5.3 cylinder wall thickness

[mudseeker]

so, i dropped my block off at the machine shop on monday to be bored out to 3.903. the shop is going to sonic test it before they bore. my question is, what is a safe cylinder wall thickness? the shop is known for building roundy round engines and has received many rewards/trophies for their work, but they seem to be a little wet behind the ears when i brought them my block. he's supposed to call me after he sonic tests it and i would like to be confident in giving him the go ahead.

[Smoky02]

I'm not sure the actual bore, but everything that I've read says that the largest a 5.3 can be bored is the stock bore of an LS1 5.7

[truckinL33]

I would never do an engine more than "0.30 over, that's just me.

[Sleaper]

What are you using it for? (N/A, nitrous, FI) The most it can safely be bored is 3.905. That's if everything checks out ok. I would be a little weary of shops that don't have much experience with LS based motors. They may know old school but it's not the same. Trust me, I went through this with a well know engine builder who did mostly dirt track engines and it didn't turn out how I would have liked it to.

[George C]

I would never do an engine more than "0.30 over, that's just me.

the 5.3/4.8 block was orignally casted to be a iron 5.7 but they decided to keep weight down in the fbodys and Vettes so they went with aluminum and used the 5.3/4.8 in the trucks. if you buy any LS book it shows repeatly this from actual GM

[mudseeker]

it will be a NA setup. my next build, if there is one will be a 6.0 w/FI.

what would be different in the machining process that they might not be able to handle? all they are doing is boring it out and as mentioned, sonic testing it first. i already have a forged rotating assembly that has been balanced by the supplier, so i don't see what could go wrong besides boring through a cylinder, which shouldn't happen due to the sonic test.

i also gave him all the paper work i got from wiseco describing where to measure and how.

[Sleaper]

it will be a NA setup. my next build, if there is one will be a 6.0 w/FI.

what would be different in the machining process that they might not be able to handle? all they are doing is boring it out and as mentioned, sonic testing it first. i already have a forged rotating assembly that has been balanced by the supplier, so i don't see what could go wrong besides boring through a cylinder, which shouldn't happen due to the sonic test.

i also gave him all the paper work i got from wiseco describing where to measure and how.

I should have specified that if they are assembling the engine, it could be an issue. Or it could have just been my builder!! Mine didn't know that 317 heads had such large combustion chambers and put -13.2cc pistons in which created a super low CR.

[mudseeker]

ah, gotcha. i will be assembling the engine and triple checking all tolerances. i will be running 10.1:1 with the current setup.

[motorholmes]

Yeah I'd be careful about who does the work too. There are alot of little things that an experienced LS machinist knows about these.

At least you're doing the assembly..

My buddy just punched his 6.0 block .125, but he's a maniac

[mudseeker]

i thought my LSX book said the 6.0 could only take a light hone. those cylinder walls have to be paper thin!