05 lq4 bottom end quesitons
Dec 7, 2009 | 03:35 PM
#21
Joined: Apr 2004
Posts: 16,820
Likes: 2
From: In a van DOWN BY THE RIVER
The current engine I picked up to do a 370 is a 02 or 03 and was a lq9.. I am waiting for a friend to get home, he has a 01 or 02 lq4.. I sold him my rods and pistons out of this motor. Once he looks at them he will be able to tell what is what.... As far as any of it goes, any of the ls motors can take 650hp on the bottom end no problem..
Dec 8, 2009 | 06:52 PM
#23
Well according to GM all the LQ9's have them, but like everything thing, you need to take what they say with a grain of salt. My truck is listed as having a 4L80E in the sales literature, but we all know regular ½ ton’s never got an 80. I'm sure some overzealous person putting the literature together assumed it had an 80 as all other trucks equipped with a 6.0L in 2001 had one.
Bottom line is if you don't trust what the documentation say's, you’re going to have to pull the pan and look for yourself.
Bottom line is if you don't trust what the documentation say's, you’re going to have to pull the pan and look for yourself.
1Bear is beyond knowledgeable 
You can learn ALOT from him,the main thing is to listen!!
Dec 8, 2009 | 08:29 PM
#24
I have a pretty detailed breakdown of what came in the LSx series engines at home and if I remember right the '04 and lower LQ4 had a slightly smaller cam than the LQ9 which had the first gen LS1 cam in all years. Also the rotating assembly in the LQ4 is identical to the LQ9 after '04 with the exception of the dished pistons. Also someone said they are dished exactly like the 5.3 piston and that's not correct. They have a cross section of relief in the middle, not a circular depression all the way around. The information about the lighter rods before '04 is correct as well as the longer crank in the iron head LQ4s.
Dec 8, 2009 | 09:59 PM
#25
I have a pretty detailed breakdown of what came in the LSx series engines at home and if I remember right the '04 and lower LQ4 had a slightly smaller cam than the LQ9 which had the first gen LS1 cam in all years. Also the rotating assembly in the LQ4 is identical to the LQ9 after '04 with the exception of the dished pistons. Also someone said they are dished exactly like the 5.3 piston and that's not correct. They have a cross section of relief in the middle, not a circular depression all the way around. The information about the lighter rods before '04 is correct as well as the longer crank in the iron head LQ4s.
Broken60LPiston.jpg?t=1260330943
LQ9-LQ4pistonsrods5.jpg?t=1260330988
Dec 9, 2009 | 04:38 PM
#26
Here are a couple of different pictures of LQ4 pistons (presumably different years as well) that have been submitted by members in the past. One is just a plain dish, while the other has a slight raised cross cast in it. The pistons with the cross are what I've encountered the most of, however in both cases you will note the piston crowns are of a full circular depression.
Dec 9, 2009 | 06:03 PM
#27
They are both from an LQ4, however I'm with you as the ones with the raised cross is what is most seen. Of course the aftermarket replacement pistons I've come across are just plain dished.
Dec 10, 2009 | 10:18 PM
#28
The current engine I picked up to do a 370 is a 02 or 03 and was a lq9.. I am waiting for a friend to get home, he has a 01 or 02 lq4.. I sold him my rods and pistons out of this motor. Once he looks at them he will be able to tell what is what.... As far as any of it goes, any of the ls motors can take 650hp on the bottom end no problem..
Not trying to thread jack either.
Dec 10, 2009 | 10:54 PM
#29
Good to hear, I'm planning on putting some stockish big chamber 317s back on my LQ9 and try and get some similar results to stock48 on his stock lq4 shortblock. I think the LQ9 should be good to 750-800 rwhp with good fuel.
Dec 10, 2009 | 11:08 PM
#30
I even have casting numbers to look for. (unfortunately my shortblock is at my father's shop and I don't have instant access to it to check what I have...)