GARY C wrote: ↑Wed May 16, 2018 2:53 am
Its interesting to see how much the LSA changes on those through out a power pull considering everyone says LSA doesn't matter yet the only real change is LSA while the lobe profiles remain the same.
The ICL and ECL changes are to optimise the events for best cylinder fill on variable cam timing engines .
As you say the LSA changes with rpm as a result of that ( chicken vs egg) so much for there being an optimum LSA for all rpm like some claim .....
I say it's interesting because during a wide open throttle power pull the computer chooses a much tighter LSA for the lobes it's given with the exception of the top of the power curve.
As for the chicken vs egg analogy everyone forgets you need a rooster to fertilize the egg.
Please Note!
THE ABOVE POST IN NO WAY REFLECTS THE VIEWS OF SPEED TALK OR IT'S MEMBERS AND SHOULD BE VIEWED AS ENTERTAINMENT ONLY...Thanks, The Management!
GARY C wrote: ↑Wed May 16, 2018 2:53 am
Its interesting to see how much the LSA changes on those through out a power pull considering everyone says LSA doesn't matter yet the only real change is LSA while the lobe profiles remain the same.
The ICL and ECL changes are to optimise the events for best cylinder fill on variable cam timing engines .
As you say the LSA changes with rpm as a result of that ( chicken vs egg) so much for there being an optimum LSA for all rpm like some claim .....
I say it's interesting because during a wide open throttle power pull the computer chooses a much tighter LSA for the lobes it's given with the exception of the top of the power curve.
As for the chicken vs egg analogy everyone forgets you need a rooster to fertilize the egg.
Except LSA is like starting out with a human, and trying to back into what the X (two for a female) and Y (male) chromosomes control.
LSA is the result of the sum of any two (intake and exhaust) centerlines and divided by two.
If I take a LSA of 106* and multiply it by 2, I get 212*. Any two integers that add up to 212* can be my respective centerlines.
The lift is varied by regulating the oil pressure to the lifter which manipulates event timing by changing the Lash. To change only the center line a mechanism would have to be designed to rotate only half of the lobes on a single cam shaft
I thought it was rotating the entire cam since it is one piece lol i could be wrong
you're incorrect with the ls although at one time I don't remember the name of it but someone in the aftermarket offered a mechanism to do this exact thing on a gen 1 small block it operated off of oil pressure and varied a chain snubber that either relaxed or put pressure on the timing chain itself changing the cam timing
I thought it was rotating the entire cam since it is one piece lol i could be wrong
you're incorrect with the ls although at one time I don't remember the name of it but someone in the aftermarket offered a mechanism to do this exact thing on a gen 1 small block it operated off of oil pressure and varied a chain snubber that either relaxed or put pressure on the timing chain itself changing the cam timing
GARY C wrote: ↑Wed May 16, 2018 2:53 am
Its interesting to see how much the LSA changes on those through out a power pull considering everyone says LSA doesn't matter yet the only real change is LSA while the lobe profiles remain the same.
The ICL and ECL changes are to optimise the events for best cylinder fill on variable cam timing engines .
As you say the LSA changes with rpm as a result of that ( chicken vs egg) so much for there being an optimum LSA for all rpm like some claim .....
I say it's interesting because during a wide open throttle power pull the computer chooses a much tighter LSA for the lobes it's given with the exception of the top of the power curve.
So you agree that rpm range comes into cam selection ?
The ICL and ECL changes are to optimise the events for best cylinder fill on variable cam timing engines .
As you say the LSA changes with rpm as a result of that ( chicken vs egg) so much for there being an optimum LSA for all rpm like some claim .....
I say it's interesting because during a wide open throttle power pull the computer chooses a much tighter LSA for the lobes it's given with the exception of the top of the power curve.
So you agree that rpm range comes into cam selection ?
Given that TimeArea must change as BMEP changes. The new required TimeArea can be met in by changes in several ways: valve lift and duration, valve size, number of valves, flow Cd, and rpm.
The actual parameters to be changed are determined by the design shortcomings of the engine, i.e. blowdown, ramming, pumping and overlap.
The ICL and ECL changes are to optimise the events for best cylinder fill on variable cam timing engines .
As you say the LSA changes with rpm as a result of that ( chicken vs egg) so much for there being an optimum LSA for all rpm like some claim .....
I say it's interesting because during a wide open throttle power pull the computer chooses a much tighter LSA for the lobes it's given with the exception of the top of the power curve.
So you agree that rpm range comes into cam selection ?
Yes, I don't know anyone who said it didn't.
Please Note!
THE ABOVE POST IN NO WAY REFLECTS THE VIEWS OF SPEED TALK OR IT'S MEMBERS AND SHOULD BE VIEWED AS ENTERTAINMENT ONLY...Thanks, The Management!
The ICL and ECL changes are to optimise the events for best cylinder fill on variable cam timing engines .
As you say the LSA changes with rpm as a result of that ( chicken vs egg) so much for there being an optimum LSA for all rpm like some claim .....
I say it's interesting because during a wide open throttle power pull the computer chooses a much tighter LSA for the lobes it's given with the exception of the top of the power curve.
As for the chicken vs egg analogy everyone forgets you need a rooster to fertilize the egg.
Except LSA is like starting out with a human, and trying to back into what the X (two for a female) and Y (male) chromosomes control.
LSA is the result of the sum of any two (intake and exhaust) centerlines and divided by two.
If I take a LSA of 106* and multiply it by 2, I get 212*. Any two integers that add up to 212* can be my respective centerlines.
Try getting a human without a human and let me know how that goes, it takes two humans by the way, we have over 7 billion tests confirming this study.
Not sure what multiplying the lobe separation by 2 has to do with it.
Please Note!
THE ABOVE POST IN NO WAY REFLECTS THE VIEWS OF SPEED TALK OR IT'S MEMBERS AND SHOULD BE VIEWED AS ENTERTAINMENT ONLY...Thanks, The Management!
I say it's interesting because during a wide open throttle power pull the computer chooses a much tighter LSA for the lobes it's given with the exception of the top of the power curve.
As for the chicken vs egg analogy everyone forgets you need a rooster to fertilize the egg.
Except LSA is like starting out with a human, and trying to back into what the X (two for a female) and Y (male) chromosomes control.
LSA is the result of the sum of any two (intake and exhaust) centerlines and divided by two.
If I take a LSA of 106* and multiply it by 2, I get 212*. Any two integers that add up to 212* can be my respective centerlines.
Try getting a human without a human and let me know how that goes, it takes two humans by the way, we have over 7 billion tests confirming this study.
Not sure what multiplying the lobe separation by 2 has to do with it.
I was hoping it wasn't just me wondering that additionally I can't put my finger on it but the question has something to do would being in control of your chromosomes now you can select the XX or XY and according to the government many years after you were born all you have to do is just feel like it hmm....
I say it's interesting because during a wide open throttle power pull the computer chooses a much tighter LSA for the lobes it's given with the exception of the top of the power curve.
So you agree that rpm range comes into cam selection ?
Yes, I don't know anyone who said it didn't.
You dont know any methods where this is not defined ?
So you agree that rpm range comes into cam selection ?
Yes, I don't know anyone who said it didn't.
You dont know any methods where this is not defined ?
I don't know every method used so I guess anything is possible.
Please Note!
THE ABOVE POST IN NO WAY REFLECTS THE VIEWS OF SPEED TALK OR IT'S MEMBERS AND SHOULD BE VIEWED AS ENTERTAINMENT ONLY...Thanks, The Management!