Engine/Transmission (1998.5 - 2002) engine rebuild questions

[Devan Manis]

I am considering rebuilding my engine because i already have the head off and have to get a new one because mine is cracked, so with 278,000 miles on it i don't want to just do the head i want to rebuild the whole engine. My question is what all will i need does cummins offer a full rebuild kit? What other machining will have to be done or potentially done to the block/crank? Any tips or idea's would be nice as well.

 

[Wyomingcowboy]

Do a search for a thread started by me on this subject. The kit is 1k +. I started mine in Oct-Nov and am just now getting it back together. (For me time has been the factor... . as in I have none!)

 

[Joe Mc]

If the cylinder walls look good why rebuild? I heard Cummins typical service life before rebuild is considered is 400 k. I've also seen pictures here of other engines with heads off that still show cross-hatch marks on the cylinder walls with over 250 k. I wouldn't be concerned with rebuild just because you are placing a new head on, unless something is wrong or you just want to rebuild the engine. I would strongly consider studding the head though. - MHO

 

[CumminsPower98]

Unless you have an obvious problem or you just have too much money and time laying around I too would suggest leaving it alone. Cummins spec is 350k but most easily go much further than this. At 262k my cylinders looked great. I now have 402k and it runs perfectly. Cylinder picture: Picasa Web Albums - Mark - Truck Stuff

 

[Devan Manis]

The head is studded, i'm also going to o-ring it. I figured as long as I have to spend the money to do the head i'm going to put the new head on something that I won't have to worry about, and at my power level I want something that is going to be just as fresh as the head. Mostly because i can see some N2O and bigger injectors in the future. I can still see the cross hatches in cly #1 but it takes some looking for, there isn't really a huge lip on the cylinder just enough to catch your finger nail on.

 

[CumminsPower98]

Sounds like yours is more worn at similar mileage than mine was. I could hardly feel the wear line let alone catch a fingernail on. I can't give any advice on rebuilding as I have not done a Cummins yet.

 

[WILLD420]

I haven't done one yet, but I have seen a couple done. They are pretty simple, just mark all the gears before you pull them out.

Replace the rod bolts, have the crank magnafluxed and polished/turned if needed. They are pretty tough engines, but I have seen more than one with a broken crank after years of abuse.

If I recall there are no liners to remove or install, and I'm not even sure they had cam bearings, I believe the cam runs on the block, but cannot swear to it.

Some will say you can re-use the rod bolts, but from years of experience, I will never re-use a rod bolt in this type of engine. The mains have never given us any issues, the head bolts are re-useable, but not if you are pushing it hard. ARP's are cheap compared to tearing it all down and starting over again.

 

[DPrew]

Running an oil sample might be the best way to tell if you have any internal issues that need to be addressed. If things in your block have abnormal wear the oil sample will tell the story. I wish I had run samples on the 97' Ferd F250 I had so I would have known the thing was getting ready to let the crank walk around in the block.

 

[Vaughn MacKenzie]

Devan, if your hone marks are worn away and you've started a wear edge at the top I would say it would be worthwhile to rebuild if you're going to increase power. Your engine has more wear than mine did when I did a valve job at 386,000 miles. Cylinder walls on a Cummins wear more slowly than rings, so if your walls are showing wear the rings definitely are.

Chances are you won't have to machine the crank or mains, just mic the journals and replace bearings (you may not even need to replace the bearings, guys have torn down at 300-400k miles and found bearings with virtually no wear). I would hone cylinders and make sure the block deck is perfectly true, might as well take a couple thou off to clean it up.

If you do build the motor spend the $$ to have it all balanced and throw a good cam in there while you got it apart

 

[Devan Manis]

Thanks for all your advice, i tore it down thursday night and checked the cylinder walls again and my finger nail was just scratching the soot off, there really isn't any wear you can see the hone marks all the way around all the cylinders. The thing that really threw me for a loop was the top bearing on ALL the connecting rods were down to the copper. The crank still looks good and the block as well, i took it to the machine shop friday morning (that is the block, crank, pistons and connecting rods). I'm supposed to talk to the machinist on monday when he gets a chance to look everything over and we'll go from there on what needs to be done, but i am getting the head o-ringed, i have studs, and also getting a cam, valve springs and push rods from an aftermarket cam company. I'm getting new tappets just to be safe with the new cam and stuff but the old ones looked perfect.

 

[Vaughn MacKenzie]

I've been told if you pull an engine it would make sense to O-ring the block, so in the future if you ever have to replace the head you won't have to do the head again. . . maybe someone else can chime in on this.