ddnspider

iTrader: (26)

Several members have pushed both hard and found the 5.3s to be stronger. I specifically remember @rotary1307cc postings pics of cracked 6.0 blocks.

truckdoug

iTrader: (26)

if you are breaking a block at 850 wheel u r doin it rong

rotary1307cc

iTrader: (5)

5.3 all day any day if pushed to that 1k+ level vs an iron 6.0

I could post 20 cracked 6.0s in here, there is no wall thickness between bores... Fatigue and then it's done

ddnspider

iTrader: (26)

I knew I wasn't crazy and you had posted pics in an old thread.

stevieturbo

Whether the 6.0 iron is a weak block, doesnt alter the fact that what the guy was told was BS. Plus the guy isnt looking for big power.

Although he also hasnt said whether his blocks are aluminium or iron...I'd always take the alloy blocks as my first choice.

ddnspider

iTrader: (26)

850whp through a th400 and 9 inch is roughly 1000hp that rotary mentions so it does seem relevant.

tblentrprz

If spending $$$ on rods and pistons (which means, more reliable to push it past 1000whp), why would you want to put them into a thinner/prone to crack 6.0 sleeve? If you want a 6.0, use a stock setup and know it's limits. If you want a stable build, a thicker walled sleeve is key. Bore stability provides strength and ring seal. Just some thoughts.

Elkwagn

None of my blocks are Aluminum, so there are no sleeves involved here

Lsx Rubi

I always thought a smaller displacement engine given that it can rev and the heads can support the air flow it will make more power than a larger displacement engine using the same size turbo . Say a 2jz will make more power with a S475 than a a 6.0 lq4 . The turbo will run a higher pressure ratio putting it in a more efficient spot on the compressor map and also the drive pressure to boost pressure ratio will be better . By the same merit a 4.8 will make more power than a 6.0 given the same size turbo is used on both engines.

forcd ind

iTrader: (7)

I always wondered if there was a strength diff bet gen 3 and 4 blocks-they moved the head bolt
depth on some bolts, not sure if that mattered.

ddnspider

iTrader: (26)

Picking the same size turbo is handicapping the larger motor for reasons you mentioned. The larger motor will make more torque at a lower RPM however so depends on use and goals.

tblentrprz

Correction - bore wall thickness.

stevieturbo

All that is doing is saying you chose the wrong turbo.

Elkwagn

Exactly, which is why is made the point of saying all things equal. Choose the correct cam, injectors, Turbo etc. for the application,and then which is easier to make POWER with, large or small cubes, and ported or unported heads?
Sounds to me like a nicely built 5.3 will make the goals I'm after handily after what has been said.
5.3 w/rods, pistons and the right cam
80lb injectors
spray meth
78/75 Turbo
Let it eat!

stevieturbo

I cant even understand why you're asking this question ?

When it has been answered over pretty much the last century for all engines.

larger engines, with better flowing heads will always make power more easily. They simply move more air.

gsteele

I dunno. He may have a point. Below are the specs on a model airplane engine.

SPECIFICATIONSDisplacement: 0.352 cu in (5.77cc)
Bore: 0.795 (20.2mm)
Stroke: 0.709 (18.0mm)
Practical RPM: 2,500-17,000
Output: 0.9PS 11,000 RPM
Weight: 12.8oz (363g) with muffler

17,000 rpm. Think of the possibilities. What would it take to get an s475 hooked up to that? It would not make much down low but it would really start to wake up somewhere around 6500 rpm. Also, don't forget the weight savings as it is all aluminum. I just remembered that it runs on nitromethane. This is really exciting. Will get back to you with the results.

ddnspider

iTrader: (26)

Holy crap

truckdoug

iTrader: (26)

so uh, what band of oil should he run then?

Elkwagn

Start back at the beginning. I am asking the question because I was informed by a reputable builder that it is EASIER to make power with a 5.3 BECAUSE of the restriction, EASIER to make boost which translates to power, holds MORE boost because of block thickness. We all know that ultimately the bigger the setup the more power can be made, question was at what point do the lines on the graph cross

AndyTA

I jumped in the middle and realized you already have your answer, so I'm removing the explanation since you don't need it a millionth time.
I guess you're wondering the following:

Added boost from more wall thickness
vs
Added Power naturally with less boost because of thinner walls

It'll come down to power goals. That will dictate it.