any one know if you can repower a 631 with a cummins ?
That would be on a par with putting a Ford into a Chev.
I am sure you can if you really want to. I have seen them before, and with 60 series detroits as well.
Sure you can do what ever you like, I've seen them too, including 8v92t's in DW 21's (went like hell) sad to say though they are now scrapped. Another thing that was very common in N.Z. for you overseas fella's was the repowering of DW 20's with 1693 Cat truck motor's, again these went well too. I guess the point I was making is there are many Chev's transplanted into ford's but you would ruin a Chev by putting a Ford into it. Likewise repowering a Cat with something alien, hey that's my opinion for what its worth. I'm sure there will be others out there with different opinion's and I guess they have had good results too.
why would you want to put a cummins in it? Cat 3406 seems like much better option to me
I suspect the reason for the other brand repower is cost and the EPA regs. A new 631 is probably somewhere in the neighborhood of a million bucks. A new Cat motor of that horsepower and size on a one time deal might be somewhere around a hundred thousand by the time all is said and done. You can probably buy a used Cummins Tier 3 and fit it for somewhere close to sixty thousand. This is a quick and dirty estimation and these numbers are all shot in the dark so don't rely on them. It would be interesting if someone looked in to this in depth.
Maybe the OP will give us some more details, but I suspect that he has or can get a cheap old 631 with a blown engine, and he either has or can get cheaply a used Cummins engine, and wants to try to combine them into a working unit. Just my guess.
No doubt will have to make everything to get it to work. I can't imagine there is an aftermarket kit to make such a conversion. Engine mounts, radiator shroud etc. and that is just the start. Now you have to make it bolt up to the torque converter housing.
"Now you have to make it bolt up to the torque converter housing." Off-road equipment and over-the-road trucks often use standard SAE bellhousings. But since CAT makes both the engine and transmission they could do whatever they want. Before you even start this I would measure the bellhousing bolts to see if they match one of the SAE patterns. ISZ
Why ?????
Some where on this forum I`ve seen pics of a tidy 623 It hink it was with a cummins or a detroit in it. cant remember where sorry. And Pecintinnis over in western Australia have reffitted a few 651`s with big cummins motors, 2 or 3 of those 651`s have 333 or 353 wabco bowls on them. so Yes I think would be your answer Earthworm, just depends how much your willing to spend really.
I can not think of what size motors that got put in them but, we have TS-14s with Deere motors in them. It makes them faster and stronger. It makes them a lot more productive and saves fuel.
Piacentinni & Sons over here in WA used to re-power their scoops with Cummins over the years, one thing is it gies alot more room to move around the engine bay and you dont need to pull the engine out to replace exhaust studs! Afew firms are going for C15/C16/C18 repowers these days for old girls