Author Topic: 318 = 340?  (Read 848 times)

Offline Dusty1

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318 = 340?
« on: September 20, 2008 - 09:58:29 PM »
This has probably been asked a thousand times, sorry. I have a '68 318, can it just be bored out to a 340 ci and be the same motor as a 340? Thanks!
Garys 1972 BS




Offline ChallengerHK

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Re: 318 = 340?
« Reply #1 on: September 20, 2008 - 10:14:11 PM »
My quick math says you can probably get to 322-323 with a .030 overbore. I'm not sure what the max safe bore for a 318 is. You could stroke AND bore it and get a lot more cubes, but if I was going to do that (and I am  :bigsmile:) I'd start with a 340 or 360 and really max it out. On the other hand, there's some guys on her running some pretty impressive 318s.
« Last Edit: September 20, 2008 - 10:25:57 PM by ChallengerHK »


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Offline GoodysGotaCuda

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Re: 318 = 340?
« Reply #2 on: September 20, 2008 - 10:40:02 PM »
I have HEARD of some being bored to a 340 with sonic checking. It's still risky.

Stroker would be the best, get up to 390 cubes from a 318 without much trouble.
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Offline Topcat

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Re: 318 = 340?
« Reply #3 on: September 20, 2008 - 11:28:11 PM »
According to an Article I have that I just read in Mopar Muscle...Nov 03.
The article "A 318 Power Trip" The guy bored out his 318 to .060"

An excellent article for anyone considering a 318 build up.
Mike, Fremont, CA.


Offline go-fish

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Re: 318 = 340?
« Reply #4 on: September 20, 2008 - 11:34:27 PM »
Getcha the 4" stroker crank and bore it .030". Swirl port heads and good intake and exhaust and you'll have a Mustang and Chevy killer.

Offline Dusty1

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Re: 318 = 340?
« Reply #5 on: September 20, 2008 - 11:44:36 PM »
Thanks for the help fellas! This helps.
Garys 1972 BS