Author Topic: 5.7 hemi crankshaft bearing identification  (Read 1251 times)

Offline gkring

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5.7 hemi crankshaft bearing identification
« on: December 11, 2007 - 10:03:09 AM »
Seems the new style Dodge hemi motors use "graded" bearings for a tighter fit. Crank is marked for each of the bearings from the factory. A, B , and C which designate .008 over or undersize or standard. Kind of weird, but whatever. My new crank is marked SBBBBC. We have decifered the BBBBC part which is each of the 5 bearings, but noone knows what the S stands for. The original crank (now trash) only had 5 bearing markings on it, without the S.
Dealership says don't worry about it, but I' a little leary of putting this together with that unknown factor. Each factory main bearing also costs $36, which also hurts when you multiply it times 5. The other choice was to turn the crank .010 on the mains and use a $40 set of clevite aftermarket bearings, but then you spend the money you saved on turning the crank.  Anyway--original question is "What does the "S" stand for on the crank stampings?"
Greg
1970 Challenger convertible-in process
1970 Barracuda driver




Offline Chryco Psycho

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Re: 5.7 hemi crankshaft bearing identification
« Reply #1 on: December 11, 2007 - 10:51:04 AM »
I wish I knew  :dunno:

Challenger - You`ll wish You Hadn`t

Offline 57hemicuda

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Re: 5.7 hemi crankshaft bearing identification
« Reply #2 on: December 15, 2007 - 09:28:15 PM »
Things sure have changed since I put mine together.The 5.7 rod bearings were 2.50 each,but they were also marked ab or c,when I ordered them.I have an extra crankshaft,where are the markings,I'll look on it to see if its the same.maybe the s is just signifying that it is a standard crankshaft?http://mysite.verizon.net/ls6ron/
« Last Edit: December 15, 2007 - 09:45:39 PM by 57hemicuda »

Offline gkring

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Re: 5.7 hemi crankshaft bearing identification
« Reply #3 on: December 15, 2007 - 11:00:11 PM »
No rod bearing markings. the Mopar rod bearings are $40 a set, it's the main bearings that are pricey at $40 each. The markings are on the tone wheel. I am worried the "s" on the marking means something special for the thrust or even the rod bearings. Going to start assembling tomorrow. Machine shop said everything looked fine, but I don't think they blueprinted the motor. I will measure twice and plastigage everything.
Greg
1970 Challenger convertible-in process
1970 Barracuda driver

Offline 57hemicuda

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Re: 5.7 hemi crankshaft bearing identification
« Reply #4 on: December 16, 2007 - 09:21:30 AM »
Sorry my crank doesn't have the toner ring,used it for the LS1 engine management conversion.I would just plastic gauge everything and as long as it is within spec.,run it.I wonder how they mark the rod bearings,I had the old ones,so I was able to order them that way,but if your changing a crank?I know I had like 5 B's and 3 C's,I guess they're really trying to keep those tolerances tight.I wish you luck. Ron  http://troyboy468.smugmug.com/gallery/1315470#62041171
« Last Edit: December 16, 2007 - 09:24:19 AM by 57hemicuda »