Engine/Transmission (1998.5 - 2002) How Far Can You Punch Out A 24v Block?

[DDouglas]

I have a 2001 2500 H. O that I just tore the engine down to do a rebuild on because the blow by was getting bad the engine had 301,000 miles on it and the bearings and crank looked excellent, all the cylinders you could still see the cross hatching in except one the second from the rear it had a slight ridge at the top of the cylinder wall I had a hard time getting the piston out of the hole,where as the others came out with a simple tap from a wooden dowel rod. should I look for another block or could this be bored out. the part the messes with me is that the ridge is only a little less that 3/4 around the top the other 1/4 is smooth. this is the first time I have ever had to rebuild a cummins engine and I figured this one would be a good one to start with.

 

[blacksheepdiesel]

Call Scheid Diesel and order a sleeve (and all the other parts you will need). Have the #5 cylinder bored to accept the sleeve. If that piston is good it will fit back in the hole.

Godspeed,
Trent

 

[ThrottleJockey]

There's enough meat in the block for 3 overbores. I skipped one and bored mine out 20 over and bought some custom pistons.

 

[Forrest Nearing]

I agree w/ blacksheep... your least expensive option will be to sleeve the one hole and hone the rest of the cylinders out to the biggest cyl.



a little wider piston/wall clearance helps prevent wall scoring if you happen to get the thing really hot some time

 

[Vaughn MacKenzie]

Since DDouglas said it was only a slight ridge I would think reboring to the next std oversize (I think it's 0. 5 millimeter which is ~20 thousandths) would easily clean it up. Just mic it to be sure. I don't think wearing on one side & not the other is unusual, probably the thrust side of the cylinder, but it's odd only #5 showed wear like that. Were the rings broken on #5? When I pulled the head on my '96 last at 386,000 none of the cylinders were even near developing a ridge.

 

[Forrest Nearing]

it would take an overbore, but then you're buying a set of pistons

 

[Vaughn MacKenzie]

I have no idea what pistons cost, probably wouldn't hurt to replace them at 300k if it's not a major investment.

 

[Joe Mc]

Confused with some of the replies? "If" it's a "ridge" at the top of #5 only, which is odd that there's only a ridge on one (?), and the remainder of the #5 cylinder is otherwise fine couldn't the ridge be "honed" out/down/sized to match the remainder of #5's hole? Then you'd only have to polish-up/re-hone all cylinders and (assuming the pistons are all OK) re-ring the pistons. Sleeving and boring an otherwise good block (from the sounds of it) doesn't make sense, unless there's a real vertical groove in the cylinder and/or piston concerns. Boring a block is expensive + cost of new pistons $$$$??? If there's "only" 300k miles on everything and all parts mic/spec out why waste the money? I'd get things checked real good, if everything is fine and you can get rid of the ridge in #5, polish up all 6 holes - then just get new rings and since it's tore down you may consider polishing up the crank and get new rod & main bearings. Since you're that far, what's the cam look like? Good time to install an HP cam . . . probably cost you less than what you spend for bore & sleeve parts & machine work . . . just my $0. 02.

 

[SSolderitch]

A ridge reemer will cut down to the first ring removing metal so the piston rings rings don't get stuck on the lip during removal. However the ridge is created when the bore is worn by the piston & rings. All the bores MUST be checked for size and out of roundness. ONLY that will determing what is needed to be done to the block for the rebuild.

 

[Joe Mc]

A ridge reemer will cut down to the first ring removing metal so the piston rings rings don't get stuck on the lip during removal. However the ridge is created when the bore is worn by the piston & rings. All the bores MUST be checked for size and out of roundness. ONLY that will determing what is needed to be done to the block for the rebuild.

Bingo!



Caution when using a ridge reamer - I've seen guys totally ruin a block, just a scrape till the piston can come out is all that's needed.