Different size pistons in my 03 ??

[hikethemtns]

My 03 cratered at 102,000 due to injectors in two cyls sticking open and flooding the cyls, subsequently washing the oil out and scorring the cyl walls. QUESTION; since i am going to have to tear it down is there any easy mods [oversize pistons, head/intake polishing etc] that would be worthwhile? At this point i plan on boring out the two scorred cyl and installing oversize pistons in only those two [mistake?] should i replace any other parts[rod, main bearing, piston rings etc in the other cyls of the engine? it only has 102,000 miles? thanks in advance jim

 

[JHardwick]

QUESTION; since i am going to have to tear it down is there any easy mods [oversize pistons, head/intake polishing etc] that would be worthwhile? At this point i plan on boring out the two scorred cyl and installing oversize pistons in only those two [mistake?] jim

huge mistake if you are boring out to the next piston size ... ... ... a light hone may not be too bad if just replacing rings.

should i replace any other parts[rod, main bearing, piston rings etc in the other cyls of the engine? it only has 102,000 miles? thanks in advance jim

all bearings and rings should be replaced ... ... ... why not while you have it unbuttoned?

 

[DPKetchum]

If your bore just two it will be unbalanced. Found some gassers from shad tree remanufacturers that way in the past. Creates a unbalanced condition.

 

[JHardwick]

If your bore just two it will be unbalanced. Found some gassers from shad tree remanufacturers that way in the past. Creates a unbalanced condition.

Not only the weight of the larger pistons, but also the increased compression of those two holes.

 

[DPKetchum]

It needs to be torn down and holes checked for taper and roundness etc. Use to use a guy years ago that had a MOBLE boring/hone equipment. Tech pulled pan and heads and he would do the measurements etc. If boring needed we ordered pistons and he would come back and mic them,bore and finish each hole in frame. Then we put it back togather. He did lots of big equipment and tractors etc. Could even turn a rod journal in frame. I bet folks still do that kind of service. Might ask some big equipment companys. We used him in a Datsun/Nissan store several times.

 

[sag2]

Based on all the CTD's I've seen, the crank, rods and mains should be perfect. if they aren't broke, don't fix them.

 

[ThrottleJockey]

If you can hone it, that's great. BUT if you have to bore one the next size up, DO THEM ALL!!!



Then call Arias Competition Pistons and get the forged Cummins set. They have the same bowl design as your stock ones and they are lighter AND you can get custom CRs if you want AND they have cool valve pockets cut in 'em for big cams, etc...



Looky here. http://www.scheiddiesel.com/trkpull.htm

 

[JHardwick]

Based on all the CTD's I've seen, the crank, rods and mains should be perfect. if they aren't broke, don't fix them.

I don't understand having a Cummins tore down with 102,000 miles on it and NOT putting new parts in. Heck, it prolly don't need bearings, but it's already tore down :-{}

 

[DPKetchum]

Inspect and do as needed.

 

[JHardwick]

It needs to be torn down and holes checked for taper and roundness etc. Use to use a guy years ago that had a MOBLE boring/hone equipment. Tech pulled pan and heads and he would do the measurements etc. If boring needed we ordered pistons and he would come back and mic them,bore and finish each hole in frame. Then we put it back togather. He did lots of big equipment and tractors etc. Could even turn a rod journal in frame. I bet folks still do that kind of service. Might ask some big equipment companys. We used him in a Datsun/Nissan store several times.

That mobile stuff is no better than the "engine builder" down the road boring blocks as they lay on the shop floor. There is no way to control perpendicularity to the deck or main journals, centerline intersection to the main journals etc etc ... ... ... this is one of those deals, if your gonna do it, do it right!

 

[hikethemtns]

I know the two cyl that were washed out are bad because they knock until the injectors for those cyl are killed. Took the pan off and grapped the rod just below the piston and was able to feel the piston was loose in cyl and had metal in pan.

 

[hikethemtns]

Why couldn't i bore and sleeve it to keep the same size pistons?

 

[keimmmo]

I don't like dry sleeves if I can avoid them. They are never as good as unrepaired factory cylinders. You will have to replace the pistons in the scored cylinders. The pistons usually have even more wear on them than the cylinders. If you replace only two pistons, you will still likely have the motor out of balance!



If you aren't willing to do a QUALITY rebuild, just buy a good used motor or a factory rebuild.



Steve

 

[Big_H316]

My dad had to do a re-build on his 7. 3 Ford because of pinholes in the cylinder walls allowing water to sit on top of the pistons and hydro-locking it. Had all 8 bored out and sleeved and zero problems after 5 years. All commercial diesel engines are sleeved for the simple fact of easy rebuilds.

 

[Loaded 45]

What does it cost to have it rebuilt properly for performance - new pistons,bored,head work with studs,cam, 75 hp injectors... .

 

[DPKetchum]

That was a known problem with the 7. 3s. Caused by cavitation. The 5. 9 Cummins does not hasve this problem. Its not a sleeved engine and can probaby take a fairly large over bore. I bet a rebuild with asll of the above mentioned by Loaded 45 would run $4500 to $6500 and I'm jusdt guessing. A good shop who does this kinda work could quote a lot closer. If a few holes are damaged slighly and nothing else it could be rwepaired a whole lot less with a overbore,pistons and gaskets,fliuds etc. Might be able to do a inframe(not pull the engine)if there are still machinests who have a portable bore/hone machine like I used in the past. Real BIG equipment with piston and wall damage can't be moved or taken to a shop. There done in the field etc. Even pulling the engine would not be THAT bad on a Dodge truck and only repairing whats needed at that low(102k)mileage,Repair shops(dealers also)have changed. In the auto repair I've handled LOTS of Z cars in the past that were bored in frame,bearings only replaced etc. We did many a NISSAN SENTRA/STANZA/Z car with smoking,oil leaks,timing belt damage and only did a hone,rod bearings,rings and a in house valve job and seals. We didn't call it a REBUILD or REBUILT its was REPAIRED cheapr then the other terms with all partys knowing what was being done. Made many a parant smile when trying to get a child through college on a budget and the last shop tried to knock their brains in with a HUGE est. and a NEW or FACTORY reman engine etc. This engine could be pulled,crank removed,bagged and sent to any DECENT mmachine shop,get bored,pistons,rings a NORMAL min. valve look at seals etc. ,new rod and main bearings and put back togather and back in the truck in a somewhat short period(2 weeks?)and a min amount of money spent compared to even buying one of those salvage engines off e/bay.

 

[keimmmo]

Many of the industrial motors come from the factory with sleeves... some wet and some dry. It is fine to change the sleeves on them. The Cummins has no sleeves from the factory. I used to work in an automotive machine shop and have put repair sleeves in motors before. Yes, it can save a block. But, they usually are not as desireable as unsleeved cylinders... expecially in high performance applications.



Steve