Re: engine builders, bearing clearance?
[Re: 68roadrunner]
#458657
09/03/09 09:58 PM
09/03/09 09:58 PM
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Anonymous
Unregistered
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Anonymous
Unregistered
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minimum .001 per inch of journal diameter is generally safe. more info would be needed to make an actual recommendation though.
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Re: engine builders, bearing clearance?
[Re: 68roadrunner]
#458659
09/04/09 12:32 AM
09/04/09 12:32 AM
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Joined: Aug 2003
Posts: 43,129
Bend,OR USA
Cab_Burge
I Win
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I Win
Joined: Aug 2003
Posts: 43,129
Bend,OR USA
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Aluminum rods or steel? When it comes to bearing clearances your way better off having them a 1/2 thousnad to loose than 1/4 thousand to tight. Use what dram recommended  Or looser  BTW, I like thin oil also, 5w20 or 5w30, especially in a drag motor that never gets the oil hot 
Mr.Cab Racing and winning with Mopars since 1964. (Old F--t, Huh)
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Re: engine builders, bearing clearance?
[Re: Cab_Burge]
#458660
09/04/09 03:23 AM
09/04/09 03:23 AM
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Joined: Jan 2003
Posts: 9,986
Frostbitefalls MN (Rocky&Bullw...
gregsdart
master
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master
Joined: Jan 2003
Posts: 9,986
Frostbitefalls MN (Rocky&Bullw...
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Ran my 499 a tad loose at .0027 to .0028 on the mains, rods about .0025 to .0027 aluminum rods. 20w50 oil, safest for the power level you will be at.
Last edited by gregsdart; 09/04/09 03:24 AM.
8..603 156 mph best, 2905 lbs 549, indy 572-13, alky
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Re: engine builders, bearing clearance?
[Re: 68roadrunner]
#458662
09/04/09 08:19 AM
09/04/09 08:19 AM
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Joined: Nov 2003
Posts: 3,060
Western New York
sixpackbee
master
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master
Joined: Nov 2003
Posts: 3,060
Western New York
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For your engine I would run about what the others have said, .0025-.003, with a thicker oil. Just an FYI on class engines I run about .0015 clearance with real thin oils.
1959 Bugeye Sprite
1967 Charger Black L code
1967 Coronet R/T Convert Green 440 auto bought from original owner
1968 Charger R/T Bronze 440 4 spd console AM/FM
1969 Super Bee WM21H B5 A40 D21 N96
1969 Barracuda Formula S 340 Convert pilot car
1969 Hemi Road Runner RM23J D32 Omaha orange 4.10 Dana N96 N85
1970 Super Bee WM23N FE5 V1X 3.91 axle package, N96
1970 Road Runner RM21N B3 V1X D13
1971 MG Midget
1971 Road Runner RM23H GW3, A57
1972 Road Runner RM23P FY1, D21
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Re: engine builders, bearing clearance?
[Re: 68roadrunner]
#458665
09/05/09 10:58 AM
09/05/09 10:58 AM
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Joined: Jan 2003
Posts: 16,923
NC
440Jim
I Live Here
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I Live Here
Joined: Jan 2003
Posts: 16,923
NC
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Quote:
if i go .003 on rods and mains both, and run a 50w or 20-50 oil this will be ok on a bracket motor? thanks guys
That does seem like a lot for the rods. Are you running steel rods or aluminum? Are they 2.200" or 2.375" journals? It will give more oil flow to the rods for cooling.
I wouldn't run straight 50 oil on a "mild" bracket motor unless you have a good reason. 20W-50 would be fine, IMO.
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Re: engine builders, bearing clearance?
[Re: 440Jim]
#458667
09/06/09 11:04 AM
09/06/09 11:04 AM
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Joined: Jun 2009
Posts: 877
ky
68roadrunner
OP
super stock
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OP
super stock
Joined: Jun 2009
Posts: 877
ky
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Quote:
Quote:
if i go .003 on rods and mains both, and run a 50w or 20-50 oil this will be ok on a bracket motor? thanks guys
That does seem like a lot for the rods. Are you running steel rods or aluminum? Are they 2.200" or 2.375" journals? It will give more oil flow to the rods for cooling.
I wouldn't run straight 50 oil on a "mild" bracket motor unless you have a good reason. 20W-50 would be fine, IMO.
steel eagle, 2.375 i suppose at .0025 i would be closer to the .001 per inch rule.
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The single wieght oil can make as much as 10 HP loss or gain depending on oil temp. differences, that is why I run 5w20 or 5w30 in my motors now. 10 HP is usually a tenth of a second defference at the track