Camless engines...
The new dodge dart multiair engine is almost a camless engine.
http://www.dart-mouth.com/engines.html
http://www.dart-mouth.com/engines.html
Last edited by 427zm; Dec 13, 2012 at 07:21 PM. Reason: Edit
I formulated a rotary valve system when I was in college, but the snag that stopped me from pursuing it was carbon deposits/buildup would cause heavy wear or failure. It could possible work nicely with propane or CNG, but it also did not have a good of a seal as poppet valves, so emissions was an issue also.
The Wankel was supposed to be the new greatest thing, but it has never been able to achieve acceptable fuel economy and emissions is a struggle as well.
The Wankel was supposed to be the new greatest thing, but it has never been able to achieve acceptable fuel economy and emissions is a struggle as well.
On The Tree
Joined: Feb 2012
Posts: 101
Likes: 0
Check out that rotary valved V8! Looks completely propietary from Coates??
Some more info on their site:
http://www.coatesengine.com/csrv-system.html
Some more info on their site:
http://www.coatesengine.com/csrv-system.html
Teching In
Joined: Dec 2010
Posts: 17
Likes: 0
When I worked for Internationals engine division I see their camless diesel engine. I never got to see inside of it but I was told that the valves were actuated by hydraulics just like the HEUI Injectors. They put a lot of miles on that engine and if I'm not mistaken I thought they said they drove the truck across the country. The downfall that they couldn't get around was the computer. Every once in a while it would have a small glich and hang a valve open and smack it on a piston. So they tried a different type of valve. Their last attempt was to keep the valve stationary and move the runner up and down. Like I said, I never got to see the inside of it but I had to walk around it every day. Hydraulic Injectors worked well and had their time but that time has passed.
This is an awesome idea. If I would have stayed in school and became an engineer I would better understand this lol. But what I have gathered is the big problems are cooling and knowing if the solenoids can handle the hardcore duty cycle correct?
On The Tree
Joined: Jun 2007
Posts: 167
Likes: 0
From: Cochrane, Alberta
The new dodge dart multiair engine is almost a camless engine.
http://www.dart-mouth.com/engines.html
http://www.dart-mouth.com/engines.html
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for my senior design project I designed/prototyped and ran a camless 1 cyl 4 stroke engine I bought from harbor freight. I used hydrualic cylinders/piston with a pretty sweet dynamic seal that a seal manufacturer donated. the fluid was controlled with the fastest solenoids I could get my hands on(afford).
The goal of the project was to run the engine on both the Otto cycle AND the Miller cycle so you could have power when needed or fuel efficiency, repsectivly.
I was able to switch between the two cycles succesfully, proving the concept(as I'm sure many others have been able to do), but the solenoids would only react fast enough to get me up to 1700 rpm. Additionally, the power consumption to pressurize the cylinders was quite high(reducing the effectivness of the miller cycle). And being a senior design project the durability wasn't exactly 100k mile type stuff.
I don't think hydraulic will be the way this stuff gets into production due to issues with the fluid inertia at higher rpm's.
Navistar had one of their heavy hitters make the Pike Peaks run in a pure camless engine that Sturman Engine systems developed for them. Not sure why they never took it to production. And while not camless, the Skyactiv achieves both otto and miller cycles throughout the entire rpm band. This technology would be killer for a vette that could maintain a smooth idle but then open up duration/lift at higher rpms, can control overlap so there isn't any reversion back up the intake manifold. Not sure anyone OEMs need to drop the cash to make it happen thoughsince everyone already has a plan for the CO2 emmisions.
The goal of the project was to run the engine on both the Otto cycle AND the Miller cycle so you could have power when needed or fuel efficiency, repsectivly.
I was able to switch between the two cycles succesfully, proving the concept(as I'm sure many others have been able to do), but the solenoids would only react fast enough to get me up to 1700 rpm. Additionally, the power consumption to pressurize the cylinders was quite high(reducing the effectivness of the miller cycle). And being a senior design project the durability wasn't exactly 100k mile type stuff.
I don't think hydraulic will be the way this stuff gets into production due to issues with the fluid inertia at higher rpm's.Navistar had one of their heavy hitters make the Pike Peaks run in a pure camless engine that Sturman Engine systems developed for them. Not sure why they never took it to production. And while not camless, the Skyactiv achieves both otto and miller cycles throughout the entire rpm band. This technology would be killer for a vette that could maintain a smooth idle but then open up duration/lift at higher rpms, can control overlap so there isn't any reversion back up the intake manifold. Not sure anyone OEMs need to drop the cash to make it happen thoughsince everyone already has a plan for the CO2 emmisions.
If any of you can think of the Florida tuners name that does training seminars for NAPA(or used to) maybe he can fill you all in on a GM prototype from the early 80's that sort of fit this bill.
If I remember correctly from the story he told. As an engineering student for GM and touring through their plant somewhere around 1983, GM had a 1ltr 4cyl that used valves controlled by electromagnets with springs on the bottom side of the head that held the valves open until the coil pulled them closed. This little treat was supposedly a full composite engine cooled by R134 refrigerant.(In 83 they were still using R12 and haven't introduced 134 in AC systems yet). The story tells,if I remember correctly, that valve events were controlled by a crank trigger type system and fueling was a direct injection style with pressure in the range of 1500psi boasting 300hp. There was no starter and starting was controlled with sensing which cylinder to inject and fire. i'm sure there was more to the story but it's been a few years since he was here to fill in for another NAPA trainer for a engine performance class.
Wish I could remember his name and see the story posted by him here.
If I remember correctly from the story he told. As an engineering student for GM and touring through their plant somewhere around 1983, GM had a 1ltr 4cyl that used valves controlled by electromagnets with springs on the bottom side of the head that held the valves open until the coil pulled them closed. This little treat was supposedly a full composite engine cooled by R134 refrigerant.(In 83 they were still using R12 and haven't introduced 134 in AC systems yet). The story tells,if I remember correctly, that valve events were controlled by a crank trigger type system and fueling was a direct injection style with pressure in the range of 1500psi boasting 300hp. There was no starter and starting was controlled with sensing which cylinder to inject and fire. i'm sure there was more to the story but it's been a few years since he was here to fill in for another NAPA trainer for a engine performance class.
Wish I could remember his name and see the story posted by him here.
