Engine Teardown, What am I Looking at?

I have an engine that has sat for a couple years and I had the itch to finally tear into it this weekend. The engine has roughly 6k on the rebuild but it had trouble making any boost (I bought it for a parts car). I did a compression test before the engine was pulled and one of the cylinders was slightly lower than the others. Unfortunately, I cannot find my notes on what those test readings were. I do recall it was either cylinder 3 or 4 that was low.

The previous owner installed Keith Black hypereutectic pistons with the rebuild. Something happened and he thought there was an issue with the piston rings. Being hypereutectic pistons I was expecting to see some sort of failure when I pulled the head off this weekend. However, it was pretty mundane and no cool carnage.

However, here is what I noticed:

• I drained the oil and although the oil had very few miles on it (maybe 10) there was a good amount of mucus like sludge that came out at the beginning and towards the end. The head gasket (Fle-Pro) showed no signs of failure. Could this just be moisture from sitting for a couple years? I let some of the sludge gather on my engine stand and took a picture of it.

https://drive.google.com/file/d/1NxV...zawMIpuv0/view

• Cylinders 2 and 3 had build up (carbon?) on the intake valve, all other valves looked smooth. Cylinder 3 was the worst, see pic. What is this buildup and what causes it?

https://drive.google.com/file/d/1Ied...mfYigLSgT/view

• The cylinders looked great except cylinder 3 had some build up at the top of the cylinder. Possibly surface rust, it looks similar to the build up on the valve. Other than that each cylinder has very nice cross hatch.

https://drive.google.com/file/d/1Cs0...VKjsFQ0Tq/view

• There was a black flakey film on 3 of the 4 cylinders. What is this? Is this just poorly combusted fuel?

https://drive.google.com/open?id=1GV...HFnWPMO8FgsRmd

I measured the bores with a caliper, which doesn't seem like the right tool. Anyway, each cylinder was ~3.47" so 0.030" over?

The engine had no knocks or rattles, it sounded fine it just wouldn't make boost and has the hypereutectic pistons. I was hoping to just pop in new forged pistons without disturbing the crank or completing a full rebuild. Thoughts on if this is wise based on the pics? Should cylinder 3 be rehoned to remove whatever is at the top of the cylinder? Should I purchase new rod bearings or can these be reused if they look to be in good shape?

I have plenty more pictures of each cylinder if it helps. I don't remember how to post images directly in a forum post though, or at least it isn't working for me from Google Drive.

This is a new learning process, and a bit of a relearning process, for me as I have stepped away from working on cars for a few years now.

Thanks,
Ryan

So pics wont load for me(Im at a Catholic Hospital for work, they have WiFi but aggressive filters) but am I reading that you DON'T have the pistons out of the block yet? If not you wont see the ringland failure. I went thru a couple KB pistons back in the day because it's 'all we had'. Theyre not nearly as strong as factory TI or TII pistons.

I wouldn't make any other plans until I pulled the pistons to inspect the ring lands. I would clean the carbon off of that cylinder and determine if there is a ridge there, or if the bore is smooth to the top. With only 6K miles on it, I'm surprised there isn't a more apparent crosshatch to the bore, but that could just the the photo.

I would order up new rod bearings. It's cheap insurance.

I'm kind of OCD with this kind of thing, so I'd be measuring all kinds of things that probably aren't necessary, but would give my worrisome mind a bit of peace...

That said, it does look like a bit of water/coolant, etc got in there with the oil, question is where'd it come from? I'd get the head pressure tested and checked to be sure it's straight and flat. Do the same for the deck of the block. This is key to good gasket sealing, regardless of gasket preference. Also, use known-to-be-good head bolts. Our torque to yield bolts sometimes get re-used too many times and will ruin an otherwise fine rebuild.

With not being there to actually see the bores, etc, and given that the engine has so few miles on it, I'd guess that the rings aren't sealed/seated/broke-in. That one pic with meant to show the "ridge" on the cylinder, seems pretty "greasy", which may be a result of poor sealing rings/poor bore finish, etc. letting too much oil get to the chamber.

Looks like all the cylinders are very sooty. This can be poor combustion, a rich condition (oversized injectors for the tune/leaky injector, etc), and/or incorrect cam timing... The cam timing could explain the lack of spool too..

Certainly not easy to diagnosis long distance, but I think you'd do best to tear things down to inspect/measure things and replace bearings, etc as needed. I'm guessing/hoping that the bottom end is OK, and maybe a new set of rings, a quick ball hone to clean the bores/establish the proper crosshatch, will get things primed and ready. BUT, that's a best case, too often folks will throw a set of bearings in and call it a rebuild, but there's much more to a proper rebuild that just replacing the wear items...

Best of luck!

Mike

two more thoughts...
make sure the head is freshly cut.. and use copper spray when installing -- to address milk stuff (aka water & oil)


carbon could be a result of way to rich, plugs probably have carbon too .. or turbo needs rebuild.. .. simple test .. leave hotside of turbo disconnected for a few drives and pull the plugs..

I popped the pistons out tonight. They were all intact and looked decent to me, there were no cracks or signs of damage. The rods and crank also look to be in great shape.

Pistons
https://drive.google.com/file/d/1xgp...Hj8-AmFZj/view

Cylinder 1
https://drive.google.com/file/d/1H1Z...vIkbHp_Cp/view
https://drive.google.com/file/d/1sxL...K57hrB0FR/view

Cylinder 2
https://drive.google.com/file/d/1TlN...Yn-ibncMA/view
https://drive.google.com/file/d/16_h..._jfhT3_LP/view

Cylinder 3
https://drive.google.com/file/d/12kc...r6sDu5RAI/view
https://drive.google.com/file/d/16HS...wNs1P0BsW/view

Cylinder 4
https://drive.google.com/file/d/1hKj...zlcV8faFg/view
https://drive.google.com/file/d/1u2m...oHLcTMuto/view

From what I have recall, hypereutectic pistons should be avoided. Is this still true? These had more than stock boost ran on them and they appear to be in decent shape. Being that it appears this engine was bored .030 over, should I ditch these pistons and order some new forged slugs?

This is another pic cylinder 2 (I mistakenly called it 3 in my initial post), there is what appears to be a small amount of pitting on the cylinder wall, however it is smooth to the touch. I couldn't hang a finger nail on it or feel it at all.
https://drive.google.com/file/d/1qNq...n6-fkercO/view

I have been measuring and trying to compare to the FSM. I only have digital caliper so the measurements have some play. I assume a micrometer would be better. Anyway, some measurements from today:

• Rod journals on crank 50.02mm, 49.98mm, 49.96mm, 50.00mm. All within spec of the FSM except for the 49.96 but could be an inaccuracy from my caliper.
• The rod bearings were 1.45 to 1.49 mm thick, if that matters.
• The pistons were 87.35mm at the top (above the top piston ring) and 88.2mm on the side skirts. I don't know what to think of these measurements...

I would absolutely put some new pistons in there. Can you move all of the rings around freely? They aren't pinched in there at all? I thought a piston from my wife's Daytona looked pretty good when I originally pulled it, but when it came down to it, the ring lands were beyond destroyed.

ETA: Here is the piston.

https://farm5.staticflickr.com/4316/...194b0578b5.jpgIMG_1763 by Brian Cordes, on Flickr

Here is what the cylinder head looked like. You can see that there was a ton of carbon build up in there. It was burning oil pretty badly, with massive blow by due to the cracked piston in I believe #3 and #4 had the ring pinched pretty well. It didn't come apart like that until I removed the broken rings.


I believe the failure was caused by a faulty LM leaning out two cylinders.

https://farm5.staticflickr.com/4318/...78edeaa12c.jpgIMG_1760 by Brian Cordes, on Flickr

Quote:

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Originally Posted by cordes

I would absolutely put some new pistons in there. Can you move all of the rings around freely? They aren't pinched in there at all? I thought a piston from my wife's Daytona looked pretty good when I originally pulled it, but when it came down to it, the ring lands were beyond destroyed.

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The piston rings moved freely and were springy.

I have a set of silv-o-lite pistons from a different engine, two of the pistons look similar to your photo above.

It's a rough spot to be in. See if you can find some Sealed Power/Federal Mogul 533P pistons anywhere in the size you need. Make sure they're the proper floating pin version. I've heard that they made more of them in the proper floating pin configuration, but at one time I had the last non-NOS set from them in the country. I had to speak with engineers and inventory guys from all over to track them down. It was a nightmare. At the same time, once I got them the ran well and held up fine.

This appears to be the pistons that were installed in this engine. These appear to be for a for a stock bore.

https://www.uempistons.com/index.php...846339f298808e

Looks like I need to acquire a bore gauge, my caliper measurement must be off.

Quote:

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Originally Posted by cordes

It's a rough spot to be in. See if you can find some Sealed Power/Federal Mogul 533P pistons anywhere in the size you need. Make sure they're the proper floating pin version. I've heard that they made more of them in the proper floating pin configuration, but at one time I had the last non-NOS set from them in the country. I had to speak with engineers and inventory guys from all over to track them down. It was a nightmare. At the same time, once I got them the ran well and held up fine.

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I am leaning towards ordering some forged pistons from one of the venders. I would like be able to build this engine up a bit before putting it into my GLH. From this thread it looks like I need to order rod bearings and a set of pistons for the bottom end. I just need to figure out what sizes. It appears I need standard rod bearings and most likely oversized pistons (.030?).

I will also have the top end pressure checked and decked.

The held bolts did not looked stretched, is there a way to identify if they are ARP bolts? I assume the ARPs can be reused.

I think the ARP head bolts need to be cut down to fit. That' should be pretty obvious.

I would take the whole thing to a good machine shop and have them measure everything up and go from there. No sense getting stuck with a set of pistons which are the wrong size. You'd probably want to have the machine shop assemble the thing too for what most places charge.

As a reference, the correct way to measure a piston is at the skirt, about pin level, and 90 degrees to the pin. The tops of the pistons are naturally smaller than the skirt when the piston is cold to account for expansion as the engine heats up.

With the engine out now, don't skimp or cheap-out on a rebuild. Replace everything. Rod & main bearings are only about $40 from Rock Auto, and that's for Clevite 77's, which IMHO, are the best. Not worth the risk to run the old stuff, especially the way the oil came out of that engine. You can buy factory Mopar head bolts on ebay for about $25 delivered. DO NOT buy Felpro's!!! Several folks have proven that they have crappy quality control, and it's a crap shoot if they will torque down correctly or not. I've never had an issue with Felpro head gaskets, some guys don't like them. Both my TM's are running the Felpro head gasket now, and I've not had issues with either of them. The one has been in there for almost two years & 30K miles of daily driving year round...

But I concur with others here, get rid of those KB paperweights before one of them grenades and takes out your engine. It's not a matter of if, but when they will fail. Especially if you plan on turning up the boost at all.

Can't really argue with any of the advice given here, pretty much what I'd prefer to do, there are a couple of things I'd like to point out though:

The picture showing the "pit" also shows me whoever did the "rebuild" needs to work on their ball-hone technique, the cross-hatch is too steep, and that could be contributing to the "oiliness" seen on the tops of some of the pistons, if not due to the crosshatch, then due to it being so light that you can still see the vertical "scuff marks" in the bore. A proper honing would remove all of that and in the process give the rings something to help them seal/seat/break-in...

Since that seems to be a bit of a half measure, I think the advice to have a machine shop go through and check it's vitals is something to consider. Good machine work is almost as important (maybe equal) as quality parts. Good machine work can make crap parts live longer, and crap machine work can destroy great parts in short order.

With regards to Hypereutectic pistons:

Hypereutectic means a solution that has more of a particular chemical than can be fully dissolved into a solution, kind of like putting too much sugar in your iced tea, too much and the tea can't dissolve it and so the crystals just collect in the bottom of your glass. In this case the solution is aluminum and the chemical is silicon.

The reason for doing this is that when there is too much silicon to dissolve, it forms crystals, which are good at preventing wear and scuffing, and cause the piston to not expand much under heat. This is all good stuff and if that were the end of it, we'd all be running Hypereutectic pistons and calling forged pistons "junk".

Unfortunately, Hypereutectic pistons, though they are stronger than typical cast pistons (if the only the material is changed), have the fatal flaw of being much more brittle than a forged piston, which have their own flaws (greater expansion requiring lager clearances resulting in noise (piston slap) and skirt scuffing (rocking in the bore, etc), oh, and they are typically WAY more expensive. The Hypereutectic piston can hang with a forged pretty well in a well tuned engine, but if it runs into detonation, say due to bad fuel or a novice tuner adding too much timing, etc, the forged piston will "flex"/bend under the strain, but the more brittle Hypereutectic, will crack/break, typically/logically where it is weakest/thinnest which is typically between the ring lands...

Much better to "build it right" once than to deal with the frustration of having to pull the head or engine because we cut too many corners. It might cost a little more, but how much is it worth to not have to do a head gasket and/or R&R and engine?...

This is probably a good place to mention that a quality tune, much like good machine work, will make whatever parts you have work better than the best parts poorly tuned.

Best of luck!

Mike

Have you checked the ring end gaps??

Hyper require a larger gap.

Any chance some of the top rings are installed up side down??

Thanks
Randy

I will ask around for a good engine shop locally. I would like them to double check my measurements and make sure I order the right size pistons and bearings. Plus it sounds like the cross hatch needs to be redone. I assume this is something I could do at home with a flex hone tool but if I am bringing the engine to a machine shop I might as well have them do it.

I want to be involved in the build process as much as possible, I would like to build this one right and learn from it. I have definitely learned a lot from this thread. Thanks everyone.

- - - Updated - - -

Quote:

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Originally Posted by GLHS60

Have you checked the ring end gaps??

Hyper require a larger gap.

Any chance some of the top rings are installed up side down??

Thanks
Randy

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I didn't look at all the pistons but I did notice the dot on a ring or two was facing up. I can look at all of them tomorrow. To measure the gap it looks like I have to pull the rings off and put them in the cylinder bore and measure with a feeler gauge. I will do this tomorrow.

As you heard the Engine running and it sounded good you might consider a home overhaul.

I've done many this way and never had a failure, even reusing main and rod bearings.

I strip the Engine down and clean and examine everything very closely.

Port the oil pump hole in the block to match your oil pump, there is usually an imprint left behind.

Obviously you need to determine what size your pistons are and if a comparable piston is readily available.

Otherwise you will have to rebore, might as well square deck it at the same time.

Naturally, the crank and bearings must be serviceable to re use.

Bearings have to snap in place, if not they have suffered some abnormal stress.

Oil pump should be opened up, cleaned and inspected, specs are in service manuals.

Many folks have had issues with new oil pumps, so it's not about cheaping out.

Machine shops make money boring and grinding, that's fine but they sometimes make things worse.

I find Plastigage is fine for checking crank clearances and rotate the Engine regularilly during assembly.

Recently a friend assembled his Engine with everything new including connecting rods.

After installing #3 the Engine was much stiffer to turn, #3 and #4 rod caps were marked incorrectly.

I'm not bashing machine shops, I worked in a few, but not all are created equal.

For some reason, like Rodney Dangerfield, our Engines don't get much respect at some shops.

Sometimes work is given to the less experienced, after all it's just an old Dodge.:banghead:

Best of luck!!!

Thanks
Randy