78'bu whats the difference between a lq4 and a lq9? Whats the designation for the 6.0 with square port heads?5.3 HP estimation?
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78'bu whats the difference between a lq4 and a lq9? Whats the designation for the 6.0 with square port heads?LQ4 was the non-performance version in the 3/4 ton/1 ton trucks & whatnot. The LQ9 was in the SS, Escalade, etc.
Ok, so the Lq9 has the square port heads and that would be some of the reason for the big HP they got.
The LQ4 use the same valvetrain, heads, block, and crank. The difference comes in with the pistons (and possibly rods). The LQ4 used dished pistons to give a CR of 9.4-1, while the LQ9 used flattop pistons to yield 10-1. Its been rumored the LQ9 had stronger rods but thats still up in the air. The LSx bottom ends have been proven to 500-600rwhp without any work. A simple oil pump and rod bolt upgrade goes a long way. The crank is usually the last thing to be replaced and can take a hell of a beating.
The heads on both are '317 castings. They have the normal cathedral style LS1/LS2/LS6 ports. They flow very close to the '243 LS2/LS6 castings but have a larger combustion chamber to lower the compression. The LQ4 is a good canidate for a power adder because of its lower compression.
The 90% of 6.0's around are LQ4s. You will pay quite a bit more for an LQ9. I bought my LQ4 for $1350 with 40k miles and all accessories (cheaper side around here). The cheapest LQ9 I could find was over $2000.
So the power difference is purely because of the compression range.
The rectangle port heads you are talking about are found on the new L76/L92 6.2 motors. They flow 325cfm bone stock, just about the same as LS7 heads. They are honestly the best deal right now for a set of heads, only downfall is they need a 4.00" min bore size as the valves are huge with an offset intake rocker. The 4.8/5.3/5.7 guys can't run em. I've seen them first hand and they are works of art.
The heads on both are '317 castings. They have the normal cathedral style LS1/LS2/LS6 ports. They flow very close to the '243 LS2/LS6 castings but have a larger combustion chamber to lower the compression. The LQ4 is a good canidate for a power adder because of its lower compression.
The 90% of 6.0's around are LQ4s. You will pay quite a bit more for an LQ9. I bought my LQ4 for $1350 with 40k miles and all accessories (cheaper side around here). The cheapest LQ9 I could find was over $2000.
So the power difference is purely because of the compression range.
The rectangle port heads you are talking about are found on the new L76/L92 6.2 motors. They flow 325cfm bone stock, just about the same as LS7 heads. They are honestly the best deal right now for a set of heads, only downfall is they need a 4.00" min bore size as the valves are huge with an offset intake rocker. The 4.8/5.3/5.7 guys can't run em. I've seen them first hand and they are works of art.
78'Bu-88SS said:
Thanks for the info, I have also seen a few sets of those square port heads at Scoggin Dickey performance center in Lubbock Texas, and one set on an engine at Ray Mac performance that is supposedly the first solid roller lsx in the country. The head guy (Chris) told me that with some port work that he got those heads to flow something like 400 or 415cfm :shock: Your right about them being a work of art, especially after a good head guy gets done with them.
So what did the escalade 6.0L have for heads? I heard that they were the square port ones? Thats why when Doober said a escalade has a LQ9 I thought that was the designation for the engine with those heads.
The 6.0 Escalades with the LQ9 had the '317 heads, same as the LQ4. They are the normal LS1/LS2/LS6 cathedral style.
The new Escalades have the 6.2, dubb'ed the L92 I believe. Those have the rectangle port heads.
The new Escalades have the 6.2, dubb'ed the L92 I believe. Those have the rectangle port heads.
