Max bore on 5.3 iron block?
The following 2 users liked this post by bgoedeker07:
AINT SKEERED (01-05-2022), tdmaker (03-23-2022)
03-17-2018, 11:57 AM
#22
TECH Senior Member
It's all good! Just don't expect an answer, as usually the poster from that long ago is long gone.
The following users liked this post:
tdmaker (03-23-2022)
03-20-2018, 06:49 PM
#25
ModSquad
iTrader: (6)
The following users liked this post:
tdmaker (03-23-2022)
03-20-2018, 11:16 PM
#26
Not sure but I've said this in countless other posts. You have to sonic check the block before you bore a block. There is core shift in the 4.8/5.3 blocks. While many are acceptable to bore to 3.905 or even 3.908; some aren't even doable to 3.898. Attached is the printout from my machine shop when they sonic checked a 5.3 block I was planning to bore to 5.7.
In short to go from a 5.3 bore to a 5.7 you have to take .118 total or .059 out of each side of the bore. In the case of the block I was considering would have left .107 ish on the thrust side of the bore on the number 8 cylinder. It is obvious there is quite a bit of core shift in this particular block. My machine shop recommended staying .150+ on the thrust side of the bores for a 450ish hp motor. If you go to0 thin cylinder walls will deform, crack, and so on.
In short to go from a 5.3 bore to a 5.7 you have to take .118 total or .059 out of each side of the bore. In the case of the block I was considering would have left .107 ish on the thrust side of the bore on the number 8 cylinder. It is obvious there is quite a bit of core shift in this particular block. My machine shop recommended staying .150+ on the thrust side of the bores for a 450ish hp motor. If you go to0 thin cylinder walls will deform, crack, and so on.
03-20-2018, 11:39 PM
#27
TECH Addict
My engine machinist won't cut without sonic checking the block and its included in the labor. If his boring machine breaks through he risks breaking a expensive bit of tooling..
I was there one evening he was cutting a brand new $25K Sprint block,, hit air long before he hit the spec'd max bore. HAd a casting fault.. Which the vendor covered..
Another thing to consider is the expected duty cycle of the engine, the walls may be strong enough , but go too thin and you'll shed massive heat in to the cooling system.
Which is OK if you planned on a 2x jump in radiator core...
I was there one evening he was cutting a brand new $25K Sprint block,, hit air long before he hit the spec'd max bore. HAd a casting fault.. Which the vendor covered..
Another thing to consider is the expected duty cycle of the engine, the walls may be strong enough , but go too thin and you'll shed massive heat in to the cooling system.
Which is OK if you planned on a 2x jump in radiator core...
03-21-2018, 06:21 PM
#28
My engine machinist won't cut without sonic checking the block and its included in the labor. If his boring machine breaks through he risks breaking a expensive bit of tooling..
I was there one evening he was cutting a brand new $25K Sprint block,, hit air long before he hit the spec'd max bore. HAd a casting fault.. Which the vendor covered..
Another thing to consider is the expected duty cycle of the engine, the walls may be strong enough , but go too thin and you'll shed massive heat in to the cooling system.
Which is OK if you planned on a 2x jump in radiator core...
I was there one evening he was cutting a brand new $25K Sprint block,, hit air long before he hit the spec'd max bore. HAd a casting fault.. Which the vendor covered..
Another thing to consider is the expected duty cycle of the engine, the walls may be strong enough , but go too thin and you'll shed massive heat in to the cooling system.
Which is OK if you planned on a 2x jump in radiator core...
12-11-2018, 09:37 PM
#29
Not sure but I've said this in countless other posts. You have to sonic check the block before you bore a block. There is core shift in the 4.8/5.3 blocks. While many are acceptable to bore to 3.905 or even 3.908; some aren't even doable to 3.898. Attached is the printout from my machine shop when they sonic checked a 5.3 block I was planning to bore to 5.7.
In short to go from a 5.3 bore to a 5.7 you have to take .118 total or .059 out of each side of the bore. In the case of the block I was considering would have left .107 ish on the thrust side of the bore on the number 8 cylinder. It is obvious there is quite a bit of core shift in this particular block. My machine shop recommended staying .150+ on the thrust side of the bores for a 450ish hp motor. If you go to0 thin cylinder walls will deform, crack, and so on.
In short to go from a 5.3 bore to a 5.7 you have to take .118 total or .059 out of each side of the bore. In the case of the block I was considering would have left .107 ish on the thrust side of the bore on the number 8 cylinder. It is obvious there is quite a bit of core shift in this particular block. My machine shop recommended staying .150+ on the thrust side of the bores for a 450ish hp motor. If you go to0 thin cylinder walls will deform, crack, and so on.
The following 2 users liked this post by LilJayV10:
LS CHEVY II (01-06-2020), theunderlord (01-20-2022)
12-11-2018, 10:29 PM
#31
TECH Senior Member
This was over 11 years old. I just said not to expect an answer as those involved are long gone. Besides, we've gotten past it a bunch of posts back.
10-24-2021, 12:02 AM
#33
Teching In
Join Date: Aug 2020
Posts: 3
Likes: 0
Received 0 Likes
on
0 Posts
4.8 5.3 6.0 casting some blocks had the 4.8 5.3 an 6.0 casting on them an where cast for all three.Rare but do exsist so question is how far to bore this one? engines master chanenge seen a 6.0 bored to 4.1 an stroked 4.
Last edited by selinkcimleh; 10-24-2021 at 12:04 AM. Reason: adding content
10-24-2021, 12:29 AM
#34
TECH Senior Member
Go back and read thru the thread, all of it. It has been said here and elsewhere to SONIC CHECK THE CYLINDER BORES. Nobody will give you an answer that can only be found by doing this.
The following users liked this post:
02*C5 (10-24-2021)
The following users liked this post:
DualQuadDave (10-28-2021)
