School Me on LS Motors

[Road Trip]

0W20?

"Mobil 1 0W-40" (p.6 Actually, the recommended break-in procedure on pp. 6-7 was an interesting read, too.)

I would have guessed what @RDF1 stated. Guess the clearances are pretty exacting...

 

[PlayingWithTBI]

"Mobil 1 0W-40" (p.6 Actually, the recommended break-in procedure on pp. 6-7 was an interesting read, too.)
I would have guessed what @RDF1 stated. Guess the clearances are pretty exacting...

Yeah, Mobil1 0w-40 is "European Spec" for Mercedes, BMW, etc. which has higher concentrations of zinc and phosphorus than "normal". My 2004 Chrysler Crossfire came with that spec. It was the 3.2L, 12 spark plug, CNP, 8.5 Qt oil out of the Mercedes SLK 320. I've been running it in all my cars since including my Mr Goodwrench crate TBI motor from Mexico - good stuff!

 

[RDF1]

"Mobil 1 0W-40" (p.6 Actually, the recommended break-in procedure on pp. 6-7 was an interesting read, too.)

I would have guessed what @RDF1 stated. Guess the clearances are pretty exacting...

Thats very similar to how I run a fresh engine on the run stand. I have a holley ECU on it and once coolant temp reaches 160* the rpms will vary from idle to 2500 rpms over a 30 second period and back down to idle over 30 seconds. It does this repeatedly till it runs out of gas, coolant temp gets above 240*, or oil pressure gets below a certain target at certain rpms.
I run it outside the shop and have the holley dash on a 72" TV inside the shop so I can keep eye on it.

I run them in with cheap 15w40 diesel oil tho.

 

[L31MaxExpress]

This was what many guys use in their GTRs and the like. I ran it in my M56S and I just changed the oil in my 383 with it. Between adding back in my OEM oil cooler and lines and changing the oil, my pressure is now much more stable. The engine is definitely quieter as well. It has performance levels of Zinc. It is also a full synthetic, not a petroleum base.

You must be registered for see images attach

 

[L31MaxExpress]

"Mobil 1 0W-40" (p.6 Actually, the recommended break-in procedure on pp. 6-7 was an interesting read, too.)

I would have guessed what @RDF1 stated. Guess the clearances are pretty exacting...

I was guessing 0w20 because that is the spec for all the direct injected engines, but 0w40 also makes sense. That was also the spec on the older 6.1L SRT8 engines.

 

[Hipster]

You know, personally I love the sound of a V8 at really high rpm.
Naturally aspirated DZ302s, HiPo289s, 340 TAs,
Can Am BBCs, they all give me the Schurkey limp, if you
catch my drift.

But at the same time, when I'm talking to friends or customers
about what they are trying to do with their engines, I always
start with this: RPM = Ruins People's Motors.

Most folks equate too much rpm with bottom end failures.
Using ARP fasteners & following tried-n-true recommendations,
I've never personally had a catastrophic failure down low.
(Maybe I simply haven't built enough power yet? :0)

On the other hand, I have experienced several failures with
the valvetrain. The one that scared me the most was a
friend's '73 C20 Camper Special that had a 454/Turbo 400
in it. After an idyllic WOT day in the mud bogs, the motor developed
an intermittent skip, with a new noise under the driver's side
valve cover in time with the skip.

When we pulled the valve cover I felt a little queasy, for one of
intake valves had broken the outer spring, leaving only the
inner spring keeping the valve from dropping into the bore
with instant widespread destruction resulting. :-(

We limped it home just off idle in 3rd, and thankfully our
guardian angels saw fit to get us back to home base
without further incident.

The silver lining? It gave us the excuse to open up the
7 year old big block & make a good thing better.
(My all time favorite truck...until the one I now have. :0)

Misc. thoughts:

* Intake valve springs are always the ones that fail
first. (They weigh the most, and are hardest to
maintain control over.)

* The sound of a valvetrain is an important clue as
to what's really going on under the valve covers.
(Especially if you are running solid lifters.)

For example, I had put together a high-winding
engine with the normal upgrades: triple valve springs,
roller hydraulic cam, aftermarket roller rockers 1 step
better than stock, etc. I ended up with not 1 but 2
intractable problems -- the first was that the valves
would float like clockwork at 6200 rpm despite the
triple springs that came with the cam, and second,
the stupid valvetrain sounded different at each &
every rpm...and not in a good way. (Note: The
rest of the motor was set up to pull like a Ducati
all the way up to 7500rpm - I was not a happy
camper!)

Trying to get a better understanding of what
kind of valvetrain dynamics I was fighting, I
waded through countless screens of armchair
conjecture & confident nonsense.

*Finally*, I came across the magic word: The Spintron!

Can't find the pic of an old Tektronix analog scope showing the valve float, but it looked kinda like this:

You must be registered for see images attach

Further digging around, and I stumbled across some ultra slow mo/stroboscopic videos showing
real valves and the shimmy shake that they do at high rpm. Here's a few links for your
viewing pleasure:

* Valve spring oscillation at 8500 rpm. (May want to turn down the sound.)

* Who knew that the valve stems oscillated side to side like this?

* And the granddaddy slow mo Spintron video. (Very informative, but caution: may cause nightmares)

****

OK, I should stop here & regroup. Seeing the carnage in your son's photos reminded
me of some of my own ad-hoc 'test to failure' episodes in my misspent youth. :0)

To summarize, back when Ford wanted the GT40 to last the full 24 hours as well as beat Ferrari
at their own game, the overriding rule was for the drivers to adhere to a strict rpm limit, despite the fact
that the engine was capable of more on the dyno.

No matter how fast you are, you still can't win if you aren't running at the end.

Great photos by the way. If you get a chance, show your son those videos on my behalf.

Cheers --

Have seen these types of tests/videos before and why I'm **** about getting the right springs on an engine, heavy components(valves, rocker gear, retainers) also make a difference. The best springs/high lift, high/rpm still need to be checked at some kind of regular interval. The one with the oscillating valve stem, I'm not liking the sweep on the rocker arm, Like the fulcrum could stand to be shimmed/raised. Go through this crap alot dealing with Mopar shaft mounted rockers, The fulcrum needs to be in the right place, with the right length pushrods, with the right length valves. The pedestals on both aftermatket and factory heads(Mopar) are 99% of the time too low for high lift situations. skimp elsewhere, not in valvetrain.

 

[Erik the Awful]

This project isn't dead, but it's certainly slow in taking off. It doesn't help that I'm buried in projects that aren't fun-related.

Today I spent all day at the church, cooking burgers for a fundraiser. While we were cooking we were chatting stuff and one of the guys mentioned that he'd been playing around with ChatGPT. I've dabbled a bit with StableDiffusion, so I took interest. Another guy, who's a retired Boeing engineer, challenged whether or not it was any good. He pulled up ChatGPT and asked for instructions on how to grill a burger, and in two seconds it gave very good, thorough instructions.

"Ha! That's easy." was the response, so the first guy hits up ChatGPT again and asked if it could give the preflight instructions for a 747. In a few seconds it responded with a full checklist. Now I'm intrigued.

I'm not too crazy about the fact ChatGPT wants access to my phone, but I'm a firm believer that in 50 years there will be no privacy, so I dove in this evening.

Suggest a funny name for a car racing team

ChatGPT
"The Speedy McZoom Zoom Racing Squad"

Not too shabby for a first go. If it can draw up a checklist, it can handle heavy tasks. Let's dive in...

Assemble a parts list with part numbers and prices for a budget naturally aspirated 5.3 LS motor build that makes 500 horsepower.

ChatGPT
Creating a precise parts list with part numbers and prices can be challenging, as prices and availability can vary based on location, brand, and current market conditions. However, I can provide a general list of components you'll need for a budget naturally aspirated 5.3 LS motor build targeting 500 horsepower. Please note that you should research and compare prices from reputable suppliers and adjust the parts to fit your budget and preferences.

Engine Block:
GM Gen IV 5.3L aluminum block (e.g., GM Part #12577927) - Price varies
Pistons and Connecting Rods:
Forged pistons and connecting rods (e.g., Wiseco, Manley) - Prices vary
Cylinder Heads:
Aftermarket cylinder heads (e.g., Trick Flow, AFR, Texas Speed) - Prices vary
Camshaft:
Performance camshaft suitable for your goals (e.g., Texas Speed, COMP Cams) - Prices vary
Valvetrain Components:
Upgraded valves, valve springs, retainers, and rocker arms - Prices vary
Intake Manifold:
Performance intake manifold (e.g., Holley, Edelbrock) - Prices vary
Throttle Body:
Upgraded throttle body (e.g., FAST, Holley) - Prices vary
Fuel Injectors:
High-flow fuel injectors (e.g., DeatschWerks, Bosch) - Prices vary
Fuel Pump:
High-flow fuel pump (e.g., Walbro, Aeromotive) - Prices vary
Exhaust Headers:
Performance headers (e.g., Kooks, Stainless Works) - Prices vary
Exhaust System:
Full exhaust system (e.g., cat-back system) - Prices vary
Engine Management System:
Standalone ECU or engine programmer (e.g., Holley EFI, HP Tuners) - Prices vary
Cooling System Upgrades:
Upgraded radiator, thermostat, and cooling fans - Prices vary
Oil Pump and Pan:
High-performance oil pump and oil pan - Prices vary
Gaskets and Seals:
Complete gasket set and seals for the engine build - Prices vary
Miscellaneous:
Bolts, fasteners, fluids, and other small parts - Prices vary
Please research and consult with a reputable engine builder or automotive performance shop to ensure the compatibility and suitability of these parts for your specific build. Additionally, consider labor costs and machine work, which will vary based on your location and the specifics of the build.

Oof. Not so good. Let's back it up a little...

Can you suggest a specific camshaft to make 500 horsepower with a naturally aspirated 5.3 LS motor?

ChatGPT
Certainly! Achieving 500 horsepower with a naturally aspirated 5.3 LS motor will require a carefully selected camshaft that optimizes power across the RPM range. Here's a specific camshaft suggestion:

Camshaft:

COMP Cams Xtreme Energy XE-R Hydraulic Roller Camshaft:
Part Number: 54-412-11
Specifications:
Duration @ 0.050" Lift: 223° intake / 230° exhaust
Lift: 0.613" intake / 0.617" exhaust
Lobe Separation Angle: 114°
Price: Prices vary, please check with suppliers for the most up-to-date pricing.
This camshaft is designed to provide excellent power gains in the mid to upper RPM range, making it suitable for achieving 500 horsepower in a naturally aspirated 5.3 LS motor. However, it's important to note that camshaft selection should be based on your specific application, goals, and other components in your engine build. Consulting with an experienced engine builder or tuner can help ensure that the camshaft is the right match for your setup.

Dang, that's not too shabby for hunting down parts! But I notice that cam has an awfully wide LSA. Let's get technical...

Would a camshaft with a 108° lobe separation angle give a lower dynamic compression ratio?

ChatGPT
Yes, a camshaft with a narrower lobe separation angle (LSA), such as 108°, can result in a lower dynamic compression ratio (DCR) compared to a camshaft with a wider LSA.

Here's a brief explanation of how lobe separation angle affects dynamic compression ratio:

Lobe Separation Angle (LSA): The lobe separation angle is the number of degrees in crankshaft rotation that separate the maximum lift points of the intake and exhaust lobes on the camshaft. A narrower (smaller) LSA, like 108°, means the intake and exhaust valves will open and close closer together in terms of crankshaft degrees.
Dynamic Compression Ratio (DCR): DCR is the effective compression ratio experienced by the engine during the intake stroke, considering the camshaft's effects on valve timing (including LSA). It's influenced by the actual static compression ratio (SCR), LSA, intake closing point, and other factors.
A narrow LSA (e.g., 108°) typically results in a higher DCR because the intake valve closes later in the compression stroke, trapping more air/fuel mixture in the cylinder.
A wider LSA (e.g., 114°) typically results in a lower DCR because the intake valve closes earlier in the compression stroke, allowing some air/fuel mixture to escape.
In summary, a camshaft with a narrower lobe separation angle (e.g., 108°) can increase the dynamic compression ratio, potentially leading to higher cylinder pressure and improved mid to upper RPM power. However, it's crucial to carefully select the lobe separation angle based on the engine's specifics, intended use, and other components to achieve the desired performance and efficiency. Always consider consulting with an engine builder or tuner for the best camshaft choice for your application.

Holy crap! This is pretty good. Next time I'm not understanding something, I might just ask GPT for an explanation. Let's adjust that last question...

Can you suggest a specific camshaft with an 108° lobe separation angle to make 500 horsepower with a naturally aspirated 5.3 LS motor?

ChatGPT
Certainly! Here's a specific camshaft suggestion with a 108° lobe separation angle that can help achieve around 500 horsepower in a naturally aspirated 5.3 LS motor:

Camshaft:

Texas Speed & Performance Stage 3 Low Lift 5.3 Truck Camshaft:
Part Number: 25-TS108-NLLSK
Specifications:
Duration @ 0.050" Lift: 227° intake / 235° exhaust
Lift: 0.610" intake / 0.600" exhaust
Lobe Separation Angle: 108°
Price: Prices vary, please check with suppliers for the most up-to-date pricing.
This camshaft from Texas Speed & Performance is designed with a narrow 108° lobe separation angle to optimize mid-range torque and horsepower. The duration and lift specifications are tailored to work well with a 5.3 LS motor, aiming for around 500 horsepower in a naturally aspirated setup.

As always, it's crucial to consult with an experienced engine builder or tuner to ensure that this camshaft is the right fit for your specific engine build and goals. They can provide additional guidance and recommendations based on your application and preferences.

Well, if one's good...

Can you suggest 3 specific camshafts with an 108° lobe separation angle to make 500 horsepower with a naturally aspirated 5.3 LS motor?

ChatGPT
Absolutely! Here are three specific camshaft suggestions with a 108° lobe separation angle that can help target around 500 horsepower in a naturally aspirated 5.3 LS motor:

Texas Speed & Performance Stage 3 Low Lift 5.3 Truck Camshaft:
Part Number: 25-TS108-NLLSK
Specifications:
Duration @ 0.050" Lift: 227° intake / 235° exhaust
Lift: 0.610" intake / 0.600" exhaust
Lobe Separation Angle: 108°
Price: Prices vary, please check with suppliers for the most up-to-date pricing.

COMP Cams Xtreme Energy XER 224/230 Hydraulic Roller Cam for GM LS GEN III/IV:
Part Number: 54-445-11
Specifications:
Duration @ 0.050" Lift: 224° intake / 230° exhaust
Lift: 0.581" intake / 0.588" exhaust
Lobe Separation Angle: 108°
Price: Prices vary, please check with suppliers for the most up-to-date pricing.

Lunati Voodoo 60102LK Street/Strip Camshaft for GM LS GEN III/IV:
Part Number: 60102LK
Specifications:
Duration @ 0.050" Lift: 233° intake / 241° exhaust
Lift: 0.616" intake / 0.624" exhaust
Lobe Separation Angle: 108°
Price: Prices vary, please check with suppliers for the most up-to-date pricing.
Each of these camshafts is designed with a 108° lobe separation angle to optimize mid-range torque and horsepower, aiming for approximately 500 horsepower in a naturally aspirated 5.3 LS motor. However, it's essential to consult with a knowledgeable engine builder or tuner to select the best camshaft for your specific engine build and intended use. They can help you tailor the camshaft choice to achieve your horsepower and performance goals.

Interesting stuff! I don't know that I'm going to farm out my engine planning just yet, but it looks like a good tool for finding parts! Let's double check its work...

...and one of those cams I can't find by the part number, another one correlates to a mild flat-tappet 350 cam, and the third doesn't have those specs. Doh!

 

[Fiddlejohn]

650hp is probably not in the cards with only 6500 RPM, naturally aspirated and stock displacement. As noted earlier in the thread, the LS7 builds these days usually cap out around the 600-650 horse mark with wildly exotic cam choices on 427 cubic inches still spinning around or even north of 8000 RPM. The only way to reliably get 650 horse out of a 6.0 spinning only 6500 RPM is boost. But you've also stated that mark is something to shoot for and if it is 550 or so, so be it.

An LQ4, some 799/243 heads and a Tick Polluter V3 cam will crank 500-530 horse all day long with ease under 7000 RPM. An L96 running some LS3 heads and the same (similar, the grinds are a little different) Tick cam choice for the LS3 will more reliably deliver 550-570 horse in the same circumstances. That's about as reliable and as powerful as a small budget will take you.

I remember just a few years ago, an LS427/570 crate from GM could be had for as little as $11000 in some places...

 

[Erik the Awful]

So I built a spreadsheet...
The forum won't let me upload a spreadsheet, so it's a text file. Change the extension to .xlsx and it should work.

Edit: Corrected the extension.

 

[BeXtreme]

So I built a spreadsheet...
The forum won't let me upload a spreadsheet, so it's a text file. Change the extension to .xlsx and it should work.

Edit: Corrected the extension.

If you are going to use a used 6.2 block, just get a 4.070 piston and have it bored/honed. I had mine measured and it is close enough for me to just run the stock pistons and new rings, but the stock hone job is sloppy and it has ovalled out a bit after many years of use. If you are already spending the $650 for new forged pistons, there is zero reason to not get the bores cleaned up a bit. The forged pistons will need more piston to wall clearance anyways, so there should be no problem cleaning it up with .005 over.