What is my engine? (i've searched)
09-17-2006, 08:38 PM
#1
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What is my engine? (i've searched) Ok, i'm getting a 6.0 from an 04 yukon denali tomorrow, and I'm not sure if its an lq4 or an lq9. I am putting this into my 97 240sx with an lsx intake mani, possibly 243 heads or 241's, and probably an ls6 cam. I plan on remaining all motor for quite a while, so i hope this is an lq9. Anyway, thanks in advance!
09-17-2006, 09:05 PM
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HA! Awesome! I know it will increase the compression, does anyone know specifically how much it will be once i put the 243 heads on? Its gonna be a daily driver, so i dont want to have to run race gas. Also, after i get it i'll be willing to trade the complete heads to a FI guy for some 243's...
Thanks again guys!
Thanks again guys!
09-17-2006, 10:32 PM
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Originally Posted by ArcticZ28
You won't have to run race gas with 243 heads on an LQ9 especially with just an LS6 cam. Stick with 93 and you should be good to go.
09-17-2006, 11:07 PM
#6
10. is stock LQ9 has a flattop piston
9.5 is a lq4 with the 243's I am told the dish piston will be 10.9
could very well put you 10.6
Edit I have since looked this up
LQ9 is 10. to 1
LQ4 is 9.4 to 1
9.5 is a lq4 with the 243's I am told the dish piston will be 10.9
could very well put you 10.6
Edit I have since looked this up
LQ9 is 10. to 1
LQ4 is 9.4 to 1
Last edited by The stunningman; 09-18-2006 at 06:57 AM.
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09-17-2006, 11:23 PM
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Ok, i'm confused now. Those are 2 very differing answers. I was under the impression that the lq4 with the 243 heads would yield about 10:1 compression, and the lq9 with 243 heads would be 11:1ish. Maybe i should start a new thread about this..haha. What is the general rule of thumb that is safe to run on pump 93?
09-17-2006, 11:41 PM
#9
LQ9's in that year come at 10.1:1, I'm not sure about the LQ4's but it doesn't matter b/c you won't have one.
Dynamic compression ratio is a more determining factor on what octane you need to run. The numbers people tend to shoot for are somewhere in the 8.5-8.6:1 DCR to be safe to run on 93 pump gas. Of course other factors come into play such as your quench area, your DA, etc. However, on a very general note, if you stay below 8.5:1 DCR you should be good to go.
Dynamic compression ratio is a more determining factor on what octane you need to run. The numbers people tend to shoot for are somewhere in the 8.5-8.6:1 DCR to be safe to run on 93 pump gas. Of course other factors come into play such as your quench area, your DA, etc. However, on a very general note, if you stay below 8.5:1 DCR you should be good to go.
09-17-2006, 11:55 PM
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All sounds well, i'm sure i'll be fine as i see lots of other people here running the lq9 with 243 heads. Hope all goes well tomorrow with getting this motor, i'm looking forward to getting started putting this swap together and making some noise with this 240!
09-18-2006, 12:27 PM
#11
Remember that the thickness of the head gasket can change your compression ratio nearly 1/2 point.
I have a stock LS1 shortblock with 62cc AFR 205's heads and GM MLS head gaskets (10.7:1). With Cometic .040" head gaskets my compression would've been about 11:1. In hindsight I should've gone with the Cometics due to more torque potential from the higher compression.... but they were twice as much and I flinched and went with the MLS.
Run the most compression you can for the best gas you can get at the pump. 11:1 for 91 octane and a big cam is easy... with 93 octane you can run more rather comfortably.
I have a stock LS1 shortblock with 62cc AFR 205's heads and GM MLS head gaskets (10.7:1). With Cometic .040" head gaskets my compression would've been about 11:1. In hindsight I should've gone with the Cometics due to more torque potential from the higher compression.... but they were twice as much and I flinched and went with the MLS.
Run the most compression you can for the best gas you can get at the pump. 11:1 for 91 octane and a big cam is easy... with 93 octane you can run more rather comfortably.
09-19-2006, 07:10 PM
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Just a little update. I tried to get the motor yesterday, and found out that the salvage yard basically took the entire intake manifold with everything on it off. And it evidently had wiring issues... On top of all that, the place still wanted $1900 for it (original price). I was a little bummed, but today i have located another engine from an 04 denali. The owner of the salvage yard thinks this is an lq4, but I trust ls1tech way more than I trust some salvage yard in Arkansas 
I let him think that it was an lq4 so i'm getting a nice deal on it because he thinks its an lq4 when i know that it is in fact an lq9. What do you guys think to reach about 450 whp with this thing running 243 heads, ls6 intake? I'm just wondering what cam would be good for my goal. Thanks again for all the help guys!
I let him think that it was an lq4 so i'm getting a nice deal on it because he thinks its an lq4 when i know that it is in fact an lq9. What do you guys think to reach about 450 whp with this thing running 243 heads, ls6 intake? I'm just wondering what cam would be good for my goal. Thanks again for all the help guys!
09-23-2006, 06:32 PM
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Ok, just picked up my new motor today. The yard i got it from provided me with a vin, so i plugged it into carfax.com and the engine is in fact from an 04 sierra denali 4 door. It is a 6.0. The only confusion is this motor is an lq9 according to people on here and some other sources. I found an online specs website that states it is an lq4. Is there any way to know for sure? I'm really hoping its an lq9, but I guess i could use cometic gaskets to get the compression up to where i want it. Any input? Thanks guys!
09-23-2006, 07:15 PM
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Originally Posted by ArcticZ28
Not sure why it's stating that but the Denali option for the Yukon in 2004 was in fact the LQ9. It was only the regular Yukon's that got the 5.3 liter LQ4.
09-23-2006, 08:01 PM
#16
Well, just did some more searching around and according to wikipedia it says you have the LQ4. http://en.wikipedia.org/wiki/GM_Vortec_engine#6000 . I could have sworn the Denali's had the LQ9 but I can't say for sure now with so many confusing sources. I know the 02+ escalades had the LQ9 and I thought the denali versions of things had them as well, but now I'm confused as all get out.
To answer your question though, the LQ9's are the "high output" versions of the LQ4 with the bumped up compression.
To answer your question though, the LQ9's are the "high output" versions of the LQ4 with the bumped up compression.
09-24-2006, 12:18 PM
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Well hell, guess its gonna be some cometic gaskets for me. I'm sure .3 difference in compression wont keep me from my goal of 430 - 450 whp. Thanks for helping me with the search!
