Premature main engine bearing failure mystery
01-01-2017 | 11:44 AM
#71
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Joined: Nov 2005
Posts: 2,399
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From: Toronto, Canada
so.. first of all where are you taking your oil temp reading? at filter head or from the cooler? what is your main bearing clearance and who's bearing are you using? this may have already been answered but I'm not backtracking thru 7 pages of posts to find it lol...
main bearing clearance when using thick oil (25/40, 20/50, etc) must be significant.. in other words enough clearance to allow the oil to do its work...
main bearing clearance when using thick oil (25/40, 20/50, etc) must be significant.. in other words enough clearance to allow the oil to do its work...
01-01-2017 | 01:20 PM
#72
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Joined: Feb 2009
Posts: 8,356
Likes: 1,515
From: NW Michigan
I ran 509's at 650 HP with stock Merc oil lines and acc. with NO oil flow problems. This was the larger cooler ( 3 inch dia.) and hoses that come on the 502 HP.
And WHY is anyone with a non stock engine running the oil bypass. I removed, tapped and plugged mine.
ALSO
90 hrs X 50 MPH = 4500 miles
since when
most cars at 50 MPH are at 1500 RPM.
Boats cruise at 3500 RPM at 50 MPH
At 3500 a car would be at or above 100 MPH
Lets see you run your car at 3500 RPM for 90 hours and see how it lasts.
And WHY is anyone with a non stock engine running the oil bypass. I removed, tapped and plugged mine.
ALSO
90 hrs X 50 MPH = 4500 miles
since when
most cars at 50 MPH are at 1500 RPM.
Boats cruise at 3500 RPM at 50 MPH
At 3500 a car would be at or above 100 MPH
Lets see you run your car at 3500 RPM for 90 hours and see how it lasts.
A nickel works fine also. Ha. Also BB touched on it it think however is it possible raw water pump has an impeller ready to go an maybe not pumping enough cool water through the engine causing to heat up...
01-01-2017 | 01:31 PM
#73
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Joined: Aug 2002
Posts: 306
Likes: 6
From: Roanoke VA
so.. first of all where are you taking your oil temp reading? at filter head or from the cooler? what is your main bearing clearance and who's bearing are you using? this may have already been answered but I'm not backtracking thru 7 pages of posts to find it lol...
main bearing clearance when using thick oil (25/40, 20/50, etc) must be significant.. in other words enough clearance to allow the oil to do its work...
main bearing clearance when using thick oil (25/40, 20/50, etc) must be significant.. in other words enough clearance to allow the oil to do its work...
01-01-2017 | 01:37 PM
#74
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Registered
Joined: Aug 2002
Posts: 306
Likes: 6
From: Roanoke VA
I ran 509's at 650 HP with stock Merc oil lines and acc. with NO oil flow problems. This was the larger cooler ( 3 inch dia.) and hoses that come on the 502 HP.
And WHY is anyone with a non stock engine running the oil bypass. I removed, tapped and plugged mine.
ALSO
90 hrs X 50 MPH = 4500 miles
since when
most cars at 50 MPH are at 1500 RPM.
Boats cruise at 3500 RPM at 50 MPH
At 3500 a car would be at or above 100 MPH
Lets see you run your car at 3500 RPM for 90 hours and see how it lasts.
And WHY is anyone with a non stock engine running the oil bypass. I removed, tapped and plugged mine.
ALSO
90 hrs X 50 MPH = 4500 miles
since when
most cars at 50 MPH are at 1500 RPM.
Boats cruise at 3500 RPM at 50 MPH
At 3500 a car would be at or above 100 MPH
Lets see you run your car at 3500 RPM for 90 hours and see how it lasts.
01-01-2017 | 07:16 PM
#76
Gold Member
Joined: Oct 2005
Posts: 11,688
Likes: 216
From: Olmsted Falls,Ohio Marblehead,Oh
rods or mains? both? and I can tell you right now if your running 20-50 thats too tight, especially at the back of the engine...
rods would be fine, mains will eventually have issues, if running 20-50..
rods would be fine, mains will eventually have issues, if running 20-50..
01-01-2017 | 08:10 PM
#77
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Joined: Oct 2007
Posts: 8,439
Likes: 93
From: yorkville,il
rule of thumb is .001 per inch of journal dia for standard engine,bigger for more power..0027 for rods .0033 for mains makes me happy on a bbc.a little more is ok if the rest of the oiling system is correct.edit in,my honda accord uses 0w20 synthetic,when i looked up the bearing clearance on the v6 engine i almost chit my pants.
Last edited by mike tkach; 01-01-2017 at 08:14 PM.
01-01-2017 | 08:26 PM
#78
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Joined: Apr 2005
Posts: 2,150
Likes: 15
From: Northport N.Y.
rule of thumb is .001 per inch of journal dia for standard engine,bigger for more power..0027 for rods .0033 for mains makes me happy on a bbc.a little more is ok if the rest of the oiling system is correct.edit in,my honda accord uses 0w20 synthetic,when i looked up the bearing clearance on the v6 engine i almost chit my pants.
01-01-2017 | 08:45 PM
#80
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Joined: Oct 2007
Posts: 8,439
Likes: 93
From: yorkville,il
i think i will go with 5w20 in the summer and stick with the 0w20 in the winter.it currently has 70 k on it.i change it every 5 k.my neighbor used 5w30 in his honda pilot for years and it called for 0w20.who knows if it really matters?i sure don,t.
