooling the pistons. I do know the set of pistons that came with these had an issue. The oil rings were gummed up with varnish. So probably need to make sure your pistons have oil relief holes in them (mine did not, only the 4 standard by wrist pin none on skirt side).
There is an R stamped on rt hand side. Then Txxx on the left. This one is T047
Last edited by weinerschizel; Jan 1, 2021 at 01:05 PM.
Launching!
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Do all the LQ4 rods have that notch, or 4 of the 8? I agree it looks factory from the finish, not added later at a machine shop.
Wondering: 1) does each journal gets 1 notched rod, 2) does each journal get 2 notched rods, 3) did GM assemble only a specific journal with a notched rod.
Wondering: 1) does each journal gets 1 notched rod, 2) does each journal get 2 notched rods, 3) did GM assemble only a specific journal with a notched rod.
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Joined: Nov 2008
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From: Arizona
Do all the LQ4 rods have that notch, or 4 of the 8? I agree it looks factory from the finish, not added later at a machine shop.
Wondering: 1) does each journal gets 1 notched rod, 2) does each journal get 2 notched rods, 3) did GM assemble only a specific journal with a notched rod.
Wondering: 1) does each journal gets 1 notched rod, 2) does each journal get 2 notched rods, 3) did GM assemble only a specific journal with a notched rod.
A buddy brought me his LQ9 to assemble. I believe it’s an 04.
All the rods have this notch.
The notches all lined up with the dot (Forward) on the pistons.
Other than the photos, first I’ve seen.
Ron
All the rods have this notch.
The notches all lined up with the dot (Forward) on the pistons.
Other than the photos, first I’ve seen.
Ron
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From: Arizona
I finally found out... The notch was a short run. I'm not sure what years exactly. It was designed to spray oil at the bottom of the piston and cool it a bit.
GM in all their infinite wisdom however, decided to use the same casting / part number as the rods w/o the notch.
I do feel the notch is far superior. However, the Achillies' Heal heal of the LS architecture is the asymmetric camshaft oiling (only one off centered port for cam oiling). As such I didn't want to mess with anything that might effect oil pressure. I also avoided a High Volume / High Pressure pump in my build as another guy I met spun cam bearings with one of those on a brand new 6.0 build.
Before I ramble on too much. I bought a set of rods w/o the notch. Not sure why GM didn't ultimately go with the relief but didn't want to do anything that might effect oiling of the cam, if even so slightly. Trying to stay right on the money with pressure specs. I'm super worried about spinning cam bearings but think my route should be fine.
GM in all their infinite wisdom however, decided to use the same casting / part number as the rods w/o the notch.
I do feel the notch is far superior. However, the Achillies' Heal heal of the LS architecture is the asymmetric camshaft oiling (only one off centered port for cam oiling). As such I didn't want to mess with anything that might effect oil pressure. I also avoided a High Volume / High Pressure pump in my build as another guy I met spun cam bearings with one of those on a brand new 6.0 build.
Before I ramble on too much. I bought a set of rods w/o the notch. Not sure why GM didn't ultimately go with the relief but didn't want to do anything that might effect oiling of the cam, if even so slightly. Trying to stay right on the money with pressure specs. I'm super worried about spinning cam bearings but think my route should be fine.
