No More LS Engines Will Be Produced...
09-18-2011, 01:07 PM
#21
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I was.
The 427 SOHC can still be purchased if you got lots of coin.
It was an engineering masterpiece for it's time.
They also produced a 429 Hemi that a lot of us in the late sixties and early seventies would of killed to own.
I am a GM guy over Ford any day of the week but, I will give credit where credit is due.
Push rods are a limiting factor in engine performance.
They still work great but, if you had to design a motor that would make power past 10,000 rpm, you wouldn't be looking at push rod design.
The 427 SOHC can still be purchased if you got lots of coin.
It was an engineering masterpiece for it's time.
They also produced a 429 Hemi that a lot of us in the late sixties and early seventies would of killed to own.
I am a GM guy over Ford any day of the week but, I will give credit where credit is due.
Push rods are a limiting factor in engine performance.
They still work great but, if you had to design a motor that would make power past 10,000 rpm, you wouldn't be looking at push rod design.
Remember that friction increases at the square of velocity. So an engine spinning at 5000 RPM is going to have 25% of the fricitional losses as it would if it was engine spinning at 10 000 RPM.
09-18-2011, 01:54 PM
#23
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I was.
The 427 SOHC can still be purchased if you got lots of coin.
It was an engineering masterpiece for it's time.
They also produced a 429 Hemi that a lot of us in the late sixties and early seventies would of killed to own.
I am a GM guy over Ford any day of the week but, I will give credit where credit is due.
Push rods are a limiting factor in engine performance.
They still work great but, if you had to design a motor that would make power past 10,000 rpm, you wouldn't be looking at push rod design.
The 427 SOHC can still be purchased if you got lots of coin.
It was an engineering masterpiece for it's time.
They also produced a 429 Hemi that a lot of us in the late sixties and early seventies would of killed to own.
I am a GM guy over Ford any day of the week but, I will give credit where credit is due.
Push rods are a limiting factor in engine performance.
They still work great but, if you had to design a motor that would make power past 10,000 rpm, you wouldn't be looking at push rod design.
A broad, flat torque curve that begins early and good horsepower from mid-range rpms to a reasonable redline is all you need for an excellent, well-rounded street engine that's tons of fun to drive under all conditions and is still manageable in day-to-day driving conditions. The trade-offs you would face to produce an engine that makes great power at 10k rpm would not be desireable in the street car.
I think you are too focused on the "limitations" of push rods and ignoring the fact that there are downsides to OHC as well.
GM has done great with OHV. Nothing about the current OHC competition seems superior to me. The LSx engines hold their own against any modern OHC that's even remotely in the same price range.
As for the old engines, I still rather have a BBC than the Ford OHC example above. Actually, I'd even rather have a Cadillac 472-500ci OHV V8 over the 427 OHC. People don't realize the kind of torque and street fun you can squeez out of a 500ci Caddy engine with nothing more than a mild street build.
09-18-2011, 02:05 PM
#25
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I'm going to be quite frank here.... personally, I don't give a rats *** about horsepower at 10,000rpm. I think a lot of other people would agree in terms of street cars.
A broad, flat torque curve that begins early and good horsepower from mid-range rpms to a reasonable redline (6-6.5k is plenty) is all you need for an excellent, well-rounded street engine that's tons of fun to drive under all conditions and is still manageable in day-to-day driving conditions. The trade-offs you would face to produce an engine that makes great power at 10k rpm would not be desireable in the street car.
I think you are too focused on the "limitations" of push rods and ignoring the fact that there are downsides to OHC as well.
GM has done great with OHV. Nothing about the current OHC competition seems superior to me. The LSx engines hold their own against any modern OHC that's even remotely in the same price range.
As for the old engines, I still rather have a BBC than the Ford OHC example above. Actually, I'd even rather have a Cadillac 472-500ci OHV V8 over the 427 OHC. People don't realize the kind of torque and street fun you can squeez out of a 500ci Caddy engine with nothing more than a mild street build.
A broad, flat torque curve that begins early and good horsepower from mid-range rpms to a reasonable redline (6-6.5k is plenty) is all you need for an excellent, well-rounded street engine that's tons of fun to drive under all conditions and is still manageable in day-to-day driving conditions. The trade-offs you would face to produce an engine that makes great power at 10k rpm would not be desireable in the street car.
I think you are too focused on the "limitations" of push rods and ignoring the fact that there are downsides to OHC as well.
GM has done great with OHV. Nothing about the current OHC competition seems superior to me. The LSx engines hold their own against any modern OHC that's even remotely in the same price range.
As for the old engines, I still rather have a BBC than the Ford OHC example above. Actually, I'd even rather have a Cadillac 472-500ci OHV V8 over the 427 OHC. People don't realize the kind of torque and street fun you can squeez out of a 500ci Caddy engine with nothing more than a mild street build.
Your missing the point totally and you need to work on that.
A good design for any "machine" that would be used on a daily basis is that it's moving parts / quantity be held to a minimum... period
More complexity always results in less operational up time.
You can split hairs, you can try an bullshit your way out of it but, it's a truth that's never been faulted.
If I had a motor company and had to design engines for any application, I would go for the best top side in growth and that is an OHC.
I love pushrod motors as they have gone farther than they have should.
OHC motors offer much more flexibility in application.
There are no down sides to OHC applications unless you try to make one up.
You can size one up to run with any push rod app their is.
You can have any valve angle you wish, not to mention port design with a DOHC design.
That cannot be said with push rods.
This post is about GM bringing on OHC designs.
They know it's time and they understand that with small cube applications, OHC is the way to go.
09-18-2011, 02:10 PM
#26
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OK, I see that you are not prepared for an honest discussion. You may have more degrees than a thermometer, but if you actually believe this then your vision is clouded and further debate is pointless.
Have a nice day.
09-18-2011, 04:57 PM
#27
Well...Not really...lol. I don't know how my thread got sidetracted to overhead cam(OHC) engine discussion? What I was inquiring about, was GM moving/evolving to a direct fuel injection(DFI) cylinder head/LS engine type design. This is where fuel injector(s) are designed directly into the combustion chamber area. Mercury Marine, as an example, has been using this technology for about eight years now, on all their larger horsepower, high-performance engines. Was just curious if anyone else heard of GM switching over to this DFI design in the next couple years on the LS series, as I have?
09-18-2011, 05:50 PM
#29
TECH Senior Member
Ford 5L pushrod and 4.6l mod motor...
LS2 and VQ35 V6
Fords 5.4L OHC vs 5.0L OHV
1Uz v8 and ls1
This kind of thing has been discussed on here countless times. I think Ill take the lighter, smaller, less complex, more powerful LS pushrod over an OHC V8...
I don't see any good reason GM would go with a DOHC V8, back in the late 90s they even admitted the Northstar V8 was made for marketing for the fanboys that want a "high tech" engine.
09-18-2011, 06:10 PM
#30
TECH Fanatic
The whole argument is stupid actually from both ends of the perspective. Both modern pushrod and modular platforms have been proven time and time again to be capable of making respectable power while still remaining relatively efficient. Who cares how much one weighs or how complex one or the other is? You have huge aftermarket support from each, might as well just pick which one you prefer and work with it.
09-19-2011, 09:48 AM
#33
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The new small-block is expected to be made with an aluminum block and heads, which will feature direct injection and a completely new “combustion system.” The new small-block is expected to keep the traditional overhead-valve layout, “ensuring compact dimensions and lower manufacturing costs."
09-19-2011, 01:03 PM
#35
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Why would GM, or any other OE manufacturer be concerned with building V8 engines for 10k+ rpm operation in a street car? This is race engine territory, and is a silly arguement to consider when discussing OE street engines in brand new cars that will be peoples' daily drivers.
09-19-2011, 01:29 PM
#37
Why would GM, or any other OE manufacturer be concerned with building V8 engines for 10k+ rpm operation in a street car? This is race engine territory, and is a silly arguement to consider when discussing OE street engines in brand new cars that will be peoples' daily drivers.
but with that being said, we don't need our ls engines to redline past 10k to beat out cars that revolve 10k+ (standard rx8 anybody?)
09-19-2011, 02:03 PM
#39
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Why would GM, or any other OE manufacturer be concerned with building V8 engines for 10k+ rpm operation in a street car? This is race engine territory, and is a silly arguement to consider when discussing OE street engines in brand new cars that will be peoples' daily drivers.
I had a similar conversation on this topic about two weeks ago with someone at work. After his 5 minute long speech, I actually simply pointed at my car and said very condescendingly, "Stttrrrreeeeeet ..... Caaaaaaaaarr."