Why GM should NOT build a DOHC V8

[surreal1272]

And one has to ask how someone goes from -95 votes to +461 in less than a day. Must be nice to have someone do your dirty work for you.

[Drew Dowdell]

It's a CTS.   The base levels of CTS come with the same gauge cluster as the ATS.  The way you can tell the difference in this case is the location of the air vent.  ATS air vent is vertical, CTS air vent is horizontal. 

 

 

It's a CTS. 

[El Kabong]

And one has to ask how someone goes from -95 votes to +461 in less than a day. Must be nice to have someone do your dirty work for you.

I suspect that admin is having a bit of fun. Doesn't change the reality of the situation though-trolling will inevitably get you called out, tossed out, laughed out, and leave your pet topic down and out.

[El Kabong]

It's a CTS.   The base levels of CTS come with the same gauge cluster as the ATS.  The way you can tell the difference in this case is the location of the air vent.  ATS air vent is vertical, CTS air vent is horizontal. 

 

 

It's a CTS.

Well, that might be the explanation for the points jump

[surreal1272]

It's a CTS.   The base levels of CTS come with the same gauge cluster as the ATS.  The way you can tell the difference in this case is the location of the air vent.  ATS air vent is vertical, CTS air vent is horizontal. 

 

 

It's a CTS. 

Good point(could not make out the vents) but that 7.3 second time is not from a 3.6L V6 CTS though. There is nothing in that video that indicates that it is a 3.6L.

 

It also cements my point that the base model gauge, whether in a CTS or an ATS, is just cheap looking and does not belong in either car, much less a $53K CTS.

Edited August 27, 2015 by surreal1272

[Drew Dowdell]

 

 

You're all arguing about dead technology. I can't wait for the 486DX4 vs Pentium 60 thread. 

#teslamasterrace

 

It's more than just that.  With these naturally aspirated DOHC V6es, I feel that customers are getting cheated a bit.  They are being sold horsepower ratings that they will never see in the real world. 

 

Drew, you really need to qualify a remark like this.  I know you are mostly referring to cam-cord V6 automobiles for the general masses, and that's fine, but there are many performance oriented vehicles that benefit with DOHC.  But that is my whole point as well, in that the benefits of DOHC path for families of engines that automakers CHOSE to follow....are far more than just a marketing gimmick.  Engineering is a balance act of trade-offs, and clearly, the scale tipped to the benefits of DOHC to invest in entire families of engines for your products. A few examples here and there of OHV offering benefits, should not and does not dictate where you invest your engineering $$$$.  So yeah, marketing is part of that equation, but a small part.

 

Here is a CTS w/ 3.6L accelerating.  I don't know what you see, but what I don't see, is a driver waiting for the hp's to kick in that supposedly never do.  What I do see, is a DOHC revving freely right out of the whole, and building momentum, well past where an OHV engine would fall flat.  

 

 

 

Am I really that unclear in my posts?  Is it just me or is it the reading comprehension around this place lately....?

 

Do you drive like that all the time?  Do you floor it at every light and let the engine wind up to red-line through every gear every time the light turns green?  Does the typical Camry or Impala driver drive that way even some of the time?

 

If you're like me, your engine rarely touches the red-line. Even then, probably less than 1% of the time will it ever even exceed 5,000 rpm. 

 

So, for "every day" driving, the way that 99.9999% of driving is done... having the horsepower peak at a much lower RPM would be an advantage during that 99.9999% of the time.    It would allow engines to turn lower RPM at cruising and better fuel economy.

 

And here's the kicker. If I'm wrong, then Ecoboost has no reason to exist.

Ecoboost allows for smaller displacement engines to produce power at a lower RPM.  Turbo-DI small displacement engines are the replacement for the bigger, slower spinning, OHV torque engines, not the OHC engines that only produce HP at or near red-line. 

[Drew Dowdell]

 

It's a CTS.   The base levels of CTS come with the same gauge cluster as the ATS.  The way you can tell the difference in this case is the location of the air vent.  ATS air vent is vertical, CTS air vent is horizontal. 

 

 

It's a CTS. 

Good point(could not make out the vents) but that 7.3 second time is not from a 3.6L V6 CTS though. There is nothing in that video that indicates that it is a 3.6L.

 

It also cements my point that the base model gauge, whether in a CTS or an ATS, is just cheap looking and does not belong in either car, much less a $53K CTS.

 

 

Yes, you only get the premium TFT screen on the Premium trim CTS 3.6.  The Luxury and Performance trim CTS 3.6 come with this base cluster. 

 

It's the same car in both runs in that video.  I can't explain the reason for the difference in the runs except for user error or perhaps a different terrain (was the first run on flat while the second run on a slight incline? we don't know)

[surreal1272]

 

 

It's a CTS.   The base levels of CTS come with the same gauge cluster as the ATS.  The way you can tell the difference in this case is the location of the air vent.  ATS air vent is vertical, CTS air vent is horizontal. 

 

 

It's a CTS. 

Good point(could not make out the vents) but that 7.3 second time is not from a 3.6L V6 CTS though. There is nothing in that video that indicates that it is a 3.6L.

 

It also cements my point that the base model gauge, whether in a CTS or an ATS, is just cheap looking and does not belong in either car, much less a $53K CTS.

 

 

Yes, you only get the premium TFT screen on the Premium trim CTS 3.6.  The Luxury and Performance trim CTS 3.6 come with this base cluster. 

 

It's the same car in both runs in that video.  I can't explain the reason for the difference in the runs except for user error or perhaps a different terrain (was the first run on flat while the second run on a slight incline? we don't know)

 

Thanks for clarifying that Drew. I have not gone to Cadillac's page until today to see those interior shots for each trim level. That makes no sense to have that cheap looking cluster in an ATS, much less the more expensive CTS. Sorry. I just really hate that cluster. It's like they ripped out a cluster from 1990's Oldsmobile and put a little screen at the bottom to make it seem "modern". It kills an otherwise great car. It is that bad to me.

[surreal1272]

 

 

 

You're all arguing about dead technology. I can't wait for the 486DX4 vs Pentium 60 thread. 

#teslamasterrace

 

It's more than just that.  With these naturally aspirated DOHC V6es, I feel that customers are getting cheated a bit.  They are being sold horsepower ratings that they will never see in the real world. 

 

Drew, you really need to qualify a remark like this.  I know you are mostly referring to cam-cord V6 automobiles for the general masses, and that's fine, but there are many performance oriented vehicles that benefit with DOHC.  But that is my whole point as well, in that the benefits of DOHC path for families of engines that automakers CHOSE to follow....are far more than just a marketing gimmick.  Engineering is a balance act of trade-offs, and clearly, the scale tipped to the benefits of DOHC to invest in entire families of engines for your products. A few examples here and there of OHV offering benefits, should not and does not dictate where you invest your engineering $$$$.  So yeah, marketing is part of that equation, but a small part.

 

Here is a CTS w/ 3.6L accelerating.  I don't know what you see, but what I don't see, is a driver waiting for the hp's to kick in that supposedly never do.  What I do see, is a DOHC revving freely right out of the whole, and building momentum, well past where an OHV engine would fall flat.  

 

 

 

Am I really that unclear in my posts?  Is it just me or is it the reading comprehension around this place lately....?

 

Do you drive like that all the time?  Do you floor it at every light and let the engine wind up to red-line through every gear every time the light turns green?  Does the typical Camry or Impala driver drive that way even some of the time?

 

If you're like me, your engine rarely touches the red-line. Even then, probably less than 1% of the time will it ever even exceed 5,000 rpm. 

 

So, for "every day" driving, the way that 99.9999% of driving is done... having the horsepower peak at a much lower RPM would be an advantage during that 99.9999% of the time.    It would allow engines to turn lower RPM at cruising and better fuel economy.

 

And here's the kicker. If I'm wrong, then Ecoboost has no reason to exist.

Ecoboost allows for smaller displacement engines to produce power at a lower RPM.  Turbo-DI small displacement engines are the replacement for the bigger, slower spinning, OHV torque engines, not the OHC engines that only produce HP at or near red-line. 

 

Excellent points and it certainly contradicts the OHC claims made by some here. Oh and reading comprehension does come at a premium. I have been guilty of it myself but some do so more than others.

[Drew Dowdell]

The cluster was actually supposed to appear different.  It was originally designed to be invisible when the car was off and then you would only see the glow of the needles and gauges floating in the dark.  It was apparently a neat effect, but Cadillac ran into a snag at the last minute.  It was too late to redesign the whole cluster, so they had to just switch out the plastic cover. 

[surreal1272]

The cluster was actually supposed to appear different.  It was originally designed to be invisible when the car was off and then you would only see the glow of the needles and gauges floating in the dark.  It was apparently a neat effect, but Cadillac ran into a snag at the last minute.  It was too late to redesign the whole cluster, so they had to just switch out the plastic cover. 

Well, hopefully they will address that in the next refresh. It's a little thing to some but to me it is something I have to look at every time I am behind the wheel and it would drive me nuts.

[ccap41]

 

It's a CTS.   The base levels of CTS come with the same gauge cluster as the ATS.  The way you can tell the difference in this case is the location of the air vent.  ATS air vent is vertical, CTS air vent is horizontal. 

 

 

It's a CTS. 

Good point(could not make out the vents) but that 7.3 second time is not from a 3.6L V6 CTS though. There is nothing in that video that indicates that it is a 3.6L.

 

It also cements my point that the base model gauge, whether in a CTS or an ATS, is just cheap looking and does not belong in either car, much less a $53K CTS.

 

BUUUUUUURRRRNNNNNNN!!! (Kelso - That 70's Show)   

   (I was hoping for something a little less drastic than an entire head on fire.. but I guess that is about all that is available..lol)

[surreal1272]

 

 

It's a CTS.   The base levels of CTS come with the same gauge cluster as the ATS.  The way you can tell the difference in this case is the location of the air vent.  ATS air vent is vertical, CTS air vent is horizontal. 

 

 

It's a CTS. 

Good point(could not make out the vents) but that 7.3 second time is not from a 3.6L V6 CTS though. There is nothing in that video that indicates that it is a 3.6L.

 

It also cements my point that the base model gauge, whether in a CTS or an ATS, is just cheap looking and does not belong in either car, much less a $53K CTS.

 

BUUUUUUURRRRNNNNNNN!!! (Kelso - That 70's Show)   

   (I was hoping for something a little less drastic than an entire head on fire.. but I guess that is about all that is available..lol)

 

Yeah, real big burn there. I was wrong and admitted it, which is more than can be said for some around here  . Someone else certainly didn't know the difference when confronted on it. He just offered up weak excuses whereas Drew offered solid facts and proof, and I appreciate that from him. 

Edited August 27, 2015 by surreal1272

[Drew Dowdell]

really, so in that night time video, any real car person can tell the difference between an ATS and CTS lights......at night.......on the dash? 

 

If you say so

I did. 

[Drew Dowdell]

Depending on the car maybe.  My car makes max horsepower at 6,000 rpm, but has a 6,500 rpm redline.

 

Do you regularly wind it up to 6,000 rpm, or is 3,000 - 4,500 rpm more typical for accelerating?  Wouldn't you want power where you can use it most often? 

 

 

 

... even money he took my advice and got the Wild Turkey

 

I'm a tanqueray 10 man with the occasional Woodford Reserve or Tennessee Honey 

 

 

 

Well, would you look at that- something I agree with.

 

Personally I will take red wine for every day drinking I love Mark Ryan wines.

Sapphire or Hendricks for my Gin.

Blue Label Johnny Walker for whiskey

Dos Armadillos Extra Anejo Reserva for my Tequila

Back on Subject, I still do not see a need for the over heavy over rated DOHC engines period. 

 

 

Gah.... I give the Sapphire to the guests who don't know any better and hide my Tang 10 so they aren't putting it in O.J.

[Drew Dowdell]

And one has to ask how someone goes from -95 votes to +461 in less than a day. Must be nice to have someone do your dirty work for you.

 

I have found the "error" and have rectified it.   The server has been set to recalculate everyone's reputation again.  Some people may see theirs go up or down based due to posts being deleted since the last tabulation. 

[surreal1272]

 

And one has to ask how someone goes from -95 votes to +461 in less than a day. Must be nice to have someone do your dirty work for you.

 

I have found the "error" and have rectified it.   The server has been set to recalculate everyone's reputation again.  Some people may see theirs go up or down based due to posts being deleted since the last tabulation. 

 

Gotcha'. Just seemed a little strange. Glitches happen though.

[Drew Dowdell]

 

 

And one has to ask how someone goes from -95 votes to +461 in less than a day. Must be nice to have someone do your dirty work for you.

 

I have found the "error" and have rectified it.   The server has been set to recalculate everyone's reputation again.  Some people may see theirs go up or down based due to posts being deleted since the last tabulation. 

 

Gotcha'. Just seemed a little strange. Glitches happen though.

 

 

This wasn't a glitch, it was an error, and I'm addressing the cause.   I am being vague intentionally on this one. 

[surreal1272]

 

 

 

And one has to ask how someone goes from -95 votes to +461 in less than a day. Must be nice to have someone do your dirty work for you.

 

I have found the "error" and have rectified it.   The server has been set to recalculate everyone's reputation again.  Some people may see theirs go up or down based due to posts being deleted since the last tabulation. 

 

Gotcha'. Just seemed a little strange. Glitches happen though.

 

 

This wasn't a glitch, it was an error, and I'm addressing the cause.   I am being vague intentionally on this one. 

 

I understand. I just used a different word for it. Glitch/error, one in the same to me. No worries.

[ccap41]

 

 

 

It's a CTS.   The base levels of CTS come with the same gauge cluster as the ATS.  The way you can tell the difference in this case is the location of the air vent.  ATS air vent is vertical, CTS air vent is horizontal. 

 

 

It's a CTS. 

Good point(could not make out the vents) but that 7.3 second time is not from a 3.6L V6 CTS though. There is nothing in that video that indicates that it is a 3.6L.

 

It also cements my point that the base model gauge, whether in a CTS or an ATS, is just cheap looking and does not belong in either car, much less a $53K CTS.

 

BUUUUUUURRRRNNNNNNN!!! (Kelso - That 70's Show)   

   (I was hoping for something a little less drastic than an entire head on fire.. but I guess that is about all that is available..lol)

 

Yeah, real big burn there. I was wrong and admitted it, which is more than can be said for some around here  . Someone else certainly didn't know the difference when confronted on it. He just offered up weak excuses whereas Drew offered solid facts and proof, and I appreciate that from him. 

 

Easy there.. Just jokin around.. Don't have to be so...grumpy... all the time.

 

You must not be much of a car guy if you can't tell the difference between a CTS and ATS dash!     lol

[surreal1272]

 

 

 

 

It's a CTS.   The base levels of CTS come with the same gauge cluster as the ATS.  The way you can tell the difference in this case is the location of the air vent.  ATS air vent is vertical, CTS air vent is horizontal. 

 

 

It's a CTS. 

Good point(could not make out the vents) but that 7.3 second time is not from a 3.6L V6 CTS though. There is nothing in that video that indicates that it is a 3.6L.

 

It also cements my point that the base model gauge, whether in a CTS or an ATS, is just cheap looking and does not belong in either car, much less a $53K CTS.

 

BUUUUUUURRRRNNNNNNN!!! (Kelso - That 70's Show)   

   (I was hoping for something a little less drastic than an entire head on fire.. but I guess that is about all that is available..lol)

 

Yeah, real big burn there. I was wrong and admitted it, which is more than can be said for some around here  . Someone else certainly didn't know the difference when confronted on it. He just offered up weak excuses whereas Drew offered solid facts and proof, and I appreciate that from him. 

 

Easy there.. Just jokin around.. Don't have to be so...grumpy... all the time.

 

You must not be much of a car guy if you can't tell the difference between a CTS and ATS dash!     lol

 

Not being grumpy Mr. Presumptuous. Just stating a fact. I also said any car guy could spot that. Never stated that I was actually one of them    but I sure knew more about it than your average engineer.

[ccap41]

You were both wrong, right? But you insulted him whilst also being wrong, right? Just checking.. :rolls eyes:

[surreal1272]

You were both wrong, right? But you insulted him whilst also being wrong, right? Just checking.. :rolls eyes:

You got the full context of that right, while I acknowledged my own mistake right? Guess you also somehow overlooked the myriad of insults he has hurled at me the past few weeks, here and in a harassing PM. It's easy to do when you spend an abnormal amount of time attacking one person like you have on two different sites now (rolls eyes right back at you). Maybe butting out is your best course of action instead of trying to attack me? 

Edited August 27, 2015 by surreal1272

[Guest Wings4Life(BANNED)]

So it is a CTS.

 

Noted.

 

And honestly, recognizing dashboard lights in the dark for those two vehicles is not easy, as I stated.

 

 

And clearly so.

 

 

And it's nice to know the same few people keep visiting my profile on a daily basis.

To those folk, at least leave a message or a hello or something.  Kind of strange to not.....right

[El Kabong]

Ok, I confess. I visited your profile.

...I wanted to see what it took to be officially described as "terribad" in the ratings system. So shoot me :D

I mean, wow. That's not exactly a subtle hint or anything

Edited August 27, 2015 by El Kabong

[surreal1272]

So it is a CTS.

 

Noted.

 

And honestly, recognizing dashboard lights in the dark for those two vehicles is not easy, as I stated.

 

 

And clearly so.

 

 

And it's nice to know the same few people keep visiting my profile on a daily basis.

To those folk, at least leave a message or a hello or something.  Kind of strange to not.....right

And I admitted my mistake while you had NO clue what it was when asked about it. Just excuses and "only a GM fan would care". Keep backpedaling and justifying your actions if you want Wings, but the truth hurts. BTW, no one has to actually go to your page to see your count (well, except for Bong anyway ). One mouse rollover your name shows that and it doesn't even require an Ivy League education to do it. Lucky me.

Edited August 27, 2015 by surreal1272

[Guest Wings4Life(BANNED)]

Anyway, CTS.....noted.

 

thanks

[surreal1272]

Anyway, deflection...noted.

[Guest Wings4Life(BANNED)]

Anyway, deflection...noted.

 

 

wait, what....???

 

Are you saying it's now my fault that the picture I posted which was in fact what I claimed in the first place.....is back-peddling?

 

my head is spinning on this one.

Of course, ouzo is flowing for cheap here due to the low euro 

well, surreal, you and bong can down vote me to your hearts content.

 

I will not play that game any longer.

 

Have fun with it.

[El Kabong]

Uh, Dood?...

Please. Just stop. You've earned the rank of "terribad." Yes, this is an intervention.

Surreal made one error. The balance ledger is still pretty stacked the other way, is what I'm saying.

[surreal1272]

 

Anyway, deflection...noted.

 

 

wait, what....???

 

Are you saying it's now my fault that the picture I posted which was in fact what I claimed in the first place.....is back-peddling?

 

my head is spinning on this one.

Of course, ouzo is flowing for cheap here due to the low euro 

well, surreal, you and bong can down vote me to your hearts content.

 

I will not play that game any longer.

 

Have fun with it.

 

You've been down voting several people here left and right since it started back up so don't even go there. Throw that in with your lovely message to me the other week, and it's not hard to see why I don't give a crap what you think.

 

BTW, the deflection is not about the CTS itself. It's your excuse making and insults that started that. 

 

Enjoy.

Edited August 27, 2015 by surreal1272

[surreal1272]

Anyway, back to the topic. 

 

There is no one right solution or answer that puts one motor over the other. Drew made some good points though about why the pushrod lives on and succeeds. It cannot be dismissed just because it doesn't serve someone's favorite brand agenda.

[Guest Wings4Life(BANNED)]

Anyway, back to the topic. 

 

There is no one right solution or answer that puts one motor over the other. Drew made some good points though about why the pushrod lives on and succeeds. It cannot be dismissed just because it doesn't serve someone's favorite brand agenda.

 

 

I agree, it can't be dismissed and as I have personally stated many times over, it offers many advantages.

[surreal1272]

 

Anyway, back to the topic. 

 

There is no one right solution or answer that puts one motor over the other. Drew made some good points though about why the pushrod lives on and succeeds. It cannot be dismissed just because it doesn't serve someone's favorite brand agenda.

 

 

I agree, it can't be dismissed and as I have personally stated many times over, it offers many advantages.

 

See? There is something we can agree on. I'll notify the blue moon and Haley's comet.

[Drew Dowdell]

So, an extreme example of the benefits of low RPM HP v. high RPM hp.

 

My old Oldsmobile 307 -  Horsepower is about 140, torque is about 240 lb-ft.   However, you get about 90% of max torque from 700 rpm - 3500 rpm.  This is from a 35 year old V8 with a 4-barrel carb.  

 

Comparison - 

 

2014 Chevrolet Cruze 1.8 - 138 horsepower and 125 lb-ft @ 3800 rpm. 

 

I have a 3-speed auto while the Cruze has a 6-speed. 

 

The Cruze gets to its peak hp at 6300rpm.   I'll get my 140 hp at around 2000 rpm.   While I'm absolutely hampered by having only a 3-speed auto, I can easily keep up with a 1.8 liter Cruze without my 35 year old car breaking a sweat while the Cruze's 1.8 liter will be screaming.   Why?  Because I get my horsepower much much lower in the RPM band. 

 

There's a whole list of apples and oranges between these two cars, but the net end is that they both produce about the same amount of horsepower at their peak.   But I get to use my 140 horsepower much more often than a Cruze driver ever does. 

[Guest Wings4Life(BANNED)]

 

 

Anyway, back to the topic. 

 

There is no one right solution or answer that puts one motor over the other. Drew made some good points though about why the pushrod lives on and succeeds. It cannot be dismissed just because it doesn't serve someone's favorite brand agenda.

 

 

I agree, it can't be dismissed and as I have personally stated many times over, it offers many advantages.

 

See? There is something we can agree on. I'll notify the blue moon and Haley's comet.

 

 

 

Cool,

And as far as the moon and comet, is that because of the increasing rarity of camaro sales?

 

 

I kid......I'm a kidder.

[Guest Wings4Life(BANNED)]

So, an extreme example of the benefits of low RPM HP v. high RPM hp.

 

My old Oldsmobile 307 -  Horsepower is about 140, torque is about 240 lb-ft.   However, you get about 90% of max torque from 700 rpm - 3500 rpm.  This is from a 35 year old V8 with a 4-barrel carb.  

 

Comparison - 

 

2014 Chevrolet Cruze 1.8 - 138 horsepower and 125 lb-ft @ 3800 rpm. 

 

I have a 3-speed auto while the Cruze has a 6-speed. 

 

The Cruze gets to its peak hp at 6300rpm.   I'll get my 140 hp at around 2000 rpm.   While I'm absolutely hampered by having only a 3-speed auto, I can easily keep up with a 1.8 liter Cruze without my 35 year old car breaking a sweat while the Cruze's 1.8 liter will be screaming.   Why?  Because I get my horsepower much much lower in the RPM band. 

 

There's a whole list of apples and oranges between these two cars, but the net end is that they both produce about the same amount of horsepower at their peak.   But I get to use my 140 horsepower much more often than a Cruze driver ever does. 

 

I don't know, I would say that the 'net end' would actually be the fact that there is far more involved than just power ratings in achieving that.

[Drew Dowdell]

 

So, an extreme example of the benefits of low RPM HP v. high RPM hp.

 

My old Oldsmobile 307 -  Horsepower is about 140, torque is about 240 lb-ft.   However, you get about 90% of max torque from 700 rpm - 3500 rpm.  This is from a 35 year old V8 with a 4-barrel carb.  

 

Comparison - 

 

2014 Chevrolet Cruze 1.8 - 138 horsepower and 125 lb-ft @ 3800 rpm. 

 

I have a 3-speed auto while the Cruze has a 6-speed. 

 

The Cruze gets to its peak hp at 6300rpm.   I'll get my 140 hp at around 2000 rpm.   While I'm absolutely hampered by having only a 3-speed auto, I can easily keep up with a 1.8 liter Cruze without my 35 year old car breaking a sweat while the Cruze's 1.8 liter will be screaming.   Why?  Because I get my horsepower much much lower in the RPM band. 

 

There's a whole list of apples and oranges between these two cars, but the net end is that they both produce about the same amount of horsepower at their peak.   But I get to use my 140 horsepower much more often than a Cruze driver ever does. 

 

I don't know, I would say that the 'net end' would actually be the fact that there is far more involved than just power ratings in achieving that.

 

 

No... again... you aren't listening.

 

Two cars:

 

140hp @ 2,000 rpm

140hp @ 6300 rpm

 

Which car is going to get to use all 140 horses most often?

[El Kabong]

Eh. Pushrods are legit technology. As Drew himself said, turbocharging OHC engines wouldn't be a thing if they were able to deliver real-world driving power as effectively in normally-aspirated form.

[Guest Wings4Life(BANNED)]

 

 

So, an extreme example of the benefits of low RPM HP v. high RPM hp.

 

My old Oldsmobile 307 -  Horsepower is about 140, torque is about 240 lb-ft.   However, you get about 90% of max torque from 700 rpm - 3500 rpm.  This is from a 35 year old V8 with a 4-barrel carb.  

 

Comparison - 

 

2014 Chevrolet Cruze 1.8 - 138 horsepower and 125 lb-ft @ 3800 rpm. 

 

I have a 3-speed auto while the Cruze has a 6-speed. 

 

The Cruze gets to its peak hp at 6300rpm.   I'll get my 140 hp at around 2000 rpm.   While I'm absolutely hampered by having only a 3-speed auto, I can easily keep up with a 1.8 liter Cruze without my 35 year old car breaking a sweat while the Cruze's 1.8 liter will be screaming.   Why?  Because I get my horsepower much much lower in the RPM band. 

 

There's a whole list of apples and oranges between these two cars, but the net end is that they both produce about the same amount of horsepower at their peak.   But I get to use my 140 horsepower much more often than a Cruze driver ever does. 

 

I don't know, I would say that the 'net end' would actually be the fact that there is far more involved than just power ratings in achieving that.

 

 

No... again... you aren't listening.

 

Two cars:

 

140hp @ 2,000 rpm

140hp @ 6300 rpm

 

Which car is going to get to use all 140 horses most often?

 

 

I get what you are saying, but that is just narrowing down the viewpoint to high praise one aspect or metric.

And in that same viewpoint, I will give you that many don't know but prefer the early torque feel - most of the time.  

But to the performance, or at least, spirited driving crowd, it's all about rpm's and that is why DOHC shines and that is why a V6 camaro feels so lively when pushed.  You would NEVER get that with an OHV V6 engine, even if they upsized it another liter, which of course would kill fuel economy.

[David]

Disagree totally on the performance crowd. I will take a pushrod over dohc engine to win every time. My performance autos can win without breaking a sweat. You get the low gut feel of rush from the torque pushing back into the seat and the ability to fly with carrying on a conversation compared to the V8 juice can rattle of 4 and 6 turbo charged engines that get terrible gas mileage when you push them to move.

Just admit each have their fans neither is better than the other to a certain point in regular driving. We are just talking apples to Orange's.

[Drew Dowdell]

 

 

 

So, an extreme example of the benefits of low RPM HP v. high RPM hp.

 

My old Oldsmobile 307 -  Horsepower is about 140, torque is about 240 lb-ft.   However, you get about 90% of max torque from 700 rpm - 3500 rpm.  This is from a 35 year old V8 with a 4-barrel carb.  

 

Comparison - 

 

2014 Chevrolet Cruze 1.8 - 138 horsepower and 125 lb-ft @ 3800 rpm. 

 

I have a 3-speed auto while the Cruze has a 6-speed. 

 

The Cruze gets to its peak hp at 6300rpm.   I'll get my 140 hp at around 2000 rpm.   While I'm absolutely hampered by having only a 3-speed auto, I can easily keep up with a 1.8 liter Cruze without my 35 year old car breaking a sweat while the Cruze's 1.8 liter will be screaming.   Why?  Because I get my horsepower much much lower in the RPM band. 

 

There's a whole list of apples and oranges between these two cars, but the net end is that they both produce about the same amount of horsepower at their peak.   But I get to use my 140 horsepower much more often than a Cruze driver ever does. 

 

I don't know, I would say that the 'net end' would actually be the fact that there is far more involved than just power ratings in achieving that.

 

 

No... again... you aren't listening.

 

Two cars:

 

140hp @ 2,000 rpm

140hp @ 6300 rpm

 

Which car is going to get to use all 140 horses most often?

 

 

I get what you are saying, but that is just narrowing down the viewpoint to high praise one aspect or metric.

And in that same viewpoint, I will give you that many don't know but prefer the early torque feel - most of the time.  

But to the performance, or at least, spirited driving crowd, it's all about rpm's and that is why DOHC shines and that is why a V6 camaro feels so lively when pushed.  You would NEVER get that with an OHV V6 engine, even if they upsized it another liter, which of course would kill fuel economy.

 

 

 

Which is why I specifically said... not for the performance crowd. 

 

A compact, lightweight, high tech (DI, VVT, Cylinder Shut-off), OHV V6 would serve 99% of consumers better than a DOHC unit of equal peak output. 

[Guest Wings4Life(BANNED)]

 

 

 

 

So, an extreme example of the benefits of low RPM HP v. high RPM hp.

 

My old Oldsmobile 307 -  Horsepower is about 140, torque is about 240 lb-ft.   However, you get about 90% of max torque from 700 rpm - 3500 rpm.  This is from a 35 year old V8 with a 4-barrel carb.  

 

Comparison - 

 

2014 Chevrolet Cruze 1.8 - 138 horsepower and 125 lb-ft @ 3800 rpm. 

 

I have a 3-speed auto while the Cruze has a 6-speed. 

 

The Cruze gets to its peak hp at 6300rpm.   I'll get my 140 hp at around 2000 rpm.   While I'm absolutely hampered by having only a 3-speed auto, I can easily keep up with a 1.8 liter Cruze without my 35 year old car breaking a sweat while the Cruze's 1.8 liter will be screaming.   Why?  Because I get my horsepower much much lower in the RPM band. 

 

There's a whole list of apples and oranges between these two cars, but the net end is that they both produce about the same amount of horsepower at their peak.   But I get to use my 140 horsepower much more often than a Cruze driver ever does. 

 

I don't know, I would say that the 'net end' would actually be the fact that there is far more involved than just power ratings in achieving that.

 

 

No... again... you aren't listening.

 

Two cars:

 

140hp @ 2,000 rpm

140hp @ 6300 rpm

 

Which car is going to get to use all 140 horses most often?

 

 

I get what you are saying, but that is just narrowing down the viewpoint to high praise one aspect or metric.

And in that same viewpoint, I will give you that many don't know but prefer the early torque feel - most of the time.  

But to the performance, or at least, spirited driving crowd, it's all about rpm's and that is why DOHC shines and that is why a V6 camaro feels so lively when pushed.  You would NEVER get that with an OHV V6 engine, even if they upsized it another liter, which of course would kill fuel economy.

 

 

 

Which is why I specifically said... not for the performance crowd. 

 

A compact, lightweight, high tech (DI, VVT, Cylinder Shut-off), OHV V6 would serve 99% of consumers better than a DOHC unit of equal peak output. 

 

 

I think we agree overall, but I want to qualify my remarks  a tad more.

That 99% you speak of, at least in my viewpoint, describes the majority of consumers who never push it past a speed limit very much.  I could guess a percent on them, but overall, I think far more people drive their cars spirited than one might think, although certainly not all the time.  And I am not talking about the performance crowd only, but as I said, spirited driving.  

 

Anyway, I think we have cleaned the bone off this topic (to use a popular Greek phrase).

[ccap41]

 

Which is why I specifically said... not for the performance crowd. 

 

A compact, lightweight, high tech (DI, VVT, Cylinder Shut-off), OHV V6 would serve 99% of consumers better than a DOHC unit of equal peak output. 

 

My only argument comes back to what we talked about probably a few pages back and it is; which one is making that power on partial throttle, the way we do that 99% of our driving?

 

THAT is what I'm really curious about. Because you're right, "A compact, lightweight, high tech (DI, VVT, Cylinder Shut-off), OHV V6 would serve 99% of consumers better than a DOHC unit of equal peak output." Unless there is a decent difference when it comes to partial throttle imputs. I would imagine with a DOHC setup there is more tuning possibilities and with that you could have less fuel used at crusing speeds(say 2000rpm for an example). I would think if a vehicle is making 90% of it's peak tq at that rpm compared to say 50% that one making 90% would also be using more fuel to do to, right(honestly asking)? So with a DOHC making less low end, usable power it is also using less fuel at the same time. I think that is one reason the EcoBoost motors get a bad rap because it is so easy to use a very large percentage of that available torque because of how early it comes on.

[El Kabong]

There is a time and a place for pushrods on the racetrack as well. If there were not then we would not be getting excited about the return of the Ford GT, because the original Ford GT40 almost certainly not have existed to begin with. Or the Shelby Cobra. Or the Shelby Daytona Coupe. Or...

[David]

Per a conversation I had with Jet performance chips. Their own engineers say it is easier to tune a custom chip for a pushrod than a DOHC engine especially if it has VVT. Per liter at least according to my conversation with this individual, they can get more raw power out of the pushrod engine, but marketing has made a case for the DOHC engines for those that like the high revving engines and complexity.

 

Comparing Pushrod to DOHC engines and especially VVT you get more weight and more complexity but not necessarily the simplest and fastest way to power efficiency.

 

I am sure engineers for both versions can make detailed cases why I am right or wrong but this is how I see it.

[ccap41]

^ I would genuinely love to hear a few engineers of both sides discuss this topic.

[El Kabong]

You already have, if the rumors are true.

[ccap41]

^ Wings?

 

You already have, if the rumors are true.

A few? Or just Wings? And I didn't know he was an engine designer/engineer.. I knew he was an engineer but I never heard what area he worked in.

[Guest Wings4Life(BANNED)]

ccap,

I work at Ford as a powertrain product development engineer / design and CAE analyst of upper end systems.  I wear several hats, because they happen to fit. I say that, because I am part of a dying breed in this industry that recognizes OHV and carburetors as more than just a museum piece, as well as someone who knows how to wrench on my own motors, having built many in my day.  Trust me when I tell you, the young whiz kids today are far more comfortable around an Android phone and Twitter accounts, than they are around my elaborate home tool set.  Just the way of things, I guess.  But it's pretty embarrassing when I have to explain fundamental engine components to employees who have been with the company long enough to know better. 

 

So, I read backwards to find your full question, but I am not certain I have it all. But I will try to answer what I can.

 

What I have tried to convey in this thread, is that there is no clear winner in valve train architecture choice, overall, and that application, packaging, cost, etc, and even driving style and yes subjectivity can have an impact on perception and certainly when choosing between OHV or OHC families of engines.  They each offer unique benefits to the other, and to complicate matters further, they have to balance them overall within a brand's portfolio of vehicles or at least, an engine family that fits many. As I see it, the balance has been found to clearly be favored toward OHC, for reasons established and learned through many years.  And contrary to some beliefs, marketing is only a small part of the reason a corporation would choose to throw so much capital and effort. GM has done well with OHV larger engines, especially where torque is needed, but it seems to have recognized the limitations in smaller applications, hence their decision to mostly abandon it.

 

And regarding the benefits of both, what I do know is that as you increase in displacement, specifically bore size for larger valve sizes, you can quickly recover some of the negatives of single valve OHV - that is why big OHV V8's still work effectively. But normally, it comes down to maximizing  volumetric efficiency of the air pump known as an IC engine.  Also, allowing for several cams will check the negative column for added friction, complexity, etc.....but it also checks the pro column for huge gains in vol-eff, especially due to twin VCT control.  Next up, packaging. We all know a twin cam head is bigger, hence the bigger package. But those negatives are small, and really only present themselves as such when packaging a small sports car where gaining fractions of a percent gains are noticed.  Obviously, OHC is more stout and capable of higher rpm's, due to the tight and rigid package of VT mechanisms relative to the load-inducing cam -- whereas OHV needs long pushrods that complicate that delicate and carefully engineered kinematic balance, and without maximizing machining and design costs to mitigate those limitations, you are stuck with them.. Placement of the plug in the center is also favored for 4v OHC, wrapped around the central plug..... where OHV is off-center, typically, and just slightly more difficult to hit that perfect stoichiometric balance, to achieve cleaner more efficient combustion, and appropriate burn rates.

 

A misnomer I have read here, is that you can just up-size a push-rod motor to match power of smaller OHC.  Well yes, you can, but things fall off the table, like fuel economy and emissions, as it gets harder to maintain good burn combustion, the larger the combustion chamber is.  Think Hemi, that had 2 plugs to help with that.

 

And finally, one of the reasons why DOHC and even GTDI is gaining in popularity, is because engineering has to recognize that futuring into new technology and advances of systems and sub-systems, will get you those additional gains you seek easier.  That's just a fact.  The analogy I use, is that today's GTDI engine is complex enough, kind of like a top end stereo system with many control knobs for tuning.  But from what I see and are learning, is that not only are we not sizing and tuning properly, but they are throwing in many more control knobs (think EGR cooling benefits, Miller cam cycle benefits, cam friction reduction technologies coming, etc....) and suddenly, that high fidelity audio you thought you had in tune....is capable of far, far more.