How Big can a 5.2 get?

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Dusterfreak

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What size can a 5.2 be bored over? I know alot of older 318`s been bored for 340 pistons but how about magnums? I just got a 5.2 thats been sitting and its got rust in the cylinders so an overbore is a must...
 
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What size can a 5.2 be bored over? I know alot of older 318`s been bored for 340 pistons but how about magnums? I just got a 5.2 thats been sitting and its got rust in the cylinders so an overbore is a must...
I think I remember seeing about .040 is the max. Anything more than about .030, I would have it sconic checked.
 
I have conveniently forgotten the name but there's a well known Mopar engine shop that builds 4" plus bore 318s. Been doin it probably 30 years. Moper will remember it if he sees this.
 
Hensley Motorsports. Dammit I nearbout burnt my brain up thinkin about that.

They've been buildin big inch 318s for a while.
 
360 bores are a +.090 but 340 bores, thats a +.130, or over a 1/4 inch diameter overbore! If thin is in, they are Flynn! Now 'big inch' is more plausable with > 4.15 stroke LA cranks available now.
 
There were some truck “premium” blocks that could be bored over.
 
Let's not forget you can stroke 'em or even just start with a 5.9 and go from there!!
 
The 318 from Hennsely gets sonic checked for a 4.00 bore.

The 318’s cylinderwalls are only so thick. How far it goes needs a sonic check to know for sure.

I suggest not think it can go to a 4.04/340 bore.
 
Let's not forget you can stroke 'em or even just start with a 5.9 and go from there!!
I was looking for a 5.9 but those are rare here in finland, pickn pulls were asking 1500€, its almost 1800$ :D
I was thinking about stroking, but that includes 0.030 overbore also and a 2000$ plus freight plus taxes so ill be in 3000$ then...
 
The 318 from Hennsely gets sonic checked for a 4.00 bore.

The 318’s cylinderwalls are only so thick. How far it goes needs a sonic check to know for sure.

I suggest not think it can go to a 4.04/340 bore.

Well of course they do. I kinda figure some things just go without sayin. lol
 
I was looking for a 5.9 but those are rare here in finland, pickn pulls were asking 1500€, its almost 1800$ :D
I was thinking about stroking, but that includes 0.030 overbore also and a 2000$ plus freight plus taxes so ill be in 3000$ then...

3K is pretty cheap for an engine.
 
I was looking for a 5.9 but those are rare here in finland, pickn pulls were asking 1500€, its almost 1800$ :D
I was thinking about stroking, but that includes 0.030 overbore also and a 2000$ plus freight plus taxes so ill be in 3000$ then...

Oh, FINLAND I didn't notice your location. I'm in "the sticks" of the N end of Idaho state, and can sometimes "*****" about the lack of used speed parts, etc. But you guys must have it ROUGH!!!
 
360 bores are a +.090 but 340 bores, thats a +.130, or over a 1/4 in.diameter overbore! If thin is in, they are Flynn! Now 'big inch' is more
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
plausable with > 4.15 stroke LA cranks available now.
.030 , is .005 over an 1/8" -----------------------1/4" is .0250
 
Now I have a plan... 0.030 over with KB 167-30 pistons, eq heads and air gap :)... Thats if water hasnt ruined two cylinders.
 
.040 with 4 inch is 392 IIRC and I think can go larger bore.

Has the OP tried honing?
 
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