Small Block Main bearing info needed !

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SS Lancer

SS Lancer

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**** Just curious Jegs has bearings for small block but they list for certain years ( LA Small block ) shouldnt any 273 thru 360 or from 1967 thru 2003 bearings interchange?
Thanks Chris
 
The 360 has a larger main bearing journal diameter...

They also made a change to the flange area of the thrust bearing on the 360 to increase strength/wear capabilities somewhere around 74 and it may have been a mid year change if I remember correctly...

But the 273-318-340 are all the same...

I would also warn you that some rod bearing manufacturers have eliminated radius in the end of the shell opposite the anchor slot for the oil squirt hole in the rod... They claim that you don't need it, but I am not willing to be the test guinea pig to prove or not... I prefer to run the rods and bearings with the oil slot and want the bearings to be made for it also... It's better to have a little too much oil in the bore than not enough, the oil ring will scrape off any extra....

Make sure that you let them know that you want the rod bearings with the "hole" for the oil squirt holes if you want them for your engine...
 
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And for harder and higher RPM use, Mahle/Clevite makes an H series of bearings in their tri-metal bearing line, versus the more 'standard use ' P series. Here is a link to their performance bearing catalog, which contains info very much worth reading IMHO for anyone learning this stuff, on the subject of bearings. (You want to download the 'Performance Bearing' catalog.) It explains the different grades of tri-metal bearings from that mfr. The Clevite77 series of bearings has been a good 'go-to' series of bearings for hot-rodders for several decades now.

MAHLE Aftermarket North America | Engine Bearing Catalogs
 
nm9stheham said:
And for harder and higher RPM use, Mahle/Clevite makes an H series of bearings in their tri-metal bearing line, versus the more 'standard use ' P series. Here is a link to their performance bearing catalog, which contains info very much worth reading IMHO for anyone learning this stuff, on the subject of bearings. (You want to download the 'Performance Bearing' catalog.) It explains the different grades of tri-metal bearings from that mfr. The Clevite77 series of bearings has been a good 'go-to' series of bearings for hot-rodders for several decades now.

MAHLE Aftermarket North America | Engine Bearing Catalogs
Click to expand...
Thanks
For info my application will require some HX bearings or
Extra clearance o
nm9stheham said:
And for harder and higher RPM use, Mahle/Clevite makes an H series of bearings in their tri-metal bearing line, versus the more 'standard use ' P series. Here is a link to their performance bearing catalog, which contains info very much worth reading IMHO for anyone learning this stuff, on the subject of bearings. (You want to download the 'Performance Bearing' catalog.) It explains the different grades of tri-metal bearings from that mfr. The Clevite77 series of bearings has been a good 'go-to' series of bearings for hot-rodders for several decades now.

MAHLE Aftermarket North America | Engine Bearing Catalogs
Click to expand...
Do All
318 from 67 to 2003 use the same main bearings ?
 
nm9stheham said:
And for harder and higher RPM use, Mahle/Clevite makes an H series of bearings in their tri-metal bearing line, versus the more 'standard use ' P series. Here is a link to their performance bearing catalog, which contains info very much worth reading IMHO for anyone learning this stuff, on the subject of bearings. (You want to download the 'Performance Bearing' catalog.) It explains the different grades of tri-metal bearings from that mfr. The Clevite77 series of bearings has been a good 'go-to' series of bearings for hot-rodders for several decades now.

MAHLE Aftermarket North America | Engine Bearing Catalogs
Click to expand...
Thanks for the link. CL 77’s were always my preference in the few V8 engines I have built. Good to know they’re still a quality bearing. I’ve been a fan of Mahle pistons since my early days building VW’s, and have built many motorcycle engines with them. A great product.
 
Jadaharabi said:
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I think in 74 the 318 middle bearing (#3) was changed.
Click to expand...
They went to a larger thrust bearing in the 360's
All sb rod bearings interchange, larger mains for 360, 273-318-340 are the same main bearings for "steel crank assembly's".

If you use an early crank in an 74 or later block...you can use the early thrust, and technically they will work whether or not they cover the entire thrust of the crank or not, but you cannot fit a later thrust bearing in an early block because it's not machined to accommodate/seat the larger thrust face.

Stroker cranks take narrow h series full groove to clear the radius at fillets, h beam rod bearings require narrow h series as well.
You can narrow them yourself, but if you're not setup for it... it's a lot of time.
If you use regular main bearings with a radius journal... it wont have any thrust clearance, n will have worn edges only on the bearings.lol I remember my first go at the 4" arm, learned many things.
 
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Main bearings for 318's changed in 1974 to a different thrust width, pre 74 used (for example) Clevite MS-540p with a max thrust diameter of 3.374 inch, then 74 on used Clevite MS-1344p with a max thrust diameter of 3.530 inch.
 
Max1196 said:
Main bearings for 318's changed in 1974 to a different thrust width, pre 74 used (for example) Clevite MS-540p with a max thrust diameter of 3.374 inch, then 74 on used Clevite MS-1344p with a max thrust diameter of 3.530 inch.
Click to expand...
Thank you Hoss
 
Max1196 said:
Main bearings for 318's changed in 1974 to a different thrust width, pre 74 used (for example) Clevite MS-540p with a max thrust diameter of 3.374 inch, then 74 on used Clevite MS-1344p with a max thrust diameter of 3.530 inch.
Click to expand...
So 74 thru 2003 on the 318 or 5.2 liter used same bearings ??
 
MOPAROFFICIAL said:
Stroker cranks take narrow h series full groove to clear the radius at fillets, h beam rod bearings require narrow h series as well.
You can narrow them yourself, but if you're not setup for it... it's a lot of time.
If you use regular main bearings with a radius journal... it wont have any thrust clearance, n will have worn edges only on the bearings.lol I remember my first go at the 4" arm, learned many things.
Click to expand...
Yup, just confirmed the need for the narrower rod bearing on a 4" stroker crank in mocking up with standard width rod bearings this evening.
 
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nm9stheham said:
Yup, just confirmed the need for the narrower rod bearing on a 4" stroker crank in mocking up with standard width rod bearings this evening.
Click to expand...
10-4
I have a 68 & 74 model blocks that were burned and blasted and are ready
To go I also have a 1970 block that can be used aftet proper cleaning
Im going 90 over to make combination a 4 " bore !!!!
Any benefit with pre 74 versus 74 to 03 with bearing change ???
Thanks Chris.
 
1Badcolt said:
10-4
I have a 68 & 74 model blocks that were burned and blasted and are ready
To go I also have a 1970 block that can be used aftet proper cleaning
Im going 90 over to make combination a 4 " bore !!!!
Any benefit with pre 74 versus 74 to 03 with bearing change ???
Thanks Chris.
Click to expand...
.
74 and up have more contact area on the thrust bearing surface.
Did you sonic test your block to be bored that far?
The early blocks may be thicker.
 
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MOPAROFFICIAL said:
They went to a larger thrust bearing in the 360's
All sb rod bearings interchange, larger mains for 360, 273-318-340 are the same main bearings.
Stroker cranks take narrow h series full groove to clear the radius at fillets, h beam rod bearings require narrow h series as well.
You can narrow them yourself, but if you're not setup for it... it's a lot of time.
If you use regular main bearings with a radius journal... it wont have any thrust clearance, n will have worn edges only on the bearings.lol I remember my first go at the 4" arm, learned many things.
Click to expand...
H series also come with increased bearing clearance versus the clevite 77 standard series so be sure to check your bearing clearances when using the "h" series.
 
Jadaharabi said:
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Look under fitment 1974-2003 The title is wrong.


56-73

Clevite MAHLE MS540P40: Main Bearing Set Chrysler 1956-1973 V8 273/277/301/303/313/318/326/340 with -.040" Undersize | JEGS

Sealed Power 4923MA10: Main Bearing Set Small Block Chrysler | JEGS
Click to expand...

Early thrust works in late block fine.
Just like you can use a later 360 crank in an early 'smaller thrust' block...same with 318. It may not be text book but it 'is' still.
Probably why they list for all, cause they work.
 
Except the part # you have listed in post # 13 (Clevite MS 1344P) Is the wide flange bearing, that does not fit pre 74 blocks unless the block is modified.
 
Jadaharabi said:
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If the 68 block can take that big of a bore use it.
Click to expand...
I did turned out nice !
Hensley Performance in TN
Did the work !

20200316_185420.jpg
 
krazykuda said:
The 360 has a larger main bearing journal diameter...

They also made a change to the flange area of the thrust bearing on the 360 to increase strength/wear capabilities somewhere around 74 and it may have been a mid year change if I remember correctly...

But the 273-318-340 are all the same...

I would also warn you that some rod bearing manufacturers have eliminated radius in the end of the shell opposite the anchor slot for the oil squirt hole in the rod... They claim that you don't need it, but I am not willing to be the test guinea pig to prove or not... I prefer to run the rods and bearings with the oil slot and want the bearings to be made for it also... It's better to have a little too much oil in the bore than not enough, the oil ring will scrape off any extra....

Make sure that you let them know that you want the rod bearings with the "hole" for the oil squirt holes if you want them for your engine...
Click to expand...
Thank you Sir
 
1Badcolt said:
**** Just curious Jegs has bearings for small block but they list for certain years ( LA Small block ) shouldnt any 273 thru 360 or from 1967 thru 2003 bearings interchange?
Thanks Chris
Click to expand...

No, 360 have larger diameter main journals, also the thrust bearing changed in '74 and are larger thereafter .

318/273 are the same until 1974 when the thrust bearing changed.
All rod bearings interchange w/stock cranks
That said you can use early pre 74 sets on all blocks... while only the later 'post 74' blocks will take the later thrust sets.

Just realized this was answered already. Lol

Nice block, port the open on the rear main for the oil pump some, more so the pump itself.
Slot the feed holes on the main bearings so they line up directly with the main feed...otherwise they only partially expose'en and more so the cam bearing feed.
 
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