StorminMatt

You know, one without such extravagances as dry sump lubrication and titanium rods and valves. Something more along the lines of a higher displacement LS2 or LS3. Certainly it does not cost much (if any) more to produce the bare LS7 block, head castings, or intake manifolds than the corresponding parts of the LS2 or LS3. And the fact that the LS3 produces almost the same HP per liter as the LS7 tells me that such a motor could probably produce close to the same HP. So why didn’t GM do this?

blackbyrd

iTrader: (14)

Ls7 sleeves are press fit in rather then being cast in place like the ls3. adding additional cost to the block as well. its an interesting question, but it likely boils down to demand.

speedfreak440

iTrader: (9)

Maybe cause they got sued enough on the no expenses spared (in the cheapest GM way possible) LS7? Why go down the road of a cheaper/possibly less reliable engine that doesn't really even fit a niche that you don't already have covered?

NHRATA01

iTrader: (10)

You could do a wet sump LS7 fairly easily, but as far as the cost and "extravagant" parts, it was driven by engineering to make the power target with (ideally) OEM reliability. The Ti rods are due to being the only 4" factory stroke LS and spinning to 7k to hit their 500hp goal so saving mass helped. Likewise the airflow to make that power N/A meant big ports, which means big valves, which means heavy valves. So titanium helped bring down the weight and again, allow 7k reliably.

The LS7 was about the max HP they were going to get out of an N/A GenIV while achieving reliability and emissions requirements. And they had to make a few compromises (such as the somewhat fragile sleeves) in the process. There's really no reason to make a "cheaper" version, I suspect it was cheaper for them just to throw a blower on a beefed up LS3 and thus we got the LSA anyway.

440_Stroker

99% of the LS7 reliability issues are the heads, more so the valve guides, which is something that should have been a design change.

The engine wasn't really suited for truck work so making it a lower revving engine really wouldn't do any favors. Also, just after the LS7 came out the LS3 was coming in at 430 hp. What would the sense have been to make say a 460 hp version? I don't see any.