How does DOHC make more power than pushrod?
02-06-2004, 05:10 PM
#61
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Originally Posted by roger
The 4.6 has proved itself.if i remmember right the fastest n/a full body car is a mod engine,not a ls1 style engine.look at www.modularperformance.com
Bob Cosby ran an 11.60 @114? I know the stock internal NA LS1's are faster than that, some trapping over 120mph.
Originally Posted by roger
another consern was NVH(noise,vibration,harshness)which for the regular customer is a big deal.the 4.6 hands down is a smoother engine.trust me i know.i work at a dealership that deals with both.
Originally Posted by roger
cam wise the 4.6 run about 10degrees less valve duration than the standard ls1.(186-194,.392lift)this does figure into the NVH side of the arguement.its been proven that by adding the fr500 cams (204-214,.472)into a mod you pick up about 35rwhp.big increase by upping the cam to similar specs of the ls1 hmmmm.
Originally Posted by roger
bottom line 4valve will make more power but its not a given.look at the old zr1 this thing would make crazy power if it were still produced today.10 years ago it was making what the zo6 is making now.thats what cubes and 4valves will do for ya. 
02-06-2004, 05:41 PM
#62
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im not talking about a stock bottom end setup,go to the site.
actually the fr500 cams were designed with emmissions in mind it does pass with these cams.
thats not true on your cam statement it was done this way for smoothness.lets face it hotrodders dont come first with the car companies.gm took a chance on adding so much power to the cars in hopes it would swing sales. it didnt.......ford didnt have to take that chance.
actually the fr500 cams were designed with emmissions in mind it does pass with these cams.
thats not true on your cam statement it was done this way for smoothness.lets face it hotrodders dont come first with the car companies.gm took a chance on adding so much power to the cars in hopes it would swing sales. it didnt.......ford didnt have to take that chance.
02-06-2004, 07:02 PM
#63
Ford sucks..........
No J/K
I believe had GM created a 4 valve motor 12 years ago, and continued to try and improve on that design we would have one hell of a motor coming in the LS2.
Ford hasn't taken advantages of the 4 valve. Their heads clearly outflow ours minus the 1,000,000 dollar C5R heads. Having about 65 more cubes is a big advantage for us and a big disadvantage for them.
To the guy that posted the LSx motors aren't making 1 hp per cube is wrong.
The current Z06 makes 405 hp with just 346 cubes, I would say that is way better then 1 hp per cube. Throw that bitch on a dyno and you are still a little over 1 hp per cube to the wheels. The great thing about that is we just geten started.
I can see why GM guys stay with GM. I dont understand why Mustang drivers that buy mustangs because they want a fast street car dont buy a GM.
I have no idea why the Mustang out sold the Camaro and TA combined by like 70%.
I guess the avarage american is not that smart.
One thing that this arguement has brought up is the fact that this car with this mad makes this much power.
GM and Ford dont make cars to see how fast they can go 20000 dollars later.
They build cars knowing that 80% of buyers will leave it stock.
All I know is that a stock LS1 blows the doors off a stock fuckstang.
The Cobra had to add a SC and still dosen't out run a stock Z06.
There are defentially some advantages with the 4 valve motors, and if Ford would ever figure out that their *** is different then their brain they most realize how to take advantage of this. Maybe their time is coming.
My neighbor had a 2001 ford mustang, after doing headers, exhaust, and a chip he thought he had a fast car. And then he raced a Stock Ls1 M6 from a stop, from a roll, and probally even in reverse.
He now has a 2001 Camaro.
Weird.
I am doing my best not to be negative to the ford guys here, there are a ton of them in my back yard that I hang with, however fact's are fact's.
Until ford does something different they will always be behind.
No J/K
I believe had GM created a 4 valve motor 12 years ago, and continued to try and improve on that design we would have one hell of a motor coming in the LS2.
Ford hasn't taken advantages of the 4 valve. Their heads clearly outflow ours minus the 1,000,000 dollar C5R heads. Having about 65 more cubes is a big advantage for us and a big disadvantage for them.
To the guy that posted the LSx motors aren't making 1 hp per cube is wrong.
The current Z06 makes 405 hp with just 346 cubes, I would say that is way better then 1 hp per cube. Throw that bitch on a dyno and you are still a little over 1 hp per cube to the wheels. The great thing about that is we just geten started.
I can see why GM guys stay with GM. I dont understand why Mustang drivers that buy mustangs because they want a fast street car dont buy a GM.
I have no idea why the Mustang out sold the Camaro and TA combined by like 70%.
I guess the avarage american is not that smart.
One thing that this arguement has brought up is the fact that this car with this mad makes this much power.
GM and Ford dont make cars to see how fast they can go 20000 dollars later.
They build cars knowing that 80% of buyers will leave it stock.
All I know is that a stock LS1 blows the doors off a stock fuckstang.
The Cobra had to add a SC and still dosen't out run a stock Z06.
There are defentially some advantages with the 4 valve motors, and if Ford would ever figure out that their *** is different then their brain they most realize how to take advantage of this. Maybe their time is coming.
My neighbor had a 2001 ford mustang, after doing headers, exhaust, and a chip he thought he had a fast car. And then he raced a Stock Ls1 M6 from a stop, from a roll, and probally even in reverse.
He now has a 2001 Camaro.
Weird.
I am doing my best not to be negative to the ford guys here, there are a ton of them in my back yard that I hang with, however fact's are fact's.
Until ford does something different they will always be behind.
02-06-2004, 07:07 PM
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The LS1's only been around half the time the 4.6 has if your talking about all out moddifications to it. Give it 11 years and see where it's at.
If you believe this statement I feel sorry for you. GM didn't bump hp at the cost of "smoothness" just to get more people to buy Camaro's and Firebirds. The Camaro and Firebird have beaten every Mustang from 1993-2002 in terms of hp and straight line performance. Ford sold the mustang because it's less of a sports car with it's upright seating. More woman found it easier to drive and that's why the Mustang's still around. The Camaro and Firebird lost huge sales because it became too sports car like. Look at road racing the F-bodies clean house every year.
Anyway back to DOHC vs OHV. You do know the LS6 makes more hp per liter than even the 320hp 4.6L DOHC engine made right? Got better gas mileage due to the low rpm torque and it's ability to use a 6-speed transmission. LS6 is a smaller lighter package that costs less money to make and is easier to work on.
DOHC in a Ferrari is definately light years ahead of Ford's offering and actually uses the DOHC design like it was intended to be used. I see no real advantage to a restrained DOHC like the Ford 4.6l over the LS based engines.
Originally Posted by roger
thats not true on your cam statement it was done this way for smoothness.lets face it hotrodders dont come first with the car companies.gm took a chance on adding so much power to the cars in hopes it would swing sales. it didnt.......ford didnt have to take that chance.
Anyway back to DOHC vs OHV. You do know the LS6 makes more hp per liter than even the 320hp 4.6L DOHC engine made right? Got better gas mileage due to the low rpm torque and it's ability to use a 6-speed transmission. LS6 is a smaller lighter package that costs less money to make and is easier to work on.
DOHC in a Ferrari is definately light years ahead of Ford's offering and actually uses the DOHC design like it was intended to be used. I see no real advantage to a restrained DOHC like the Ford 4.6l over the LS based engines.
02-06-2004, 08:49 PM
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Originally Posted by Heretic
LS6 OHV vs LT5DOHC both 5.6l
405hp to 405hp
$5200 vs $20,000 (current crate engine cost)
OHV>DOHC
405hp to 405hp
$5200 vs $20,000 (current crate engine cost)
OHV>DOHC
02-06-2004, 09:20 PM
#66
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I don't know where people get some of this stuff but the 4 valve is always gonna be superior to the 2 valve except in packaging and cost. The reality though is what ChrisB said and that's that all the real numbers favor the larger 2 valve LS1 which can't really even be argued anymore. To overcome the size advatage Ford had to put on a supercharger basically because they don't want to twist a production engine to the moon to keep up with the mountain motor LS1.
4 valves though still beats everything all the time from large diesels to F1 you won't see any 2 valve stuff that's competitive if it's stuck up against 4 valves. In NASCAR Ford and Yates and others looked at running the mod motor as a winston cup type deal but preliminary versions were already nearing 1000 hp in that trim so NASCAR said no. The LSx stuff we're talking about can't even touch this stuff although the C5R would be probably capable of getting closer. Now if there was a larger bore 4 valve in the picture there would again be no contest at all.
All that said the LSx series are better because of one thing mainly and that's engine size. You can't beat cubic inches unless you can turn a lot more rpm with the smaller engine and Ford's 4V doesn't so it's down on power and slower. The Cobra R had a larger 5.4 mod motor and was faster by a lotover the regular 4.6 stuff.
4 valves though still beats everything all the time from large diesels to F1 you won't see any 2 valve stuff that's competitive if it's stuck up against 4 valves. In NASCAR Ford and Yates and others looked at running the mod motor as a winston cup type deal but preliminary versions were already nearing 1000 hp in that trim so NASCAR said no. The LSx stuff we're talking about can't even touch this stuff although the C5R would be probably capable of getting closer. Now if there was a larger bore 4 valve in the picture there would again be no contest at all.
All that said the LSx series are better because of one thing mainly and that's engine size. You can't beat cubic inches unless you can turn a lot more rpm with the smaller engine and Ford's 4V doesn't so it's down on power and slower. The Cobra R had a larger 5.4 mod motor and was faster by a lotover the regular 4.6 stuff.
02-07-2004, 07:52 AM
#67
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Originally Posted by FAST LS1
The LS1's only been around half the time the 4.6 has if your talking about all out moddifications to it. Give it 11 years and see where it's at.
If you believe this statement I feel sorry for you. GM didn't bump hp at the cost of "smoothness" just to get more people to buy Camaro's and Firebirds. The Camaro and Firebird have beaten every Mustang from 1993-2002 in terms of hp and straight line performance. Ford sold the mustang because it's less of a sports car with it's upright seating. More woman found it easier to drive and that's why the Mustang's still around. The Camaro and Firebird lost huge sales because it became too sports car like. Look at road racing the F-bodies clean house every year.
Anyway back to DOHC vs OHV. You do know the LS6 makes more hp per liter than even the 320hp 4.6L DOHC engine made right? Got better gas mileage due to the low rpm torque and it's ability to use a 6-speed transmission. LS6 is a smaller lighter package that costs less money to make and is easier to work on.
DOHC in a Ferrari is definately light years ahead of Ford's offering and actually uses the DOHC design like it was intended to be used. I see no real advantage to a restrained DOHC like the Ford 4.6l over the LS based engines.
If you believe this statement I feel sorry for you. GM didn't bump hp at the cost of "smoothness" just to get more people to buy Camaro's and Firebirds. The Camaro and Firebird have beaten every Mustang from 1993-2002 in terms of hp and straight line performance. Ford sold the mustang because it's less of a sports car with it's upright seating. More woman found it easier to drive and that's why the Mustang's still around. The Camaro and Firebird lost huge sales because it became too sports car like. Look at road racing the F-bodies clean house every year.
Anyway back to DOHC vs OHV. You do know the LS6 makes more hp per liter than even the 320hp 4.6L DOHC engine made right? Got better gas mileage due to the low rpm torque and it's ability to use a 6-speed transmission. LS6 is a smaller lighter package that costs less money to make and is easier to work on.
DOHC in a Ferrari is definately light years ahead of Ford's offering and actually uses the DOHC design like it was intended to be used. I see no real advantage to a restrained DOHC like the Ford 4.6l over the LS based engines.
4 valve heads have poor swirl and tumble characteristics, making LS1 style chamber have more Homogenous fuel mixture, this is how great torque output is achieved in any normally aspirated engine. If velocity of 4v head is so great why is it so dependant on multi stage intake manifolding? Do you ever think about how much 4 cams and their clumsy chains and tensioners take to drive along with the weight of these items? Ford has also found out that these are more things that can go wrong!Dont believe me ask Cobra owners of the last almost 10 years.
02-07-2004, 11:59 AM
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Originally Posted by racer7088
I don't know where people get some of this stuff but the 4 valve is always gonna be superior to the 2 valve except in packaging and cost. The reality though is what ChrisB said and that's that all the real numbers favor the larger 2 valve LS1 which can't really even be argued anymore. To overcome the size advatage Ford had to put on a supercharger basically because they don't want to twist a production engine to the moon to keep up with the mountain motor LS1.
4 valves though still beats everything all the time from large diesels to F1 you won't see any 2 valve stuff that's competitive if it's stuck up against 4 valves. In NASCAR Ford and Yates and others looked at running the mod motor as a winston cup type deal but preliminary versions were already nearing 1000 hp in that trim so NASCAR said no. The LSx stuff we're talking about can't even touch this stuff although the C5R would be probably capable of getting closer. Now if there was a larger bore 4 valve in the picture there would again be no contest at all.
All that said the LSx series are better because of one thing mainly and that's engine size. You can't beat cubic inches unless you can turn a lot more rpm with the smaller engine and Ford's 4V doesn't so it's down on power and slower. The Cobra R had a larger 5.4 mod motor and was faster by a lotover the regular 4.6 stuff.
4 valves though still beats everything all the time from large diesels to F1 you won't see any 2 valve stuff that's competitive if it's stuck up against 4 valves. In NASCAR Ford and Yates and others looked at running the mod motor as a winston cup type deal but preliminary versions were already nearing 1000 hp in that trim so NASCAR said no. The LSx stuff we're talking about can't even touch this stuff although the C5R would be probably capable of getting closer. Now if there was a larger bore 4 valve in the picture there would again be no contest at all.
All that said the LSx series are better because of one thing mainly and that's engine size. You can't beat cubic inches unless you can turn a lot more rpm with the smaller engine and Ford's 4V doesn't so it's down on power and slower. The Cobra R had a larger 5.4 mod motor and was faster by a lotover the regular 4.6 stuff.
And to all the people that think a 4.6L is junk, can't make any power, the fastest mod motor is what, high 6's in 1/4mi?? That's impressive for any engine!
Ryan
02-07-2004, 12:58 PM
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Originally Posted by Juggernaut
And to all the people that think a 4.6L is junk, can't make any power, the fastest mod motor is what, high 6's in 1/4mi?? That's impressive for any engine!
Ryan
Ryan
02-07-2004, 01:38 PM
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you guys have made a lot of good points but also, dont forget about combustion chamber design. your cc design will also determine if your head is gonna be a peice of junk or not. i predict we will have a 4valve pushrod head for the ls1's in the comming years. best of both worlds
02-07-2004, 01:45 PM
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Originally Posted by FAST LS1
I don't think the 4.6L is junk, but like you said cubic inches matter. In the real world the LS1 has decent heads and a lot more cubic inches and can be bored and stroked to even even larger size. The 4.6 has supperior heads, but is much smaller, and can't be bored and stroked to as many cubes.
Last edited by Juggernaut; 02-07-2004 at 02:01 PM.
02-07-2004, 04:17 PM
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Originally Posted by LS1derfull
I couldnt agree with this guy more, also if 4 valves is so superior to 2 valves, than why does more exhaust flow thru one 3" pipe than two 2" pipes? The surface area in two intake ports has more resistance to flow than one, and all the surface area of 4 valves in its combustion chamber give less thermal efficiency because of total area and shape. You really cant take one superior detail about a design and make a blanket statement comparing it to others.
02-07-2004, 11:16 PM
#73
Originally Posted by 427
Thumbs up for the Gen III
On a warm, sunny day in May 1992, a ‘blind’ comparison test was performed by General Motors’ executives on a massive pavement area called Black Lake, deep within the secretive GM Milford Proving Grounds outside of Detroit, Michigan. The conclusions drawn from this test would change the course of history for General Motors Powertrain, its customers and the automobile industry.
At the time, the automotive business was ferociously arguing the merits of building complex, seemingly high tech, dual overhead cam (dohc) internal combustion engines versus building simple, seemingly low tech, pushrod engines. This hands-on comparison by the execs was to put the debate to a seat-of-the-pants experience and allow the leaders of GM to decide the course for the future for GM Powertrain.
The executive leadership of GM would drive pairs of similar appearing vehicles and compare how each vehicle felt—not knowing what engine type was powering the vehicles. Of most interest to readers of this book were two black Corvettes parked at the end of the lineup. One ‘Vette was fitted with a 330 hp, early version of the LT4 Gen II V8 pushrod engine. The other ‘Vette was equipped with the ZR1-spec, Lotus-designed, all-aluminum, dohc engine. Both vehicles were equipped with automatic transmissions. Both were fully integrated for their specific powerplants to give a real world experience to the executives.
The results surprised even the most ardent supporters of the pushrod architecture. The executives couldn’t get over how one of the ‘Vettes pulled from the moment they pressed on the throttle. The surge. The thrust. The torque.
In contrast, they commented on how the engine in the other ‘Vette seemed to take a moment to ‘wind up’ before pushing them back in the seat. This vehicle required more precision and planning when driving fast, to keep the engine up in the RPM band when the power was needed.
As the day went on, executive after executive came to the same conclusion. After all had tested the vehicles, the hoods were raised. To anyone who has driven or ridden in a 300+ hp small block Chevy V8 engine powered vehicle, it comes as no surprise the Corvette the executives liked was the Gen II pushrod V8-equipped vehicle.
From then on, the course for GMs V8 powertrain was set. The world’s finest pushrod V8 would be created to power the most profitable vehicle’s in the General Motors fleet. This was the birth of the Gen III small block V8.
This might be of interest to some.
Kurt
On a warm, sunny day in May 1992, a ‘blind’ comparison test was performed by General Motors’ executives on a massive pavement area called Black Lake, deep within the secretive GM Milford Proving Grounds outside of Detroit, Michigan. The conclusions drawn from this test would change the course of history for General Motors Powertrain, its customers and the automobile industry.
At the time, the automotive business was ferociously arguing the merits of building complex, seemingly high tech, dual overhead cam (dohc) internal combustion engines versus building simple, seemingly low tech, pushrod engines. This hands-on comparison by the execs was to put the debate to a seat-of-the-pants experience and allow the leaders of GM to decide the course for the future for GM Powertrain.
The executive leadership of GM would drive pairs of similar appearing vehicles and compare how each vehicle felt—not knowing what engine type was powering the vehicles. Of most interest to readers of this book were two black Corvettes parked at the end of the lineup. One ‘Vette was fitted with a 330 hp, early version of the LT4 Gen II V8 pushrod engine. The other ‘Vette was equipped with the ZR1-spec, Lotus-designed, all-aluminum, dohc engine. Both vehicles were equipped with automatic transmissions. Both were fully integrated for their specific powerplants to give a real world experience to the executives.
The results surprised even the most ardent supporters of the pushrod architecture. The executives couldn’t get over how one of the ‘Vettes pulled from the moment they pressed on the throttle. The surge. The thrust. The torque.
In contrast, they commented on how the engine in the other ‘Vette seemed to take a moment to ‘wind up’ before pushing them back in the seat. This vehicle required more precision and planning when driving fast, to keep the engine up in the RPM band when the power was needed.
As the day went on, executive after executive came to the same conclusion. After all had tested the vehicles, the hoods were raised. To anyone who has driven or ridden in a 300+ hp small block Chevy V8 engine powered vehicle, it comes as no surprise the Corvette the executives liked was the Gen II pushrod V8-equipped vehicle.
From then on, the course for GMs V8 powertrain was set. The world’s finest pushrod V8 would be created to power the most profitable vehicle’s in the General Motors fleet. This was the birth of the Gen III small block V8.
This might be of interest to some.
Kurt
Kurt - What book is this from????? Thanks .
joel
02-08-2004, 09:05 AM
#74
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Originally Posted by binksz06
Kurt - What book is this from????? Thanks .
joel
joel
Kurt
02-08-2004, 12:48 PM
#75
Originally Posted by 427
The book is in proofreading stage now. I don't have the title yet. When it is released I will be sure and get a copy to a sponsor so it gets on this site.
Kurt
Kurt
joel
02-08-2004, 06:13 PM
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Originally Posted by binksz06
Thank you. I would like to read it. Are you the author?
joel
joel
The book was written by Will Handzel. We (Wheel to Wheel Powertrain) helped him gather some info on simple set ups and "how to remove engine from Y F or truck".
It is full of interesting story's on the original ideas and why certain things went the way they did. Should be available soon, but I don't know exactly when.
Kurt
02-08-2004, 07:34 PM
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Originally Posted by Juggernaut
This is probably the best post I have ever seen on this site about the DOHC vs Pushrod argument. Engine size is the key here. It is hard to say "Well, a ZO6 makes 405hp and the best a 4.6L can do is 320hp. These numbers are more strongly correlated to cubic inches, not the style of the heads! The best anyone can wring out of a poppet-valve engine is around 2hp per ci. So, at best an LS1(346ci) can produce around 700hp NA, and the 4.6(281) around 600hp NA,,,and this is full on race version of each.
And to all the people that think a 4.6L is junk, can't make any power, the fastest mod motor is what, high 6's in 1/4mi?? That's impressive for any engine!
Ryan
And to all the people that think a 4.6L is junk, can't make any power, the fastest mod motor is what, high 6's in 1/4mi?? That's impressive for any engine!
Ryan
My friends GSXR has poppet valves and at approx. 55cu in is making 145hp at the rear wheel.
02-15-2004, 07:13 PM
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Pushrod 32 valve heads! http://www.ronsraceshop.com/companie...ng_chevyBB.php
Check these out, neat as hell. Would like to try a set on a 632 ci. someday.
Check these out, neat as hell. Would like to try a set on a 632 ci. someday.