Why hasn't VTEC been adapted to pushrod engines?
TECH Senior Member
Joined: Apr 2002
Posts: 6,080
Likes: 17
From: So.Cal.
Originally Posted by menudoman
damn....beat me to it. i had a teacher mention rotary valves to me back in 99. i kinda hoped it would have caught on more by now. seems like a really good idea, especially with the cam phasing technology thats out now.
rotary valves seem like a way better solution to me than SOVs. ridiculous rpm, ridiculous flow, and the valve assembly is constantly turning and doesn't heat soak like a poppet valve setup does. i don't pretend to be an engineer, but seems like a pretty good setup to me. but for one reason or another, it's never seemed to catch on.
rotary valves seem like a way better solution to me than SOVs. ridiculous rpm, ridiculous flow, and the valve assembly is constantly turning and doesn't heat soak like a poppet valve setup does. i don't pretend to be an engineer, but seems like a pretty good setup to me. but for one reason or another, it's never seemed to catch on.
Launching!
Joined: Mar 2004
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From: Exton, Pennsylvania
Originally Posted by MrDude_1
where did you get THAT from?
It is likely never to see production, but GM did experiment with a dual cam in block motor.
Teching In
Joined: Nov 2001
Posts: 29
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Originally Posted by RussStang
http://www.carcraft.com/techarticles...GM/index3.html
It is likely never to see production, but GM did experiment with a dual cam in block motor.
It is likely never to see production, but GM did experiment with a dual cam in block motor.
TECH Senior Member
Joined: Apr 2002
Posts: 6,080
Likes: 17
From: So.Cal.
Originally Posted by RussStang
http://www.carcraft.com/techarticles...GM/index3.html
It is likely never to see production, but GM did experiment with a dual cam in block motor.
It is likely never to see production, but GM did experiment with a dual cam in block motor.
Teching In
Joined: Nov 2001
Posts: 29
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Originally Posted by joecar
Wouldn't it just be easier and more productive to design in dual overhead cams instead (and it would allow 4V/cyl)...?
Launching!
Joined: Mar 2004
Posts: 231
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From: Exton, Pennsylvania
Originally Posted by joecar
Wouldn't it just be easier and more productive to design in dual overhead cams instead (and it would allow 4V/cyl)...?
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Verdad Gallardo TECH Senior Member
Joined: Apr 2002
Posts: 6,080
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From: So.Cal.
Originally Posted by RussStang
4V/cyl are still possible with pushrod engines. The Dominion/Arao SBC heads are 4V. Dunno why GM only went with 3V for this concept engine.
TECH Fanatic
Joined: Jun 2002
Posts: 1,979
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From: Upstate NY
Originally Posted by THE_SUPRA
isnt the new Escalade a vvt pushrod v8?
A similar system has been used on the exhaust cam only on the 4200 I6 (Trailblazer) engine for years. On that one the phasing was as much as 50 crank degrees (25 cam degrees).
Cam phasing on a single-cam engine does not vary the intake and exhaust timing separately, of course. Neither is it the sole reason for the 403 hp/ 417 lb-ft of the Escalade engine. The head is similar to the LS7 which is similar to the C5R. It that "trickle down theory" or all part of the grand plan for the GenIII/IV from it's inception.
Teching In
Joined: Jul 2005
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From: Baltimore co. Md.
Just save alot of engineering and unneeded parts, supercharged 2 stroke no valving needed.see how easy that was? 
I see alot of interesting ideas here and would not be supprised to see more than one of them in the next 10 years.
Imagine tuning when you can infinitely control valve duration,lift and timing!
cant wait 
I see alot of interesting ideas here and would not be supprised to see more than one of them in the next 10 years.
Imagine tuning when you can infinitely control valve duration,lift and timing!
cant wait 
Teching In
Joined: Apr 2006
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STRIPSTAR corrction. hey STRIPSTAR, actually to correct you, on the BMW thing. Vanos is just adjustable time on the cams, but you are right they have adjustable lift also, its actually caled "valvetronic" but you wouldnt really want it on any drag motor just becuase when it broke at the end of the season i would cost about 5 to 6 grand just to replace the adjustable lift mecinasims, and the motors, not to mention cams and other hard parts. but for street vehicles there awsome, because if you work at the dealerhship like me you can caliberate and make some adjustments to give you almost an inch of lift, and on the new v-10 that would make some major power, way above the stock power they put on the street.
Originally Posted by kabbott
Just save alot of engineering and unneeded parts, supercharged 2 stroke no valving needed.see how easy that was?
Wouldn't most of the boost blow through the engine at dead bottom then? That is what it looks like from a model airplane engine.
Teching In
Joined: Aug 2005
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I'm guessing nobody here has been to www.pattakon.com. He's got a relatively simple design that allows infinately variable valve lift from completely closed to max lift and anywhere in between. It's a good read if you've got some time on your hands. I've personally found it very interesting.
Domestic drivers wouldn't be able to handle the insane, mind numbing power that the Vtec God grants imports. I mean it's like at least a bazillion extra ponies....GOD!!!
No, I know it could actually be awesome. I just had to be a jackass
Wow... deff check out the pattakon site. That is some awesome stuff!!! Almost brings out the mad scientist in me.
No, I know it could actually be awesome. I just had to be a jackass
Wow... deff check out the pattakon site. That is some awesome stuff!!! Almost brings out the mad scientist in me.
Last edited by Rothman; Aug 22, 2006 at 08:23 PM.
Teching In
Joined: Sep 2006
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An animation for 'VTEC' on pushrod engines Just take a look at the animation:
http://www.pattakon.com/vva/SideCam.exe
Click the hyperlink above and then Open or Run the file.
Then use the mouse to change the rhythm and the SpaceBar key to change from LowLift to HifhLift mode (only two modes are shown to keep the size of the file small).
In practice, instead of pressing the SpaceBar key of a keyboard, the driver presses the gas pedal and the gas cable rotates the 'control shaft' -that red piece at top - to another angle to get the desirable valve lift.
The typical pushrod engine (V-8, V-10, V-2 etc) is changed to an improved VTEC (instead of two modes the Honda VTEC offers, now they are available infinite modes of operation).
The system works more reliably than the conventional valve train (most of the time the intake valves operate at 1 to 3 mm valve lift).
Thanks
Manolis Pattakos
http://www.pattakon.com/vva/SideCam.exe
Click the hyperlink above and then Open or Run the file.
Then use the mouse to change the rhythm and the SpaceBar key to change from LowLift to HifhLift mode (only two modes are shown to keep the size of the file small).
In practice, instead of pressing the SpaceBar key of a keyboard, the driver presses the gas pedal and the gas cable rotates the 'control shaft' -that red piece at top - to another angle to get the desirable valve lift.
The typical pushrod engine (V-8, V-10, V-2 etc) is changed to an improved VTEC (instead of two modes the Honda VTEC offers, now they are available infinite modes of operation).
The system works more reliably than the conventional valve train (most of the time the intake valves operate at 1 to 3 mm valve lift).
Thanks
Manolis Pattakos
Originally Posted by manolis
Just take a look at the animation:
http://www.pattakon.com/vva/SideCam.exe
Click the hyperlink above and then Open or Run the file.
Then use the mouse to change the rhythm and the SpaceBar key to change from LowLift to HifhLift mode (only two modes are shown to keep the size of the file small).
In practice, instead of pressing the SpaceBar key of a keyboard, the driver presses the gas pedal and the gas cable rotates the 'control shaft' -that red piece at top - to another angle to get the desirable valve lift.
The typical pushrod engine (V-8, V-10, V-2 etc) is changed to an improved VTEC (instead of two modes the Honda VTEC offers, now they are available infinite modes of operation).
The system works more reliably than the conventional valve train (most of the time the intake valves operate at 1 to 3 mm valve lift).
Thanks
Manolis Pattakos
http://www.pattakon.com/vva/SideCam.exe
Click the hyperlink above and then Open or Run the file.
Then use the mouse to change the rhythm and the SpaceBar key to change from LowLift to HifhLift mode (only two modes are shown to keep the size of the file small).
In practice, instead of pressing the SpaceBar key of a keyboard, the driver presses the gas pedal and the gas cable rotates the 'control shaft' -that red piece at top - to another angle to get the desirable valve lift.
The typical pushrod engine (V-8, V-10, V-2 etc) is changed to an improved VTEC (instead of two modes the Honda VTEC offers, now they are available infinite modes of operation).
The system works more reliably than the conventional valve train (most of the time the intake valves operate at 1 to 3 mm valve lift).
Thanks
Manolis Pattakos