jeepsuck

my buddy is taking a diesel class at a local CC and he asked me if the 5.9 cummins in our trucks is "disposable", meaning it does not have removable cylinder liners that can be removed in-frame and rebuilt?

G1625S

He's taking the class--he should know! hehe, just kidding. The b5.9 is, as far as I know, a 'parent bore' block, meaning that the block itself provides the sealing surface for the pistons, as opposed to a block with removable sleeves. I wouldn't go so far as to call it disposable, but I guess that's just an industry term

bgilbert

Yes they are disposable.

jeepsuck

are they at least rebuildable? are over bore pistons made for them?

12valve@heart

It's been years since I checked on this but back in the early '90s, I heard that they could be bored and dry-sleeved back to stock bore just like a big-rig. The trick was that the first time, they had to be bored out to accept the sleeve. After that, they could be rebuilt in-frame. The real problem is finding a chassis and body that will survive the miles that the motor will run. The body and chassis is what is disposable in most cases.

loch

Seeing how the castings on them is harder that god, it will outlast several sets of pistons, it has no cam bearings so that should give you an idea of the wear factor on these monsters.

12valve@heart

Yes.

There are many reported cases where the cylinder bore crosshatch is still visible after several hundred thousand miles so overbore is often not an issue and if it is, often a lower-mile used motor is less expensive than a major overhaul as there are lots of wrecked trucks to become motor donors.

Not saying that it can't be done, just that it's not always the less expensive option.

John Faughn

If you want to dispose of one you PM me .

spunbearing

I second the motion.

PeytonMaterne

Really, no cam bearings in these engines???? Did not know that.

flashgordon

I think theres acually 1 cam bearing, one in the front next to the gear.

DODGE 92

if you ask me taking a class on rebuiding these engines is a waste of money

Ace

Dammit! I just bought a shop manual. Now you're telling me I'll never have to use it?

JDGnut

There's only one cam bearing.. at the front.. You could always have the block bored for the others.. This is common... You can buy over sized pistons.. Just bore the block.. Or have it sleeved back to standard..

Rampage1967

These engines are getting so common people are giving away the vehicles they are in. . . . ask me how I know that. ;-) :-)