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-   -   8.1 (https://67-72chevytrucks.com/vboard/showthread.php?t=438988)

chevyndn 01-05-2011 07:55 PM

8.1
 
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 01-05-2011 08:02 PM

Re: 8.1
 
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 01-05-2011 08:14 PM

Re: 8.1
 
that would be a Vortec?

chevyndn 01-05-2011 08:36 PM

Re: 8.1
 
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 01-05-2011 08:47 PM

Re: 8.1
 
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 01-05-2011 08:51 PM

Re: 8.1
 
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 01-05-2011 11:37 PM

Re: 8.1
 
if you need that torque for pulling....then it would probably be worth the horrific fuel economy.

Critter 01-06-2011 12:46 AM

Re: 8.1
 
Quote:

Originally Posted by 68GMCCustom (Post 4390933)
....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 01-07-2011 11:49 AM

Re: 8.1
 
.http://www.hotrodlane.cc/Streetstories/81%20swap.pdf

That may have some helpful information in it

Mr. 250r 01-14-2011 07:15 PM

Re: 8.1
 
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 01-16-2011 01:03 PM

Re: 8.1
 
1 Attachment(s)
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

dan42 01-20-2011 11:52 AM

Re: 8.1
 
That would be interesting in a little shortbed.

Clyde65 01-20-2011 12:34 PM

Re: 8.1
 
That would be fantastic in just about anything!

chevyndn 01-20-2011 06:35 PM

Re: 8.1
 
hmmmm, if i had the space and money to come get it id be all over it!

Zoomad75 01-21-2011 01:38 AM

Re: 8.1
 
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 01-21-2011 01:38 AM

Re: 8.1
 
Double post....sorry.

tonypaul 01-21-2011 06:55 PM

Re: 8.1
 
Quote:

Originally Posted by tonypaul (Post 4415371)
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 01-30-2011 02:06 AM

Re: 8.1
 
Quote:

Originally Posted by jdmathes074 (Post 4393808)
.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.

http://farm3.static.flickr.com/2745/...88e3e750_b.jpg

http://farm5.static.flickr.com/4001/...4db530f9_b.jpg

http://farm3.static.flickr.com/2758/...5e88d2d7_b.jpg

Smaller coils on 2004 - 2010 engines.
http://farm5.static.flickr.com/4003/...e34995df_b.jpg

Critter 01-30-2011 12:16 PM

Re: 8.1
 
http://farm3.static.flickr.com/2745/...88e3e750_b.jpg

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 01-31-2011 12:53 AM

Re: 8.1
 
http://farm3.static.flickr.com/2745/...88e3e750_b.jpg

That is art...

3r!c84 02-01-2011 01:04 AM

Re: 8.1
 
This is what dreams are made of
Posted via Mobile Device

chevyndn 02-01-2011 01:33 AM

Re: 8.1
 
amen to that!!!

DirtyLarry 02-01-2011 03:07 AM

Re: 8.1
 
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 03-13-2011 05:58 PM

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

1tonjimmy 03-15-2011 05:43 PM

Re: 8.1
 
Quote:

Originally Posted by 1BadAction (Post 4550037)
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.


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