Hypothetically, could a 3 valve head have been made without swapping the intake and exhaust orientation?

 

Do GM engineers not talk to each other? GM has been using the tri-lobe for many years so why would it be something new for the LT1. That was my only point.

 

Ah yes, but imagine what a bit of fuel when the exhaust valve is open would do for spooling a big turbo!

 

perhaps the ecm has an antilag function as well.. lol

 

So this is a question, We have been putting Nitrous onto the DI 3.6 with no problems, will this motor take nitrous hits as well as the LSX based motors?

If we were to put a nitrous system on a new LT1 motor, would the ECU compensate the usually rich base tuneup? Would it try to lean out the mixture on the DI side by spraying less fuel? I'm just wondering how this engine is going to react to nitrous and fuel being injected threw the intake.

The nitrous is going to love the compression is something that I do know.

 

I am also extremely curious to see how it likes the nitrous.

 

Nitrous LOVES compression. It should be a win/win. One thing that i see is direct port on the stock manifold is going to be tricky. The runners are short with no rooms to put nozzle in up top. We are going to have to get a hold of an intake manifold to do a little R&D.

On a side not the throttle body looks awfully similar to the coyote throttle body. The bolt patter looks close for sure. Even the TPS/motor connection looks almost the same.

Problem that we had with the Mopar guys was timing pulling on the newer motors. Since the ECU has been cracked recently, you should see some newer Hemis getting more juice than 75. Their second problem is that the ringlands are narrow on the hemi.

If you have new internals the hemi can take large hits. We have a customer on 600 hp worth of nitrous on a modern hemi. 4000# four door, leaving off idle with IRS in low 9's and 140 traps. That's a freight train coming at you.

 

this is curious...

R07 Chamber/Valve configuration:


LT1 Chamber/Valve configuration:


R07 Exhaust Port (unfinished):


LT1 Exhaust Port:


R07 Intake Runner (unfinished):


LT1 Intake Runner:



there seems to be quite a lot of cues from the R07 in the new head. i dont think its all coincidence either.

my question is: did GM/the engineers do this on purpose? (eg. use the R07 as a sort of "proof of concept" of sorts before designing/building engines for use in ALMS)

 

You sir are a very smart man. You are the only one that picked up on this similarity. And you are correct 100% and I will explain why.

Heads are all about Velocity, Air Speed, Air Density and then Air Volume/AirFLOW/CFM.

The most important area in heads as far as I'm concerned is the valve inner diamater below the face of the valve. This sets the air speed in which the air enters and exits the combustion chamber.

The best heads on the market have people that understand the basics of fluid dynamics. At higher velocity and airspeed it becomes and behaves just like "karo-light corn syrup." When you have good shaped ports in which you designed your port to hit a velocity target/airspeed/ with the cross-sectional aresa. Your CFM number will always conformed to that.

I will get back to "CFM" in a moment and why you should not get caught up in the HYPE of high CFM rated heads.

Why are these heads similar?

The tightest part of the intake port through the bowl is subjective to the push rod pinch area. This is why we keep using offset rockers, and this is why these rockers are far off and mounted differently than any other LS ENGINE SERIES HEAD. We needed to make the port bigger. We did this for many reasons for N/A and future forced induction purposes. The HIGHEST AIRSPEED, VELOCITY, AND DENSITY is measured from the intake manifold plenum to the back of the valve.

For you guys that like to port or develop heads here is the key. The back of the valve is 2nd and 3rd place you can set the air velocity. At the pushrod subjective choke point as well. This is located of course in the intake port as mention earlier. This is the highest velocity cross sectional area in the heads. This is where those SUPER HIGH CFM numbers can get you into trouble. Going too fast and you develop pressure waves in the intake port and manifold. A good set of designed heads has the velocity set at the pushrod cross sectional areas in the heads and your air speed in the chamber at the inner valve diameter.

Going out grabbing the highest CFM rated heads is nothing but problems especially if they aren't refined and tuned heads for VELOCITY, AIR SPEED/AIR DENSITY and FLOW/CFM.

Always remember buying your heads based on CFM is a bad idea. Why? Because the Air Speed is too slow for the increase in RPM and increase size of the motor/stroked/bigger/bore etc. The Air Speed will be Slow because of those extra large valves and intake port is over sized. Pressure waves and slow air speed means your car will not live up to its full potential.

I am glad to see someone with the ability to see the attention to details. I am impressed.

The heads on the LT1 2014 are monsters in AIR VELOCITY, AIR SPEED, AIR FLOW/CFM. They are the best heads from a such a large automotive company. These heads have a job to do and they perform like you wouldn't believe.

These heads output insanely high horsepower numbers. Especially in forced induction.


Bigg Gunz.

 

To be honest we never test the engines with oxides. To put an oxide on this engine it's behavior would be unpredictable that's for sure. The engine is structurally solid but that is only part of the equation. The major question is how would the ECM react? Someone is going to have to get the 2014 CORVETTE and find out because they will not allow us to oxide a engine.


Bigg Gunz

 

No



Bigg Gunz

 

Nothing about this engine or ECM is a fail. This engine will perform as expected and will be the most amazing platform to get alone with. The N/A version of this engine is kinder and sweeter of what is too come. And this engine is no nancy itself.

The ECM is capable of doing many things we are at the point where technology allows many things. Begrateful it's not a harddrive there are others that wanted to put a harddrive in it reliability out the window and all sorts of issues.

We've had enough time to get this right and we think we nailed it. We aren't blind to the fact that at the end of the day. The consumer has the finally verdict on our development. So with that said enjoy the fruits of our labor when the moment arrives.


Bigg Gunz.

 

Thanks for the response. Im sure the engine is going to take it quite well. The LSX motors are doing great with large amounts of nitrous. We have customers hitting 350 horsepower on stock rotating assemblies. You guys are making solid motors. Kuddos to your engineers. Im sure we will have a customer coming to us soon after they come out.

Question, do you think that the ECU would demand timing to be pulled if it is seeing an elevated oxygen level? Something that came to mind is if the ECU is smart enough to pull some timing if a dry shot was introduced before the mass air flow sensor. (if there is a MAF sensor). On the flip side, would the fuel be added to compensate for the elevated oxygen levels if nitrous was sprayed pre mass air flow.

 

Why use rectangular style heads instead of cathedral style if intake velocity is so important? It would seem that rectangular style heads were designed with volumetric flow rate in mind and not air velocity. This becomes very apparent when the ports are enlarged between the two designs and cathedral style can flow as much if not more on a smaller cc port due to the venturi effect.

 

This engine was developed for other purposes than N/A. Which is why we went with larger ports/rectangular shapes. Cathedrals are great port shapes they have limits in OEM form. In the aftermarket I'm sure they are capable of great VELOCITY and VOLUME. However for what we need to accomplish in OEM and expand output later, they wasn't up to the task.
I will say that you are correct. A lot of volume flowing thru smaller ports = HIGH VELOCITY = Makes for a fun engine.

However we have to remain in OEM form.


Bigg Gunz

 

For extra VOLUME in air the engine would add more fuel and more timing. A spike in EGT the engine would pull timing for sure. It's difficult to predict what the ECM would do on oxides as they due drop intake temps and burn hotter which would raise EGT. This is a grey area and I can honestly say... I don't know what would happen. Since no two oxide strikes are the same. If the ECM determine there was variables that was too radical expect 231cu in mode.
A dry shot sounds good in theory, however the ECM parameters and the oxides aren't going to play together well is my guess. But then again... I'm honestly saying. I don't know what would happen.


Bigg Gunz

 

Good stuff!

 

So it sounds like these motors will have EGT probes from the factory, which would also explain the exhaust manifold ports on the production truck engine picture released a couple months back. Can you tell us what the accesory was on the lower left of that motor BG? It looked like a smog pump.

 

Ok cool EGT is a nice addition for close loop controls.

 

Looking forward to news on BIG BROTHER, can you say when the silence may be broken?.... could it be a 427 or did I miss a yes or no on that earlier in this thread ?