does this exist?
I'm a nissan tech and the cvt is awesome. It's been out since 2003 and has really worked well. Its main drive is a wide steel belt that runs between two sets of pulleys, rather cool to see. They however do not make and rwd cvt transmissions, which is a buzz kill for sure! Check out the newer nissan and infinity 3.7L v-6 vq37vhr it has vvel which is awesome and had huge performance gains. It still has the conventional cam timing that's cam sprocket controlled but also has a motor on the cam that's like a varraible vtec. Check it out rather innovative
First off, I never said it was a new idea. I heard of this about 15 years ago, as Im sure other have too, or probably longer.
TECH Addict
Joined: Aug 2004
Posts: 2,866
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have you seen sleave valves? They where used heavily in British WW2 aero engines in the later stages of the war. supposed to give significant performance advantages of poppet valves (although they had aot of problems sealing poppet valves back in the 1940's).
Chris.
back in the day, fighter planes used a dual lobe cam shaft that the pilot could pull a lever and it would move the camshaft to its high lobe profile. this allowed more power and speed to let them get away. or so I am told by an old college professor...
hasnt there been a nagging heat issue with the mag actuated valves? i know MB has been trying to come up with something. theres been stuff flying around since it was released they wanted to go to a 43 volt system.
i think hydraulic would be more feasible, less heat issues.
i think hydraulic would be more feasible, less heat issues.
TECH Addict
Joined: Aug 2004
Posts: 2,866
Likes: 4
hasnt there been a nagging heat issue with the mag actuated valves? i know MB has been trying to come up with something. theres been stuff flying around since it was released they wanted to go to a 43 volt system.
i think hydraulic would be more feasible, less heat issues.
i think hydraulic would be more feasible, less heat issues.
Would hydraulics work fast enough?
Registered User
Joined: Oct 2011
Posts: 3
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Didn't mean to come across as an *ss mate. sorry.
have you seen sleave valves? They where used heavily in British WW2 aero engines in the later stages of the war. supposed to give significant performance advantages of poppet valves (although they had aot of problems sealing poppet valves back in the 1940's).
Chris.
have you seen sleave valves? They where used heavily in British WW2 aero engines in the later stages of the war. supposed to give significant performance advantages of poppet valves (although they had aot of problems sealing poppet valves back in the 1940's).
Chris.
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9 Second Club
Joined: Nov 2003
Posts: 13,616
Likes: 185
From: Norn Iron
It'll probably end up going to a rotary valve type system.
But it all boils down to cost. At the minute, valve/springs are just the cheapest option, they work very well, and work for a very long time.
Until emissions targets cannot be met with existing systems, doubtful they will change.
But it all boils down to cost. At the minute, valve/springs are just the cheapest option, they work very well, and work for a very long time.
Until emissions targets cannot be met with existing systems, doubtful they will change.
Teching In
Joined: Nov 2011
Posts: 12
Likes: 0
From: Mid-MO
We have the technology, I just haven't seen anyone put it all together yet.
I've been fortunate to have had my hands in a number of shops, working for some pretty old guys, seen and done a lot, and often think too much.
Mercury Marine built a neat engine for the Corvette years ago that used a 4 valve head with two intake paths, one had a butterfly that stayed closed, using only one port/valve to keep airflow/speed high until engine speed and load require the additional flow of both valves/ports. The motor had a lot of promise.
Back in '79 while working in a bike shop (HD's and Kawasaki's) I was degreeing cams on a KZ900 and started wondering about how I could build a set of 3 adjustable idlers such that I could vary the LSA of the cams and also advance/retard each cam. maximizing HP and torque throughout the entire RPM range.
A four valve head, total VVT, dual intake path, need I say more?
I've been fortunate to have had my hands in a number of shops, working for some pretty old guys, seen and done a lot, and often think too much.
Mercury Marine built a neat engine for the Corvette years ago that used a 4 valve head with two intake paths, one had a butterfly that stayed closed, using only one port/valve to keep airflow/speed high until engine speed and load require the additional flow of both valves/ports. The motor had a lot of promise.
Back in '79 while working in a bike shop (HD's and Kawasaki's) I was degreeing cams on a KZ900 and started wondering about how I could build a set of 3 adjustable idlers such that I could vary the LSA of the cams and also advance/retard each cam. maximizing HP and torque throughout the entire RPM range.
A four valve head, total VVT, dual intake path, need I say more?
9 Second Club
Joined: Nov 2003
Posts: 13,616
Likes: 185
From: Norn Iron
There is ample technology out there. Making it affordable, reliable and of enough benefit to make it worth putting into either low volume or mass production is a different matter though.
At the minute the only thing forcing some change, are emissions targets.
At the minute the only thing forcing some change, are emissions targets.
