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View Full Version : HELP! Big end bore spec

Davis
March 5th, 2010, 12:27 PM
I have my connecting rods at the machine shop getting inspected and they need to know the big end bore (4.6l) but I don't have my manual--can someone let me know if they have theirs handy?
Antichrist
March 5th, 2010, 01:01 PM
RAVE says
Davis
March 5th, 2010, 01:06 PM
That gives us the crankshaft journal diameter, but they are checking my rods and resizing the big ends--can't find the spec for that anywhere! Help if you know it. THanks!
Antichrist
March 5th, 2010, 01:22 PM
Oh, sorry. I don't see oversize OD bearings in Microcat, so don't know what to tell you.
Ren Ching
March 5th, 2010, 01:53 PM
journal diameter + (recommended clearance x 2)+(bearing shell thickness x 2)?. I've had big ends reground where the caps got mixed up. Didn't ask for any figures I guess they just took off as little as possible. Plastigaged everything on re assembly and we were fine. i know that is not the answer you are looking for, sorry.

That gives us the crankshaft journal diameter, but they are checking my rods and resizing the big ends--can't find the spec for that anywhere! Help if you know it. THanks!
Antichrist
March 5th, 2010, 02:06 PM
For some engines you can get oversize OD bearings, like my Perkins, but I've never seen any for Rover V8's. Then again I've never looked really hard either. The factory engine manual doesn't even mention checking rod big end dimensions.
o2batsea
March 5th, 2010, 02:44 PM
Don't allow them to do anything but mike the rod ends for roundness. I don't think there's anything else that can be done to them. If they are out of round they should be replaced.
Davis
March 5th, 2010, 05:43 PM
2.315" in case someone needs it. And yes, there are procedures for correcting rods--it happens all the time that they get trued up. Just couldn't find the value anywhere.
Ren Ching
March 6th, 2010, 09:20 AM
I think what they do is mill a bit off the mating surface of the rod cap. Then they can rebore the interior to the correct size. Same can be done with main bearing bores

2.315" in case someone needs it. And yes, there are procedures for correcting rods--it happens all the time that they get trued up. Just couldn't find the value anywhere.
Davis
March 6th, 2010, 11:20 AM
Yep--that is correct. Thing is, this number is not printed in any RAVE or any of the engine rebuild manuals. One would think it might be handy to have printed there but...