GMCproject

What kind of power are these engines capable of? I know they are choked up beyond belief. I'd think a set of LT's, an x-pipe, and cat back, and a new intake would probably be worth like 50hp. Throw a BIG *** cam in with some worked over heads, I'd think you'd have a heckuva a beast on your hands.

8100hammer

Well depends on how you look at. Yes they are stuff up beyond reason. But you are not going to find a whole lot of speed parts, just your basics, cam, rocker arms, intake filters kit, and computer tune. I don't know why people always come up to me say" what kind mpg you get with that thing, like 1". Then I kindly say 12-13 in town and 14-16 highway. Granted I can't match a 5.3 liter. But have match the 6.0 liter in mpg. I work with 3 guys who have them. So I don't not know why they are not popular(the 8100). Who couldn't use 455 ftlbs of torque stock?


Aluminum heads will cost you $2800 assembled , I don't why they cost that much, when a guy with LS1 style engine can get cnc ported, performance valves and springs for $1750 assembled. Oh yeah you get a S\C for $4200 then need to get a ATS or SUNCOST STAGE 5 Allison transmission for $4500+ but do come with no HP or torque limits!

Just to give an idea of how stuffed up they are last year I ran 16.7 at 79mph and now have run a 15.42 at 87.0mph with just westers and home made intake kit.

Snake Eater

Most people dont get the 8.1 because they are not as strong as the LS1 with its 6 bolt main. They also wont take the 6500+ revs the LS1 will. Dont get me wrong, they are awsome engines, just not up to doing what the LS1 will with less money invested.

Keith

Aint no replacemant for displacement.
A 496 is pretty cool in my book.

GMCproject

Agreed 2002.

tbyrne

iTrader: (15)

The LS1 heads have been around for years with most of them being reworked factory castings. The aluminum 8.1 heads are new castings so that adds to the cost. Plus seeing that they a new product the manufacturer has to recoup some of the R&D costs. We might see pricing for these come down a little in a few years.

I have three 8.1 motors (supercharged version in my Suburban, bolt-ons + cam an HD and a stock motor in my boat) so I like displacement! The boat will run about 70MPH with this and 2 people.

8100hammer: That is a very good improvement for a few basic mods!

Tom



2002 8.1 Silverado HD - Full Throttle lift, 37" tires, Comp Cam, TOG headers, Volant induction plus more!
2002 8.1 Suburban -Intercooled Whipple supercharger, 22" wheels/tires + more - 407hp/558 ft-lb torque at the rear wheels - 13.93 @ 95.79 MPH

www.tbyrnemotorsports.com

8100hammer

The ZZ572 has a redline of 6000 rpm, and that does not have 6 bolt mains, 6 bolts mains are for the alum verison of the ls1 for stronger, and stabilty. I all think that I would be better buying a 572 short block, high flow heads, stand alone EFI, then a turbo. I am think would be about the same price?

GMCproject

Ok. A 572 is just slightly bigger than a 496.lol. If you want to talk that, a 572 with a MUCH bigger cam, single plane intake, EFI, some heavily ported heads, twin turbos cranking about 14 or so psi into it. All connected to a Turbo 350 and sent back to a 14 bolt with some 3.73's and ET streets. Oops. I wasn't supposed to say that.

Visionxorb

I just thought I heard TH-350s scream in fear from all over the country when i read this.

8100hammer

The reason I am talking zz572, is that it come with strong internals. Where the stock 8100 has nodular iron crank, hypertonic pistons (know to be brittle), rods are ok. The pistons in the 8100 are know to be weak in boosted apps. But trying to decide between building a 8100 or buying 502 or 572 short block with preminum internals and go ***** to the wall. might go with 502 do to more speed parts. Just don't if it will bolt up the Allison trans?

To do a 8100 right need to have forged internals, and better heads which are rare.
Learn couple weeks ago that GMPP canceled the Hp3 8100 engine that would of made a sweet engine 525hp 560ftlbs on 87 octane. All you need is a S\C or Turbo.