Is a LQ9 a Gen III or IV?
03-17-2007, 09:57 AM
#1
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Is a LQ9 a Gen III or IV? I'm looking to build a LQ9 short block w/l92 heads and carb'd intake for my 68' chevelle. Would this be considered a Gen III or IV? I've read that the LQ9 blocks were mirror images of an LS2 block only iron. BTW I work for a dealership and can get the parts at really good prices, hence the reason for not building a 402, I want an Iron block, and I can get a LS2 crank w/58x reluctor wheel much cheaper that a LQ9 crank. Any problems with this? This will be my first LS build. Not looking for a monster motor, but want a strong power plant for a driver. Any ideas will be much appreciated!
03-17-2007, 01:07 PM
#3
Originally Posted by hulley
I'm looking to build a LQ9 short block w/l92 heads and carb'd intake for my 68' chevelle. Would this be considered a Gen III or IV? I've read that the LQ9 blocks were mirror images of an LS2 block only iron. BTW I work for a dealership and can get the parts at really good prices, hence the reason for not building a 402, I want an Iron block, and I can get a LS2 crank w/58x reluctor wheel much cheaper that a LQ9 crank. Any problems with this? This will be my first LS build. Not looking for a monster motor, but want a strong power plant for a driver. Any ideas will be much appreciated!
lq4 and lq9 share the same block, the rotating assembly and balance is
different, the lq9 has true flat tops, and differnt casting cylinder heads
035, for the lq9
and the lq4 has a spherical dish piston, with a 317 head casting
also the lq9 is not an iron version of a gen 4 ls2, since it still circulates
coolant around the cylinders where the ls2 is a siamese design,and doest have the "distributor hole" at the rear of the block for the cam reluctor
sensor.
both cranks are interchangeable, but if u are going witha ls2 crank then also convert your camshaft to use the ls2 timing cover and timing cain gear
so u can msd's new ls2 ignition controller as if it were an ls2.
or just stick with the lq4 crank and gen 3 ls1/ls6 cam with the reluctor ring
at the end of the cam core.
Last edited by NemeSS; 03-18-2007 at 01:59 PM. Reason: wrong digit for lq9 cylinder head casting 095-035
03-17-2007, 01:08 PM
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LQ9 is a GENIII based iron block. It is the same block as the LQ4. The only difference between the 01+ LQ4 and LQ9 is the rods and pistons. LQ9's have beefier rods (LS2 I think?) and flat top pistons for about .5 or so greater compression. In 05+, the 6.0L truck motors both had LS2 rods, LS2 sized cam bearings (Clevite p/n CH23) and LS2 timing set.
03-17-2007, 01:48 PM
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Who said anything about a lq4? 
I read a chevy high performance article on a build up of a 6.0 iron block and they stated it was a "mirror image" of the ls2 block. Thanks for the info on the coolant passages nemeSS I wasnt sure if I should treat this as a gen III build or a gen IV. If I get a ls2 crank, should I swap out the reluctor for the 24x? or is there a benefit to staying with the 58x? This is going to be a carb'd build up.
I read a chevy high performance article on a build up of a 6.0 iron block and they stated it was a "mirror image" of the ls2 block. Thanks for the info on the coolant passages nemeSS I wasnt sure if I should treat this as a gen III build or a gen IV. If I get a ls2 crank, should I swap out the reluctor for the 24x? or is there a benefit to staying with the 58x? This is going to be a carb'd build up.
03-17-2007, 01:55 PM
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Thunder550, in the GM performance catalog, the iron block shows up to 04' is the 05+ a different block? maybe for variable fuel thing they got going? BTW thats a Badass looking truck you got there! I'm on the hunt for something similar to replace my 94' Z71.
03-17-2007, 02:02 PM
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Originally Posted by hulley
Thunder550, in the GM performance catalog, the iron block shows up to 04' is the 05+ a different block? maybe for variable fuel thing they got going? BTW thats a Badass looking truck you got there! I'm on the hunt for something similar to replace my 94' Z71.
Thanks for the comment about my truck too
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03-17-2007, 02:57 PM
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I wasnt trying to be a smartass about the lq4 comment, The catalog I'm looking at is the 07' GM catalog. The only Iron block listed is pn 12572808 LQ9 6.0l 1998-2004. Sorry If I seem like a dumbass! But I kinda am!!!! I'm just trying to learn the differences so I can make the right choice before I order parts which will be very soon. I really appreciate all the input. My goal is to build a Iron block 6.0l L/92 heads and carb'd intake. Any suggestions?
03-17-2007, 03:11 PM
#10
Originally Posted by NemeSS
lq4 and lq9 share the same block, the rotating assembly and balance is
different, the lq9 has true flat tops, and differnt casting cylinder heads
095, for the lq9
and the lq4 has a spherical dish piston, with a 317 head casting
also the lq9 is not an iron version of a gen 4 ls2, since it still circulates
coolant around the cylinders where the ls2 is a siamese design,and doest have the "distributor hole" at the rear of the block for the cam reluctor
sensor.
both cranks are interchangeable, but if u are going witha ls2 crank then also convert your camshaft to use the ls2 timing cover and timing cain gear
so u can msd's new ls2 ignition controller as if it were an ls2.
or just stick with the lq4 crank and gen 3 ls1/ls6 cam with the reluctor ring
at the end of the cam core.
different, the lq9 has true flat tops, and differnt casting cylinder heads
095, for the lq9
and the lq4 has a spherical dish piston, with a 317 head casting
also the lq9 is not an iron version of a gen 4 ls2, since it still circulates
coolant around the cylinders where the ls2 is a siamese design,and doest have the "distributor hole" at the rear of the block for the cam reluctor
sensor.
both cranks are interchangeable, but if u are going witha ls2 crank then also convert your camshaft to use the ls2 timing cover and timing cain gear
so u can msd's new ls2 ignition controller as if it were an ls2.
or just stick with the lq4 crank and gen 3 ls1/ls6 cam with the reluctor ring
at the end of the cam core.
03-17-2007, 05:34 PM
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I plan on using l92 heads and carb intake. The ls2 crank would be used because I can get it much less than a lq9 crank. I suppose I could install a 24x wheel on the ls2 crank and keep the whole set up a gen III. Thats what I trying to figure out!
03-17-2007, 07:06 PM
#17
Originally Posted by JB2wheeler
I am new to LS engines, so please explain to me why an LS2 crank would be half the price of an LQ9 crank. I just dont understand why. JB
because GM pricing makes no sense?
03-17-2007, 08:55 PM
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I thought it was odd the ls2 crank is less than the lq9 crank. Check pricing at gmpartsdirect.com. As long as I can change the reluctor wheel, I'm ok with that. The GM performance catalog only shows the ls2 crank coming with the 58x wheel now. pn 12588612