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Joined: Apr 2011
Posts: 12
Grease Monkey
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Grease Monkey
Joined: Apr 2011
Posts: 12 |
Can anyone give me the standard sizes for the three main bearing journals on the crankshaft of a 1930 Chevrolet six? The one I am working on is as follows:
Front: 1.927-1.934 (has some wear);
Center: 1.990-1.9935
Rear: 2.054-2.059
I need to get this one turned, but also need to know what the standard size is supposed to be, so I know how much off this one is.
Thanks for any help. It's not in the maintenance manual.
Pete Phillips
Leonard, Texas
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Joined: Jan 2002
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ChatMaster - 25,000
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ChatMaster - 25,000
Joined: Jan 2002
Posts: 30,701 Likes: 141 |
front to rear, 1.937, 2.00, 2.062"
Gene Schneider
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Joined: Apr 2011
Posts: 12
Grease Monkey
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Grease Monkey
Joined: Apr 2011
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Gene,
Thanks so much.
Pete Phillips
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Joined: Apr 2011
Posts: 12
Grease Monkey
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OP
Grease Monkey
Joined: Apr 2011
Posts: 12 |
Now the machine shop is asking me for a high number and a low number for the main bearing journal diameter before they can regrind the crankshaft. And for the rod bearing journal diameter.
This engine has been such an ordeal to get rebuilt, and specifications like this are just not available in the repair manual or on the internet--I don't understand why. Any help appreciated.
Pete Phillips
Leonard, Texas
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Joined: Nov 2002
Posts: 3,163
ChatMaster - 3,000
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ChatMaster - 3,000
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When I had the 33 engine done here in Tucson, the engine builder had the crank grinder turn the journals round as he had to pour & fit each rod & main anyways...Joe
See America's First...Chevrolet
1931 Sedan Delivery 31570
1933 Standard Sports Coupe 33628.
1934 Master Sedan Delivery Canadian 177/34570
1968 Z/28 Camaro
1969 SS 396 Camaro
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Joined: Nov 2002
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ChatMaster - 7,000
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ChatMaster - 7,000
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The crank only needs to be reground the minimum it takes to get it round and smooth with no scoring. Then the main and rod bearings are fitted to match. They will need to be oversize babbited and the mains line bored. If the shop you are using is asking these questions I would have serious concerns about their ability to do a good job. This is explained in the 29-32 repair manual .
Steve D
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Joined: Nov 2001
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Tech Advisor ChatMaster - 25,000
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Tech Advisor ChatMaster - 25,000
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The Mangy Old Mutt
"If It's Not Junk.....It's Not Treasure!"
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