GM why not a DOHC LS motor?
#41
TECH Addict
iTrader: (21)
Join Date: Dec 2006
Location: Port Saint Lucie,Florida
Posts: 2,767
Likes: 0
Received 1 Like
on
1 Post
![Default](https://ls1tech.com/forums/images/icons/icon1.gif)
GM was going to go w/a DOHC motor but they put 2 Vettes w/ different motors 1 as a LT4 and he other w/a LT5 (ZR-1) and let the big wigs drive both cars w/out telling them which car had which motor and in the end they all picked the LT-4 Vette so the designed the LS-1 and stayed w/ the pushrod motor.
#42
LS1Tech Administrator
iTrader: (3)
Join Date: Nov 2001
Location: Schiller Park, IL Member: #317
Posts: 32,338
Likes: 0
Received 1,775 Likes
on
1,265 Posts
![](https://ls1tech.com/forums/images/ranks/ls1tech20year.png)
![Default](https://ls1tech.com/forums/images/icons/icon1.gif)
Agreed.
Which is why I can't understand how anyone can be excited about the possibility of the next generation of LSx's being smaller displacement. There is a thread going in the Auto News section about the "LS5" being a 5.5L to replace the current 6.2L. I don't see this as a good thing for a street engine, yet some seem to like it. I do understand the benefits of a smaller displacement/lighter rotating mass engine and the potential for higher rpm operation, and how this can be desireable in certain race applications. But I don't see that being more desireable than a larger displacement engine that makes more power and torque at lower rpms for a factory street motor.
Like I said in the other thread, I'd like to see the LS3-replacement debut with 6.5L, not 5.5L.
Which is why I can't understand how anyone can be excited about the possibility of the next generation of LSx's being smaller displacement. There is a thread going in the Auto News section about the "LS5" being a 5.5L to replace the current 6.2L. I don't see this as a good thing for a street engine, yet some seem to like it. I do understand the benefits of a smaller displacement/lighter rotating mass engine and the potential for higher rpm operation, and how this can be desireable in certain race applications. But I don't see that being more desireable than a larger displacement engine that makes more power and torque at lower rpms for a factory street motor.
Like I said in the other thread, I'd like to see the LS3-replacement debut with 6.5L, not 5.5L.
#48
TECH Resident
Join Date: Apr 2009
Location: Wouldnt believe me if i told you
Posts: 768
Likes: 0
Received 0 Likes
on
0 Posts
![Default](https://ls1tech.com/forums/images/icons/icon1.gif)
Get some low rolling resistance tires, keep them over inflated.
Set up a nitrous system or if you dont want spray set up some sort of a turbo or twin turbo system.
Tune in a lean cruise.
Reduce weight.
Lower car.
Improve aero in a few ways.
Reduce weight.
And with that you should be pretty close, i can see how C6 vettes can easily get over 30mpgs since i get almost 30, sometimes right at 30 or rarely slightly above on the highway, and the vette has 1000 less pounds, longer gears, and better aero.
#50
TECH Addict
iTrader: (8)
Join Date: Oct 2008
Location: toronto ontario canada
Posts: 2,047
Likes: 0
Received 2 Likes
on
2 Posts
![Default](https://ls1tech.com/forums/images/icons/icon1.gif)
i don not understand why people just judge cylinder heads by flow, what about port velocity...... ?
#51
TECH Enthusiast
iTrader: (2)
Join Date: Aug 2008
Location: Alberta, Canada
Posts: 617
Likes: 0
Received 0 Likes
on
0 Posts
![Default](https://ls1tech.com/forums/images/icons/icon1.gif)
When an OEM makes an engine, they have the following priorities to worry about (there are a lot more, but this answers the question)
Packaging size
Power output
Emission
Weight
Cost
Lets compare the 5.0 mustang motor to the LS3
LS3 is smaller
LS3 makes more power
LS3 is lighter
LS3 is cheaper (parts are used on all ls series of motors to get quanities of scale vs a single application)
The last time I was having a beer with some GM employees at a Ford event, this question came up.
Ryan
Packaging size
Power output
Emission
Weight
Cost
Lets compare the 5.0 mustang motor to the LS3
LS3 is smaller
LS3 makes more power
LS3 is lighter
LS3 is cheaper (parts are used on all ls series of motors to get quanities of scale vs a single application)
The last time I was having a beer with some GM employees at a Ford event, this question came up.
Ryan
Dont get me wrong here but, the new 5.0L is rated at 412HP, if you do some reading online and in the magazines out there, Ford is supposedly flat out lying, 1960's style, about this. Its been pegged at near 500HP at the crank.
I have been a GM guy all my life and owned one Ford and trust me, I will never make that mistake again. I hated it, I hated the dealerships, I hated working on it, I hated when I contacted Ford themselves, I hated the parts guys...hate hate hate. I LOVE the LS engines, especially the LS3, but Ford has FINALLY figured out this mod motor with DOHC. This thing is a monster. That new Mustang is an unbelievable package....styling, power, interior, mileage. Now just wait will they come out with the 6.2L version in the trucks.
Also, I see no one has mentioned GM's new Gen V V8s that will be hitting when the new 1/2 tons come out in 2014.
http://www.allpickuptrucks.com/blog/...ciency-e85-use
All aluminum and 'all new combustion system'. This means direct injection, IMO. Ford flat out said when the new 5L came out that it was designed for direct injection, so theres more in the that engine then there is new.
GM makes push rods work because they put the R&D into the engines, so when the new Gen V comes out I think itll be a road marker in the timeline of engine development.
#52
TECH Senior Member
iTrader: (7)
![Default](https://ls1tech.com/forums/images/icons/icon1.gif)
On the 5.0 vs LS3, the power "ratings" the ls3 makes more. In real works applications, lets say the 2 motors make very similar power numbers. The new 5.0 is not making 500 hp at the crank, stock. Our car stock puts down 365 or so. (2011 5.0 mustang automatic on a dynojet 224xLC) Our stock Stock 2010 Camaro LS3 puts down about the same numbers on the same dyno a year before. I cannot compare to a stock automatic, since the camaro automatic gets the l99 not a ls3 and makes far less power then the mustang automatic. The Camaro also has the IRS to suck out extra power.
The Ford 6.2 in the trucks is not the same engine, we're talking about a 2 spark plug per cylinder engine vs a single spark plug engine (far more technical differences, but a good way for the average person to know the head design is not the same) The 6.2 I tuned 3-5 months ago had good torque gains for a F350 superduty application on 87 octane.
To my knowledge the 5.0 was targeted for direct injection, but ford was able to meet all of the performance goals on conventional injection, which is better imho, it makes adding larger injectors and fuel pumps a simple parts bin excercise for performance shops, vs trying to figure out what bosch high performance units could be sourced from porsche and audi applications to support increased performance. (at a far higher cost than a $200 fuel pump or $400 set of injectors)
Ryan
The Ford 6.2 in the trucks is not the same engine, we're talking about a 2 spark plug per cylinder engine vs a single spark plug engine (far more technical differences, but a good way for the average person to know the head design is not the same) The 6.2 I tuned 3-5 months ago had good torque gains for a F350 superduty application on 87 octane.
To my knowledge the 5.0 was targeted for direct injection, but ford was able to meet all of the performance goals on conventional injection, which is better imho, it makes adding larger injectors and fuel pumps a simple parts bin excercise for performance shops, vs trying to figure out what bosch high performance units could be sourced from porsche and audi applications to support increased performance. (at a far higher cost than a $200 fuel pump or $400 set of injectors)
Ryan
Last edited by slow; 08-01-2010 at 12:45 PM.
#53
LS1Tech Administrator
iTrader: (3)
Join Date: Nov 2001
Location: Schiller Park, IL Member: #317
Posts: 32,338
Likes: 0
Received 1,775 Likes
on
1,265 Posts
![](https://ls1tech.com/forums/images/ranks/ls1tech20year.png)
![Default](https://ls1tech.com/forums/images/icons/icon1.gif)
As stated in the post above (and everywhere else you look where 5.0s have been dynoed or raced), their factory rating is pretty close to accurate.
#54
TECH Apprentice
iTrader: (15)
Join Date: Mar 2009
Location: Greenville, SC
Posts: 365
Likes: 0
Received 0 Likes
on
0 Posts
![Default](https://ls1tech.com/forums/images/icons/icon1.gif)
A DOHC LS motor??? Why don't they just go ahead and throw VTEC on it while their at it, and while you're in there, might as well chop 4 cylinders off so we can mod our cars to be JDM AZ *** just like all the other cool kids??
I'll keep my pushrods, thanks.
I'll keep my pushrods, thanks.
#55
TECH Fanatic
iTrader: (41)
Join Date: Jul 2007
Location: Lancaster California
Posts: 1,431
Likes: 0
Received 0 Likes
on
0 Posts
![](https://ls1tech.com/forums/images/ranks/ls1tech10year.png)
![Default](https://ls1tech.com/forums/images/icons/icon1.gif)
Here are a bunch of various OHC, DOHC, OHV engine designs from the past.
http://www.museumofamericanspeed.com...LLThumbs.shtml
.
http://www.museumofamericanspeed.com...LLThumbs.shtml
.