Ls5?
TECH Fanatic
Joined: Aug 2005
Posts: 1,691
Likes: 1
From: Sunny London, UK
How do you know the new LS7 tyep heads with larger intake valve dont have more cross sectional area for better max bhp?
These heads might be good for low end torque and power due to high velocity ports. But whether they flow any more than the new larger single valve heads remains to be seen.
Question is are they slated for production or just some of the many prototype builds that never get used?
These heads might be good for low end torque and power due to high velocity ports. But whether they flow any more than the new larger single valve heads remains to be seen.
Question is are they slated for production or just some of the many prototype builds that never get used?
Launching!
Joined: Jul 2004
Posts: 204
Likes: 0
From: Arizona.
This is a big development. I'll trade torque for HP anyway within reason. All HP is, is high RPM torque. If you have great torque still but you make HP out to higher RPMs, the you get to stay in your lower gears much longer going down the track.
It makes sense that these heads are going to make more HP gains than torque gains. Torque is all about how much air you can burn in a given rev. These heads on a 6+L bottom end will do fine in that dept. But with the extra flow, the real advantage is that they can burn more air over time in the higher revs.
A stalled A6 and these, IMHO, will be a freakin nightmare. Lots of old school guys will laugh at it untill they see the numbers.
It makes sense that these heads are going to make more HP gains than torque gains. Torque is all about how much air you can burn in a given rev. These heads on a 6+L bottom end will do fine in that dept. But with the extra flow, the real advantage is that they can burn more air over time in the higher revs.
A stalled A6 and these, IMHO, will be a freakin nightmare. Lots of old school guys will laugh at it untill they see the numbers.
On The Tree
Joined: Jan 2004
Posts: 188
Likes: 0
From: Houston/ Austin, TX
Am I the only person that thinks these arent a good idea? That exhaust rocker system looks very unstable, not to mention a very heavy valvetrain.
IMO, it looks like it would have alot of the problems associated with Ford modular V8 motors. If you have seen how bass ackwards those heads are, you would understand what I am talking about, namely the intake valve and its crazy angle to the port.
Im gonna stick with my 2v heads, I dont like the thought of all that crazieness. I like to stay simple and have it work. Not a huge fan of lots of little moving parts to break and kill a motor.
-2c
IMO, it looks like it would have alot of the problems associated with Ford modular V8 motors. If you have seen how bass ackwards those heads are, you would understand what I am talking about, namely the intake valve and its crazy angle to the port.
Im gonna stick with my 2v heads, I dont like the thought of all that crazieness. I like to stay simple and have it work. Not a huge fan of lots of little moving parts to break and kill a motor.
-2c
The question I have is, why go multi-valve on the intake side?? The LS7 and L92 heads have PLENTY of intake flow... what we really need is more exhaust flow.
Don't get me wrong, the engineers know a lot more about this than I do (and their goals are likely different, since they have to design with emissions, etc... in mind), but that just seems pretty obvious.
Also, like many of the others, I have to wonder where the torque is... and the only thing that I can conclude is that those two intake valves each have a pretty good sized port, which isn't conducive to high port velocity/good cylinder filling at "low" revs.
One more thing... I, too, distrust the additional pushrod... just seems like another point of failure.
I dunno... I like the HP number, but that's really about it... the torque number isn't bad, but frankly, the torque is part of what makes the Corvette the car that it is... because of the low rev torque, the car doesn't have to have crazy gears in order to be able to perform. That allows relatively low revs when cruising, which in turn allows for a 400 hp car to get around 30 mpg on the highway.
Like I said, 385 ft/lb is nothing to sneeze at, but it's also nothing to write home about (in light of the HP number).
Don't get me wrong, the engineers know a lot more about this than I do (and their goals are likely different, since they have to design with emissions, etc... in mind), but that just seems pretty obvious.
Also, like many of the others, I have to wonder where the torque is... and the only thing that I can conclude is that those two intake valves each have a pretty good sized port, which isn't conducive to high port velocity/good cylinder filling at "low" revs.
One more thing... I, too, distrust the additional pushrod... just seems like another point of failure.
I dunno... I like the HP number, but that's really about it... the torque number isn't bad, but frankly, the torque is part of what makes the Corvette the car that it is... because of the low rev torque, the car doesn't have to have crazy gears in order to be able to perform. That allows relatively low revs when cruising, which in turn allows for a 400 hp car to get around 30 mpg on the highway.
Like I said, 385 ft/lb is nothing to sneeze at, but it's also nothing to write home about (in light of the HP number).
Originally Posted by BurnOut
The question I have is, why go multi-valve on the intake side?? The LS7 and L92 heads have PLENTY of intake flow... what we really need is more exhaust flow.
I I agree with the above statement. That is what most of the world fails to understand is that torque is what allows the LSx series of engines to be as efficient as they are. What we call torque most of the time is not really torque though. What we are referring tpo is low rpm HP. Torque is a measure of the ability to hold. HP is the measure of the ability to move.jmho
dunno... I like the HP number, but that's really about it... the torque number isn't bad, but frankly, the torque is part of what makes the Corvette the car that it is... because of the low rev torque, the car doesn't have to have crazy gears in order to be able to perform. That allows relatively low revs when cruising, which in turn allows for a 400 hp car to get around 30 mpg on the highway.
Originally Posted by Katech
I'm thinking the 2 smaller intake valves placement allows for a larger exhaust valve.
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Originally Posted by Katech
I'm thinking the 2 smaller intake valves placement allows for a larger exhaust valve.
(trying to keep you out of trouble here...)Anyhow, the other big factor here is that we don't know what the cam looks like. If I were a betting man, I'd say that it has a pretty wide LSA...
Launching!
Joined: Jul 2004
Posts: 204
Likes: 0
From: Arizona.
The fact that there are two intake valves and a larger ex valve also means you dont need massive lift to get decent flow. Someone was saying it would have a wide LSA, and I think so too.
I don wonder about the geometry too, but modern metalurgy is pretty amazing. Im sure they can make it work just fine.
I don wonder about the geometry too, but modern metalurgy is pretty amazing. Im sure they can make it work just fine.
Originally Posted by BurnOut
Given that you may have seen the heads, I'm thinking that you may be on to something. (trying to keep you out of trouble here...)
Anyhow, the other big factor here is that we don't know what the cam looks like. If I were a betting man, I'd say that it has a pretty wide LSA...
(trying to keep you out of trouble here...)Anyhow, the other big factor here is that we don't know what the cam looks like. If I were a betting man, I'd say that it has a pretty wide LSA...
TECH Addict
Joined: Aug 2004
Posts: 2,866
Likes: 4
well in my eyes its simple! you got dissplacment and now you got valves to! thats a gooooddddd mix in anyones books! 
seriously though people this thing will allways be better. it will let you run big power with less cam and that negates the heavy vavle train. simple as
would anyone like to say what might happen to the head manufactures (aftermarket) if these heads are as good as everyone thinks, and they retro fit well????????
thanks Chris.
seriously though people this thing will allways be better. it will let you run big power with less cam and that negates the heavy vavle train. simple as
would anyone like to say what might happen to the head manufactures (aftermarket) if these heads are as good as everyone thinks, and they retro fit well????????
thanks Chris.
Staging Lane
Joined: Mar 2006
Posts: 56
Likes: 0
Originally Posted by Katech
I haven't seen one disassembled.
Adam
The only way I could see this as a good thing (i.e. improvement over the pre-existing 2 valve heads) is that it has an incredibly small camshaft yet still able to make that much hp. That would explain the relatively low torque but have very low emissions and get better gas mileage. I may be wrong, someone correct me if I am.
Two things come to mind when I see these heads.
1. What does the combustion chamber look like, flow is great, but combustion chamber shape has almost an equal effect on power production.
2. With the 3 valve set up the heads are as bid as DOHC heads, why not just do that? then we get two of each valve.
Never the less I wait in anticipation for this motor.
Josh
1. What does the combustion chamber look like, flow is great, but combustion chamber shape has almost an equal effect on power production.
2. With the 3 valve set up the heads are as bid as DOHC heads, why not just do that? then we get two of each valve.
Never the less I wait in anticipation for this motor.
Josh
Originally Posted by svsgt1
Katech, In your opinion "based only on seeing it" (and nothing else so you don't get in trouble) do you think this head will bolt up to the LS1/2 engines?
Adam
Adam
from the pics it looks like it will not be a simple retrofit, if its possible at all
on ls1/6 bores
perhaps the min. bore would have to be 4.065 or the l92's bore or bigger
ls7 block, LSX block etc.
Originally Posted by DesertFox
Two things come to mind when I see these heads.
1. What does the combustion chamber look like, flow is great, but combustion chamber shape has almost an equal effect on power production.
2. With the 3 valve set up the heads are as bid as DOHC heads, why not just do that? then we get two of each valve.
Never the less I wait in anticipation for this motor.
Josh
1. What does the combustion chamber look like, flow is great, but combustion chamber shape has almost an equal effect on power production.
2. With the 3 valve set up the heads are as bid as DOHC heads, why not just do that? then we get two of each valve.
Never the less I wait in anticipation for this motor.
Josh
Got one word for ya ... expensive .. GM power train has made the decision long time ago that the LS series engine is the long term power plant in V8 applications..GM is not going to spend a bunch of money in R&D to produce a low volumn speciality motor.. they have the right engine now.. you are going to see more refinments of the LS engine family for a long time to come..forget about the 4 valve per cyl. DOHC engine configuratin.. it is not happening ..
Originally Posted by slt200mph
Got one word for ya ... expensive .. GM power train has made the decision long time ago that the LS series engine is the long term power plant in V8 applications..GM is not going to spend a bunch of money in R&D to produce a low volumn speciality motor.. they have the right engine now.. you are going to see more refinments of the LS engine family for a long time to come..forget about the 4 valve per cyl. DOHC engine configuratin.. it is not happening ..
