Quick Ranger

iTrader: (2)

Has anyone ever seen a gen III 5.3 block NOT be able to handle a 3.900 bore? I'd like to bore it to 3.900 and boost it with a turbo. Am I pushing it boring that far and boosting to say a max 15 psi?

DavidBoren

People have certainly done it. I would definitely get it sonic checked. I cannot remember the specific agreed upon safe minimum wall thickness for boost, but I am sure that piece of information isn't too hard to find searching this forum.

Looks like anything over .200" is considered safe for boost, from what I just found on google.

JE has ready to go pistons in 3.898" and 3.905" bore sizes with a compression height of 1.175, which is perfect for 6.25" rods. Eagle and Scat both make relatively cheap 6.25" forged rods, which give you a 1.73 rod ratio with a 3.622" stock stroke crank.

KCS

iTrader: (20)

We were taking about this on another forum. A 6.0L at 4.00" is already less than .150" thick without taking into consideration the effect of core shift.

DavidBoren

After a little more research, it looks like anything over .18x" is regarded as safe for boost. Obviously there are going to be people who have boosted thinner walls, but the research I have seen concludes that anything over .180" is plenty for boost.

pantera_efi

iTrader: (1)

My experience IS more directed at the "late" 5.3 Aluminum Block @ 88mm (3.86") bored.
This block has "equal" head bolts, NO breather hole between Main/Cam, Cam Timing Chain block, .etc.
Sonic Tested @ .160" is common.

Would this be the one you are speaking about ?

Lance

Quick Ranger

iTrader: (2)

I forgot to mention, this is a Gen III iron block. I was just wondering if some of these blocks wouldn't handle a 3.900 bore. My block is gonna need a bore, and i figured why not take it out a bit more.

I just don't know if it is worth it or not to bore it say .030 over and use a Speed Pro hyper piston or not.

redtan

iTrader: (5)

IMO, I would bore/hone it out only as far as it needs to cleaup up and/or for the next sized up shelf piston.

You won't notice a few extra CI in a 15psi turbo motor...so no sense in overboring it just for the sake of it. And don't bother with hyper pistons at that point, get some budget forged units.

kinglt-1

iTrader: (26)

^This!

1FastBrick

iTrader: (16)

Depends on core shift in the block. Some have actually broken through the walls on blocks with bad core shift going that far.

Quick Ranger

iTrader: (2)

.
Thats the thing, only wiseco makes a piston in a bore that small, 3.800. At $750, they aren't really budget. Any thoughts on using a mahle 4032 piston? It would be much quieter than a 2618 piston.

Quick Ranger

iTrader: (2)

That's something I haven't heard before, thanks for that info. Ah decisions.....

sbdgbody

iTrader: (11)

I sent u a pm

1FastBrick

iTrader: (16)

If you go back aways you might find the thread. We have had this discussion a few times and I got someone to actually post a picture. I believe it was 3.898 when it broke through on 1 side of the block.

If I have time later I might dig it up.