LQ4, LQ9; true or false
Feb 16, 2005 | 09:41 PM
#21
Originally Posted by Randy Grabert
well if you think they are the same then you go ahead and use them you use the ones off the lq4 and sell me the ones off of the lq9
Please see this thread: https://ls1tech.com/forums/showthread.php?t=268249
Feb 16, 2005 | 10:04 PM
#22
No, the aluminum LQ4 heads are all the same from 01-05. The iron LQ4 heads are a different casting number. I've never seen an 035 casting on a production vehicle, only 317 castings on both LQ4 and LQ9s. If they were made for CNG vehicles, then thats why no one can find them. All those illusive 035 heads must be on government vehicles.
If I took a set of LQ4 heads and set them beside the heads off my LQ9, you wouldn't be able to tell the difference. But I could charge you more because they are better, right?
Originally Posted by Randy Grabert
well if you think they are the same then you go ahead and use them you use the ones off the lq4 and sell me the ones off of the lq9
Feb 16, 2005 | 10:22 PM
#23
Originally Posted by BigTex
No, the aluminum LQ4 heads are all the same from 01-05. The iron LQ4 heads are a different casting number. I've never seen an 035 casting on a production vehicle, only 317 castings on both LQ4 and LQ9s. If they were made for CNG vehicles, then thats why no one can find them. All those illusive 035 heads must be on government vehicles.
If I took a set of LQ4 heads and set them beside the heads off my LQ9, you wouldn't be able to tell the difference. But I could charge you more because they are better, right?
If I took a set of LQ4 heads and set them beside the heads off my LQ9, you wouldn't be able to tell the difference. But I could charge you more because they are better, right?
Feb 16, 2005 | 10:54 PM
#25
Originally Posted by David Cairns
eeeeeewww!!!!! 
I guess that would make for "crappy" peformance!!!!!
I guess that would make for "crappy" peformance!!!!!
But the fact that some of the parts are not as "beefy" on my LQ4 doesn't help...
Feb 17, 2005 | 12:33 AM
#27
On The Tree
Joined: Jun 2004
Posts: 178
Likes: 0
From: connecticut
Originally Posted by Randy Grabert
The Heads Are Also Different The Lq9 Heads Are Compare To The Zo6 Heads With Out The Lighter Valves The Flow Numbers Are Also Differentstock To Stock. Comprssion Is Not Going To Give You That Much Hp Difference.lq9 Has 10.4 And Lq4 Has 9.8.not Even A Whole Piont.07 Difference. Not 45 Hp Worth.
LQ4 9.41:1
99-00
300 hp at 4,800, 355 ft-lb at 4.000 rpm
01
300 hp at 5200, 360 ft-lb at 4000 rpm
(first year for aluminum heads and different cam)
LQ9 10.08:1
02-03
lq4 325 hp at 4800 rpm, 370 ft-lb at 4000 rpm
lq9 345 hp at 5200 rpm, 380 ft-lb at 4000 rpm
04
lq4 p/u 325 4400, 370 4000
suv 325 5000, 365 4000
lq9 345 5200, 380 4000
camshaft
lq4 99-00 191/190 0.457/0.466 114
01-04 196/207 0.467/0.479 116
lq9 02-03 is same as above
the heads of the lq4 are 317 for 01 and newer aluminum
i have gotten conflicting info for this next part
lq9 are 035 (some say 317 and are the same as newer lq4) and are almost identical to the ls6 heads.
they have improved intake and exhaust ports
Feb 17, 2005 | 12:38 AM
#28
Originally Posted by mjgjr72
actually its only 20 hp worth for same year motors
LQ4 9.41:1
99-00
300 hp at 4,800, 355 ft-lb at 4.000 rpm
01
300 hp at 5200, 360 ft-lb at 4000 rpm
(first year for aluminum heads and different cam)
LQ9 10.08:1
02-03
lq4 325 hp at 4800 rpm, 370 ft-lb at 4000 rpm
lq9 345 hp at 5200 rpm, 380 ft-lb at 4000 rpm
04
lq4 p/u 325 4400, 370 4000
suv 325 5000, 365 4000
lq9 345 5200, 380 4000
camshaft
lq4 99-00 191/190 0.457/0.466 114
01-04 196/207 0.467/0.479 116
lq9 02-03 is same as above
the heads of the lq4 are 317 for 01 and newer aluminum
i have gotten conflicting info for this next part
lq9 are 035 (some say 317 and are the same as newer lq4) and are almost identical to the ls6 heads.
they have improved intake and exhaust ports
LQ4 9.41:1
99-00
300 hp at 4,800, 355 ft-lb at 4.000 rpm
01
300 hp at 5200, 360 ft-lb at 4000 rpm
(first year for aluminum heads and different cam)
LQ9 10.08:1
02-03
lq4 325 hp at 4800 rpm, 370 ft-lb at 4000 rpm
lq9 345 hp at 5200 rpm, 380 ft-lb at 4000 rpm
04
lq4 p/u 325 4400, 370 4000
suv 325 5000, 365 4000
lq9 345 5200, 380 4000
camshaft
lq4 99-00 191/190 0.457/0.466 114
01-04 196/207 0.467/0.479 116
lq9 02-03 is same as above
the heads of the lq4 are 317 for 01 and newer aluminum
i have gotten conflicting info for this next part
lq9 are 035 (some say 317 and are the same as newer lq4) and are almost identical to the ls6 heads.
they have improved intake and exhaust ports
I still have not ever seen 035 heads on anything.
Feb 17, 2005 | 11:44 AM
#30
Originally Posted by Randy Grabert
The Heads Are Also Different The Lq9 Heads Are Compare To The Zo6 Heads With Out The Lighter Valves The Flow Numbers Are Also Differentstock To Stock. Comprssion Is Not Going To Give You That Much Hp Difference.lq9 Has 10.4 And Lq4 Has 9.8.not Even A Whole Piont.07 Difference. Not 45 Hp Worth.
As has been said over and over, the heads are the same -- 317 castings (and I have two sets of them to show you the casting numbers on -- both off of LQ9s). Your compression numbers are also wrong. LQ9 = 10.1:1, LQ4 = 9.4:1. The rest of the difference? Tune. As I recall, LQ4's can run "any" octane and LQ9s "require" 91. That's a pretty big indicator of a hotter spark table.
But hey, what would I know