WARNING - LONG POST
There is little to no info on here that I can find for people who have spun a cam bearing or two. If you spun #2 or #3 bearing, you can bore the hole out to fit a #1 or #4 cam bearing as they are already +0.020" larger OD than the #2 and #3 bearings. If your problem is more serious, then what are the options? I decided to contact Clevite and see what they had to offer.
I had basically a question and answer session with them on the web. Here is our texts:
Email to Clevite: I have a 3.8L turbo V6 that spun the #2 cam bearing. I understand I might can get oversized cam bearings for this engine. I need to have the cam journals in the block line bored which will make them larger ID. I assume I can get oversized OD cam bearings?
Response from Clevite: SH1448S is a set with a .020" larger OD. Make sure you have them in-hand and measured before boring the block cam bores!
Reply to their response: In my case, I had been told the #1 and #4 cam bearing was already larger OD than #2 or #3. My machinist bored out the #2 block journal to accept a replacement bearing for #1 since it was bigger OD. The cam journals in the block were not line bored. I now don't think the #2 journal is in perfect alignment with the other 3 journals. The set you recommend above, is it +.020 on all the original bearing OD's? Am I making any sense?
Response 2 from Clevite: All the bearings are the same OD on the 3.8L GM. 1.9155 to 1.9175" for the stock bearings and 1.9355" to 1.9375" for the .020" over bearings.
My reply: Just so I am not confused, please confirm: Original bearing dimensions: #1, and #4 are 1.935" OD, #2 and #3 are 1.915" OD. Your part number SH1448S is available in a 0.020" oversize. This bearing set has the following dimensions: #1 and #4 - 1.955" OD and #2 and #3 - 1.935". Do you have to specify anything special for the oversize set part number? Like SH1448S +0.020? Or does SH1448S automatically mean you are getting the .020 over bearings?
SH1448 is a bearing .020" measuring 1.9355-1.9375". SH1448S is a set for the 231, 20 bolt oil pan model and contains 2-SH1448 and two SH1361 bearings. If you need all 4 positions oversized, you'd have to order 2 sets of SH1448S and throw away the SH1361 pieces you didn't need.As long as you insure oil hole alignment, you should be fine!
I was able to confirm this with their online catalog.
One last thing. I talked with someone on this subject of line boring the cam journal bores. They said the block would bore/hone much better if all the journal bores were the same ID. The logic is you can stroke the hone much further than if you had to bore/hone the two inner ones at a different diameter. I would think it would be "easier" for a machinist to get "right" as well. The factory had the two inner journals .020" smaller ID than the outer two journals..... Applying this logic, I would think you might want to buy 2-sets of the 1448S and use only the #1's and #4's from each set to make one set of bearings (qty. of 4) that would all be 1.9375" OD. Per their recommendation, buy the bearings and give them to the machinist prior to line boring / honing the block.
Maybe this info will helpe someone down the road looking for oversized cam bearing information.
There is little to no info on here that I can find for people who have spun a cam bearing or two. If you spun #2 or #3 bearing, you can bore the hole out to fit a #1 or #4 cam bearing as they are already +0.020" larger OD than the #2 and #3 bearings. If your problem is more serious, then what are the options? I decided to contact Clevite and see what they had to offer.
I had basically a question and answer session with them on the web. Here is our texts:
Email to Clevite: I have a 3.8L turbo V6 that spun the #2 cam bearing. I understand I might can get oversized cam bearings for this engine. I need to have the cam journals in the block line bored which will make them larger ID. I assume I can get oversized OD cam bearings?
Response from Clevite: SH1448S is a set with a .020" larger OD. Make sure you have them in-hand and measured before boring the block cam bores!
Reply to their response: In my case, I had been told the #1 and #4 cam bearing was already larger OD than #2 or #3. My machinist bored out the #2 block journal to accept a replacement bearing for #1 since it was bigger OD. The cam journals in the block were not line bored. I now don't think the #2 journal is in perfect alignment with the other 3 journals. The set you recommend above, is it +.020 on all the original bearing OD's? Am I making any sense?
Response 2 from Clevite: All the bearings are the same OD on the 3.8L GM. 1.9155 to 1.9175" for the stock bearings and 1.9355" to 1.9375" for the .020" over bearings.
My reply: Just so I am not confused, please confirm: Original bearing dimensions: #1, and #4 are 1.935" OD, #2 and #3 are 1.915" OD. Your part number SH1448S is available in a 0.020" oversize. This bearing set has the following dimensions: #1 and #4 - 1.955" OD and #2 and #3 - 1.935". Do you have to specify anything special for the oversize set part number? Like SH1448S +0.020? Or does SH1448S automatically mean you are getting the .020 over bearings?
SH1448 is a bearing .020" measuring 1.9355-1.9375". SH1448S is a set for the 231, 20 bolt oil pan model and contains 2-SH1448 and two SH1361 bearings. If you need all 4 positions oversized, you'd have to order 2 sets of SH1448S and throw away the SH1361 pieces you didn't need.As long as you insure oil hole alignment, you should be fine!
I was able to confirm this with their online catalog.
One last thing. I talked with someone on this subject of line boring the cam journal bores. They said the block would bore/hone much better if all the journal bores were the same ID. The logic is you can stroke the hone much further than if you had to bore/hone the two inner ones at a different diameter. I would think it would be "easier" for a machinist to get "right" as well. The factory had the two inner journals .020" smaller ID than the outer two journals..... Applying this logic, I would think you might want to buy 2-sets of the 1448S and use only the #1's and #4's from each set to make one set of bearings (qty. of 4) that would all be 1.9375" OD. Per their recommendation, buy the bearings and give them to the machinist prior to line boring / honing the block.
Maybe this info will helpe someone down the road looking for oversized cam bearing information.
