bore size of a Gen V BBC

[SuperBuickGuy]

What's the largest overbore you can do on a Gen V block? I read an article that implied 4.5 bore size..... but I'd rather something more concrete then an implication.

[BlackoutSteve]

Re: bore size of a Gen V BBC

Stock is 4.47" and you should be able to go 0.090" without a problem.. (4.560") Maybe even 0.125" with a sonic check.

[SuperBuickGuy]

Re: bore size of a Gen V BBC

I thought stock 454 gen v was 4.25 with a 4.00 stroke.?

[urwurznitmahre]

Re: bore size of a Gen V BBC

I thought stock 454 gen v was 4.25 with a 4.00 stroke.?

but what is the bore of a 502?

[SuperBuickGuy]

Re: bore size of a Gen V BBC

I thought stock 454 gen v was 4.25 with a 4.00 stroke.?

but what is the bore of a 502?

thus the essence of my question - can you bore a gen V 454 to the 502 bore (4.47)?

[BlackoutSteve]

Re: bore size of a Gen V BBC

You never mentioned cubes and I simply assumed a 502 when you were talking a 4.5" bore.

Yes, a 454 is a 4.25" bore and no, it can't go to 4.5" because it's bores are not siamesed like the 4.47" bore blocks.

[SuperBuickGuy]

Re: bore size of a Gen V BBC

thanks - so there are two different versions of the Gen V block..... how does one tell them apart?

[urwurznitmahre]

Re: bore size of a Gen V BBC

thanks - so there are two different versions of the Gen V block..... how does one tell them apart?

pull a core plug and look for water jackets aroung the cyl..
if saimeced(sp?) it should go to at least the 502 bore size

[BlackoutSteve]

Re: bore size of a Gen V BBC

Casting numbers..
You'll need to Google for a list of what's what..

If you're buying, see if you can get your hands on a BowTie block. They are 4.25" bore (one is a 4.125") that can all go to 4.6".

Also, good idea urwurznitmahre.

[CaminoKid]

Re: bore size of a Gen V BBC

My understanding of the V gen bbc is that its only difference was the fact that it has no provision for a mechanical fuel pump and the VI bbc then went back to having the fuel pump provision.

And the only true way to know the thickness is the sonic test.

[min301]

Re: bore size of a Gen V BBC

Am I correct in the fact that the 502 and 454
have two different deck heights?

[BlackoutSteve]

Re: bore size of a Gen V BBC

My understanding of the V gen bbc is that its only difference was the fact that it has no provision for a mechanical fuel pump and the VI bbc then went back to having the fuel pump provision.

...and a 1 piece rear main seal.

Min. No.. The 454 and 502 are both 9.8". Tall decks (10.2") was available in BowTie and standard on truck applications.

Also, correction. The 502 has a 4.466" bore and not 4.47" as previously mentioned.

[min301]

Re: bore size of a Gen V BBC

Thanks for straightening that up... ;)

[BlackoutSteve]

Re: bore size of a Gen V BBC

Thanks for straightening that up... ;)

It's not that easy to find definite information. Much of Google just has casting numbers, deck height and CI.

And the books I have aren't very specific..

[SuperBuickGuy]

Re: bore size of a Gen V BBC

Thanks for straightening that up... ;)

It's not that easy to find definite information. Much of Google just has casting numbers, deck height and CI.

And the books I have aren't very specific..

thanks for the info - I googled and failed before I posted my question.....