Porting Heads
- Thread starter Zuffen
- Start date
The 1UZFE EGR Delete Kit is available for sale here.
ya, that they would. what with the oil-less "cams" that only run on ceramic bearings. thats a big mistake. even a trickle of oil would help the friction and wear problems.
as for the sealing problem, engineering closer tolerances would fix that. but with the materials used in most commercial car engines, the expansion rate would be different. so its difficult to calculate the tolerances you need when the engine is cold. once ceramics in piston engines are perfected, i think it would be a bit more viable. now im rambling.....
they did say one of them lasted 150,000 mi so far. so it cant be as bad as you say, or as i think.
valve spring energy is quite regenerative - ie as one spring is compressed by a lobe's rotation, another spring is expanding, helping push the lobe and cam around. but yes, friction none the less...
If that is true, why does it take quite some force turning only one cam (when setting the timing etc etc) let alone 2.
I tried this on my 20V when it was on the engine stand, and it surprized me that it took so much force, regenerative....? could be but very odd then.
The pneumetic system in F1 engines, is very good actually, the peumatics only shut the valve, and they do that without taking any energy of the engine because it runs on presurized air from a canister NOT a compresoor driven by the engine. the canister is charged with enough air to run the race.
the only thing is that there are still valve springs to keep it shut when the valve is completly closed there's no presure during the closed time, only whenm the valve is returning to it's seat.
So F1 engines have the same problem as we do with springs the only make up for the to slow cloding during stratospheric RPM rates using presurized air.
regulations forbid the coates design head to be used, although I doubt that they would indeed make more power then a normal F1 engine considering the amount of engineering that allready has been done on improving the poppet heads.
the bishop artical is however a very good read! though completly different in design versus the coates which I think is far better because of very fewer parts (coates is only 2 parts)
grtz Thomas
E
ed_ma61
Guest
random cool drag racing high speed footage...
...just because
http://break.com/index/drag_racing_filmed_at_1000fps.html
...just because
http://break.com/index/drag_racing_filmed_at_1000fps.html
- Messages
- 5,632
- Location
- Sydney, Australia
Some other cool info on top dragsters is:
The spark plugs have no electrodes left by half track. At this point the engine is running on pre-ignition alone.
The fuel is fed in so fast it is almost a solid.
It cost $5,000 a run in parts and labour.
The spark plugs have no electrodes left by half track. At this point the engine is running on pre-ignition alone.
The fuel is fed in so fast it is almost a solid.
It cost $5,000 a run in parts and labour.
E
ed_ma61
Guest
[SIZE=-1]One dragster's 500-inch Hemi makes more horsepower then the first 8 rows at Daytona.[/SIZE] [SIZE=-1]Under full throttle, a dragster engine consumes 1 1/2 gallons of nitro per second, the same rate of fuel consumption as a fully loaded 747, but with 4times the energy volume.
[SIZE=-1]The supercharger takes more power to drive then a stock hemi makes.[/SIZE]
[SIZE=-1]Even with nearly 3000 CFM of air being rammed in by the supercharger on overdrive, the fuel mixture is compressed into nearly-solid form before ignition.[/SIZE]
[SIZE=-1] Cylinders run on the verge of hydraulic lock.[/SIZE]
[SIZE=-1] Dual magnetos apply 44 amps to each spark plug. This is the output of an arc welder in each cylinder.[/SIZE]
[SIZE=-1] At stoichiometric (exact) 1.7:1 air/fuel mixture (for nitro), the flame front of nitro methane measures 7050 degrees F.[/SIZE]
[SIZE=-1]
Nitro methane burns yellow. The spectacular white flame seen above the stacks at night is raw burning hydrogen, dissociated from atmospheric water vapor by the searing exhaust gases.[/SIZE]
[SIZE=-1]Spark plug electrodes are totally consumed during a pass. After 1/2 way, the engine is dieseling from compression plus the glow of exhaust valves at1400 degrees F. The engine can only be shut down by cutting off it's fuel flow.
[/SIZE]
[SIZE=-1]If spark momentarily fails early in the run, unburned nitro builds up in those cylinders and then explodes with a force that can blow cylinder heads off the block in pieces or blow the block in half.[/SIZE]
[SIZE=-1]
Dragsters twist the crank (torsionally) so far (20 degrees in the big end of the track) that sometimes cam lobes are ground offset from front to rear to re-phase the valve timing somewhere closer to synchronization with the pistons.[/SIZE] [/SIZE] [SIZE=-1]To exceed 300mph in 4.5 seconds dragsters must accelerate at an average of over 4G's. But in reaching 200 mph well before 1/2 track, launch acceleration is closer to 8G's.
[SIZE=-1]If all the equipment is paid off, the crew worked for free, and for once NOTHING BLOWS UP, each run costs $1000.00 per second.[/SIZE]
[SIZE=-1]Dragsters reach over 300 miles per hour before you have read this sentence.[/SIZE] [SIZE=-1]* Top Fuel Engines ONLY turn 540 revolutions from light to light![/SIZE]
[SIZE=-1]
The redline is actually quite high at 9500rpm.
[/SIZE]
[SIZE=-1]To give you an idea of this acceleration, the current TF dragster elapsed time record is 4.477 seconds for the quarter mile. This means that you could be coming across the starting line in your average Lingenfelter powered "twin-turbo" Corvette at 200 mph (on a FLYING START) and the dragster would BEAT you to the finish line FROM A DEAD STOP in a quarter mile distance![/SIZE]
[/SIZE]
[SIZE=-1]The supercharger takes more power to drive then a stock hemi makes.[/SIZE]
[SIZE=-1]Even with nearly 3000 CFM of air being rammed in by the supercharger on overdrive, the fuel mixture is compressed into nearly-solid form before ignition.[/SIZE]
[SIZE=-1] Cylinders run on the verge of hydraulic lock.[/SIZE]
[SIZE=-1] Dual magnetos apply 44 amps to each spark plug. This is the output of an arc welder in each cylinder.[/SIZE]
[SIZE=-1] At stoichiometric (exact) 1.7:1 air/fuel mixture (for nitro), the flame front of nitro methane measures 7050 degrees F.[/SIZE]
[SIZE=-1]
Nitro methane burns yellow. The spectacular white flame seen above the stacks at night is raw burning hydrogen, dissociated from atmospheric water vapor by the searing exhaust gases.[/SIZE]
[SIZE=-1]Spark plug electrodes are totally consumed during a pass. After 1/2 way, the engine is dieseling from compression plus the glow of exhaust valves at1400 degrees F. The engine can only be shut down by cutting off it's fuel flow.
[/SIZE]
[SIZE=-1]If spark momentarily fails early in the run, unburned nitro builds up in those cylinders and then explodes with a force that can blow cylinder heads off the block in pieces or blow the block in half.[/SIZE]
[SIZE=-1]
Dragsters twist the crank (torsionally) so far (20 degrees in the big end of the track) that sometimes cam lobes are ground offset from front to rear to re-phase the valve timing somewhere closer to synchronization with the pistons.[/SIZE] [/SIZE] [SIZE=-1]To exceed 300mph in 4.5 seconds dragsters must accelerate at an average of over 4G's. But in reaching 200 mph well before 1/2 track, launch acceleration is closer to 8G's.
[SIZE=-1]If all the equipment is paid off, the crew worked for free, and for once NOTHING BLOWS UP, each run costs $1000.00 per second.[/SIZE]
[SIZE=-1]Dragsters reach over 300 miles per hour before you have read this sentence.[/SIZE] [SIZE=-1]* Top Fuel Engines ONLY turn 540 revolutions from light to light![/SIZE]
[SIZE=-1]
The redline is actually quite high at 9500rpm.
[/SIZE]
[SIZE=-1]To give you an idea of this acceleration, the current TF dragster elapsed time record is 4.477 seconds for the quarter mile. This means that you could be coming across the starting line in your average Lingenfelter powered "twin-turbo" Corvette at 200 mph (on a FLYING START) and the dragster would BEAT you to the finish line FROM A DEAD STOP in a quarter mile distance![/SIZE]
[/SIZE]
E
ed_ma61
Guest
E
ed_ma61
Guest
well its never reallly quite been on topic after the first post has it?
bango
Member
- Messages
- 323
- Location
- Sydney/Australia
Still,Dam interesting reading...surely these must be the end of the line for pistons types with these sort of power..?
that is the most brilliat Blow-Up-Your-Engine piccie I've ever seen.
the forces in such applications are fenomenal, hat's of to the guys designing and building that stuff.
back to topic, Someone posted about the golfball profile, you could never use that in an engine intake trackt, because that form of difusing/laminating only works on a round/ballshape form travveling through a fluid such as air,
spiral form intakes are however a different story, but very hard to design and build methinks
just let's take all valve out of the arrangement and do it like coates.
seems that the breakthrough in racing usage is held up by regulations.
Though what about this technique: looks very promissing to me.
http://www.coatesengine.com/images/graphics/product.jpg
www.coatesengine.com
grtz Thomas
the forces in such applications are fenomenal, hat's of to the guys designing and building that stuff.
back to topic, Someone posted about the golfball profile, you could never use that in an engine intake trackt, because that form of difusing/laminating only works on a round/ballshape form travveling through a fluid such as air,
spiral form intakes are however a different story, but very hard to design and build methinks
just let's take all valve out of the arrangement and do it like coates.
seems that the breakthrough in racing usage is held up by regulations.
Though what about this technique: looks very promissing to me.
http://www.coatesengine.com/images/graphics/product.jpg
www.coatesengine.com
grtz Thomas
speeed_dmonx
New Member
- Messages
- 15
- Location
- Fort Collins, Colorado
a TOP FUEL DRAGSTER(if that is what is being spoken about) bounces off of more than 7 GRAND on average..I grew up around them since I was 5 years old...there is a reason some of the first intakes were called BIRD CATCHERS...there was so much vacuum being pulled in through the air cleaner mouth that the first foam elements on there were sucked in..so hence the partial disregard of the air filters...the engines idle around 1500 rpm..because of so much mass and power..not to mention 6000 horsepower or so to feed..
E
ed_ma61
Guest
rotary valves have friction/wear and sealing issues unfortunately...
ya, that they would. what with the oil-less "cams" that only run on ceramic bearings. thats a big mistake. even a trickle of oil would help the friction and wear problems.
as for the sealing problem, engineering closer tolerances would fix that. but with the materials used in most commercial car engines, the expansion rate would be different. so its difficult to calculate the tolerances you need when the engine is cold. once ceramics in piston engines are perfected, i think it would be a bit more viable. now im rambling.....
they did say one of them lasted 150,000 mi so far. so it cant be as bad as you say, or as i think.
Hey all,
Let's asume tha coates know what they're doing, and the tollerances doable today far outnumber the ones 10 years back, Why would ceramic bearings be inducing friction and wear at a rate beyond that of an 150 year old oiled shell bearing design used in today's petrol burners.
remember that todays production diesels run pumps that do close to 2000bars and survive that abuse for years and years on end, something unthinkable 10 years ago on production cars
I seriously doubt that considering todays manufaturing techniques it would not be possible to make a dry ceramic bearing that is combustionpresure proof for extended periods of time (ie production engine)
coates have got a serioulsy good thing in their hands methinks.
on the friction part: remember that this design carry's no springs or whatever, so the win hands down in that field to any poppetvalve assembly that carry's valvesprings, remember on of the biggest powerlosses in an 4stroke engine come from driving the intire valve train springs, you'd don't have that loss in coates design.
grtz Thomas
Let's asume tha coates know what they're doing, and the tollerances doable today far outnumber the ones 10 years back, Why would ceramic bearings be inducing friction and wear at a rate beyond that of an 150 year old oiled shell bearing design used in today's petrol burners.
remember that todays production diesels run pumps that do close to 2000bars and survive that abuse for years and years on end, something unthinkable 10 years ago on production cars
I seriously doubt that considering todays manufaturing techniques it would not be possible to make a dry ceramic bearing that is combustionpresure proof for extended periods of time (ie production engine)
coates have got a serioulsy good thing in their hands methinks.
on the friction part: remember that this design carry's no springs or whatever, so the win hands down in that field to any poppetvalve assembly that carry's valvesprings, remember on of the biggest powerlosses in an 4stroke engine come from driving the intire valve train springs, you'd don't have that loss in coates design.
grtz Thomas
E
ed_ma61
Guest
valve spring energy is quite regenerative - ie as one spring is compressed by a lobe's rotation, another spring is expanding, helping push the lobe and cam around. but yes, friction none the less...
E
ed_ma61
Guest
If that is true, why does it take quite some force turning only one cam (when setting the timing etc etc) let alone 2.
I tried this on my 20V when it was on the engine stand, and it surprized me that it took so much force, regenerative....? could be but very odd then.
The pneumetic system in F1 engines, is very good actually, the peumatics only shut the valve, and they do that without taking any energy of the engine because it runs on presurized air from a canister NOT a compresoor driven by the engine. the canister is charged with enough air to run the race.
the only thing is that there are still valve springs to keep it shut when the valve is completly closed there's no presure during the closed time, only whenm the valve is returning to it's seat.
So F1 engines have the same problem as we do with springs the only make up for the to slow cloding during stratospheric RPM rates using presurized air.
regulations forbid the coates design head to be used, although I doubt that they would indeed make more power then a normal F1 engine considering the amount of engineering that allready has been done on improving the poppet heads.
the bishop artical is however a very good read! though completly different in design versus the coates which I think is far better because of very fewer parts (coates is only 2 parts)
grtz Thomas
the Bishop design would be a better solution for what they wanted to use it for, because they wouldnt need cutouts in the pistons for the "lobes" that are used in the Coates design. not to mention the Coates design is designed for production cars, not F1 cars. and if something lasts in a F1 race, at F1 stresses, it will likely last in a run-of-the-mill production engine, at production car stresses.
