| Another spun rod bearing [message #371311] |
Sat, 06 May 2023 18:52  |
bwevers
Messages: 597
Registered: October 2010
Location: San Jose
Karma: 5
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I'm at a loss to figure out why this happened again. My 455 spun the #7 rod bearing while cruising on Interstate 5 near Los Banos. This engine had more than 10,000 miles on it since the last rebuild. The crankshaft was turned .010/.010" by a reputable shop. And this engine had previously spun the same rod bearing 7 years ago. It has a high-volume oil pump. I had changed the oil within the last 3000 miles. The oil pressure was good, 40 PSI hot. Usually I get 60 PSI cold oil pressure, using 15W/40 Delo. I'm thinking maybe the rod bearing clearance was too tight.
Bill Wevers GMC49ers, GMC Western States
1975 Glenbrook - Manny Powerdrive, OneTon
455 F Block, G heads
San Jose
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| Re: Another spun rod bearing [message #371313 is a reply to message #371312] |
Sun, 07 May 2023 11:35  |
bwevers
Messages: 597
Registered: October 2010
Location: San Jose
Karma: 5
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The crankshaft is toast. I ordered a new Eagle crank 104554260, standard stroke. They said it has to be balanced. The bob weights are lighter than stock.
Bill Wevers GMC49ers, GMC Western States
1975 Glenbrook - Manny Powerdrive, OneTon
455 F Block, G heads
San Jose
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| Re: Another spun rod bearing [message #371314 is a reply to message #371311] |
Sun, 07 May 2023 12:20 |
roy1
Messages: 2126
Registered: July 2004
Location: Minden nevada
Karma: 6
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Bill #7 and #8 are what usually spin on a 455. You probably checked the clearance on the crank when you last put it together. I’m sure it was spotlessly clean and you used assembly lube. Did you bypass the old oil cooler and add a new air over cooler? In my opinion it is not likely you could get all the metal out of the old cooler all it takes is one little metal particle to damage a bearing. Had an almost new aluminum radiator flushed it back and forth for a week hours each day never got it 100% clean. On my last engine I blocked off the old cooler added an air over cooler and had the new bearings sent to North Carolina coated with a nascar coating as an extra precaution . I drove the coach a couple thousand miles before selling it the new owner went from Oregon to Key West and back trouble free … Roy ( hope you got the throttle fixed in your Alpine)
Roy Keen
Minden,NV
76 X Glenbrook
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| Re: Another spun rod bearing [message #371316 is a reply to message #371311] |
Sun, 07 May 2023 13:14 |
JohnL455
Messages: 4447
Registered: October 2006
Location: Woodstock, IL
Karma: 12
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Since our fuel rate is roughly 2x what the 455 experiences in the Toronado, as well as more revs pre mile with 3.55, 3.70 etc my humble opinion is 3000 miles is like 6000 miles of car service and too long on an oil change. I try not to exceed 2000 miles when possible. Also even with T6 full syn, I always see oil consumption increase after 2000 miles on the oil, which I think indicates it’s time to drain. May I ask what filter you were using as the Wix 51258 has no bypass.
John Lebetski
Woodstock, IL
77 Eleganza II
[Updated on: Sun, 07 May 2023 13:17] Report message to a moderator |
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| Re: Another spun rod bearing [message #371317 is a reply to message #371316] |
Sun, 07 May 2023 19:06 |
Carl S.
Messages: 4186
Registered: January 2009
Location: Tucson, AZ.
Karma: 13
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You may need to put restrictors in the cam bearings so you get more oil into the bottom end. Also, due to the larger size of the main bearings on a 455, they require more clearance and a somewhat heavier oil than most engines. I don't know how that affects the rod bearings.
Carl Stouffer
'75 ex Palm Beach
Tucson, AZ.
Chuck Aulgur Reaction Arm Disc Brakes, Quadrabags, 3.70 LSD final drive, Lenzi knuckles/hubs, Dodge Truck 16" X 8" front wheels, Rear American Eagles, Solar battery charging. GMCSJ and GMCMI member
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| Re: Another spun rod bearing [message #371318 is a reply to message #371311] |
Sun, 07 May 2023 21:18 |
bwevers
Messages: 597
Registered: October 2010
Location: San Jose
Karma: 5
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Roy, I put in an external oil cooler in front of the radiator. Also, put a heavier spring in the oil filter bypass (was 5.7 PSI now 20 PSI).
John, I had a Mobile1 M1-203 oil filter on it.
Carl, The shop drilled the cam bearings with smaller oil feed holes and installed them rotated with the oil gallery feeding the newly drilled holes. I don't know what size drill he used.
Bill Wevers GMC49ers, GMC Western States
1975 Glenbrook - Manny Powerdrive, OneTon
455 F Block, G heads
San Jose
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| Re: Another spun rod bearing [message #371320 is a reply to message #371311] |
Mon, 08 May 2023 08:59 |
JohnL455
Messages: 4447
Registered: October 2006
Location: Woodstock, IL
Karma: 12
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The basic Wix has a 21 micron rating. The Mobil 1, from what I can find, has a 30 micron rating. They, like Wix XP get the longer life by filtering less small particles. The Wix XP has no micron rating from Wix. That says a lot! 30 microns won’t block an oil passage to a rod bearing, but the larger particles will in my opinion cause more wear on sliding surfaces like rings and walls. The Mobil does not have a bypass which is like the Wix and I prefer. Just bringing this all up as I too have had a rod bearing failure years ago and and trying to find a common cause.
John Lebetski
Woodstock, IL
77 Eleganza II
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| Re: Another spun rod bearing [message #371323 is a reply to message #371318] |
Mon, 08 May 2023 12:05 |
Carl S.
Messages: 4186
Registered: January 2009
Location: Tucson, AZ.
Karma: 13
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bwevers wrote on Sun, 07 May 2023 19:18
Carl, The shop drilled the cam bearings with smaller oil feed holes and installed them rotated with the oil gallery feeding the newly drilled holes. I don't know what size drill he used.
Okay, that's what they did on mine as well. The rebuild now has over 30,000 miles on it over a five year period and is still going strong. Like I said, they set up the bearing clearances for heavier oil and recommended 20W50, which is what I have always used in it anyway.
Carl Stouffer
'75 ex Palm Beach
Tucson, AZ.
Chuck Aulgur Reaction Arm Disc Brakes, Quadrabags, 3.70 LSD final drive, Lenzi knuckles/hubs, Dodge Truck 16" X 8" front wheels, Rear American Eagles, Solar battery charging. GMCSJ and GMCMI member
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