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#1
11-14-2010, 02:32 PM
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Bearing inspection Q
I just pulled the caps after about 3K on the motor the thrust bearing looks ugly on both sides, also bearing (all) have light scratches.Normal? I dont know what good used bearing should look like. it is a 4spd if that matters Thanks - Ryan
__________________
 1970 gto (4spd) 462 500 hp 11.940@114.21 / 1.843 60'/ 3980 lbs 1964 corvette roadster 1968 corvette roadster 1962 corvette "equal rights, not equal things" if you want to know the future, read "atlas shrugged" I dont race a 4spd because it is easy, I race a 4spd because it is hard. 
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#2
11-14-2010, 03:01 PM
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They look pretty good to me. The front and back look like that when new. Copper colored from the start.
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Come take a ride http://www.youtube.com/watch?v=P7Y8Awfk2I0 2008, 2013, 2015, 2016, 2019 Central Il Dragway Mod track champion and 2015 IHRA Div 5 Mod champion 
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#3
11-14-2010, 04:06 PM
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4 speed car will have more thrust bearing wear vs a stock automatic trans car. You are pushing the clutch/ crank against the thrust every time you shift. High spring pressure clutch housings have even more wear as it takes even more force to free up the clutch disc from the clamping force.
Pictures are not that great but basic inspection looks "normal" Tom Vaught
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"Engineers do stuff for reasons" Tom Vaught Despite small distractions, there are those who will go Forward, Learning, Sharing Knowledge, Doing what they can to help others move forward. |
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#4
11-14-2010, 06:18 PM
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What was/is the measured endplay?
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#5
11-14-2010, 06:31 PM
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Parting line shows evidence of cap walk.Bill C.
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Checkered Flag Machine & Ceralli Competition Engines Racing engines and induction development http://www.checkeredflagmachine.net/ |
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#6
11-14-2010, 07:29 PM
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andyleonard
already apart, only measured endplay when i built it 4 years ago, i thought it was .003? cfmcnc: when i bought the block it came with a collection of mismatched caps, so when they line bored the block they did some work on the caps too. is that what you are seeing? i am using arp studs. this motor rarely saw 6K.
__________________
1970 gto (4spd) 462 500 hp 11.940@114.21 / 1.843 60'/ 3980 lbs 1964 corvette roadster 1968 corvette roadster 1962 corvette "equal rights, not equal things" if you want to know the future, read "atlas shrugged" I dont race a 4spd because it is easy, I race a 4spd because it is hard.
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#7
11-14-2010, 09:37 PM
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Until you measure the endplay you're just guessing as to whether anything's actually wrong with the thrust bearing. Simply knowing its "ugly" isn't going to help us help you. Maybe the last man in there put it up against his disc sander. Put the shells back in the block, drop the crank in and tighten up the thrust saddle. Stick a feeler gauge in there and work the crank back and forth until you get a measurement. It should be around .006. If it's not, tell us.
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#8
11-14-2010, 11:40 PM
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The one side of the thrust bearing look great to me - your two side views are of the same side. The scratches present in the bearing were probably all there at the end of your initial break-in run. Grit left in oil passages and hard to reach corners all comes loose with the hot oil and circulates until either permanently embedded in the Babbitt material or trapped by the oil filter. I'll leave it up to the experts, but I'd probably bolt them back up and run them.
Any specific problems why you tore the engine down?
__________________
Mick Batson 1967 original owner Tyro Blue/black top 4-speed HO GTO with all the original parts stored safely away -- 1965 2+2 survivor AC auto -- 1965 Catalina Safari Wagon. |
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#9
11-15-2010, 10:30 AM
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Quote:
If it's a complete tear down. I would have the line bore rechecked to make sure everything is settled. |
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#10
11-15-2010, 05:51 PM
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Quote:
__________________
1970 gto (4spd) 462 500 hp 11.940@114.21 / 1.843 60'/ 3980 lbs 1964 corvette roadster 1968 corvette roadster 1962 corvette "equal rights, not equal things" if you want to know the future, read "atlas shrugged" I dont race a 4spd because it is easy, I race a 4spd because it is hard.
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#11
11-15-2010, 05:53 PM
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Quote:
__________________
1970 gto (4spd) 462 500 hp 11.940@114.21 / 1.843 60'/ 3980 lbs 1964 corvette roadster 1968 corvette roadster 1962 corvette "equal rights, not equal things" if you want to know the future, read "atlas shrugged" I dont race a 4spd because it is easy, I race a 4spd because it is hard.
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#12
11-15-2010, 10:06 PM
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For $60 I'd replace the mains with new and save the ones you took out for the shop truck beater motor. They're too good to throw away and not nice enough to put back in a motor that's torn down. FWIW.
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#13
11-15-2010, 10:11 PM
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Quote:
__________________
1970 gto (4spd) 462 500 hp 11.940@114.21 / 1.843 60'/ 3980 lbs 1964 corvette roadster 1968 corvette roadster 1962 corvette "equal rights, not equal things" if you want to know the future, read "atlas shrugged" I dont race a 4spd because it is easy, I race a 4spd because it is hard.
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#14
11-16-2010, 12:38 AM
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http://www.enginebuildermag.com/Arti...g_failure.aspx
Go search the mod of grinding an angle on the joining thrust faces. And don't forget to tap the thrust cap rearward before tightening and THEN checking thrust clearance. IIRC .006 is what the book wants. |
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