charlie97z28

iTrader: (2)

I jus picked up two 5.3 blocks at a steal I thought got both short blocks for 100 bucks so from what I read and research the only difference between them and a 5.7 is jus the bore so with it bein cast iron what is the potential cid and still be durable I was looking to do somewhere between a 383 to 440 CID I know there are probaly a lot better blocks to start with but for 100 bucks for two shortblocks I couldn't pass it up any help will be greatly appreciated .

matrixiskool

iTrader: (12)

383 and 408's are popular with the truck blocks. I don't know what the max bore is though, the more you keep boring the less reliable it becomes with the walls getting thinner.

Rick_Vor

iTrader: (36)

The 5.3l iron blocks can be safely bored out to 3.910 (LS1 standrard bore + .005). That would make a 383 with a 4.00 stroker crank. A 408" would take a LQ4 or LQ9 block + the 4.00" crank.

matrixiskool

iTrader: (12)

Wait arent the lqx blocks the same as the 5.3 blocks. I think Im misunderstanding something.

xpndbl3

iTrader: (23)

no 4.8L/5.3L blocks are the same

6.0L blocks are their own thing

matrixiskool

iTrader: (12)

Damn. So to clear things up then 5.3 blocks are one thing and lqx blocks are 6.0 blocks?

krissoto

iTrader: (3)

^^^^^^^^Yes Sir^^^^^^^^^^

Isolde

iTrader: (4)

Not quite. LS1 and LS6 standard bore was 3.898". There are plenty of piston choices at 3.905", for both stock and 4.00" strokes.

charlie97z28

iTrader: (2)

So basicly even tho it's a cast iron block it is still limited to the same CID of the 5.7 ls1 383 or 394 being the max and still have enough block left to still be safe

StrokerAce03

iTrader: (7)

The 4.8, 5.3, 6.0, and LS1 all have the same external dimensions though, the cylinder walls are just different.

Sales2@Texas-speed

iTrader: (5)

The largest I'd recommend with that 5.3L block is a 383ci stroker. That's 3.903" or 3.905" bore, and a 4.0" stroke.

BigEd_72455

iTrader: (7)

I know this is reviving a thread from the dead, beat, buried, shot, and decomposed....


But I have to ask this cause I am about to start on this project engine.


Does any cylinder grinding/clearance work have to be done to the 5.3 LM7 block GEN III (12567392 block ID number) in order to make the 383 stroker?


Can you use a stock 6.0 crank for it's 4 inch stroke and use forged rods and pistons to obtain this 383 CI displacement?


If the answers to the above are no for clearance work and yes on the crank, what kind of power levels would the engine hold up to reliably? And I do plan on using nitrous for drag racing (primary use of the engine).


And has anyone actually gone out to a 4.00 bore and the engine survive race use? I don't expect it to last for forever.. just a good season or two would suit me just fine. That will give me time to get another engine together and ready to go in when this one bucks the kicket.

KCS

iTrader: (20)

Stock 6.0 crank is not 4" stroke, it's 3.622".

As far as grinding, it may need it depending on the rods. Some will be close, others won't.

redbird555

iTrader: (14)

what kcs said. you have to just see what rods you end up with mostly. every ls crank besides the 4.8 and ls7 are a 3.622" stroke. the ls7 has a 4" stroke but needs machine work for the crank to fit in a wet sump motor

BigEd_72455

iTrader: (7)

Can you bore the stock 5.3 block to a 4 inch bore though??


And what crank would you guys recommend? I am shooting for 7-800 horsepower including the pro fogger nitrous kit.

alowerlevel

iTrader: (1)

Already answered a few posts up

BigEd_72455

iTrader: (7)

I was more curious if anyone had actually done it and it worked or not.

Johnv

I have read of it being done, a 5.3 bored to 4", but i wouldn't recommend it with a power adder, as the cylinder walls would be getting thin. you would need to sonic test bores to determine thickness before boring.

if you want a 408 just start with a 6.0l block and be done.

big hammer

I've read of a 4" being done and still having enough meat left over.

I have not done it myself however.

BigEd_72455

iTrader: (7)

Where does my post say I want a 408? I simply asked if these could be bored 4 inches. And if I could have found a 6.0 as cheap as I did this 5.3, I would have bought it instead.