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Author
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Topic: Check out the bearing wear...
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Rustang
Gearhead Posts: 805
From: Clarion PA
Registered: Nov 2000
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posted 03-09-2005 11:10 AM
   
Just as soon as I figure out how to post the pics 
[This message has been edited by Rustang (edited 03-09-2005).][This message has been edited by Rustang (edited 03-09-2005).] [This message has been edited by Rustang (edited 03-09-2005).] [This message has been edited by Rustang (edited 03-09-2005).]
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Rustang
Gearhead Posts: 805
From: Clarion PA
Registered: Nov 2000
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posted 03-09-2005 02:47 PM
This is probably the one that I'm wondering about the most. The upper bearings all show thru to the copper next to the crank radius. Also across the bearing near 11:00 the bearing surface looks "smeared". This is typical of all 8 upper bearings. This is in a 347, chevy v6 bearings, eagle crank, GRP aluminum rods, after 16 passes.
 ------------------
'68 mustang 351 clevor- 10.92@124
'67 Stang, 351W -11.18@118
'69 351C Torino-14.90@100
'78 Pickup 351W-15.56@88
'79 Pickup 460 ET=??
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n2oMike
Gearhead Posts: 2694
From: Spencer, WV
Registered: Jan 2001
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posted 03-09-2005 03:31 PM
Did both these bearings come off the same rod?If so, it looks like a bent rod. If you put those bearing halves together, see how one end of the bottom and the opposite end of the top are worn away? A bent rod would do that. You might want to check. ------------------
Mike Burch
66 mustang real street
302 4-speed 289 heads
10.63 @ 129.3
http://www.geocities.com/carbedstangs/cmml_mburch.html
http://www.fortunecity.com/silverstone/healey/367
http://www.mustangworks.com/cgi-bin/moi-display.cgi?220
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Rustang
Gearhead Posts: 805
From: Clarion PA
Registered: Nov 2000
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posted 03-09-2005 03:53 PM
Mike,
They're both off the same rod. All the rest are showing similar wear.I don't know if you can see it in the pics or not, but on the same side the copper's showing, both halves have a polished appearance for about the first 1/8" in from the chamfered edge. The only other thing I've noticed is the crank journals are about .0005" larger on the diameter near the journal radius than what they are near the journal's center.
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n2oMike
Gearhead Posts: 2694
From: Spencer, WV
Registered: Jan 2001
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posted 03-09-2005 04:25 PM
Oh, the worn part of the bearings are both on the SAME side, and are both toward the journal radius side of the crank... That's easy.  Aftermarket cranks often have wider fillet radius than stock. This causes unmodified bearings to rub on the raius. This can choke off the oil supply and cause the bearing to spin. You got LUCKY! You'll need to buy bearings that have that corner chamfered off, or take a knife or something to a stock set and knock the corner down where it fits the crank journal better. (of course you'll have to smooth it all out when you are finished) I'd probably just purchase a set of racing bearings. Most of those are already clearanced for aftermarket cranks with the larger radius. Alex might be able to give you a specific number reference. Check your rod side clearance next time, as that should have given you an indication something wasn't right. You should also be able to wiggle the rod when it is right up against the side of the crank just as much as at the middle. Good Luck! ------------------
Mike Burch
66 mustang real street
302 4-speed 289 heads
10.63 @ 129.3
http://www.geocities.com/carbedstangs/cmml_mburch.html
http://www.fortunecity.com/silverstone/healey/367
http://www.mustangworks.com/cgi-bin/moi-display.cgi?220 [This message has been edited by n2oMike (edited 03-09-2005).]
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Rustang
Gearhead Posts: 805
From: Clarion PA
Registered: Nov 2000
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posted 03-09-2005 04:38 PM
Actually, the bearings have already been chamfered. When you put them in the rod half on the journal up against the radius, they appear to clear. However the crank's journals seem to get larger by .0005 before the radius begins. I don't know if that would cause this wear or not.
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Mpcoluv
Gearhead Posts: 1333
From: Charlotte NC usa
Registered: Apr 2001
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posted 03-10-2005 12:37 PM
I had wear like that due to the big end of the rods being .001 too tight.
POOR MACHINING was the cause.
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Rustang
Gearhead Posts: 805
From: Clarion PA
Registered: Nov 2000
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posted 03-10-2005 01:18 PM
quote:
Originally posted by Mpcoluv:
I had wear like that due to the big end of the rods being .001 too tight.
POOR MACHINING was the cause.
I know Eagle has a reputation for less than perfect machining. I just don't know if the .0005 dia at the outer edges of the journal would cause it. There's alot of things that have gone on in those 16 passes- 1 pass the motor was pretty hot, 1 pass I locked up the engine at the top of second gear when the tranny went into reverse  and with the aluminum rods maybe I didn't have enough heat in the motor before I started zinging it 
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