main bearings ????
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Senior User
Joined: Jan 2007
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From: modesto,ca
main bearings ????
just got 390 from machine shop, with master rebuild kit. putting in main bearings, noticed oil holes not lining up properly, all holes in block are off center, all holes in bearings are in center. the bearing are clevette 77 all .010. this block was re-done from a 360 to a 390.
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It's okay (and normal) that they don't line up exactly. Not sure exactly why, but it has something to do with the machining of the block. Use the shank end of a drill bit to ensure that the following opening is available in the appropriate oil holes:
1: 7/64
2: 9/64
3: 9/32
4: 5/32
5: 9/32
As per Steve Christ's "How to Rebuild Big Block Ford Engines" (which I'd highly recommend you'd pick up).
1: 7/64
2: 9/64
3: 9/32
4: 5/32
5: 9/32
As per Steve Christ's "How to Rebuild Big Block Ford Engines" (which I'd highly recommend you'd pick up).
Hotshot
Joined: May 2003
Posts: 11,141
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From: south louisiana
Yea that's what I did on my last 390. I opened the passage from the pump to the filter mount up, and chamfered all the passage corners and the main bearing misalignment with a die grinder and porting bits. I also installed restrictors under the rocker stands.
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Brett Foote
Fleet Mechanic
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From: Iowa
Like baddad said, be sure to get the shavings out of the oiling system, or you'll destroy those new bearings when you start that 390.
The modification is not nesessary for a stock built engine. There are original 30+ year old 390's running around today with mis-matched oiling holes. When you start turning serious rpm's and making gobs of power, then maximizing the oiling system is key.
My opinion, of course...
The modification is not nesessary for a stock built engine. There are original 30+ year old 390's running around today with mis-matched oiling holes. When you start turning serious rpm's and making gobs of power, then maximizing the oiling system is key.
My opinion, of course...
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Senior User
Joined: Jan 2007
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From: modesto,ca
this is basically a rebuilt stock 390, the only addition is a edelbrock cam at .494 lift with edelbrock intake and new double timing chain with a holley 2 bbl at 550 cfm
and also i want to thank all who have answered my question
and also i want to thank all who have answered my question
Post Fiend
Joined: Sep 2006
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From: Island Southeast Alaska
Sounds like a strong daily driver. Don't now much about cam specs but that seem high to me. Will it idle smooth? my 390 with 427 rotating assembly and RV type cam starts and idles while warming up. Than it flat hauls.
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From: In the Middle
Originally Posted by shauk
As per Steve Christ's "How to Rebuild Big Block Ford Engines" (which I'd highly recommend you'd pick up).
.
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Senior User
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From: modesto,ca
with this cam, it will rock the truck side to side, this is the same cam and top end i had on my 360 block. when im going down the highway it also flattens out. but with my dual exhaust with 45 deg turn down after the mufflers, u can hear me coming up and wave as i pass ya. lol
the only draw back is the low geared rear end. eventually this will be replaced at a later date. for now the gas mileage is only about 6-7mpg
the only draw back is the low geared rear end. eventually this will be replaced at a later date. for now the gas mileage is only about 6-7mpg
FE "Freakin Expensive"
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From: Smith Mountain Lake, VA
Well actually those offset main hole's were made for a purpose..To restrict some of the lower end Oiling and keep it up on top at the shaft rockers and Valvetrain...
But with guys running upgraded Rockers and Valvetrain components of today, we dont need all that Oil on the top end..So the Bearings are either chamfered to let in more oil, Or the holes are opened up to keep more oiling to the Mains for High rpm motors, and motors that are drivin under harsh conditions!! Like me! LOL
RJ
But with guys running upgraded Rockers and Valvetrain components of today, we dont need all that Oil on the top end..So the Bearings are either chamfered to let in more oil, Or the holes are opened up to keep more oiling to the Mains for High rpm motors, and motors that are drivin under harsh conditions!! Like me! LOL
RJ