2004 KW T300 C7 questions

[gyman98]

Hi everyone looking for opinions on what I need to look at to get a new (used) engine for my truck. It's a c7 cat 300hp in front of a 10spd.

What years of engine will work?

Will any HP version of a C7 work if I use my injectors and Ecm?

Does it matter if the engine was hooked to a auto or standard?

My engine has a connecting rod through the side of the block

 

[gyman98]

Also have a guy trying to sell me a 3126b that's says it's a direct replacement. Ecm plugs right in, just need to modify the AC lines

 

[DMiller]

C7 and 3126B are essentially same engine, one has more emissions loading(C7) as to ECM working with the B off the C7 that I would have serious doubts but the harnesses may interchange where the ECM for the B could swap for the C7 if swap engines. I would run that thru the Cat forums.

 

[Birken Vogt]

I remember a thread on here about somebody having a bad time trying to do just this swap, C7 to 3126, nothing worked electronically.

I think there are differences in pistons and such for some horsepower levels so it might not work just to change injectors and turbo but that is a case by case basis.

I don't think the C7 is anybody's favorite engine. I would give serious thought to replacing it with a Cummins ISC of similar year so this kind of thing doesn't happen again.

 

[crane operator]

I haven't heard anything great about the 3126 either, so I don't see the advantage of swapping to that.

I would think a swap to a M11 or 8.3 would be a big improvement.

 

[gyman98]

Thanks for all the replies, very much appreciated.

I agree a cummins replacement especially a 8.3 would be ideal but I think the electronics would be a nightmare

 

[Junkyard]

Go all mechanical. I can show you something in a 3306 or an 8v71! It is challenging to repower an electronic truck with a different brand electronic motor. If you were able to find a similar year salvage truck that has a Cummins in it you could rob motor, harness etc and hopefully have less trouble with it.

 

[bam1968]

I agree with Junkyard. A couple years ago we purchased a project truck. It was a 2006 International with an ISX with a hole in the block. We replaced that motor with a 2011 ISX. Even though the 2011 came with the ECM it was far from a 'plug N play' situation. Basically it was an electrical nightmare swapping pins in the harnesses etc. Next time it will be a mechanical motor for sure. Just my $.02

 

[gyman98]

Aren't all the gauges and most cab functions controlled by the ecm? I think it would be a nightmare to go mechanical although I agree that it would be ideal

 

[Birken Vogt]

I was under the impression that most everything in the T300 was pretty standard, I think it has a mechanical oil gauge, air gauge for sure, brake application gauge, voltmeter and temperature gauge. I suppose the tach is ECM driven and I don't know about the speedometer. It is a classic KW style dash board with two screws and everything flops out and easy to work on apart from the rats nest of wires everywhere but at least they are well marked.

If it was mine I would give serious thought to it but I tend to be more electronically minded.

 

[Tags]

In the end a short block would be the quickest way, but, you're still left with the garbage C7. I had one in a freight liner years ago that ate itself with only 90,000 miles on it. I was the second owner and have a feeling oil changes didn't happen very often before I got it. I ended up putting a short block in it and sold it a year later, that may have been one of the best days I had when that thing went down the road.....