8.1L Chevy motor - LS1TECH - Camaro and Firebird Forum Discussion

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8.1L Chevy motor

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Old 07-24-2009, 06:14 PM   #1
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Default 8.1L Chevy motor

Mods, please move if it not in the right spot.

The Chevrolet 8.1 liter engine was produced from 2001-2006 and installed in HD 2500 and larger trucks and vans, as well as motor homes, Suburbans and

Does anyone know much about this motors?
I can pick one up for a couple hundred dollars out of a wrecked 2003 HD2500.
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Old 07-24-2009, 06:42 PM   #2
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They are 375hp and 495 torque Factory so thats pretty good. If you tune them put a good exhaust and cold air I am sure they would be 400hp and well over 500 torque. I am not sure about the Aftermarket fo them but I do believe the block is based on a tall deck big block of old, thats what i have read anyways. They have the same bolt pattern bellhousing as any sbc does or bbc. I Have one at work with 245,000 oilfield miles in a one ton 2001 chevy and it still runs good. It gets about 10 mpg in a 12,500 pound truck thats always loaded to that weight. Surprisingly the only problem is that one of the mounting ears on the tranny which is the allison broke where the transfercase mounts to it but thats about it. I also had to do a cam sensor a while ago but nothing major. I think it is a solid engine but not sure about the aftermarket. How many miles on the motor?
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Old 07-24-2009, 06:45 PM   #3
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it seems like hi mileage 8.1 come apart when hi perf. parts are swapped in,
it is not uncommon for the pistons to break ringlands.
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Old 07-24-2009, 07:14 PM   #4
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it there much in the aftermarket for these. is it worth building?
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Old 07-24-2009, 07:29 PM   #5
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1969mach1 I have one for sell out my wrecked 2003 Hd with less then 20000 miles if you need one.. Clean motor never saw and upgrade.
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Old 07-24-2009, 08:46 PM   #6
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I'm wondering why the f*** these things don't have as much aftermarket support. It is almost literally a 496ci, canted valve LS1. They have cathedral ports like the LSx engines, but it's not an inline valve head. There is no conventional distributor, but I hear it has an ignition like an LT1...

I'm trying to get my hands on a set on one and see what I could do. Aftermarket or not, I'd bet you can make an EASY 600whp on pump gas with the iron heads, unless they are just absolute junk. Wild card would probably be the intake, but I hear the marine industry (Arizina Speed & Marine) has something for them.

Last edited by KCS; 07-24-2009 at 08:55 PM.
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Old 07-24-2009, 08:51 PM   #7
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this would certainly be an interesting build. if i had money, i'd try it out, but that just isn't in the cards for me.
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Old 07-24-2009, 11:10 PM   #8
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i would like to see someone build one, but it would be like a boat anchor in the front of most cars. to offset the weight you would have to make some serious power becasue people complain about the extra 88 pounds a iron block adds over the aluminum.
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Old 07-25-2009, 01:26 AM   #9
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Speaking of "boat anchors"


The automotive aftermarket is more comfortable building Gen IV and Gen V BBC engines. For the most part, only the Marine aftermarket has forged ahead with developing the 8100 engines. There, you don't have the tall-deck clearance concerns. Also, a bit of boost can overcome the shortcomings of an OEM cylinder head until demand warrants aftermarket support for the unique design.

With most of the truck tuners embracing diesel performance, the 8100 has been left behind.
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Old 07-25-2009, 10:12 AM   #10
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Old 07-25-2009, 11:33 AM   #11
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heres a page from a diesel form im on


i think its everything you want to know about the 8.1. theres a guy on the sight doing a cam install on his 8.1, ill read up on it and post that thread if it helps.
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