LQ4 and LQ9 bore question
Jul 19, 2020 | 02:47 AM
#11
The 243's and the 317's flow about the same and since you're not building a high performance engine... I'd save the 243's for a future build or sell to fund the current build.
Correct on the camshaft specs. All LQ9's were equipped with the better rods with the dimple and floating pins even with the 99-00 iron head LQ9. The LQ4's had the better rods 2004+
I pulled and cleaned the 120,000 mile varnish from the pins & pin bore during my build. I trust these rods more than the standard GEN III rods... enough so I just upped the rev limiter to 7000 today after banging off the 6500 limiter earlier today
Correct on the camshaft specs. All LQ9's were equipped with the better rods with the dimple and floating pins even with the 99-00 iron head LQ9. The LQ4's had the better rods 2004+
I pulled and cleaned the 120,000 mile varnish from the pins & pin bore during my build. I trust these rods more than the standard GEN III rods... enough so I just upped the rev limiter to 7000 today after banging off the 6500 limiter earlier today
All Gen 3 engines starting for 2005 Model year got the "2nd design" rods Which are the floating pin rods that are known as Gen 4 rods.
Jul 19, 2020 | 01:43 PM
#12
Staging Lane
Joined: Dec 2019
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Jul 19, 2020 | 01:49 PM
#14
Staging Lane
Joined: Dec 2019
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I tried to nail down when the 2nd design rods started and never could find an exact VIN or model year range. I've most often seen "sometime in 2004," which I've found accurate based on my own lq4 6.0 Denali engine which had the 2nd design "Gen 4" rods when I opened it up to my surprise.
Jul 19, 2020 | 09:26 PM
#16
All LQ9's ( started in 2002 Escalades) and the LQ4 (2001 and newer) use identical cams. Bore is identical as is everything else short of the piston. The 2002 LQ9's were the first engine to use what guys love to incorrectly call Gen IV rods. All LS engines got the same full floating pin rod in the 2004 calendar year... not model year. Easy way to tell is the block changed to the equal length head bolt in 2004 (calendar year) and they increased the bolt head size of the valley cover and exhaust manifolds to 13 mm from 10 mm.
Not much crazy to it.
Not much crazy to it.
Last edited by 1994Vmax; Jul 21, 2020 at 06:04 PM.
Jul 19, 2020 | 11:16 PM
#17
100% Redneck
Joined: Mar 2005
Posts: 2,098
Likes: 1,344
From: MAGA COUNTRY
All LQ9's ( started in 2002 Escalades) and the LQ4 (2001 and newer) use identical cams. Bore is identical as is everything else short of the piston. The 2002 LQ9's were the first engine to use what guys love to incorrectly call Gen IV rods. All LS engines got the same full floating pin rod in the 2004 calendar year... not model year. Easy way to tell is the block changed to the equal length head bolt in 2004 (calendar year) and they increased the bolt head size of the valley cover and exhaust manifolds to 13 mm from 10 mm.
Jul 20, 2020 | 07:57 AM
#18
Yeah some LQ4s did have full float rods... to the tune of half of the aluminum headed ones production run. All there was for 6 liters in 1999 and 2000 were LQ4's and the LQ9 didn't exist until 2002... but honestly it's one of those instances where that 99/00 engine should have been a different RPO code. Cast iron cylinder heads, the puny cam used in the 4.8 and 5.3 and a specific crankshaft with a long rear snout is enough differences that it doesn't really qualify as the same engine lol. But GM is fun like that and loves building totally different engines under the same RPO.
Last edited by 1994Vmax; Jul 21, 2020 at 06:05 PM.
Jul 21, 2020 | 02:11 AM
#19
All LQ9's ( started in 2002 Escalades) and the LQ4 (2001 and newer) use identical cams. Bore is identical as is everything else short of the piston. The 2002 LQ9's were the first engine to use what guys love to incorrectly call Gen IV rods. All LS engines got the same full floating pin rod in the 2004 calendar year... not model year. Easy way to tell is the block changed to the equal length head bolt in 2004 (calendar year) and they increased the bolt head size of the valley cover and exhaust manifolds to 13 mm from 10 mm.
Not much crazy to it.
Not much crazy to it.
Jul 21, 2020 | 09:14 AM
#20
100% Redneck
Joined: Mar 2005
Posts: 2,098
Likes: 1,344
From: MAGA COUNTRY
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