Slant Six Forum :: Why are my rods like this? Has anyone seen this before?

I imagine V8s never had this, and so the K1 folks just left it out, and it would have almost certainly been fine, especially with modern oils.

Lou

Quote:

It also means that likely we don't need an oil spurt hole at all!

Gonna disagree there. "Things work better when the oil squirts over here instead of over there" is not the same as "Oil doesn't have to squirt anywhere in this vicinity".

Every machining operation cost Chrysler money. Chrysler never met a penny they didn't pinch as hard as they could. If the oil squirt hole weren't needed, this TSB would have said it had been eliminated.

Whether the spit hole is necessary or not, other manufacturers decided it wasn't. Why Chrysler continued to use this feature can only be answered by them.

Ok I can see plating a part to shrink clearances and make a part usable that would otherwise be scrapped. The next question becomes how durable that coating is in a moving part that is anticipated to experience wear with usage?

Quote:

I actually found another seemingly oe rod with the squirt hole facing the incorrect direction too. It was machined correctly but hung on the rod/ piston backwards.

Y'mean like this?

TSB_D63-11.jpg

When I dis assembled the engine, the squirt holes were facing the left. Now upon reassembly should I flip them towards the camshaft side? They will be going back into a '62 block with a '62 crank and new pistons. What do 'yall think?

Author:	Charrlie_S [ Tue Nov 28, 2023 2:42 pm ]
Post subject:	Re: Why are my rods like this? Has anyone seen this before?
Quote: I imagine V8s never had this, and so the K1 folks just left it out, and it would have almost certainly been fine, especially with modern oils. Lou I don't have any V-8 rods available to look at but I think the V-8 rods don't need the hole. According to the 1979 factory service manual. Small block, and big block "each bearing cap has a small "V" groove across the parting face. When installing the lower bearing shell, make certain that the "V" groove in the shell is in line with the "V" groove in the cap. This provides lubrication of the cylinder wall in the opposite bank.

Author:	CNC-Dude [ Tue Nov 28, 2023 5:25 pm ]
Post subject:	Re: Why are my rods like this? Has anyone seen this before?
Quote: Quote: It also means that likely we don't need an oil spurt hole at all! Gonna disagree there. "Things work better when the oil squirts over here instead of over there" is not the same as "Oil doesn't have to squirt anywhere in this vicinity". Every machining operation cost Chrysler money. Chrysler never met a penny they didn't pinch as hard as they could. If the oil squirt hole weren't needed, this TSB would have said it had been eliminated. Many automotive brands such as Ford and GM had connecting rods that started out in the early 60's with split hole oiling in their connecting rods and later on in life in the 70's was eliminated. Some even had a v-notch machined on the rod caps mating surface to act as a spray oiler that also eventually was eliminated as a feature. The rods that had the spit hole in the beam of the rods would often fail in that spot when used in performance applications, as Rick Covalt discovered some years ago with one of his race engines. Companies that make performance connecting rods will never drill through the beams of their rods because they know this is a failure spot for such a feature. Whether the spit hole is necessary or not, other manufacturers decided it wasn't. Why Chrysler continued to use this feature can only be answered by them. Eliminating that feature didn't cause any issues with the other big car manufacturers, so having it omitted from aftermarket rods isn't something to worry about. Also, many Ford and Chevy as well as Chrysler engines were copper dipped to correct wrist pin machining error in the small ends of the rods. I've also seen many connecting rods that were built back up on their big ends as well to repair batches of rods that were machined too big and out of spec. These aren't anything to cause concern either, but explains why they are done this way.

Author:	SlantSixDan [ Tue Nov 28, 2023 6:49 pm ]
Post subject:	Re: Why are my rods like this? Has anyone seen this before?
Quote: Whether the spit hole is necessary or not, other manufacturers decided it wasn't. Why Chrysler continued to use this feature can only be answered by them. Okeh, sure. Now…what's one of the reasons why we like the Slant-6 better than a Ford or GM inline-6? Longevity/durability. You do the rest of the math.

Author:	CNC-Dude [ Wed Nov 29, 2023 2:14 am ]
Post subject:	Re: Why are my rods like this? Has anyone seen this before?
Agreed....The Slant is a very rugged and durable engine! The Ford 240/300 six cylinder was also very durable and has a history of being capable of going over 300,000 miles on many occasions. It's one of those engine designs that originally had a connecting rod spit hole feature and then later was omitted. Several of their V8's also did and a couple of 4 cylinders did as well. There is plenty of evidence seen in many other manufacturers, especially Toyota's and Nissan that also are known for 300,000+ miles that never had the spit hole feature at all. So I really doubt having that feature contributed in any way the those engines longevity, but more to the care and servicing provided by their owners...

Author:	SlantSixDan [ Wed Nov 29, 2023 10:04 am ]
Post subject:	Re: Why are my rods like this? Has anyone seen this before?
Well…h'mm. On the one hand, Chrysler Engineering kept that oil hole through at least four prime opportunities to eliminate it: two new-rod designs, and two directives to take build cost out of the Slant-6 engine. But on the other hand, some dude sits at his puter and sez lolnope it's not needed bcuz Ford and Toyota and stuff. Now If anyone needs me, I'll be over here chuckling at the idea of definitively adjudging the utility of a feature on an engine made by one company by pointing at engines made by other companies. If my ribs start to ache from the chortling, I'll scare myself by fretting about Slant-6 connecting rods breaking on account of the oil hole having been drilled. It could happen; there's always a first time for everything!

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Author:	CNC-Dude [ Wed Nov 29, 2023 10:44 am ]
Post subject:	Re: Why are my rods like this? Has anyone seen this before?
Just take a break from the action there pumpkin....we'll try not to disturb you too much!

Author:	volaredon [ Wed Nov 29, 2023 2:38 pm ]
Post subject:	Re: Why are my rods like this? Has anyone seen this before?
Ok I can see plating a part to shrink clearances and make a part usable that would otherwise be scrapped. The next question becomes how durable that coating is in a moving part that is anticipated to experience wear with usage?

Author:	SlantSixDan [ Wed Nov 29, 2023 5:16 pm ]
Post subject:	Re: Why are my rods like this? Has anyone seen this before?
Quote: Ok I can see plating a part to shrink clearances and make a part usable that would otherwise be scrapped. The next question becomes how durable that coating is in a moving part that is anticipated to experience wear with usage? Given this thread started with a decades-old engine being taken apart for the first time, I'd say that's one data point it worked just fine.

Author:	DadTruck [ Wed Nov 29, 2023 7:50 pm ]
Post subject:	Re: Why are my rods like this? Has anyone seen this before?
Don, engine bearing are copper / aluminum / tin plated over a steel backing. The plating in bearing uses he is quite a bit thicker than what would be used in a repair. The nature of the thin plating will give the copper decent hardness. Not as hard as the base steel, but being so thin, there is not room for much deflection. Remember the bearing shell is fixed and does not move, so wear because the copper is as not as tough as as steel is not an issue. With the improved repeatability and accuracy of modern machining available today, I doubt if any OEM use plating to salvage rods today. Although I would not be surprised to find it used in some special antique engine re builds.

Author:	Greg Ondayko [ Sun Dec 24, 2023 11:38 am ]
Post subject:	Re: Why are my rods like this? Has anyone seen this before?
Quote: Quote: I actually found another seemingly oe rod with the squirt hole facing the incorrect direction too. It was machined correctly but hung on the rod/ piston backwards. Y'mean like this? TSB_D63-11.jpg So I am beginning to hang the rods on the pistons. When I dis assembled the engine, the squirt holes were facing the left. Now upon reassembly should I flip them towards the camshaft side? They will be going back into a '62 block with a '62 crank and new pistons. What do 'yall think? Best, Greg

Author:	SlantSixDan [ Sun Dec 24, 2023 1:44 pm ]
Post subject:	Re: Why are my rods like this? Has anyone seen this before?
Quote: When I dis assembled the engine, the squirt holes were facing the left. Now upon reassembly should I flip them towards the camshaft side? They will be going back into a '62 block with a '62 crank and new pistons. What do 'yall think? I think Chrysler were very specific about putting the pre-'63 engines back together the way they were originally built in this respect. Would've been nice if they'd explained why, but regrettably they did not. Still, it strikes me that if there were some improvement to be made by building the '62-down motors with the oil holes aligned as in the '63-up motors, they'd advise doing that, and if it didn't much matter, they'd've said that. So in the absence of definitive information from the likes of Doug Dutra, I'd tip my hat to this '62 engine's long years of service up to now and do as the factory engineers recommended: put 'em back the way they were.

Author:	Dart270 [ Sun Dec 24, 2023 2:09 pm ]
Post subject:	Re: Why are my rods like this? Has anyone seen this before?
Hmm. I would have thought that since the alum motors had no replaceable cam bearings (cam rides on alum block material), you'd want the most oil splashed/squirted toward the cam. I have no idea about Chrysler's motivations or what is better, but this is just my 2 cents... Lou

Author:	SlantSixDan [ Sun Dec 24, 2023 4:10 pm ]
Post subject:	Re: Why are my rods like this? Has anyone seen this before?
…Chrysler were also very specific about the other-side-oil-hole change not applying to aluminum engines.

Author:	Greg Ondayko [ Sun Dec 24, 2023 5:47 pm ]
Post subject:	Re: Why are my rods like this? Has anyone seen this before?
It does make me wonder what changed from '62-'63 engines in build or engineering that would require this squirt hole swap. Thanks for clarifying the TSB Dan, now I want to know what is different on these engines between '62-'63? I have a '60 core that I have yet to take apart. I should check that one as well.

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Author:	Dart270 [ Mon Dec 25, 2023 3:00 am ]
Post subject:	Re: Why are my rods like this? Has anyone seen this before?
On some of the early engines, the crankshafts were larger and heavier than even the mid-late 60s and 70s forged cranks. I've seen 88 lb versions on early engines. Maybe some kind of blockage/windage issue? Around 76 lbs is standard for a 63-ish and up forged crank. ??? Lou