Ok, how about electromagnetic valvetrain
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Ok, how about electromagnetic valvetrain I read/saw a quick blurb about it in an industry specific magazine (automotive engineering)
Anyone know anything or is this another magic product with no fruitation.
Anyone know anything or is this another magic product with no fruitation.
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I wonder what sort of power would be required to pulse the coil several times
per second on every valve.
With a 'normally closed valve', the spring would have to be overcome as well.
I'm sure they're not going to use 150# seat pressures, but something needs
to send the valve back to home position...gravity isn't going to cut it.
I don't think reversing the current (AC ) is an option because of the duty cycle. That will change as RPM changes too.
If it's a normally open valve, same applies, but reverse mechanics.
Then think about the shielding needed to prevent cross talk on sensor wires,
sensors, etc.
Seems like a very complex design. As always, there will be pros and cons.
Do you have a link to this article?
per second on every valve.
With a 'normally closed valve', the spring would have to be overcome as well.
I'm sure they're not going to use 150# seat pressures, but something needs
to send the valve back to home position...gravity isn't going to cut it.
I don't think reversing the current (AC ) is an option because of the duty cycle. That will change as RPM changes too.
If it's a normally open valve, same applies, but reverse mechanics.
Then think about the shielding needed to prevent cross talk on sensor wires,
sensors, etc.
Seems like a very complex design. As always, there will be pros and cons.
Do you have a link to this article?
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From: Mefis
Watching the pikes peak hill climbs on espn2 a couple years ago, there was mention of a big rig running solenoid actuated valves. It climbed the hill from what I remember. I wonder if diesel was the only option, due to their low redline?
I wonder how far it has come along today.
I wonder how far it has come along today.
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i'm really suprised fluids can be used aid in this process. in F1at redline the valve opens and closes in 0.004 seconds (est.) i cant believe you can create pressure and they remove it that fast. makes my head boggle.
Point of this story is that the "yes" and "no" can easily be determined. Magnitude of forces and things like that usually are more difficult to estimate
Point of this story is that the "yes" and "no" can easily be determined. Magnitude of forces and things like that usually are more difficult to estimate
Last edited by treyZ28; Nov 5, 2005 at 11:17 AM.
Here's an article that I found about valvetrain technology being developed by Lotus:
http://www.all4engineers.com/index.p...alloc=33/id=45
Its electrohydraulic instead of electromagnetic, but still an interesting read.
http://www.all4engineers.com/index.p...alloc=33/id=45
Its electrohydraulic instead of electromagnetic, but still an interesting read.
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i calculated at 18k or 19k rpm. I cant remember.
assuming 200% VE at this point and .004 seconds (assuming peak torque isn't at redline. and i'm stubborn)
density of air = 1.29 g/liter
displacement- 3.0 liters
airflow (volume) 6.0 liters/ opening
airflow (mass) = 7.74 grams /opening
250 openings per second
1935g/second mass air flow rate. Or almost 2.0 KG OF AIR PER SECOND (its a few degrees below STP) or 7200 KG/ HR
assume 13:1 A:F (why not!)
mass fuel flow 148g/second or 535846g /hr or 535.8 KG/hr
density of gasoline = .720Kg /liter
volume fuel flow rate = 740,000 L/Hr or over 195,000 gallons/hr.
what gives here.
assuming 200% VE at this point and .004 seconds (assuming peak torque isn't at redline. and i'm stubborn)
density of air = 1.29 g/liter
displacement- 3.0 liters
airflow (volume) 6.0 liters/ opening
airflow (mass) = 7.74 grams /opening
250 openings per second
1935g/second mass air flow rate. Or almost 2.0 KG OF AIR PER SECOND (its a few degrees below STP) or 7200 KG/ HR
assume 13:1 A:F (why not!)
mass fuel flow 148g/second or 535846g /hr or 535.8 KG/hr
density of gasoline = .720Kg /liter
volume fuel flow rate = 740,000 L/Hr or over 195,000 gallons/hr.
what gives here.
Last edited by treyZ28; Nov 4, 2005 at 10:53 PM.
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Actually they use pneumatic springs actuated by hydraulics, and the solenoids are computer controlled. They're expensive even for Indy cars. http://www.indiacar.com/index2.asp?p...l/pvengine.htm
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Originally Posted by 8KickassRS9
hmm, since they still need springs but as to not prematurely wear out the e-mag servos, what if they actually used engine compression to help close it?
Originally Posted by treyZ28
i calculated at 18k or 19k rpm. I cant remember.
assuming 200% VE at this point and .004 seconds (assuming peak torque isn't at redline. and i'm stubborn)
density of air = 1.29 g/liter
displacement- 3.0 liters
airflow (volume) 6.0 liters/ opening
airflow (mass) = 7.74 grams /opening
250 openings per second
1935g/second mass air flow rate. Or almost 2.0 KG OF AIR PER SECOND (its a few degrees below STP) or 7200 KG/ HR
assume 13:1 A:F (why not!)
mass fuel flow 148g/second or 535846g /hr or 535.8 KG/hr
density of gasoline = .720Kg /liter
volume fuel flow rate = 740,000 L/Hr or over 195,000 gallons/hr.
what gives here.
assuming 200% VE at this point and .004 seconds (assuming peak torque isn't at redline. and i'm stubborn)
density of air = 1.29 g/liter
displacement- 3.0 liters
airflow (volume) 6.0 liters/ opening
airflow (mass) = 7.74 grams /opening
250 openings per second
1935g/second mass air flow rate. Or almost 2.0 KG OF AIR PER SECOND (its a few degrees below STP) or 7200 KG/ HR
assume 13:1 A:F (why not!)
mass fuel flow 148g/second or 535846g /hr or 535.8 KG/hr
density of gasoline = .720Kg /liter
volume fuel flow rate = 740,000 L/Hr or over 195,000 gallons/hr.
what gives here.
250 revs/second * 3.0 liters/rev * 1.29 g air / L air * 1 g fuel / 13 g air * 1 L fuel / 720 g fuel * 3600 s / hr = 372 L/hr
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yes F1 guys use pneumatics! they were outawed in the early nineties i think and the peak RPM dropped to just over 10K on the V8's of the day! now they are upto 20K on the lastest (next season) 2.4 ltr V8!! the only way to get the valves to open and close that fast is using air!
as for the orignal post about electromagnetic valve gear, well i think i read a piece about it a couple of months back. it said that it requiers something like 5kw (about 6.667bhp) of power to drive the system! and that was on a single cylinder! think about the energy required for a V8!!
will try and find more info on it!
thanks Chris.
as for the orignal post about electromagnetic valve gear, well i think i read a piece about it a couple of months back. it said that it requiers something like 5kw (about 6.667bhp) of power to drive the system! and that was on a single cylinder! think about the energy required for a V8!!
will try and find more info on it!
thanks Chris.
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it said that it requiers something like 5kw (about 6.667bhp) of power to drive the system! and that was on a single cylinder! think about the energy required for a V8!!
what sort of power supply would be needed (several batteries), and how long
the charge could hold? I don't think a high output alternator (or two) would be sufficient?
Since not all valves are opening at the sime time, the total power might not
be much more than 10KW?
What do the Spintron users have to say about total power needed to run
the valves?
Maybe we can do a reverse calculation based on 6.7 HP per cylinder?
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The power demands of EVA were one of the main reasons the automotive sector was eyeing 42 V. electrical systems (which seem to have faded away of late..) The first time I ran into this concept, a guy at the Sears Point CA race track early in 1986 claimed to be on the brink of volume manufacturing. His T. Bird even had an 'Eva' license plate. Can't count the number of times since it has been just months from production...
Re P Mack's 'revised' F1 calculation, if you use the rule of thumb that it takes one half a pound of gasoline per hour to make a horsepower, then 96 gal/hr. = 96 x 6 = 576 lb. = 1152 HP. A little high, but then at 18,000 + RPM, the friction might start cutting into the B.S.F.C. On the other hand, if we assume a 'slightly' more modest V.E., say 120%, and a better B.S.F.C., say 0.4, then we get 58 gal/hr. and 870 HP...
Re P Mack's 'revised' F1 calculation, if you use the rule of thumb that it takes one half a pound of gasoline per hour to make a horsepower, then 96 gal/hr. = 96 x 6 = 576 lb. = 1152 HP. A little high, but then at 18,000 + RPM, the friction might start cutting into the B.S.F.C. On the other hand, if we assume a 'slightly' more modest V.E., say 120%, and a better B.S.F.C., say 0.4, then we get 58 gal/hr. and 870 HP...
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dont forget that F1 cars have 100%+ cyclinder filling due to variable length intakes!! very trick system that uses the sound of the vavles shuting and thries to capture the compresed air in the cylinders! and i think there is a little ram air effect aswell!
thanks Chris.
thanks Chris.
