School Me on LS Motors

[RDF1]

The good thing about the Holley is, you can use the 58x or 24x and you can mix up the cam reluctors with crank reluctors.
So you can have a combo of a 58x crank/ 1x cam. Its just a simple change in the tune.


The whole flexplate spacer deal will be null since your going to buy a new torque converter for the 4l80. You can have it made to fit any flexplate combo you have.
the 4.8, 5.3, 6.0, and 6.2 in the 1500 trucks use the dished flexplate
the 6.0 in the 2500 trucks have the flat flexplate with a spacer and longer bolts.

But you mentioned sustained high rpms, so i would get a SFI flexplate so all that above doesnt mean anything.

 

[Erik the Awful]

Re-reading this thread with some more of the stuff I've learned, I have a new question. What's the difference between a 4x cam sprocket and a 1x cam sprocket?

It doesnt really matter but if you get a aftermarket cam with 3 bolt then you will need the correct sprocket.

Also, it looks like we might be running this thing on 98 octane. That makes things a little more exciting. From what rando idtiots on the internet say, I can safely run 11.0:1 compression, and 11.5:1 is pushing it, but I'm wondering if dynamic compression on a big cam would allow a 12.0:1 static ratio if I tightened the lobe separation angle? What would that do to fuel economy, which is actually a concern in endurance racing?

 

[Road Trip]

might be running this thing on 98 octane. That makes things a little more exciting. From what rando idtiots on the internet say, I can safely run 11.0:1 compression, and 11.5:1 is pushing it, but I'm wondering if dynamic compression on a big cam would allow a 12.0:1 static ratio if I tightened the lobe separation angle? What would that do to fuel economy, which is actually a concern in endurance racing?

ETA,

Your theoretical build of a LS-based endurance engine is an interesting proposition.
I have been looking, but it seems that there is a dearth of information for setting up
LS motors for 24-hour style racing? But there's *plenty* of info for short-duration
racing like the drag strip?

I got to thinking about this. Syracuse & it's suburbs are ~650,000 people. At the
local drag strip (ESTA Safety Park) I'll bet that there is a max of 650 different participants
from the metro area during the year? So if you are a drag racer, you make up 0.1% of the population?

And what is the ratio of 24-hour endurance racers to drag racers? 1 endurance racer for every
1000 drag racers? Making you and your ilk such a tiny audience (0.0001%?) that
this is the reason for so few articles/discussions?

****

Anyway, there are countless articles about making huge amounts of LS power for short bursts,
but that's not solving your stated problem. You've already said as much, but it seems that the
key to success to still be hard charging after 24 hours of max effort is thermal management.
Instead of discussing the obvious about cooling systems, I thought that I'd discuss an area that
may give you a performance & reliability edge over your competition.

More specifically, I'm thinking of cooling the underneath of your pistons using piston oil squirters.
(Note: Chevy does this to the LS9 & LSA motors -- both boosted from the factory.) Simply put,
the piston face is the bottom 1/2 of the combustion chamber, and normally ALL of the heat that
the piston gains during operation is sinked to the water jacket via the piston rings. Of course,
the center of the piston is the furthest away, so there's a distinct thermal gradient from the
center to the ring lands > rings > bore > water jacket. And this also helps to explain where
the majority of heat-related holing of the pistons occurs.

Meanwhile, the upper half of the combustion chamber is surrounded by the water jacket,
so the excess heat from combustion doesn't have nearly as far to travel.

So the idea of oil-cooling the inside center of the pistons makes perfect sense. Of course
there's always a tradeoff, in that you will need more oil volume from the oil pump, and also
that you really need to employ a good crank scraper/windage tray combo to take that (hopefully)
heated additional engine oil and get it back to the pan asap...instead of it all winding up in long
hp-robbing viscuous ropes around the spinning crank assembly.

Since GM reserves the piston oil squirters for factory supercharged motors, most folks
don't think it's necessary. But *you* the endurance racer are a 0.0001%'er, so even
though you're staying NA, you are doing so for 24 hours at a time. Not only will you be
gaining piston strength (by lowering it's operating temperature) you can also avoid
having to use excess fuel for cooling like some short event competitors do. (Or looking
at it another way, avoid having full power available at the beginning of the race, but having the
knock sensors/computer pulling timing at the end of the race where you still need all the
power possible?)

EDIT: It was your 12:1 compression comment that got me to thinking about what
you would need to do in order to be able to up your mechanical compression ratio
without having to pull timing out of the tune, especially after hours of running at WOT.

Poking around a bit, I found 3 photos of interest showing LS owners adding piston
oil squirters to their motors. (Discussion here.)

****

And while we are busy thinking about keeping things cool while running nonstop
for 24 hours at a time, how about the valvesprings? Every time we compress &
relax a valve spring, this creates heat. In your travels around the interwebs, have
you read about anyone using oil to control valve spring heat in LS motors?

Bottom line, I think that doing this upgrade to a LQ9 endurance motor would
be something to look into. Food for thought...

 

[Road Trip]

Since you are schooling yourself up on these new generation LS engines,
it never hurts to see what Chevrolet is offering racers for crate engines.
I stumbled across this 24-page .pdf file which has a lot of good tech having to
do with a 525+hp LS circle track crate motor. (Chevy LS Racing Crate Motor.)

Here's the specs page for your viewing pleasure:

You must be registered for see images attach

This brochure could be anything from very helpful to explain what the Chevy engineers want in a racing version LS
to a complete rehash of stuff you've already found elsewhere...but just in case. :0)

EDIT: I found that the oil they specified for this engine to be very interesting. Didn't see that coming. (!)

 

[Road Trip]

Here's one more article that has helped me come up to speed -- the complete
history of all the members of the LS motor family -- 33 web pages worth: (Here)

For example, here's a helpful chart I found on pg. 7:

You must be registered for see images attach

You must be registered for see images attach

(credit: Motortrend article -- LINK)
I'm on a laptop, so once I've looked at all 33 pages, I just leave it in a tab, and thanks to the nice formatting I can
quickly back arrow <> forward arrow through all these motors. Really helps this old guy navigate through the LS alphabet soup.

Funny, growing up with the old SBC I always just knew that the 307 wasn't 5 better than the DZ302. Guess it's time for
Rip van Road Trip to wake up & get acquainted with the new stuff.

Hope this proves helpful --

 

[RDF1]

Re-reading this thread with some more of the stuff I've learned, I have a new question. What's the difference between a 4x cam sprocket and a 1x cam sprocket?


Also, it looks like we might be running this thing on 98 octane. That makes things a little more exciting. From what rando idtiots on the internet say, I can safely run 11.0:1 compression, and 11.5:1 is pushing it, but I'm wondering if dynamic compression on a big cam would allow a 12.0:1 static ratio if I tightened the lobe separation angle? What would that do to fuel economy, which is actually a concern in endurance racing?

So the 1999-2007 Trucks used a 1 tooth cam reluctor (rear of the camshaft) and also they used a 24 tooth crank reluctor.
In 2008 for the trucks they started using a 4 tooth reluctor (Cam sprocket had the tooth count) and 58 tooth crank reluctor.

Here is some pics to maybe make it easier.
A is a 2008-2014 Cam sprocket that had one bolt holding it in and didnt have the Variable Valve TIming
B is a 3 bolt cam sprocket for the Gen 4 Stuff.
C is a LS2 that was a 1x cam and had 3 bolts
D is a 99-07 Truck cam sprocket with no "teeth" as the camshaft has the reluctor on the rear of it.

 

[RDF1]

Re-reading this thread with some more of the stuff I've learned, I have a new question. What's the difference between a 4x cam sprocket and a 1x cam sprocket?


Also, it looks like we might be running this thing on 98 octane. That makes things a little more exciting. From what rando idtiots on the internet say, I can safely run 11.0:1 compression, and 11.5:1 is pushing it, but I'm wondering if dynamic compression on a big cam would allow a 12.0:1 static ratio if I tightened the lobe separation angle? What would that do to fuel economy, which is actually a concern in endurance racing?

Here is a close up pic of the 58x on the left and a 24x on the right.
11.5 is still nothing crazy these days for 93 octane. we have run some 12.0 on 93 just have to pay attention to spark plugs and timing.
I would talk to a cam guru for that kinda question tho, If you need rpms your going to have to run a certian size cam that plays nice with your intake/exhaust setup.

 

[RDF1]

Since you are schooling yourself up on these new generation LS engines,
it never hurts to see what Chevrolet is offering racers for crate engines.
I stumbled across this .pdf file which has a lot of good tech having to
do with a 525+hp LS circle track crate motor. (Chevy LS Racing Crate Motor.)

Here's the specs page for your viewing pleasure:

You must be registered for see images attach

This brochure could be anything from very helpful to how the Chevy engineers went about it to a complete
rehash of stuff you've already found...but just in case. :0)

EDIT: I found that the oil they specified for this engine to be very interesting. Didn't see that coming. (!)

0w40?
Im guessing they go with 0 for the cold starting.
I use 5w40 in a lot of turbo LS trucks but 20w50 in the race cars.

 

[L31MaxExpress]

ETA,

Your theoretical build of a LS-based endurance engine is an interesting proposition.
I have been looking, but it seems that there is a dearth of information for setting up
LS motors for 24-hour style racing? But there's plenty of info for short-duration
racing like the drag strip?

I got to thinking about this. Syracuse & it's suburbs are ~650,000 people. At the
local drag strip (ESTA Safety Park) I'll bet that there is a max of 650 different participants
from the metro area during the year? So if you are a drag racer, you make up 0.1% of the population?

And what is the ratio of 24-hour endurance racers to drag racers? 1 endurance racer for every
1000 drag racers? Making you and your ilk such a tiny audience (0.0001%?) that
this is the reason for so few articles/discussions?

****

Anyway, there are countless articles about making huge amounts of LS power for short bursts,
but that's not solving your stated problem. You've already said as much, but it seems that the
key to success to still be hard charging after 24 hours of max effort is thermal management.
Instead of discussing the obvious about cooling systems, I thought that I'd discuss an area that
may give you a performance & reliability edge.

More specifically, I'm thinking of cooling the underneath of your pistons using piston oil squirters.
(Note: Chevy does this to the LS9 & LSA motors -- both boosted from the factory.) Simply put,
the piston face is the bottom 1/2 of the combustion chamber, and normally ALL of the heat that
the piston gains during operation is sinked to the water jacket via the piston rings. Of course,
the center of the piston is the furthest away, so there's a distinct thermal gradient from the
center to the ring lands > rings > bore > water jacket. And this also helps to explain where
the majority of heat-related holing of the pistons occurs.

Meanwhile, the upper half of the combustion chamber is surrounded by the water jacket,
so the excess heat from combustion doesn't have nearly as far to travel.

So the idea of oil-cooling the inside center of the pistons makes perfect sense. Of course
there's always a tradeoff, in that you will need more oil volume from the oil pump, and also
that you really need to employ a good windage tray to take that (hopefully) heated
additional engine oil and get it back to the pan...instead of it all winding up in long hp-robbing
viscuous ropes around the spinning crank assembly.

Since GM reserves the piston oil squirters for factory supercharged motors, most folks
don't think it's necessary. But *you* the endurance racer are a 0.0001%'er, so even
though you staying NA, you are doing so for 24 hours at a time. Not only will you be
gaining piston strength (by lowering it's operating temperature) you can also avoid
having to use excess fuel for cooling like some do. (Or looking at it another way,
not having full power at the beginning of the race, but having the knock sensors/computer
pulling timing at the end of the race where you still need it all?)

EDIT: It was your 12:1 compression comment that got me to thinking about what
you would need to do in order to be able to up your mechanical compression ratio
without having to pull timing out of the tune.

Poking around a bit, I found 3 photos of interest showing LS owners adding piston
oil squirters to their motors. (Discussion here.)

****

And while we are busy thinking about keeping things cool while running nonstop
for 24 hours at a time, how about the valvesprings? Every time we compress &
relax a valve spring, this creates heat. In your travels around the interwebs, have
you read about anyone using oil to control valve spring heat in LS motors?

Bottom line, I think that doing this upgrade to a LQ9 endurance motor would
be something to look into. Food for thought...

Definitely consider the piston squirters. Not on a LS, but the VK56VD all came with piston squirters from the factory. My Infiniti M56S was close to 12:1 from the factory and ran well on 93 octane pump gas. It could be run WOT for a mile or more at a time without having any signs of detonation. That car had close to 150K on it when it met its demise. It was a very strong runner at that time even. I hit the remains of an aluminum ladder at 80 mph that the truck in the next lane over hit and spun in front of me, which took out the front subframe, steering racks (both front and rear), and transmission case.

 

[L31MaxExpress]

Since you are schooling yourself up on these new generation LS engines,
it never hurts to see what Chevrolet is offering racers for crate engines.
I stumbled across this .pdf file which has a lot of good tech having to
do with a 525+hp LS circle track crate motor. (Chevy LS Racing Crate Motor.)

Here's the specs page for your viewing pleasure:

You must be registered for see images attach

This brochure could be anything from very helpful to how the Chevy engineers went about it to a complete
rehash of stuff you've already found...but just in case. :0)

EDIT: I found that the oil they specified for this engine to be very interesting. Didn't see that coming. (!)

0W20?