[ThomsonCharm]

Ok this is for all you mad scientists. Time for a new science experiment. Anyone thought about messing with the cams.....actually forget about cams who needs em. Lets go indy car technology no cams just solenoids. First off ill explain how it works for the most part. Instead of an overhead cam like we use on our motors a solenoid is placed on top of the head with the valves connected to one or multiple solenoids. Now as the crank rotates a computer determines when to open and close the solenoid resulting in the valves opening and closing. Now here is the next kicker lets make this a variable solenoid meaning it can vary with how much it opens in closes ie. at low RPMs you have it open only a little bit much like a smaller cam BUT you gain torque this way, now say our motor starts to get moving and the turbo starts spooling well now send a signal to the solenoid to open the valve even further. Suddenly its like you got a new cam in your car as the valves open farther, you can vary duration, and lobe with the solenoid. So now that I have introduced some of you to the concept anyone have anymore info on it? Any mad scientists experimenting? Anyone work for a solenoid company that could design something to withstand this. Not only can you vary your torque curve with this type of technology BUT you can also rev higher as you dont have to worry about your valve train anymore. Just a balanced bottom end. For the most part F1 and Indy I believe are presently utilizing this technology just wondering if anyone else has any input on it?

 

[Guest]

The theory is very valid, the technology is lacking. If you could get solenoids that reacted fast enough (under 1ms response time), do so reliably for millions of cycles, and stand the underhood heat, then great. You could even control them just about perfectly with the AEM EMS, the injector outputs could be used as valve actuator signals just by changing the way you set the tables.

Good luck finding solenoids that can do that. Even F1 solenoids fail quite a bit. And they are probably $5k/each knowing F1.

I don't think Indy does it. Only F1. And I think it's like electro-hydraulic.

 

[65vette396]

Thought about this a long time ago. Two problems: One it has already been patented. Two, It requires the use of A/C current to open and close the valves that fast with a valvespring as resistence. If you look on the U.S. patent site and search hard enough this was already done in a locamotive application. It was done so you could run the engine in any direction. Drew

 

[RabidChild]

If you look on the U.S. patent site and search hard enough this was already done in a locamotive application. It was done so you could run the engine in any direction. Drew

That's an odd one. . .an engine on a locomotive is essentially used as a generator. . .all the drive is done with electric motors. So there really isn't any reason to reverse the spin of a locomotive engine, only the polarity of the motors.

 

[65vette396]

Sorry but it is patented either way. I don't really care what a locamotive engine is used for or how. Just stating the facts. But why would you use massive diesle engines to power generators to run electric motors. When you could just use the deisels? Makes no sense. Drew

 

[G]

Good luck finding solenoids that can do that. Even F1 solenoids fail quite a bit. And they are probably $5k/each knowing F1.

I don't think Indy does it. Only F1. And I think it's like electro-hydraulic.

I thought F1 was running some kind of pneumatic valve system to drive the valves.

 

[Guest]

All righty, fact time.

First off, there's all sorts of people experimenting with electromechanical valve actuation. I got product information from a couple people at the SAE World Congress a couple years ago... they and one of the SAE magazines a couple months back say mass production within the decade. Would be nice, but we'll see. The demonstrator used just the solenoid, no valve spring in it anywhere. They ran it up to "6k RPM" but they said that was the limit right now. Part of the issue is "soft closure"... it's a lot more aprupt of motion than normal cams/springs, and just going as fast as the solenoid does puts a helluva lot of fatigue on the valves. So they modulate things a bit to slow the velocity, and that adds complication and also takes more time.

Now, Formula 1. Formula 1 cars use pneumatic valvetrains. However, this is misleading; it would be better termed pneumatic valve return. The valves are still opened by camshafts! What the have instead of valve springs is a series of small pistons filled with high pressure nitrogen, which allows valve accelerations far greater than is possible with metal springs. 19k RPM and change on an NA 3 liter V-10, and fairly reliably... they say 900hp, but most everyone's probably a bit beyond that.

Hope that cleared some stuff up.

 

[Fii]

That's an odd one. . .an engine on a locomotive is essentially used as a generator. . .all the drive is done with electric motors. So there really isn't any reason to reverse the spin of a locomotive engine, only the polarity of the motors.

I think they use electric motors because of the transmission issues. Imagine how much it would be necessary to slip the clutch, in order to start moving the train. Electric motors does not have the clutch.

 

[Guest]

I think they use electric motors because of the transmission issues. Imagine how much it would be necessary to slip the clutch, in order to start moving the train. Electric motors does not have the clutch.

Well, another big reason is that the maximum torque from electric motors is at *zero* RPM. So that's kind of a good thing for getting an enormously massive train moving.

 

[RabidChild]

I'm not denying that it isn't patented, but i do question the reason for developing it as being to reverse the direction of the engine. Using the diesels to power electric motors on a locomotive does however makes a lot of sense if you think it through. . .we're talking Very low continual RPM's and thousands of tons being moved.

Here's why:
http://travel.howstuffworks.com/diesel-locomotive1.htm

As for loads that are carried, a BNSF intermodal train with 4 - 4400hp Dash 9-44 Locomotives will pull on average between 7000 and 8000 gross tons. This will be between 70 and 90 cars in length which equates to between 6800' and 8800' depending on the car configuration.

Why do I know or care? I do a lot of consulting work in the form of fuel efficency and derailment studies for BNSF (biggest railroad company in the US) and parts design work for Railworks (a smaller independent firm that makes custom railway devices.)