Re: How much can you bore a 360?
[Re: KGorney]
#260568
03/21/09 11:16 AM
03/21/09 11:16 AM
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Joined: Nov 2003
Posts: 36,040
Lincoln Nebraska
RapidRobert
Circle Track
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Circle Track
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Posts: 36,040
Lincoln Nebraska
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.060" would "probably" be Ok but I'd have it sonic checked. It doesn't cost that much & with the block being the foundation & you wouldn't want to go any further with machining $$$ without knowing that your core is going to be good. I dont assume anything these days. Been bit too many times
live every 24 hour block of time like it's your last day on earth
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Re: How much can you bore a 360?
[Re: KGorney]
#260573
03/21/09 05:07 PM
03/21/09 05:07 PM
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Joined: Jun 2005
Posts: 30
Louisville Ky.
Pir8Darryl
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member
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Posts: 30
Louisville Ky.
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The 360 is one of the very rare engines that can handle a big overbore with no problems... Provided it's one cast after 1975.
When the 360 was released in 1970, it used it's own unique sand casting molds, but there were problems as the longer stroke would side-load the pistons and casue the block to crack in the main web area.
To remidy the problem, Mopar re-designed the casting by using the 340 internal cylinder molds, and adding additional meat in the main web areas.
Since the later 360 uses the 340 mold cores, if you bore it out to 4.04 [.040 over], it's just a standard 340 bore... But there's lots more meat to exploit if you choose.
Back in the late 70's and early 80's, there were a few guys who bored the 360 block .130 over, and use ford 428 flattop pistons for a 383 small block.
Needless to say, if your gonna hog out the holes like that, it's going to need to be sonic checked to find the center of the casting... But there is enough meat there to do it.
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Re: How much can you bore a 360?
[Re: Pir8Darryl]
#260574
03/22/09 01:53 AM
03/22/09 01:53 AM
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Joined: Dec 2003
Posts: 2,042
Leucadia, Ca.
vdriver
top fuel
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top fuel
Joined: Dec 2003
Posts: 2,042
Leucadia, Ca.
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Quote:
The 360 is one of the very rare engines that can handle a big overbore with no problems... Provided it's one cast after 1975.
When the 360 was released in 1970, it used it's own unique sand casting molds, but there were problems as the longer stroke would side-load the pistons and casue the block to crack in the main web area.
To remidy the problem, Mopar re-designed the casting by using the 340 internal cylinder molds, and adding additional meat in the main web areas.
Since the later 360 uses the 340 mold cores, if you bore it out to 4.04 [.040 over], it's just a standard 340 bore... But there's lots more meat to exploit if you choose.
Back in the late 70's and early 80's, there were a few guys who bored the 360 block .130 over, and use ford 428 flattop pistons for a 383 small block.
Needless to say, if your gonna hog out the holes like that, it's going to need to be sonic checked to find the center of the casting... But there is enough meat there to do it.
  Straight from my Mopar "Engines" book, pg 31:
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Re: How much can you bore a 360?
[Re: vdriver]
#260575
03/22/09 07:43 AM
03/22/09 07:43 AM
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Joined: Jun 2005
Posts: 30
Louisville Ky.
Pir8Darryl
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member
Joined: Jun 2005
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Louisville Ky.
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Quote:
Straight from my Mopar "Engines" book, pg 31:
My most humble appologies, and a sincere thank you for setting my facts straight.
So it was the early 360 blocks that were the "good ones", and not the late blocks. Ok, I'm down with that. I was going off memory of something I saw 30-some years ago... Sux getting older.
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Re: How much can you bore a 360?
[Re: derekeh]
#260577
03/22/09 08:28 AM
03/22/09 08:28 AM
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Joined: Nov 2003
Posts: 36,040
Lincoln Nebraska
RapidRobert
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Lincoln Nebraska
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have it sonic checked & read Andys extensive block sonic check procedure that he did with a # of blocks that's probably in the archives
live every 24 hour block of time like it's your last day on earth
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Re: How much can you bore a 360?
[Re: RapidRobert]
#260578
03/22/09 08:43 AM
03/22/09 08:43 AM
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Joined: Jan 2003
Posts: 74,942
U.S.S.A.
JohnRR
I Win
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I Win
Joined: Jan 2003
Posts: 74,942
U.S.S.A.
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Quote:
have it sonic checked & read Andys extensive block sonic check procedure that he did with a # of blocks that's probably in the archives
That only pertains to BIG BLOCKS .
But yes have it cleaned and sonic checked first .
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Re: How much can you bore a 360?
[Re: dogdays]
#260581
03/22/09 03:52 PM
03/22/09 03:52 PM
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Joined: Nov 2003
Posts: 36,040
Lincoln Nebraska
RapidRobert
Circle Track
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Circle Track
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Posts: 36,040
Lincoln Nebraska
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Thanks Dog, backup is always appreciated. When the "thin wall" casting started in I think the '75 model year the first # went from a 3 to a 4 in the block casting # on the side of the block on both sb's and bb's but how/why alot of these "later" ones ended up being thicker I dont have a clue.
live every 24 hour block of time like it's your last day on earth
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Re: How much can you bore a 360?
[Re: vdriver]
#260582
03/22/09 04:42 PM
03/22/09 04:42 PM
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Joined: Feb 2003
Posts: 21,318
Manitoba, Canada
DaytonaTurbo
Too Many Posts
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Too Many Posts
Joined: Feb 2003
Posts: 21,318
Manitoba, Canada
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Quote:
Straight from my Mopar "Engines" book, pg 31:
Don't put too much stock in something just because it's written in a book. For 30 years the mid-late 70's 440's suffered from the 'thin wall' label too, which turned out to be BS.
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