8.1

[chevyndn]

im not sure if im in the right place for this, but has anyone messed with an 8.1 for a mid 2000's chevy pick up?

[Critter]

Dirty Larry has one in his 78 truck. Technically they aren't an LS engine, but I don't think anyone is going to bash you for posting here. Here is the link to his swap pics.

[68GMCCustom]

that would be a Vortec?

[chevyndn]

ok, i wasnt sure what class it fell under. i found one and was thinking about buing it but i wasnt sure if anyone had done this swap or not.

[Critter]

I guess you could call them a Vortec Engine, but not an LSx. I'm no expert but I believe they are based off the old Big block engine same as a 7.4 liter 454, but the firing order is different. I'm assuming a lot of the wiring and computer adaptation would be similar to that of a 4.8/5.3/6.0 etc...but I'm just speculating. They make GOBS of torque and in my opinion are awesome for a swap. What were you thinking of putting it in?

[chevyndn]

well i either want to put it in my 98 gmc or my 72 chevy pick... we have a 3500 flat bed pick up at my job and holy crap its a torque monster for a stock motor...

[68GMCCustom]

if you need that torque for pulling....then it would probably be worth the horrific fuel economy.

[Critter]

Originally Posted by 68GMCCustom

....then it would probably be worth the horrific fuel economy.

Also the bad@ss-ness of having 496 fuel injected cubic inches would be worth the mileage.

[jdmathes074]

.http://www.hotrodlane.cc/Streetstories/81%20swap.pdf

That may have some helpful information in it

[Mr. 250r]

My friend has one and i got to drive it and yes it is a powerful motor but it only gets 9.5mpgs at the best which is really a buzzkill for it but if your not worried about mpg's and want some power its got that, also while towing a 20ft trailer with a 3/4 ton suburban on 39.5s and a big block got same gas mileage so thats always a plus

[tonypaul]

I got a brand new 8.1l crate engine in my garage that I was going to use in my 68 GMC. I went with a different motor. I will sell it cheap if interested. I have a ecu and a dbw pedal for it but no harness.

[dan42]

That would be interesting in a little shortbed.

[Clyde65]

That would be fantastic in just about anything!

[chevyndn]

hmmmm, if i had the space and money to come get it id be all over it!

[Zoomad75]

The 8.1 really only shares basic architecture with the early big block. Heads DO NOT interchange and the deck height differs. You can't bolt a conventional 396-454 intake on one. This means you have to run the injection. I've got one came from a motorhome, but am trading it to DirtyLarry with some cash for the pcm and harness for my 5.3 swap.

Also, the head design could be considered similar to LS but on a larger scale due to the tall cathedral intake ports. Sharing with the LS/gen3 is the changed firing order.

8.1's are amazing engines in that I've driven many a motorhome over mountain passes in coaches from 20,000 to 26,000 pounds. They still get 6-8 mpg in a 24,000 pound coach. Then again in 3/4 ton trucks your lucky to get 14mpg. They are way underrated in that the same engine sold for Mercruiser for marine applications with a non-emissions type tune is pushing over 400hp with a proportional increase in torque. Larry's 78 with his 8.1 is an animal. Considering he's spinning heavy biasply Q78 swampers it will absolutely flat haul the mail and is a stump puller.

[Zoomad75]

Double post....sorry.

[tonypaul]

Originally Posted by tonypaul

I got a brand new 8.1l crate engine in my garage that I was going to use in my 68 GMC. I went with a different motor. I will sell it cheap if interested. I have a ecu and a dbw pedal for it but no harness.
Attachment 682972

If anyone is interested in this motor I will let it go for $2000.00. Shop around all other new 8.1l engines are $5000.00 and up.....

[DirtyLarry]

Originally Posted by jdmathes074

.http://www.hotrodlane.cc/Streetstories/81%20swap.pdf

That may have some helpful information in it

Man, I dunno…..Helpful information as to what not to do maybe. I personally wouldn’t follow his complete recipe. While he did do an extremely clean install, he went to a lot more work than ever needed to be done. There is no reason to cut the frame to make room for the 8.1L specific exhaust manifolds as any big block (396, 402, 427 & 454) exhaust manifold or header will fit an 8.1L. There is also no need to cut the frame for the A/C compressor as there are alternate bracket options (medium duty truck and RV) for the 8.1L that puts the A/C compressor up high on the driver’s side nor do you need to make room for the EGR valve at the firewall when you can simply remove it all together and have the ECM tuner toggle off the EGR portion of the calibration. 8.1L engines after 2003 didn’t even have EGR valves from the factory. You also do not need to run electronic throttle unless you want to deal with a big hassle and spend more money on parts. If you must have cruise control, yes…electronic throttle will get you that much easier.

Lastly, you do not need to use a gimmicky Dakota Digital tachometer adapter when all you really need to do is set your existing tachometer to 4 cylinder mode providing you are using an aftermarket tach. If running an OEM tach….you may need this hokie thing. MSD sells one as well.

Now this one is a true hack job.

Tonypaul,

What is that 8.1L out of? Looks like a 2001-2003 medium duty truck or Workhorse RV engine by the location of the water inlet, existence of an EGR valve and black valve covers opposed to bare aluminum. Nothing wrong with that….all years of 8.1L are good. 2004 and are a bit better though in terms of electronics (upgraded sensors, coils, etc).

As for the fuel consumption comments, my 6.0L Silverado 2500HD drinks just as much as my 8.1L Silverado 2500HD under normal driving while the 6.0L drinks even more when loaded.

Here are a few pictures I took at work of the last of the production 8.1L’s. 8.1L production ended with the 2010 model year.







Smaller coils on 2004 - 2010 engines.

[Critter]

That's a beautiful pic but a terribly sad story that goes along with it.

I used to work as a production engineer for an auto manufacturer that I disliked...lets just say it WASN'T GM. Even though I hated the brand it was still awesome to see all those drivetrains, body panels, and frames stacked up everywhere. If I could have been in a Chevy plant it would have been a dream come true, probably would have worked for free...or at least a little cheaper.

[Pop's C-10]

That is art...

[3r!c84]

This is what dreams are made of
Posted via Mobile Device

[chevyndn]

amen to that!!!

[DirtyLarry]

Yeah, every time I go to the plant I wish I could walk around with a shopping cart and pretend I was at the automotive version of Home Depot. Each crate holds 3 engines. I would be happy to take home just one crate.

[1BadAction]

What kind of crossmember mods does it take to get a 8.1 into a 4x4 K5? lift necessary?

[1tonjimmy]

Originally Posted by 1BadAction

What kind of crossmember mods does it take to get a 8.1 into a 4x4 K5? lift necessary?

Nothing, the motor is basically a like an old BBC but with a taller deck height and cathedral port heads. Dirty Larry, if I am wrong correct me please. I was going to put an 8.1 in my Jimmy and it got destroyed. I did a lot of reach on stuffing the big ole motor in a 73 to 87 K5/Jimmy.