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Architecture differences between 3.8 and 5.7

Old 02-26-2024, 11:18 AM
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Default Architecture differences between 3.8 and 5.7

I’m wondering what the major architectural differences are between the 3800 v6 and the 5.7L LS1. Aside from the obvious differences in cylinder count, what major differences are there in the water jacket, block angle, camshaft bore, etc.? I find it a little odd considering the massive performance potential of the 3.8L motor that GM never experimented with stretching it a little bit and making a 5.06 L v8. Obviously the 5.7 is a tried and true design, but what if, hypothetically, someone wanted to make a v8 with the same architecture as the 3.8 L to glean some of the benefits that came with the v6 with the higher HP threshold of a v8? What parts of the engine architecture would stand in the way of that, and would there be any major benefit to choosing that smaller 5.06 over the LS1?
Old 02-26-2024, 12:03 PM
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The, 3.8V6 is a descendant of the early Buick small block V8. So there WAS a related V8. Not a bad engine, but not a lot of performance potential. The latest versions of the 3.8 V6 are obviously much further developed than those early V6 and V8s.
Having said all that, the LS is an even better design being a clean sheet from the late 90's
Old 02-26-2024, 09:44 PM
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I think the story is that the V8 version was a 60's Buick engine that was then sold to AMC and then after AMC went belly up GM got it back and made the V6 3.8 version
Old 02-26-2024, 11:17 PM
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Originally Posted by wannafbody
I think the story is that the V8 version was a 60's Buick engine that was then sold to AMC and then after AMC went belly up GM got it back and made the V6 3.8 version
KINDA true. Buick made the V6 at first, and sold it to Kaiser to put in CJ5s until AMC bought Jeep and put their own inline 6 and V8 in them. By this time Buick was designing small cars that could use the V6, so bought it back and a few years later came out with the even-fire version upon which all future 90 degree Buick V6s would be based.
Only thing I'm not sure of is if Kaiser bought the rights and tooling or if they just bought whole engines. Foggy on that part....
Old 03-18-2024, 11:19 PM
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I was very into the Buick GN turbo engines in the late 90's.... ported heads flowed just over 200cfm, 2 bolt main caps didn't offer a ton of bottom end strength nor did the 4 bolt heads, the factory rocker arm setup was pretty sloppy but did work. It used an old school flat tappet cam with a total dinosaur style front cover/oil pump built into it..... none of the gaskets could be reused.... for a mid 1980's engine it was great and easily ran 11's with bolt ons.... but thank God the all aluminum LS came out with stronger bottom ends, cylinder heads that flow well, and about the same weight (420lbs or so). The other Achilles heel for the Buick GN engine was the chip burned technology based ECM. It was super old tech and if modern EFI was available back then they probably would've been even better.

If you had a Buick Motorsports Stage2 setup... that was the bees knees... but also crazy $ and hard to find parts.
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