XLR8R

The 6.7L piston bowls are similiar to '03-'04, so injectors have to be matched accordingly; also, the 6.7L CP3 flows a bit more than the 5.6L version.

If you have access to any parts from a 6.7L long block, you probably have the whole thing, so why not swap the entire engine in? Still no replacement for displacement, and the 6.7L has a stronger block... only issue I can think of is the 6.7L rods bend more easily than the 5.9L at 1KHP+ levels (but most of us won't have to worry about that! ).

For now, of course, you'd have to leave the VGT & intake horn with EGR paraphernalia off.

Mike Holmen

Why not just run the 6.7L and forget about mixing in 5.9L parts. Painless build wiring harness for stick trucks for the new engines, so its will just drop in. Put on two modifed CP3 pumps, big sticks and twins. I don't know if the motor mounts are different and you need a different motor supports, but you can build them.

As Tate said the only thing you have to modify is the gear box for a pump or VP. then injectors lines. New injectors, and so on. I think cummins sells a complete 6.7L with ECM/harness that will work as well but might be a tad pricey. Using an auto might be abit more work but still do able.

HOHN

It's odd. With the blue-collar guys, it's pretty popular to mod the CTD. Most of the modded trucks at work are driven by hourly workers.

From what I've gathered at work, most of the engineers don't care. They sorta roll their eyes at HP mods. I find that odd-- if you aren't passionate about engines, why work on designing them?

But I've met one or two engineers who are into HP-- they just haven't done much yet (EZ or basic timing box and maybe some gauges).

Justin

XLR8R

Engineers look at BOMBers like pilots look at paratroopers .... "why would you jump out of a perfectly good airplane?"

They figure their design is just fine!

logskidder

If the bearings are the same, you could use a 6.7 crank in a 5.9 block with 5.9 pistons........3406 B cat












I said it first

Mike Holmen

I know at what I do, I'm aways looking for ways to pull extra hp but its has to be reliable. I'm dreaming about the 6.7L twin cp pump, twin turbo engine, big sticks for my daily ride. Its just the matter of buying a decent 6.7L thats priced right and available. Its just a matter of time. Its can be done, its just you have to try.

GTPaul

With all the crate motors in the performance world wonder why they don't seem to be used that much in Cummins World? The Used prices seem pretty insane.

Paul

12v rollincole

why not just p-pump a 6.7, get ride of junk "computer". im sure there would need to be some work with applying 12v sticks but if you can p-pump a 24v why not a 6.7

Flatbed24v

I thought they changed the block design in the cr trucks from the vp trucks? Did they keep enough of it the same to swap crank and have it line up right?

patdaly

Last year Mast Motorsports was working on a standalone computer for the CR trucks, I just looked on their website and the page regarding Cummins was gone, so I dunno if they are still playing. Their ECM was certainly stout enough.

That would be the ultimate, Aftermarket tunable ECM and a 6.7..... A guy can dream.

Tate

Bosch has a ECM that you can scratch build a tune for, but its a bit pricey. Somewhere in the $6k range.

Fueling around

A comon rail block is much better than the previous 5.9 blocks. As Tate pointed out, you have to customize a P pump timing cover. It bolts up the block, but the oil pan is different and requires a bit of .. rework.

I really doubt the 5.9 & 6.7 will interchange in the displacement arena. Iin-line diesels are pretty closly matched for bore & stroke due to the combustion chamber laying in the piston. I used to work at an OEM that uses Cummins engines. I took one of the former Engineers (he now works for CAT) out for a spin in my truck. I'm only at 300 rwhp which is impressive to a novice, but his eyes got very large as the tach spun up to 3,500 rpm. He went back to Cummins and asked around to find the stock valve springs were rated to 3,600 rpm.

patdaly

Most of the Mast stuff is very sophisticated and very affordable, that is why I was so stoked to see them playing with a CR Cummins.

2K for an easily tunable ECM with all the toys....... We can only hope they have just taken it off the website because they were being inundated with inquiries.

Mike Holmen

6.7L engines are getting cheaper by the year. Tate, how much info you have the controller? 6K. Does the VNT stuff work good on 6.7L? Its one heck of motor, just has that emission junk on it.

Mike Holmen

Engineers are so closed minded into only one solution. High performance, no emission stuff to mess with. Whats that a dream? Do you know if there doing anything different to the combustion chamber vs. the older style? I saw lot of shops offering HP injectors for the engine.