What kind of motor is this???? Its a 8.1liter V8 from some GM car or truck
08-13-2006, 10:51 PM
#21
335 hp and over 400 ft lb stock aint too bad.
I had one in my short bed pickup, real tire frier. 55mph downshift to 2nd it would break loose and start spinnin.
Pistons are weak, only draw back on the stock motor.
The are a 4.250 bore, same as 454 bbc, stroke is 4.370, (same stroke as ZZ572 by the way)
I had one in my short bed pickup, real tire frier. 55mph downshift to 2nd it would break loose and start spinnin.
Pistons are weak, only draw back on the stock motor.
The are a 4.250 bore, same as 454 bbc, stroke is 4.370, (same stroke as ZZ572 by the way)
08-14-2006, 06:43 AM
#22
I have the 8.1/Allison in my HD. I get 8-10 towing my 28' car trailer and 13 or so empty.
I have heard of 8.1s using a lot of oil. Mine is about 3/4 qt low when it's time to change the oil.
I certainly wish it had a larger gas tank. 26 gallons when towing isn't a lot of range ...
And because it's gas, I don't have all the maintenance required by diesels. I used to own a diesel ... never again ....
I have heard of 8.1s using a lot of oil. Mine is about 3/4 qt low when it's time to change the oil.
I certainly wish it had a larger gas tank. 26 gallons when towing isn't a lot of range ...
And because it's gas, I don't have all the maintenance required by diesels. I used to own a diesel ... never again ....
08-14-2006, 06:13 PM
#23
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I used to work at a GMC dealership. From what I saw, that motor had alot of problems, like someone said before, they burn alot of oil. The performance applications are very limited because the flow like crap, dont turn up very fast, and are heavy, and to put them in an f body, you have to relocate the strut towers. The lsx motors are far superior. Those are towing motors.
08-15-2006, 07:58 PM
#25
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I’ve got some positive 
. Besides being an LS1 F-body owner we also have a 2001 Silverado 2500HD 4x4 SBCC with the 496 cu. in. big block and Allison 5-speed automatic. I absolutely love it. When you can smoke half-tons and normal cars towing a T-bird on a car trailer down the highway how bad can it be? I'll run anyone from a dig and usually win against all but the quickest cars and light trucks and my junk weighs 7,000 lbs. unloaded. I get 9.5 city with long warm ups and 10.5 doing 85 on long trips with the occasional 110 MPH rice cook off. Guys with stock tires and body-work get 11.5+. It will pull a damn house off the foundation or stop it in the same block from 70MPH, truly a totally excellent tow rig. And as Mitch said the maintenance is much lower than the equally bad azz Duramax. It's been said that you have to drive the wheels off a truck in a short time to surpass the purchase price difference and higher maintenance of the diesel compared to the 8.1. In reality Diesel performance is easier more popular due to the factory turbo but you can build the 8.1 desired. I'm working on my parts collection one Ebay at a time. There are aluminum heads and an intake from a company named Raylar. They offer a 600 cu.in. version that betters 750 HP before 6000 RPM. http://www.raylarengine.com/index.html Headers are available as are cams and superchargers, forged pistons, and stroker kits, etc. It's what the newer boats race on so it's not just a slug go agricultural mill but it does both equally well.
First off it's a major redesign borrowing heavily from the Gen 3 SBC engineering to become the Gen 7 BBC. It has LS1 style cylinder cathedral intake ports and D shaped exhaust so I don't know why others are knocking head flow. It's the Vortec intake manifold and cam that chokes it. The heads are better than normal oval ports especially when ported like my HP3 type factory CNC'd versions from the speedboat 8.1. That engine makes over 500 HP with a light cam stock N/A. The firing order is LS1 like with the coil near plug crank triggered ignition. The intake no longer carries coolant, the 8.1 uses a crossover pipe connected to the front of the heads with a thermostat on it. It has a crankshaft oil deflector (windage tray or scraper). There are no expansion plugs on the sides of the block. It has an internal PCV system. It’s drive by wire with the auto. It uses a cassette style rear main seal. It uses studs and nuts to retain the rocker arms whereas the 454 used bolts. It does not have a distributor or rear mounted cam sensor, it’s on the front cover. Mine uses about 2 quarts between 4300-mile oil changes. The pan holds up to 7 quarts.
My current mods are a Volant cold air system with ram air, BBK 80MM throttle body and port matched inlet plenum, Granetelli MAF, Hypertech programmer, factory 3” dual exhaust with a Magnaflow muffler, raised fuel pressure. With just that the engine is a lot more powerful than stock and the truck will go even with the family and a boat behind it. When it’s empty I can wreak havoc on unsuspecting gomers who attempt to cut me off or see my SS style hood and give it a try. I have to feather the throttle to avoid wheel spin with 3.73’s, 265/70-16’s and a posi.
Things in my warchest that I haven’t installed yet because I still need a few things and want to do it all at once are: Whipple supercharger, 44 lb/hr marine injectors, Duramax intercooler, HP3 heads, double roller timing chain, and front and rear 4.56 gears. Once I get a blower cam and big headers the truck will be transformed into a pony car killer. At least stock ones.
I don’t take it too seriously, I don’t think I can beat the world in it, but it’s a heck of a lot of fun to have such a fast big truck to mess with minds nevertheless.
Check out this video of a fellow HP 8.1 guy in Kansas who goes by Tie-Rod around the net. He runs some Raylar parts and a bunch of N02 into the 12’s in his 2500 HD. When it gets near the end turn the volume up and listen to what the guy in the wasted 5.0 says, it’s classic.
http://video.ls1tech.com/search/2500...a8e78dc1b8.htm
Vernon
. Besides being an LS1 F-body owner we also have a 2001 Silverado 2500HD 4x4 SBCC with the 496 cu. in. big block and Allison 5-speed automatic. I absolutely love it. When you can smoke half-tons and normal cars towing a T-bird on a car trailer down the highway how bad can it be? I'll run anyone from a dig and usually win against all but the quickest cars and light trucks and my junk weighs 7,000 lbs. unloaded. I get 9.5 city with long warm ups and 10.5 doing 85 on long trips with the occasional 110 MPH rice cook off. Guys with stock tires and body-work get 11.5+. It will pull a damn house off the foundation or stop it in the same block from 70MPH, truly a totally excellent tow rig. And as Mitch said the maintenance is much lower than the equally bad azz Duramax. It's been said that you have to drive the wheels off a truck in a short time to surpass the purchase price difference and higher maintenance of the diesel compared to the 8.1. In reality Diesel performance is easier more popular due to the factory turbo but you can build the 8.1 desired. I'm working on my parts collection one Ebay at a time. There are aluminum heads and an intake from a company named Raylar. They offer a 600 cu.in. version that betters 750 HP before 6000 RPM. http://www.raylarengine.com/index.html Headers are available as are cams and superchargers, forged pistons, and stroker kits, etc. It's what the newer boats race on so it's not just a slug go agricultural mill but it does both equally well.First off it's a major redesign borrowing heavily from the Gen 3 SBC engineering to become the Gen 7 BBC. It has LS1 style cylinder cathedral intake ports and D shaped exhaust so I don't know why others are knocking head flow. It's the Vortec intake manifold and cam that chokes it. The heads are better than normal oval ports especially when ported like my HP3 type factory CNC'd versions from the speedboat 8.1. That engine makes over 500 HP with a light cam stock N/A. The firing order is LS1 like with the coil near plug crank triggered ignition. The intake no longer carries coolant, the 8.1 uses a crossover pipe connected to the front of the heads with a thermostat on it. It has a crankshaft oil deflector (windage tray or scraper). There are no expansion plugs on the sides of the block. It has an internal PCV system. It’s drive by wire with the auto. It uses a cassette style rear main seal. It uses studs and nuts to retain the rocker arms whereas the 454 used bolts. It does not have a distributor or rear mounted cam sensor, it’s on the front cover. Mine uses about 2 quarts between 4300-mile oil changes. The pan holds up to 7 quarts.
My current mods are a Volant cold air system with ram air, BBK 80MM throttle body and port matched inlet plenum, Granetelli MAF, Hypertech programmer, factory 3” dual exhaust with a Magnaflow muffler, raised fuel pressure. With just that the engine is a lot more powerful than stock and the truck will go even with the family and a boat behind it. When it’s empty I can wreak havoc on unsuspecting gomers who attempt to cut me off or see my SS style hood and give it a try. I have to feather the throttle to avoid wheel spin with 3.73’s, 265/70-16’s and a posi.
Things in my warchest that I haven’t installed yet because I still need a few things and want to do it all at once are: Whipple supercharger, 44 lb/hr marine injectors, Duramax intercooler, HP3 heads, double roller timing chain, and front and rear 4.56 gears. Once I get a blower cam and big headers the truck will be transformed into a pony car killer. At least stock ones.
I don’t take it too seriously, I don’t think I can beat the world in it, but it’s a heck of a lot of fun to have such a fast big truck to mess with minds nevertheless.
Check out this video of a fellow HP 8.1 guy in Kansas who goes by Tie-Rod around the net. He runs some Raylar parts and a bunch of N02 into the 12’s in his 2500 HD. When it gets near the end turn the volume up and listen to what the guy in the wasted 5.0 says, it’s classic.
http://video.ls1tech.com/search/2500...a8e78dc1b8.htm
Vernon
08-15-2006, 09:48 PM
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Damn, good job, I had no idea there had been parts like that made for that engine. I looked into putting one of those into an f body a few years ago and got nothing but a bunch of "why?" questions from people. I guess there is no replacement for displacement. I guess you do learn something new every day.
