valiant65

Is it 5.3? Have I understood correctly that 4.8 to 6.0 have same outside cylinder diameter? If that is correct, why is everyone doing their street turbos (under 1000 hp) out of 6.0?

stevieturbo

They are not the same bore size.

valiant65

Yes, I know 4.8 and 5.3 have 96mm and 6.0 has 101.6mm bore size, but if they all have same casting outside, then smaller engines will have stronger (thicker walls) cylinders than 6.0 ? Am I wrong with this?

stevieturbo

They will of course be stronger....but they are also much smaller cubes.

And when a 6.0 bore is perfectly strong for say 1000bhp ( LS2 or iron block ) then why would you choose a smaller one ?
Also, the chambers on most decent flowing heads are to suit the larger bore...

So fitting heads to suit a very small bore, would restrict airflow potential.

valiant65

Simple answer: Pricing, I could get three 5.3s at a price of one 6.0

stevieturbo

Then you would need heads with a small chamber, perhaps small valves, and less airflow.

So while you have gained bore strength.....you have massively reduced airflow.

And when you want to make power....airflow is everything, and a 6.0 bore is quite strong enough.

TS6

iTrader: (41)

Jesus, a 6.0 block might cost you $600 at most, and if you're willing to look they are out there for alot less. If the cost of the block is a concern, go ahead and get out of the FI game now. That few hundred bucks is almost nothing in comparison to what the rest of the stuff will cost you.

Red99C5

I was thinking the same thing.

valiant65

Sorry guys, I forgot one word: Lowbudget. I'm having thoughts of using as many production parts as possible (block, crank, heads, intake) and making +600 rwhp with them.

If I would build all out race engine I would buy LSX-block for foundation but thats not the name of the game now (I know what it takes overall, have been in the sevens with twinturbo sbm).

stevieturbo

On a forced induction setup....the block is hardly a big expense no matter what one you go for. And an LSX block is hardly necessary, unless well over 1000rwhp.
And even at that, apparently there are some LSX block issues.....so buying one could be dodgy.

600rwhp is hardly pushing things either, considering totally stock 5.7's and 6.0's can do that without too much difficulty, and probably a 5.3 too.
Pistons would be the weak link internally, not any of the blocks.

Dragframe

iTrader: (14)

Yeah... dont even worry about the block.. Whatever you buy will work.. .Stock rods (i'd prolly do rods anyways) and crank will work... use forged pistons (dish)... stock heads... good valve springs... Good hardware throughout the motor. The truck intake will pose sort of a problem because they got odd ball injectors. So i suggest the ls1 intake so finding injectors won't be a problem for that power level.

Then pound it with boost. 600rwhp should be no problem


Put it this way. My buddy (on the forum also) made 500rwhp out of his stock 4.8. He has vavle springs, cam, and turbo (with all the supporting things of course).

So an extra hundred is nothing.

trtturbo

iTrader: (25)

the 4.8/5.3 block is a different casting in more ways than bore. You cant safely bore a 4.8/5.3 block to 4.0" like a 6.0 block.
There are however, several people making crazy power with iron 347's (5.3 bored to 3.9); like 800 and 900+. That is the budget motor, buy not by much; basically the difference is in the cost of the blocks; usually around $300.

MIGHTYMOUSE

iTrader: (59)

i ran a 5.3 al block in 2004, made around 790rwhp and ran my only 9 second pass w/ the manual trans