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Old 07-15-2022, 02:20 PM   #1
SlimTim
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Default SN 6400 VT365_ISL400 Repower

I decided to repower my 2010 6400 SN with a Cummins ISL 400 and an Allison 3000 transmission. I am not quite finished with the project but I feel I am close enough to start posting some photos.

To start I looked at the International DT466/570, Cummins 6.7 ISB and Cummins ISL 400 as possible replacement engines. However Ultimately I decided on the Cummins ISL for the following reasons:

The DT466/570 would have been the simplest but unless you want to purchase a remanufactured engine it is hard to find one with less than 250k miles. Also the max stock HP for these engines is around 300 HP, but high HP/torque DT466's are nearly impossible to find. Because of this I dropped the DT466/570 from my list of possible engines.

The Cummins 6.7 ISB was a very strong contender and if I was to do this again I would likely go with this engine. The 6.7 engine was used in many RV's and low mileage engines can be easily found. Another advantage of the 6.7 is that you can retain the stock SN Allison 2500 transmission and this would make the repower much easer (and cheaper). Ultimately the reason I dropped this from my list of possible engines was because I wanted more HP.

With the DT and ISB engines eliminated the Cummins ISL 400 (8.9L Engine) seemed to be the best choice. However because the ISL has 400 HP and 1200 FT LB torque I needed to also upgrade the Allison 2500 to a 3000 series transmission adding a significant amount of work and additional cost.

Assuming I can remember how to upload photos to the forum I will start posting some pictures.
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Old 07-15-2022, 03:01 PM   #2
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Here are a phew photos of setting the ISL in the frame. I had to change the motor-mount location, change the oil pan on the engine from a rear sump to a front sump, modify the front frame cross member, and change the turbo location to get everything to fit.

Sorry about the sideways images. I am not sure how to rotate them once they are uploaded.
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Old 07-15-2022, 03:13 PM   #3
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Making a new fan shroud out a fiberglass. I should have spent more time filling and sanding down the finished shroud before painting it. But I was tired of fiberglass dust on everything and wanted to get on with other tasks.
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Old 07-15-2022, 03:22 PM   #4
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Several months into this project I followed this rig into the gas station and I thought to myself "Maybe this person is onto something".
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Old 07-24-2022, 01:21 PM   #5
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I was wondering when you were gonna start a thread on this!!!

Looks great!!

Also, I have a 6x6 military deuce. My favorite part about driving it is after I get out of it and into the supernova, it makes the supernova feel like a hot rod !
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Old 07-25-2022, 01:31 PM   #6
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ST, Great to see someone take the leap. I am considering on swapping mine to a 6.7 Cummins mainly thinking it will be the most affordable and easiest way to get better reliability. I am pretty good at the fab aspect so I'm thinking getting it in wont be to bad but as far as getting it to run, work with the trans, and have working gauges I'm kind of lost. I don't even know what it will require or where to find what I need. I will be following your build for sure..
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Old 07-26-2022, 10:45 AM   #7
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Very, very cool. It would have been nice if Navistar had been made to come up with a repower kit as part of the lawsuit.
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Old 07-30-2022, 03:54 PM   #8
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Quote:
Originally Posted by bhplumber View Post
ST, Great to see someone take the leap. I am considering on swapping mine to a 6.7 Cummins mainly thinking it will be the most affordable and easiest way to get better reliability. I am pretty good at the fab aspect so I'm thinking getting it in wont be to bad but as far as getting it to run, work with the trans, and have working gauges I'm kind of lost. I don't even know what it will require or where to find what I need. I will be following your build for sure..

A 6.7 repower would be very easy to do. The stock Allison 2500 could be used and I donít t think you would need to move the transmission back. The only big purchase item would be the Cummins 6.7. You would want to get a complete engine out of a wrecked RV or a delivery truck. DO NOT GET a 6.7 from a Dodge truck. If you get a RV/truck 6.7 ISB it will be basically plug and play. All gauges will work you just need to connect the Cummins J1939 communication bus into the International trucks J1939 communication bus. You may want to open up 6th gear on the Allison transmission as the 6.7 turns a few less RPM than the VT365.
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Old 07-31-2022, 06:25 PM   #9
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Cummins offers a 6.7 repower for the 4200 bus chassis but they told me it will only work on a bus not a truck chassis. It’s just hard for me to believe the 2 chassis are different. Would I want an 08 cummins engine so it’s pre def? I’m just thinking it might be hard to find a low mile engine that old. Thanks for your input
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Old 07-31-2022, 11:27 PM   #10
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Cummins offers a 6.7 repower for the 4200 bus chassis but they told me it will only work on a bus not a truck chassis. Itís just hard for me to believe the 2 chassis are different. Would I want an 08 cummins engine so itís pre def? Iím just thinking it might be hard to find a low mile engine that old. Thanks for your input
Yes I would get an 07 to 09 pre DEF engine. In regards to finding a low mileage engine I would look at the RV salvage yards such as https://colawrvsalvage.com. Also keep a look out for engines on your local Craigslist. You will want to purchase a complete engine with electronics pumps motor mounts plugs and etc. you will also want an engine with the turbo mounted Toto the front of the engine.
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Old 07-31-2022, 11:38 PM   #11
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The hardest part for me when doing the repower was identifying the correct electrical connectors and other fuel and oil fittings. For example my ISL uses a 50 pin connector to the ECM. Unknown to me there is multiple different variants of the 50 pin connector with the only difference being an alignment key. Let’s just say it took me two try’s to let the correct 50 pin connector. at approx $50 each.
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Old 08-01-2022, 06:42 PM   #12
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Thanks ST,
I found this today at Visonerv.com

PRICE $13500.00 KEEP YOUR CORE
REAR GEAR DRIVE
FAMILY NUMBER - 7CEXH0408BAC
SERIAL SER. NUMBER - 46764471
MILES - 16,000
YEAR 2007
CPL - 1388
LITER - 6.7L
but it says "rear gear drive" ?? and the turbo is mounted mid motor on the passenger side of the engine. doesn't look like it includes the harness.
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Old 08-01-2022, 10:42 PM   #13
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Originally Posted by bhplumber View Post
Thanks ST,
I found this today at Visonerv.com

PRICE $13500.00 KEEP YOUR CORE
REAR GEAR DRIVE
FAMILY NUMBER - 7CEXH0408BAC
SERIAL SER. NUMBER - 46764471
MILES - 16,000
YEAR 2007
CPL - 1388
LITER - 6.7L
but it says "rear gear drive" ?? and the turbo is mounted mid motor on the passenger side of the engine. doesn't look like it includes the harness.
I am not a 6.7 expert but I believe the Dodge 6.7 are a front gear drive and the Cummins 6.7 are a rear gear drive. If this is correct then the engine you have located should work.

One thing I can not stress enough is to get a complete engine. Because Cummins and the chassis builders do everything off of engine number and VIN itís difficult to get parts some times;; itís also expensive. Unfortunately you canít just go to the auto parts store and say; I need an alternative bracket for a 6.7 cummins.
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Old 08-06-2022, 06:03 AM   #14
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Default Interesting

Just bought a 2008 SN with the VT365, I have owned 3 6.0 fords already, I know what Iím in forÖ but this one only has 7,800 miles on the whole rigÖ hoping it will last a while before re-power. I am very interested in this build, I have sourced a ISL locally with Allison trans, but interested to know how it is all going together. Would it truly be easier to swap in a ISB 6.7 say 350HP? Havenít even picked up the rig yet and already looking at repower 🙃
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Old 08-06-2022, 11:17 PM   #15
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Default 5.9 isb??

Would it be worth wild to swap in a 5.9 isb pre 6.7 ?
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Old 08-08-2022, 10:23 AM   #16
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Originally Posted by CTMICH5 View Post
Just bought a 2008 SN with the VT365, I have owned 3 6.0 fords already, I know what Iím in forÖ but this one only has 7,800 miles on the whole rigÖ hoping it will last a while before re-power. I am very interested in this build, I have sourced a ISL locally with Allison trans, but interested to know how it is all going together. Would it truly be easier to swap in a ISB 6.7 say 350HP? Havenít even picked up the rig yet and already looking at repower 🙃

I had no issues with my VT365 and I actually like the engine. I am a firm believer that the primary issue with the VT365 and 6.0 engines was the oil-to-water cooler. Once the cooler gets plugged on the water side you will see EGR Cooler failures, HPOP failures, Turbo failures and injector failures. Because of this I replaced my stock cooler with the Bullet Proof Diesel air to oil cooler and never had an issue.

The reason I wanted to do the repower is that I wanted more HP. The only company I found that made a programer for the VT365 was Hypermax, but they were sold out and could not tell me when they would get new units in. I think pwerwagon may have gotten his hands on one if you want to look into the Hypermax.

In regards to your 6.7 vs. ISL question, yes it would be way easer to install a 6.7 vs. the ISL. The ISL is a significantly larger engine (longer and wider). Plus you will need to upgrade from the Allison 2500 to the Allison 3000 series as the ISL has way to much torque for the 2500 transmission. Even the 350HP 6.7 has to much torque for the 2500, but I would probably still use the 2500.

The biggest fitment issue with the ISL is the turbo. Most ISL's have the turbo located on the right side below the exhaust manifold and towards the back of the engine. The 4200 chassis is very narrow in this area and there is just not enough room for everything to fit. So for the ISL to work you will need one that has the turbo mounted as far forward as possible and preferably above the exhaust manifold.

Upgrading from the Allison 2500 to 3000 is a significant amount of work as well. The 2500 is a partial electronic transmission vs. the 3000 is fully electronic. The 2500 uses a manual push/pull cable to shift vs. the 3000 uses an electronic push pad. So if you upgrade to a 3000 series you will need to modify the the transmission wiring harness, purchase or make a pedestal for the new 3000 series shift pad, change your driveline yoke, and remove all the shifter and push/pull cable used for the 2500. Depending on how much work you do yourself. Upgrading from the 2500 to the 3000 series can add several thousand dollars to the project. Also if you upgrade to the Allison 3000 you will need a 4th Gen transmission. I believe a 5th Gen would also work. You absolutely "do not want" a 2nd or 3rd Gen transmission.

Let me know if you have more questions.

Tim
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Old 08-08-2022, 10:37 AM   #17
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Quote:
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Would it be worth wild to swap in a 5.9 isb pre 6.7 ?
I think the max HP for a Cummins 5.9 is 300HP. Having personally driven a number of Supper C's equipped with a 300HP 5.9 engines I personally don't think it would be worth the effort and cost.

If your idea was to go with an older non-common rail engine I would not recommend this. The reason is, if you go to old the engine will have no way to talk to the transmission, or chassis computer. This means no speedo or any other gages will work. You need an engine that has J1939 communication so it can talk to the other components. The Cummins I have uses the CM850 and has J1939 and it seems to talk to both the transmission and chassis just fine.
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Old 08-08-2022, 11:06 AM   #18
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I don't want to mislead anybody into thinking this is a simple plug and play project. If you plan on doing it yourself make sure you have the equipment and skillset to complete the project. For example an ISL mated to an Allison 3000 ways between 1.5 and 2 tons; you are not going to pick it up with a Harbor Fright cheery picker. Also if you plan on having a third party company make the new wire harness for you, it will be expensive. For example when I was talking to companies about making a new transmission harness the pricing started at around $1,500.00; I made the new harness myself. You will also spend a bunch of time online looking for miscellaneous parts/items. As I mentioned in an earlier post everything on these trucks and engines is via VIN or engine number. For example my ISL did not come with a power steering pump. I call Cummins with the engine number and all they will tell me is that my engine did not have a power steering pump and they don't know what will fit it. So your only recourse is to go to a truck wrecking yard or start looking online until you find a power steering pump you think will fit.

In summary, this has been a fun project and I would encourage anybody that is thinking about doing it to take the leap. Just be realistic in what you can and can not do.
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Old 08-09-2022, 09:30 AM   #19
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The reason I wanted to do the repower is that I wanted more HP. The only company I found that made a programer for the VT365 was Hypermax, but they were sold out and could not tell me when they would get new units in. I think pwerwagon may have gotten his hands on one if you want to look into the Hypermax.
Power Hungry Performance has a tuner for the VT365, its called the Orion. The Hypermax was simply a few different FICM (IDM) tunes (probably PHP's eco/atlas40/80/100 tunes) on a tuner, and not an ECM tuner. The PHP tuner is far better, and has diagnostic capability as well.

Quote:
Originally Posted by SlimTim View Post
I think the max HP for a Cummins 5.9 is 300HP. Having personally driven a number of Supper C's equipped with a 300HP 5.9 engines I personally don't think it would be worth the effort and cost.

If your idea was to go with an older non-common rail engine I would not recommend this. The reason is, if you go to old the engine will have no way to talk to the transmission, or chassis computer. This means no speedo or any other gages will work. You need an engine that has J1939 communication so it can talk to the other components. The Cummins I have uses the CM850 and has J1939 and it seems to talk to both the transmission and chassis just fine.
I thoroughly agree with Tim here on both accounts. I even have a buddy with a Force with the 300hp 6.7 and before he did the dpf delete/tune, it didnt run any better than my 365 does in all honesty. Maybe 3-5mph faster up hills, but thats about it. Now that its deleted and tuned to 360hp, it does run better than mine. But its not drastic enough, in my opinion, to warrant the ~15-20K cost to do the swap. It should be more reliable than the VT365, but a cp3/injector failure in a CR cummins gets expensive FAST as well and it does happen.

Also, unless you want to gut the dash and put in mechanical gauges, figure out other work arounds for cruise control, hvac, etc etc, I think going full mechanical would be more work than doing something similar to Tim. However, a full mechanical 8.3/3060 would be bulletproof. I had dreams of a compound turbo p pump 8.3 until Tim talked some sense into me!!!

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Old 08-17-2022, 08:51 AM   #20
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Thanks for the info gentleman! good stuff, i may plan an isl swap in the future, i want it to run for 1,000,000 and keep going... Not anything i plan to do immediately as the rig has 7,800 miles, but before i retire (or right when i retire) it will be on the books.... slimtim, when you are wrapping up, let me know what the biggest hurdles were so i can start putting them down and working on them over time... thanks a million!!!
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