Chevy 8.1L - School Me

gas mileage = sux


:D that's all I have
 
adamk said:
Anyone on here have some knowledge/insight on the Chevy 8.1L V8? I'm looking at a used work truck to use as the tow rig for my Jeep. It's high mileage but was been well maintained. Any and all insight/experience/knowledge would be greatly appreciated.

Thanks,
Adam
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Keep it full of oil and gas and enjoy a terrific tow rig engine. The manifolds tend to lose bolt and/or warp. Aside from that, they're a great engine
 
last iteration of the "big block chevy", although GM does not consider it a Gen 7. Earlier versions had some issues (piston slap?)....if it isn't a problem now, you are probably in the clear.

496 ci motor, rumor is loaded or unloaded you can expect to get just below double digits. I would try to grab one with a 6 speed allison....

You can toss an 87 octane tune on there to bring it down to 310hp (?) which is what the C4500/5500 chassis rigs ran....I would imagine it slows it down a bit, but if cheap gas is your bag, it will probably ensure you never wear out anything in the drivetrain.

There is one company that offers aftermarket support parts for upping performance and they ain't cheap!

Leave it stock and I have seen K2500's with almost 500k on the clock.
 
Darn good engine. Use them in industrial engine applications still to this day.

Dont gloss over one key point @Jody Treadway just made....the engine is designed with an acceptable oil consumption rate when new. As rings age and wear it will burn even more oil.
Nothing crazy alarming but at 200k miles Id plan to expect maybe 1-1.5 quarts every 3k miles.
Nothings wwrong its the way GM designed it. Just dont get lazy and forget to check and run her dry.
 
I had an 02 K2500 Suburban with the 8.1, it was a great engine. I got around 12mpg just driving around and around 7-8mpg towing. The Burban came with the 4L85 trans and the trucks got the Allison. Mine had 185k when I sold it, it used about a quart of oil between changes.
 
Yep, other than the oil consumption issues they are good motors. Just keep an eye on things.

I have an 8.1L that we are building now to go into my 95 Suburban. They are awesome motors and will do everything you'll need.
 
I loved my 8.1. I had it from 76k miles to 145k miles.

Early ones pre 03 had some lifter issues.

Used a qt of oil every oil change.

Could hammer on it all day towing, never hiccuped.

Never got worse than 6 mpg, never better than 14.

The 6mpg was a thrash fest on the way to Harlan, trying to beat the clock and the sun pulling 8500 lbs and trying to stay around 75-77 mph.

I wish mine had the Allison or even a 6l90 trans. Just had to keep the Rpms in the sweet spot to pull the big hills without losing any speed.

Stupid torque, great motor. A tune really wakes them up. They are massively detuned in factory mode.
 
adamk said:
Well...this thread can go into the scrap bin now...

Thanks to all for the replies.
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:lol: Just trying to motivate you to go get the dang thing! There is no Dave :smokin:
 
CasterTroy said:
:lol: Just trying to motivate you to go get the dang thing! There is no Dave :smokin:
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I don't know anyone who has an 8.1l who wishes they hadn't gotten it, if it is going to be a tow rig....get it, if it will be a glorified grocery getter, grab a 6.0l instead.

The duramax and cummins crew may tell you differently, but in the long haul, I suspect the increased price of diesel, the extra cost/frequency of fuel filters, and the price of oil changes makes the actual cost of ownership/mile closer to equal than most will admit.....let alone the cost of DEF and the maintenance costs if something big like IP or injectors need replacing.
 
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Had a 8.1 in an uparmored suburban while deployed to Iraq. It was a total tire fryer but it would get the job done and I couldn’t imagine any other platform to tote a 9k platform around in the shit and heat of Iraq in the summer. We were there for 15 months and did nothing but dump some oil in every once in a while and it got the job done NOT treating it nicely.
 
Truck in question...

300k, has the Allison, new tires, recent tune up, new AC system, serviced regularly. One of my clients has it for sale at a steal and hopefully y’all are talking Adam into scooping up this thing! It just got replaced with a newer model and rolled out of service.
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77GreenMachine said:
Truck in question...

300k, has the Allison, new tires, recent tune up, new AC system, serviced regularly. One of my clients has it for sale at a steal and hopefully y’all are talking Adam into scooping up this thing! It just got replaced with a newer model and rolled out of service.
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If he falls through, put me in line on it lol
 
Mac5005 said:
If he falls through, put me in line on it lol
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He has an 04 Ford V10 dually CCLB also. 2wd, same mileage, same condition. $3600. He has trucks like this come out of service 2, sometimes 3 times a year. I have sold 3 of them for him lol.

Next time one comes up, I’ll post it here for everyone.
 
So I'm picking up the truck Wednesday. Any suggestions for where I start the maintenance? My plan is the obvious fluid changes (oil, trans, diff). Is there anything else I should go for? It's got a new water pump so the coolant should be good to go. I do know I'll need to replace the oil cooler lines but, from what I've read online, it's very common to have them leak.
 
adamk said:
So I'm picking up the truck Wednesday. Any suggestions for where I start the maintenance? My plan is the obvious fluid changes (oil, trans, diff). Is there anything else I should go for? It's got a new water pump so the coolant should be good to go. I do know I'll need to replace the oil cooler lines but, from what I've read online, it's very common to have them leak.
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Change the fluids in everything, filters in everything.

Just check and prep everything as if you were going to drive cross country with it next week.

Then you have a good starting point, and have a chance to look everything over while doing so.

My truck would wear out the rear brake pads 2x faster than the fronts.

Auxiliary bigger trans cooler is a good idea.

My truck did not like a k&n filter due to oil getting on maf.

Get a wix hd paper filter. 2x tall pleated filter.

Change fluid out of brake Master’s as well.

Check hydroboost for weeping p/s fluid.
 
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