Lifter Rod Off & Engine Knock

[sag2]

You can usually get it to rotate from the generator nut, but you have to rotate backwards or it just slips.

 

[Sneaklylilpetey]

Just a little update. I started taking parts off the block. Took lots of pictures to help me put it back together on new engine

I bought a engine stand. My plan is to take the head off then move the block into my garage and up on the engine stand. Once that's done I'll inspect the bottom side and cylinder walls to see what happened.
I can't decide if I take the long block somewhere and have them completely rebuild it or buy a rebuilt long block then bolt all the extras on...thoughts anyone?

 

[Tuesdak]

Price a longblock from Cummins. Look at the warranty From Cummins.

Shop that rebuilt my Cummins went Tango Uniform and the warranty went with it.

Then what do you want to do with it stock or not? I would start with a better Hamilton cams camshaft grind, HD pushrods, new tappets, Total Seal gapless rings, and maybe Mahle Monotherm forged steel pistons... all to better support that nice aftermarket turbo you will be needing cuz that one is hurt from loss of oil. Just saying. And consider a Garrett Ball Bearing turbo if you can find one... Did you have a budget?

 

[Sneaklylilpetey]

Price a longblock from Cummins. Look at the warranty From Cummins.

Shop that rebuilt my Cummins went Tango Uniform and the warranty went with it.

Then what do you want to do with it stock or not? I would start with a better Hamilton cams camshaft grind, HD pushrods, new tappets, Total Seal gapless rings, and maybe Mahle Monotherm forged steel pistons... all to better support that nice aftermarket turbo you will be needing cuz that one is hurt from loss of oil. Just saying. And consider a Garrett Ball Bearing turbo if you can find one... Did you have a budget?

I can only imagine how much $ Cummins would want for a long block. I sent a request through to them, I'll post the amount when I get it.
Good point about going with a shop to do the rebuild. You don't know how long they'll stay in business, especially now with the Covid.

 

[cerberusiam]

Cummins long block is likely going to be much more expensive than a shop or doing it yourself and finding a machine shop to do the work. Depends on where you are and what industries around you, shops can and will disappear in this mess we have right now. Try to find one that has been around a long time, more likely to be there tomorrow.

Given the crank and block are good, now you can fix some of the factory issues like the 2 piece thrust bearing, short gapped rings, and cracked cap crap rods. Source yourself a set of reconditioned and checked 12V rods and you balance the assembly much better than OE, makes big difference in smoothness. Clevite bearings and make sure you get the 1 piece thrust bearing. I would get the QSB pistons, pretty good price point for a re-entrant double heat treated piston. Mahle is just way to proud of their stuff unless you are shooting for big HP. I would not use gapless rings on an FI engine and never on a diesel, too much heat for them to last like they should and with boost the strength is a question. Good street and race ring and works well with alcohol engines but not so much with FI and high heat engines. Gap then at .020-.021, should be able to buy rings already gapped at that number.

This is what happens with stock gapped rings and too much heat.

 

[sag2]

Cerb, just wondering why you don't like the cracked cap rods? Is it because of the cracked cap, or is there some other concern you have with them?

 

[cerberusiam]

Inability to balance them and they are usually so far out on weights it is criminal, biggest complaint. In the 6.7's it is even worse as it generates vibes and torsional harmonics that are impossible to track down, not as bad as the 5.9's but it is still there. Adding a fluid damper to address cheap engineering and build parts is a hack, especially on an expensive engine. There is a HUGE differences in a balanced set of rods and pistons when it comes to engine smoothness.

The cracked cap rods do not seem to age as well. New they are as strong or stronger than the old rods but there is enough failures from micro fractures as they age it calls into question the expect life time. They may be touted as being stronger but they are more brittle. Reconditioning is also a pain, you cannot resize the rod end as easily, IF you can find the right bearings you have to use oversizes to compensate for resizing.

Any engine that has damage from a dropped valve, overheated, melted a piston, or even just a injector gone bad creating a bad knock has suspect rods in it. It is one thing to throw an NA back together if everything mic's out and checks out, but, not so good with an FI engine of any kind. With the cost of the parts and machining, wanting to turn the wick up, and wanting some peace of mind the next time one is lugging 20k over a mountain pass it won't spill its guts in the middle of the road, it is worth it to switch to reconditioned true machined forged rods.

Feel the same way about the gen III hemis, toss every internal piece and bolt then start over with good forged parts and real studs\bolts instead of the cracked cap TTY hypertechnic stuff that is a couple detonations away from imploding. Gonna build it do it right, would not ever think of putting used injectors in a diesel engine, why do so with other critical parts? Seen too many examples of what COULD happen.

 

[Tuesdak]

. I would not use gapless rings on an FI engine and never on a diesel, too much heat for them to last like they should and with boost the strength is a question. Good street and race ring and works well with alcohol engines but not so much with FI and high heat engines. Gap then at .020-.021, should be able to buy rings already gapped at that number.

Have you any experience with gapless rings? Let me double down and ask specific to diesel engines? FWIW the 2nd ring only is the gapless ring as the top ring plows into too much carbon. I have run gapless rings in a dirty IDI for 38,000 miles before the IP governor let go and took the engine with it at 4300+ RPM (Redline 3600 RPM). You could read the dipstick through the oil instead of it being soot black the second the engine started. You could eat out of that engine it was so clean: normally they are internally soot coated. Further there was ZERO blowby on this engine for the entire time it ran. I also installed them in a second 6.5 and my 2003 5.9 on it's first rebuild.

Now with opening up the top ring gap IMO the gapless second ring would be a good idea to keep the blowby down as well as cleaner oil.

The "fear" of something new that no one has any experience with and can't give any reason to not use them other that "We always do it this way." gets tiring. This exact nonsense is why the shop refused to use gapless rings again on a warranty rebuild of my 5.9. (Built it and didn't tell me till it was done. Bad sleeve job and used oil pump with low oil pressure. ) Every time I pulled the dipstick and noted the black oil I was pissed because it didn't have to be black from normal ring sooty blowby.

Later, I found an engine builder here in Phoenix recommended by Total Seal Rings that builds 5.9 Cummins engines with gapless rings.

 

[cerberusiam]

You did not specify top or 2nd ring, that is always a question to answer when discussing. Fearing something new? Gapless rings have been around a lot longer than you evidently realize as there is no "fear", just practicality for application. In alcohol engines they are great and almost a must to stop oil contamination. In gasoline engines, NA or FI, there are definitely 2 schools of thought and application.

It ain't a given there are the best thing because they have their drawbacks. Those noted drawbacks play right to the areas of a FI diesel engine that are critical, heat transference and cylinder seal. The gapless set does not transfer heat as well a solid ring, solid physics there so not much to argue. Biggest problem in hard working or tuned up CTD is the in-cylinder heat soak, one really wants the heavier better suited parts rather than the go-fast engine parts because it goes directly to longevity. Cylinder seal is the downside to a low tension ring, if you have a cooled block rather than a solid one there will be size creep on the walls that impact both 1st and 2nd ring seal. The cost and minimal gains (any concrete numbers I have seen are in the 3-4 HP and 3% better seal than correctly setup moly rings) weight against the potential problems becomes a decision point. There are more effective things to spend the money on.

If you think the dirty oil is all from blowby you have a bit to learn. Yes, blowby can contribute but it is an effect not the cause. Far more contributory is the real cause, stoich rich mixtures. Clean those up and your dirty oil problem goes away also. Instead of fancy rings, let's put that money towards a cam that will address the real problem and still have clean oil up to close to change time. I have a dirty 6.7 that has been "fixed" to where at 5k miles it is very hard to see the oil level on the dipstick because it is so clean. 12V's were all that way until you turned them up too much for intake system to compensate.

What your IDI engines do I am uncertain, they are a different critter. Just because something seems to work doe snot mean it is a good idea, all things being equal.

 

[Sneaklylilpetey]

Well... I found the problem.....took the head off and said holy ****. #2 and #6 are really bad

 

[cerberusiam]

Injectors failed and it was not caught in time. Next thing would have likely been kicking a rod out the side of the block. Need new pistons obviously, if the bore will clean you might get away without doing a liner.

 

[Sneaklylilpetey]

Injectors failed and it was not caught in time. Next thing would have likely been kicking a rod out the side of the block. Need new pistons obviously, if the bore will clean you might get away without doing a liner.

I'm putting it up on the engine stand tomorrow and inspecting the bottom end and removing pistons. If no holes punched in block or walls I'm rebuilding this one. Jasper Engines wants $9,200 for a new long block, no thanks.

 

[cerberusiam]

Yeah, that is steep. We spent $6k on a rebuild and that included rods, fire ring on the block, new cam, new dual filter setup, a bunch of fittings and piping to clean, and all quality bearings and rings.

FYI, when you bolt the oil pump pickup to the block use some type of stickum on the gasket. Seems the oils can suck a golf ball thru a garden hose.

 

[Sneaklylilpetey]

What are the chances of me just having to hone the cylinders walls and slap some new pistons in there?

 

[cerberusiam]

How bad is the scoring in the bad cylinders? With light scoring, a good hone job with moly or iron rings you likely will not be able to tell the difference on a DD truck. If they are really deep then it will likely need sleeved. Have the bore checked for round in case you have other issues in addition to any scoring, then you can make an informed decision. Don't order parts until you have the block back or agreed on the needed work. Like I said earlier QSB pistons form Cummins are a good value product, re-entrant bowl, double heat treating, etc. You will have to grind the rings to get the correct gap IIRC, or see if the will sell the piston without rings and just by the correct gapped set.

 

[Sneaklylilpetey]

Cylinder walls look fine except #2. Posting them in order starting with #1
Looks to be melted piston material in #2 walls

 

[cerberusiam]

Got some scuffing on 2 and 6 for sure. I don't any large gouges, it might just hone out if it is egg shaped or tapered.

 

[Sneaklylilpetey]

It's worth a shot, I'll get a honing stone and see if it'll clean up.. what about the crank where the bearings go. 2 and 6 are a little rough

 

[cerberusiam]

Probably will have to have it ground if they look rough. Hopefully it would clean to .010 under.

 

[Sneaklylilpetey]

Probably will have to have it ground if they look rough. Hopefully it would clean to .010 under.

Darn, was hoping it could be done without removing crank. Think maybe I should just buy a Mahle rebuild kit and take the block somewhere to get cleaned up and assembled.