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Old 06-12-2013, 07:27 PM   #15
cbass

 
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There are pros and cons to anything, but the pros of overhead cams greatly outweigh any cons versus a pushrod motor. It is not even close. Again, what other manufacture puts any push rod motors in their cars?
That is actually not true. The reason manufacturers went to overhead cam motors was driven by taxes. There are countries that do or maybe did tax based on displacement. An overhead cam motor has advantages at high rpm traditionally (although looking at the redlines of the LS7 and LS3 they have managed to worked around that quite successfully). You could spin the engine at higher rpm to produce more peak hp and did not have to rely on displacement which has tax implications.
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Old 06-12-2013, 07:31 PM   #16
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Originally Posted by TexasChile View Post
The Coyote is a much better engine from a technical perspective for performance, but it is limited by cubic inches. If there was an LS7 sized coyote, that would be one bad engine. The LS engine is a great engine for durability, but nobody on the planet Earth uses push rods in engines other than GM, and for good reason: Over head Cams are much more sophisticated and efficient for performance. An LS would not have a prayer against a coyote if the LS was limited to 5.0 cubes. The LS only competes because it uses more cubes to make up for its obsolete push rod design. Push rods are obsolete much like the flat head design was obsolete by over head valves. I don't understand why GM insists on using push rod engines. Of course, I also don't understand why GM insists on using fiberglass on Corvettes. No car company on Earth other than GM uses fiberglass--its used on cheap replica cars and bass boats. By the way, I am not a Ford guy. I have always been a GM guy but I do like the old Fords and Mopars too. Just keeping it real and honest. By the way, I am looking into buying a Camaro 1LE.
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Old 06-12-2013, 07:41 PM   #17
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Originally Posted by TexasChile View Post
The Coyote is a much better engine from a technical perspective for performance, but it is limited by cubic inches. If there was an LS7 sized coyote, that would be one bad engine. The LS engine is a great engine for durability, but nodody on the planet Earth uses push rods in engines other than GM, and for good reason: Over head Cams are much more sophisticated and efficient for performance. An LS would not have a prayer against a coyote if the LS was limited to 5.0 cubes. The LS only competes because it uses more cubes to make up for its obsolete push rod design. Push rods are obsolete much like the flat head design was obsolete by over head valves. I don't understand why GM insists on using push rod engines. Of course, I also don't understand why GM insists on using fiberglass on Corvettes. No car company on Earth other than GM uses fiberglass--its used on cheap replica cars and bass boats. By the way, I am not a Ford guy. I have always been a GM guy but I do like the old Fords and Mopars too. Just keeping it real and honest. By the way, I am looking into buying a Camaro 1LE.
I guess you've never heard of a Hemi engine huh? Or the Viper 10cyl?
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Old 06-12-2013, 07:44 PM   #18
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At the gatornationals this year I watched pushrods engines producing horsepower in the thousands...watched the top fuel cars run over 300 mph in the quarter mile....didn't see any formula 1 cars there. Go NHRA
You probably did not read the posts above or you would have seen that I already answered this. Drag racing has rules that work against any V8 overhead cam cars. In fact, if you read the rules, they prohibit overhead cams in the pro classes. Sort of hard to compete when the rules won't allow it. If you took one of those push rod engines and designed the same engine with an double overhead cam, it would produce more HP and dominate the drag racing class. That's why they don't allow them.
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Old 06-12-2013, 07:46 PM   #19
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ls cheaper to get the power and more c.i.d. but ls has been around for a while. i personally know 2 coyotes that #7 has failed. and one of them is about to go down again. using tons of oil. if u look on their forums they are droppin like flies .

the coyote is a good motor. but it limits out faster the a ls. go with what u know tho. if u like and know coyotes go with that. if u worked on ls stuff and like it go with them. its all it what u want and what u comfortable with.
For reliability, I do prefer the LS, but that has nothing to do with it using push rods. The LS engine is a proven reliable motor. No doubt about it. In fact, that is one reason I am considering getting a Camaro 1LE. I tend to keep my cars a long time and I require long-life reliability. The Ford coyote is not proven in that regard yet.
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Old 06-12-2013, 07:47 PM   #20
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The Coyote is a much better engine from a technical perspective for performance, but it is limited by cubic inches.
It's limited by cubic inches because overhead cam motors have packaging problems that a push rod motor does not. They are much wider. Take a look how much space a coyote motor takes compared to the ls3.
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Old 06-12-2013, 07:50 PM   #21
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I guess you've never heard of a Hemi engine huh? Or the Viper 10cyl?
You got me on that one. I was thinking about that driving home from work after I made the post that you quoted. I forgot about Dodge. Of course, the V10 is again doing it with cubic inches.

I change my statement above to say no car on Earth beside GM and Dodge uses push rods. And I still stand by my statement that the pushrod motor is obsolete and does not match up with the overhead cam in performance with the same cubic inches. It is not even close.
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Old 06-12-2013, 07:54 PM   #22
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Originally Posted by cbass View Post
That is actually not true. The reason manufacturers went to overhead cam motors was driven by taxes. There are countries that do or maybe did tax based on displacement. An overhead cam motor has advantages at high rpm traditionally (although looking at the redlines of the LS7 and LS3 they have managed to worked around that quite successfully). You could spin the engine at higher rpm to produce more peak hp and did not have to rely on displacement which has tax implications.
No you have that backwards. An overhead cam motor produces more HP per displacement, and thus to get the power from smaller motors (that were required by the laws you cite), they had to use over head cams, turbos, etc. The Japanese used overhead cam 4 cylinders when they came to the US and made the American 4 cylinders look way under powered. The overhead cam is the better design.
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Old 06-12-2013, 07:55 PM   #23
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Originally Posted by TexasChile View Post
I change my statement above to say no car on Earth beside GM and Dodge uses push rods. And I still stand by my statement that the pushrod motor is obsolete and does not match up with the overhead cam in performance with the same cubic inches. It is not even close.
Why do you only care about cubic inches? It doesn't even have an impact on fuel economy as a bigger displacement push rod motor has less frictional losses and thus the same fuel economy.

What advantage does smaller displacement give you?

There are so many other factors that matter in the real world to the performance of a motor that a push rod motor is superior.

Cost
Weight
Packaging
Fuel economy
Weight distribution
Power throughout the powerband

How are all these trumped by displacement when it has no bad impact on weight and fuel economy?
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Old 06-12-2013, 07:58 PM   #24
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Originally Posted by cbass View Post
It's limited by cubic inches because overhead cam motors have packaging problems that a push rod motor does not. They are much wider. Take a look how much space a coyote motor takes compared to the ls3.
They are wider because they are using 4 valves per cylinder and two cams per head, which is a much better design than 2 values per cylinder and one cam way down in the block and connected to the values with lifters, pushrods, and rocker arms (lots of valve train wasted energy). I don't think the overhead cam engine is limited on cubic inches. Ford just did not design the coyote to be a large displacement engine. Ford used to have a 427 big block overhead cam engine way back in '60's as a special race engine, so overhead cam motors can have large displacement.
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Old 06-12-2013, 07:58 PM   #25
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Originally Posted by TexasChile View Post
No you have that backwards. An overhead cam motor produces more HP per displacement, and thus to get the power from smaller motors (that were required by the laws you cite), they had to use over head cams, turbos, etc. The Japanese used overhead cam 4 cylinders when they came to the US and made the American 4 cylinders look way under powered. The overhead cam is the better design.
Yes, but who cares about hp per displacement unless you live in some stupid country that taxes based on it?

The bigger motor when compared to the smaller motor has the same peak hp and more throughout the entire powerband than just at a very few rpm at the top and yet still manages to consume no more fuel with larger displacement and weight less.
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Old 06-12-2013, 08:01 PM   #26
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They are wider because they are using 4 valves per cylinder and two cams per head, which is a much better design than 2 values per cylinder and one cam way down in the block and connected to the values with lifters, pushrods, and rocker arms (lots of valve train wasted energy). I don't think the overhead cam engine is limited on cubic inches. Ford just did not design the coyote to be a large displacement engine. Ford used to have a 427 big block overhead cam engine way back in '60's as a special race engine, so overhead cam motors can have large displacement.
How is it a better design?

The LS3 produces more peak hp and more through the powerband and thus has less moving parts. With a disadvantage of 2 valves per cylinder and no VVT like the coyote.

What's better about that?

Why focus on displacement?
Why aren't you saying wow the LS3 produces more hp with 2 less valves per cylinder?

The coyote needs 2 more valves per cylinder and two cams and yet still 6 hp short of the LS3 even with VVT that the LS3 doesn't have.

Then with all that crap the motor has packaging problems compared to the LS3 and all those extra parts on top of the motor effect handling negatively compared to one cam low in the block.
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Old 06-12-2013, 08:06 PM   #27
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Originally Posted by cbass View Post
Why do you only care about cubic inches? It doesn't even have an impact on fuel economy as a bigger displacement push rod motor has less frictional losses and thus the same fuel economy.

What advantage does smaller displacement give you?

There are so many other factors that matter in the real world to the performance of a motor that a push rod motor is superior.

Cost
Weight
Packaging
Fuel economy
Weight distribution
Power throughout the powerband

How are all these trumped by displacement when it has no bad impact on weight and fuel economy?
My statement about the overhead cam motor being the better design is based on performance only--not cost. I think you are wrong about weight, fuel economy, and power throughout the powerband. I am not sure what you even mean with weight distribution and packaging.

I don't just care about displacement, but as someone above pointed out, there is no substitute for displacement for making power, all things being equal.

I am amazed that anyone would think the pushrod motor is a better motor for performance from a design standpoint than an overhead cam. I wonder why all performance motorcycles use overhead cams if the overhead cam has all of the disadvantages that you cite above. I also wonder why the most fuel efficient small cars use overhead cams if the motors weigh more and get less fuel economy than a pushrod motor.

I think people on websites become fans of something even when logic and facts say otherwise. After all, I am on a Chevrolet forum. In short, nothing you wrote above is true and you should know that.
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Old 06-12-2013, 08:11 PM   #28
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My statement about the overhead cam motor being the better design is based on performance only--not cost. I think you are wrong about weight, fuel economy, and power throughout the powerband. I am not sure what you even mean with weight distribution and packaging.

I don't just care about displacement, but as someone above pointed out, there is no substitute for displacement for making power, all things being equal.

I am amazed that anyone would think the pushrod motor is a better motor for performance from a design standpoint than an overhead cam. I wonder why all performance motorcycles use overhead cams if the overhead cam has all of the disadvantages that you cite above. I also wonder why the most fuel efficient small cars use overhead cams if the motors weigh more and get less fuel economy than a pushrod motor.

I think people on websites become fans of something even when logic and facts say otherwise. After all, I am on a Chevrolet forum. In short, nothing you wrote above is true and you should know that.
Ok.

The coyote makes 420 hp compared to 426 hp for the LS3.
426 > 420 hp. Thus the LS3 has better performance.

Everything I wrote is true.

The coyote motor weights 430 lbs. The LS3 weights 418 lbs.
The LS3 is a lighter motor.

Having the weight down low in the block like the LS3 has a handling advantage and having the weight up high like in the overhead cam coyote has a handling disadvantage.

The coyote motor is larger physically and thus uses more space in the engine compartment. The LS3 is able to fit in much smaller spaces.

What have I said that is false?

I think people get brainwashed into thinking a particular motor is a better design and more advanced without actually doing some research and thinking for themselves.
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