#1 Upper Main Bearing ---Anything Special ?

[70rcode]

The Service Manual notes there is something Unique & Not Interchangeable with the # 1 Upper Main Bearing shell having a Special Tab side Front Chamfer for timing chain oiling ?? I'm looking over my new set of Sealed Power 119M bearings & only the # 3 Thrust of course looks different.....Do I have the Wrong Main Bearing set or what ?

 

[451Mopar]

No difference that I know of?

 

[70rcode]

I always wondered exactly How the Timing chain gets Positivity Oiled..... Manual states this is for directed oil squirt Timing Chain lubrication & the Unique # 1 Upper Bearing shell is Red marked identified ?? I'm Not seeing it in this bearing set..

 

[451Mopar]

Interesting, which manual and year are you using?

 

[70rcode]

1970 Plymouth Service Manual 383-440 & 426 Street Hemi engines # 1 Upper Main Bearing shell Non--interchangeable...

 

[t.flatt]

I noticed the same thing in my manual. I assumed bearing manufactures realized a special #1 is not necessary. But, it would be nice to hear from someone that knows!

 

[70rcode]

I recall somewhere,. The Oem Mopar Individual Main Upper bearings # 2, 4 & 5 is part # 2448380 with # 1 Upper Main is # 2448380 for Individual bearing shells....The Oem set has a single Red marked Upper Shell identifying # 1 Upper...I would like to know how to file or scrape a regular Upper bearing to the correct Oem "Chamfer" to meet the factory Oem requirement...I would think proper timing chain Lubrication would reduce chain & sprocket premature wear & stretch issues..

 

[70rcode]

Part # 2448379 the # 1 Upper bearing....

 

[Ceedawg]

Maybe cut or file a small groove at top on the pass side down 1/2 way from feed hole, like the thrust bearing

 

[RemCharger]

Time to start drilling out rod bearings like the factory did too?
Guys are getting carried away

 

[70rcode]

Plz explain a factory drilled out rod bearing .....Don't remember seeing or hearing about that..... How is following the factory service manual "carried". away ?? Isn't basic factory Lubrication of moving parts fairly normal ? I missed the Tom Hoover memo about timing chain assembly lubrication deleat mod...

 

[pnora]

I have built more motors than I can count and never once did I worry about a different bearing for timing chain lubrication. Get it together and quit worrying.

 

[451Mopar]

1970 Plymouth Service Manual 383-440 & 426 Street Hemi engines # 1 Upper Main Bearing shell Non--interchangeable...

Your right! My 1969 Dodge factory Service Manual has the same text it it about the #1 upper bearing shell.
I checked the only mains I have here, the Clevite MS-2233HG and all the upper shells are the same.
These are a narrower bearing for the radius of the stroker crank, and the short thrust bearing face for a 1966 440 block.
It looks like the distance from the outer edge of the bearing to the locating notch is only around 0.060"? Not sure how wide the stock bearings are from the locating notch to the outer edge of the bearing?
These MS-2233HG are 3/4 groove on 1,2,4,&5, and full groove on #3.

You could always add a chamfer to the bearing if you wanted?

 

[R413]

Just like the rod bearings originally had the oil hole and now it is missing in aftermarket bearings.

My old school machinist said it’s not needed.

 

[70rcode]

R413.. Isn't the connecting Rod bearing hole intended for optional Aluminum Rod locating Dowel Pin clearance application not same as a No longer used lubrication issue example.... Back in the day (Mopar ignorant & without a Service Manual) I never bothered to notice the Original # 1 factory Bearing that closely .....

 

[70rcode]

I have noticed the occasional Postings of Dryer than Expected Timing Chain Lubrication issues in the past & just ignored them.....In this Lubrication issue, Did Chrysler Engineering officially Obsolete the bearing Specification design ?? Some old school Mopar knowledgeable may know .....

 

[RemCharger]

R413.. Isn't the connecting Rod bearing hole intended for optional Aluminum Rod locating Dowel Pin clearance application not same as a No longer used lubrication issue example.... Back in the day (Mopar ignorant & without a Service Manual) I never bothered to notice the Original # 1 factory Bearing that closely .....

One can only assume you've never looked at a stock dodge engine before,,
But a no longer used lubrication issue is exactly what the 'Rod journal side oiling' deal is.
Nothing to do with the optional dowel pin hole.
Take a look at a stock Rod if you have one, there's a oil trough opposite of the numbered side.

 

[pnora]

I have noticed the occasional Postings of Dryer than Expected Timing Chain Lubrication issues in the past & just ignored them.....In this Lubrication issue, Did Chrysler Engineering officially Obsolete the bearing Specification design ?? Some old school Mopar knowledgeable may know .....

Where do you see dry timing chain failures to? I have been in a dealership service department since 1972 and have never seen any mopar with dry timing chain failures. So since 1972 I have never heard of any changes that affect timing chain oiling. There always have been changes like the slinger removal and maybe a few other items that we might of questioned. Never a main bearing change related to chain oiling that I am aware of. Your beating a dead horse here in my opinion.

 

[70rcode]

I'm just asking for accuracy of maintenance replacement part info, as that particular part # seems no longer available & someone may remember it's design features & Any Functional importance...That was "Dryer lubrication than expected" as in "not as oily" as expected,... not Dry !!......Mopar part # 2448379 (# 1 Main Bearing Only) 426 Hemi application still exist in 1970 Mopar replacement inventory Records & seemed to be Oem significant & critical enough to be specified..... Obviously, there's Some Indirect oil sling in the sprocket/ chain area But is the Incorrect # 1 Upper Bearing causing less than Oem design/desirable sprocket / chain Lubrication Starvation issues that Could be easily corrected ??

 

[70rcode]

Pnora, ...I appreciate your dealership service dept experience & wished I had similar,.....Did you seem to miss or not notice the 1970 Plymouth Service Manual (group index 9--82) huge, Bold, black Warning Notation ? .... It's Much Bigger, blacker, Bolder Notation than even the Critical # 3 Main Thrust/Flanged Bearing (big deal important !! ). Non--interchangeable issue so I interpreted That # 1 Main Upper of Some Chrysler significance affecting issue to attend to......I remember back in '72 (my 1st Mopar engine teardown) asking myself "how does this well engineered, impressive Double Roller timing chain assembly get Adequately Directly lubricated",. but youthfully & ignorantly (no service manual),. assumed "it somehow just does" & tended to more Impressive sights as the huge ports, valves & piston valve relief Hemi things.....I was Super youthfuly Excited wrenching on my 1st New 426 Hemi !!!