8.1 vs Duramax engine replacement

[hookooehoo]

Hi All this is my first time posting here. I hope i got the right area and am doing this right.

Anyways, I have read a few post about 'do i buy a truck with 8.1l or a Duramax.' Well my situation is a little different. I have a '05 2500 Suburban with a 496 and 4L85E. My 496 is burning oil like non other and everyone (including 3 dealerships) says to just rebuild/replace motor since I have 176K miles on her. I have always wanted to send my suburban to Eric at Duraburb and get a duramax & Allison put in. But now that I am in a position that I HAVE to get something done, I dont know which direction would be the best overall choice. I am stuck between getting the Duramax put in or getting a Raylar Motor which is bumped up to a 540ci! I have always loved my gas motors and had no issues. But have always thought, well i have a 2500 rig a nicely tuned diesel would be a great way to go. But after finding the Raylar guys and their motor a almost 700 hp 540ci suburban sounds pretty bas ass too! She's my daily driver. We sold the boat a few years ago and are looking to replace it with a 28ft or larger travel trailer or a Tritoon boat. So she still needs to be able to tow. 

Any personal thoughts on which way to go are welcome! Thanks in advance for any feedback.

[KARNUT]

I would check out the GM replacement, possibly adding a supercharger. Fuel mileage may be better that way. The only diesel conversion I’ve seen a shop owner put a Cummings in an old Chevy dually, he still drives it.


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[lordathey]

I would just stick with the gas motor. By the time you put a tuned diesel in there it will cost more then to just build the 496. I personally love the 496 and it would make a super fun ride with close to 700hp. If I didn't have my 2014 truck I would go buy one with the 496. 

[hookooehoo]

3 hours ago, KARNUT said:

I would check out the GM replacement, possibly adding a supercharger. Fuel mileage may be better that way. The only diesel conversion I’ve seen a shop owner put a Cummings in an old Chevy dually, he still drives it.


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The funny part about the GM replacement is i had 2 of the 3 dealerships i spoke to tell me that the average life of the 496 is 150k-175k and a long block from GM could have the same issues show up as I am having, not to mention its $7,000 and in CA there is only 1 motor in the system. If you haven't seen or  heard of Duraburb Inc, check them out, I first saw their stuff about 5 years ago.  Here is an example of what they do.

 

 

[hookooehoo]

27 minutes ago, lordathey said:

I would just stick with the gas motor. By the time you put a tuned diesel in there it will cost more then to just build the 496. I personally love the 496 and it would make a super fun ride with close to 700hp. If I didn't have my 2014 truck I would go buy one with the 496. 

I think cost will be almost a wash. the Raylar motor is $12,200 and it comes as a kit. You still have to assemble and install the motor. The Duraburb option is around $15k installed. At that point im thinking which is better for longevity. 

[lordathey]

hmm how many miles are on the diesel motor and transmission they install? Are you able to troubleshoot diesel problems? At least with the gas motor it will be a brand new motor and should last at least another 100K. Either way let me know what choice you make. I'm interested to see what happens. 

[lordathey]

1 hour ago, hookooehoo said:

The funny part about the GM replacement is i had 2 of the 3 dealerships i spoke to tell me that the average life of the 496 is 150k-175k and a long block from GM could have the same issues show up as I am having, not to mention its $7,000 and in CA there is only 1 motor in the system. If you haven't seen or  heard of Duraburb Inc, check them out, I first saw their stuff about 5 years ago.  Here is an example of what they do.

 

 

Average life 150K to 175K that seems pretty low. I have seen 496's around here with 250K plus on the original motor and they are still running strong. 

[swathdiver]

Duraburb!  You'll make the same or more horsepower, way more torque and get better mileage and the fuel is less expensive.  Check out their youtube channel, especially that one with the truck on the dyno, it's ridiculous.

[bgbdwlf2500]

if the price is even remotely close between the options get the duramax put in with a built transmission.

[Raptordude]

You won't make 700 hp with the duramax, that's for sure. But it will make more torque. The newer ones are around the 800-900 ft lb range, even the older ones (Lbz) put out around 650 ft pounds.

 

That 540 gas motor would be a lot of fun but you'll probably get like 5mpg where as the diesel will get you 15-20

 

 

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[hookooehoo]

Hi All! Well Eric from Duraburb just emailed me back. As of 1 Jan 2018 they discontinued doing the GMT800 platform. So that route to get a duramax is now dead.

[Firestone]

Thanks for the update. I would like to mention that owning a 2500HD Duramax and the 2500 Burb 8.1L that I don't think a D-Max would be that fun to drive in the Burb. The 8.1L feels lighter and has better street manners than a D-Max with a 5 speed, in my opinion. Let us know if you build the motor. 

[bgbdwlf2500]

On ‎2‎/‎8‎/‎2018 at 5:15 PM, Raptordude said:

You won't make 700 hp with the duramax, that's for sure. But it will make more torque. The newer ones are around the 800-900 ft lb range, even the older ones (Lbz) put out around 650 ft pounds.

 

That 540 gas motor would be a lot of fun but you'll probably get like 5mpg where as the diesel will get you 15-20

 

 

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All it takes is a tune to get an 02 duramax to 500 rwhp and 1000ftlbs of torque on the stock engine. the transmission is where the money is. 700hp on a dmax isn't hard at all

[Raptordude]

There's no way a simple tune will get you to 1000 ft pounds. An lb7 only makes 500ft pounds at the crank stock. There's no way just a tune would yield 1000ft pounds. To put this in perspective, my buddy has an 04 6.0 powerstroke. He has an oversized ball bearing turbo, ported intake manifold, and race tuning. They make 560 at the crank stock, and he dynoed it after his mods. It yielded 730 at the crank after those mods


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[bgbdwlf2500]

7 hours ago, Raptordude said:

There's no way a simple tune will get you to 1000 ft pounds. An lb7 only makes 500ft pounds at the crank stock. There's no way just a tune would yield 1000ft pounds. To put this in perspective, my buddy has an 04 6.0 powerstroke. He has an oversized ball bearing turbo, ported intake manifold, and race tuning. They make 560 at the crank stock, and he dynoed it after his mods. It yielded 730 at the crank after those mods


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Here ya go, the 6.0 was junk and if he didn't head stud or do any of the other bullet proofing it took to keep that engine together he isn't running a race tune. This is the tune I ran in my truck every day. truck ran 13.10 @ 102 just like I drove it on the street every single day.  https://www.ppediesel.com/shop/duramax-hot-2-e-t-race-xcelerator-gm-6-6l-duramax-diesel-2001-2007-111040000.html           click on the application tab at the bottom.   you also didn't mention a built transmission which I did have. none of the trucks from that era could handle the hot tuning that was and is available and not rip the trans out of the truck. Keep in mind I haven't had my truck for 11 years at this point but when I was in it I was in it and knew what it took for every truck out there to run well with what was available. The 6.0 was never really a contender between the duramax and cummins from back then due to reliability