electrical valvetrain
electrical valvetrain
(OP)
I've just been reading "The Engineer" magazine in which there is an article about rotary valves by Coates and Roton.
I remember reading the threads about the Coates valves, and how people weren't impressed by the claims, but it got me to thinking about variable valve timing, and I wondered if anyone had tried an electrically powered valve train.
I can see it offering a fairly simple way of altering timing, but would the energy losses in running a large alternator outweigh the gains in timing and directly powering the valve train.
Apologies if this has been covered before, but I couldn't find it in a thread search.
(I should also make clear that my practical engine experience is limited pretty much to completely rebuilding my landrover engine when it seized, but I do enjoy reading this forum...)
I remember reading the threads about the Coates valves, and how people weren't impressed by the claims, but it got me to thinking about variable valve timing, and I wondered if anyone had tried an electrically powered valve train.
I can see it offering a fairly simple way of altering timing, but would the energy losses in running a large alternator outweigh the gains in timing and directly powering the valve train.
Apologies if this has been covered before, but I couldn't find it in a thread search.
(I should also make clear that my practical engine experience is limited pretty much to completely rebuilding my landrover engine when it seized, but I do enjoy reading this forum...)
"I love deadlines. I love the whooshing noise they make as they go past." Douglas Adams





RE: electrical valvetrain
I was a witness to the results of testing of an all-electrical valve train installed on an experimental diesel engine in the Detroit Diesel Engine factory in Detroit Michigan back in the winter of 1995. I was at the factory school to obtain my Detroit series 92 and 149 engine certifications. I have to say that the experimental engine was in fact in very bad shape because they had just completed a test in which the electrical power was interrupted to the valve train and a backup system was to take over instantaneously while in operation. The test was a failure because of their inability at that time to provide a formidable backup to the interrupted valve train power. This problem may have been overcome since that time however I really never heard anything of the program again. They have a great facility up there in Detroit and I fully recommend factory training to all the automotive heads out there.
RE: electrical valvetrain
This web site has information: http://www.fev.com/index3.htm
RE: electrical valvetrain
There is considerable advantage to having variable valve capability. "Internal EGR" can be accomplished in this manner, and the system can function as a "Miller Cycle" -- where the piston compression ratio is less than the piston expansion ratio.
As far as I can tell, the Caterpillar valves sound similar to what EdDanzer describes above. I suspect they use the valves for both internal EGR and Miller cycle operation.