Please advise... do I need a complete head rebuild?

[Robert92867]

I thought I was going to get away with surfacing the head, but after getting into lapping the valve, and finding excessive slop in the valve guides, it would appear that I need new valve guides drilled in and pressed, new valve seats, valve seats cut. I haven't tested the springs, but seeing how many valve guide bores are out of tolerance I wouldn't be surprised.  #4 Exhaust valve "B" looks heavily pitted, the rest may suffice to be reground, although replacing might be cheaper.  To the best of my knowledge, Cummins USA doesn't make drill-in interference fit valve guides for the 5.9 24 valve, the Cummins service manual says "replace the head".  But there are aftermarket valve guides made by reputable companies,  such as SBI and Goodson (and some not-so-reputable).  Goodson also makes the tooling (pilot drill and reamer and press tool) for their valve guides. I will get Caliber Diesel, in Ontario to look at it Monday.  Remanufactured head, with new head castings are also and option, but often put together with the cheapest of parts.

[DavidL]

4 minutes ago, Robert92867 said:

I thought I was going to get away with surfacing the head, but after getting into lapping the valve, and finding excessive slop in the valve guides, it would appear that I need new valve guides drilled in and pressed, new valve seats, valve seats cut. I haven't tested the springs, but seeing how many valve guide bores are out of tolerance I wouldn't be surprised.  #4 Exhaust valve "B" looks heavily pitted, the rest may suffice to be reground, although replacing might be cheaper.  To the best of my knowledge, Cummins USA doesn't make drill-in interference fit valve guides for the 5.9 24 valve, the Cummins service manual says "replace the head".  But there are aftermarket valve guides made by reputable companies,  such as SBI and Goodson (and some not-so-reputable).  Goodson also makes the tooling (pilot drill and reamer and press tool) for their valve guides. I will get Caliber Diesel, in Ontario to look at it Monday.  Remanufactured head, with new head castings are also and option, but often put together with the cheapest of parts.

I don't know the specifics of that head, but if it ain't right, now's the time to fix it.  Don't put it back together until you know all parts are sound.

Sounds like you are doing good work and research.

Edited September 16 by DavidL

[jacwjames]

X2 on fixing it right, now is the time as the hard part is done "you've started".   If you have a good core and a shop that can repair it that might be the way to go, depending on price. 

I assume there would be some sort of warranty, although sometimes these aren't worth the paper they are written on BUT a shop that offers a warranty indicates they may have some skills that they are willing to stand behind. 

Good Luck

[Rikadoo]

So good morning to all, well robert this cyl head sounds like its in very poor shape, just how many miles has this rig have on it? And to what was the reason why you took it off? As for repair or replace, if you bought a new head what kind of warranty comes along with it? When you mention the repair process im reminded of when i found a place to repair my alternator vs new, its all well and good to invest in the shops that rebuild things( i am a mechanic of over 50 years) however… If something WAS to happen on the road, then where is that shop when your in nowhere USA??? Dont get me wrong i will always choose to invest in the trades when at all possable, except when it comes to having to use a shop because of proximity rather than choice that could leave me at the mercy of yet some shop with unknown abilitys. My advise on this repair is to go with the Cummins part, mostly cause Cummins has been in bussiness quite awhile an “for me” i know they build quality parts, the same with other manufactures however especially in todays markets of part availabiltys your never really sure of the quality of parts your getting, much of which are coming from other countrys that dont use the same “specs” though they look identical. I could go on an on, but i will leave it at this, the best machinist in the world could be undermined by one wrong part that he may have to use because of a supply chain issue, an if your engine sucks a valve cause a keeper or  a guide failure are they willing to stand behind there repair… 

[Robert92867]

128,000 miles.  Cummins engines have a reputation for high mileage, but this is a relatively low power ISB 5.9 (260hp) pushing 26k lbs (with toad) so maybe working harder than a IS/C/L/X/M with a higher GVW. The reason I pulled the head was coolant leaking off the side of #1 cylinder.  The head was not warped (.002 max feeler gauge under a 3' straight edge) and none of the valves or pushrods are bent.

Cummins does not make valve guides for this motor. the guides are integral with the head casting and the Cummins shop manual simply says to replace the head if guides are out of spec.  Cummins no longer sells heads for this 22 y.o. engine either. Because of the millions of Dodge-Cummins trucks on the road, a thriving aftermarket does exist.  Cummins has authorized CDEC in China to manufacture parts for the ISB under their banner, and "Genuine Cummins" often means made in Guangdon China.

Finding a knowlegable shop to do the work does worry me.

 

[dl_racing427]

1 hour ago, Robert92867 said:

128,000 miles.  Cummins engines have a reputation for high mileage, but this is a relatively low power ISB 5.9 (260hp) pushing 26k lbs (with toad) so maybe working harder than a IS/C/L/X/M with a higher GVW. The reason I pulled the head was coolant leaking off the side of #1 cylinder.  The head was not warped (.002 max feeler gauge under a 3' straight edge) and none of the valves or pushrods are bent.

Cummins does not make valve guides for this motor. the guides are integral with the head casting and the Cummins shop manual simply says to replace the head if guides are out of spec.  Cummins no longer sells heads for this 22 y.o. engine either. Because of the millions of Dodge-Cummins trucks on the road, a thriving aftermarket does exist.  Cummins has authorized CDEC in China to manufacture parts for the ISB under their banner, and "Genuine Cummins" often means made in Guangdon China.

Finding a knowlegable shop to do the work does worry me.

 

Those 5.9's are common as dirt.
Find a shop that specializes in diesel pickups, and that has a good reputation among local Dodge groups.
It's not that complicated to ream and install valve guides, as well as a standard valve job.
Aftermarket should have you covered as far as valves, springs, retainers and keepers.

Good luck.

[Robert92867]

Thanks for all your input.  I decided to cut my losses and ordered a complete assembled head from Fleece.  Fleece checks all the right boxes:

Specialized in Dodge-Cummins, Duramax, & Powerstroke.

Modern CNC tooling.

Clean factory.

Also build Diesel racing engines.

Good looking shipping crate!

[dl_racing427]

2 hours ago, Robert92867 said:

Thanks for all your input.  I decided to cut my losses and ordered a complete assembled head from Fleece.  Fleece checks all the right boxes:

Specialized in Dodge-Cummins, Duramax, & Powerstroke.

Modern CNC tooling.

Clean factory.

Also build Diesel racing engines.

Good looking shipping crate!

Curious, what was the cost?

[Robert92867]

$2599 +tax, +freight, +insurance... total 2800.  Does not include rocker arms or injectors. Does upgrade freeze plugs under the rocker cover to threaded and bumps up stock springs from 78 to 100#.

[jacwjames]

Looks good.

No idea of the price, I've been out of the loop on this type of item, but you have to assume this company is competitive and that they do quality work.  Shipping crate is a good indication of what the final results might be.

 

 

I use to (a life time ago) be involved in maintenance in underground mines.  Large diesel engines, we'd track all costs and hours so we could determine how we were taking care of equipment.  Use to get the engines rebuilt from local shops, Cummins, Cat, Deuts, Detroit.  Back 35 years ago a rebuild was ~$30K.  I started to question the quality of rebuilds for the mine I managed so I started insisting that the shops would notify me when the engine was run on a dyno and I'd go watch them run.  Amazing how the quality improved. 

Good luck