Cam Data from Well-Developed Engines

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GARY C
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Re: Cam Data from Well-Developed Engines

Post by GARY C » Wed May 16, 2018 11:25 am

digger wrote:
Wed May 16, 2018 2:57 am
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.
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THE ABOVE POST IN NO WAY REFLECTS THE VIEWS OF SPEED TALK OR IT'S MEMBER AND SHOULD BE VIEWED AS ENTERTAINMENT ONLY...Thanks, The Management!

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Re: Cam Data from Well-Developed Engines

Post by hoffman900 » Wed May 16, 2018 12:32 pm

GARY C wrote:
Wed May 16, 2018 11:25 am
digger wrote:
Wed May 16, 2018 2:57 am
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.
-Bob

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Re: Cam Data from Well-Developed Engines

Post by Orr89rocz » Wed May 16, 2018 12:54 pm

B Original wrote:
Wed May 16, 2018 11:20 am
Orr89rocz wrote:
Wed May 16, 2018 10:58 am
B Original wrote:
Wed May 16, 2018 10:48 am


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
http://www.hotrod.com/articles/hrdp-100 ... -test/amp/

This seems to point to centerline advance only

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Re: Cam Data from Well-Developed Engines

Post by B Original » Wed May 16, 2018 2:04 pm

Orr89rocz wrote:
Wed May 16, 2018 12:54 pm
B Original wrote:
Wed May 16, 2018 11:20 am
Orr89rocz wrote:
Wed May 16, 2018 10:58 am


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
http://www.hotrod.com/articles/hrdp-100 ... -test/amp/

This seems to point to centerline advance only
You are correct I was apparently describing active fuel management or AFM I had a brain fart

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Re: Cam Data from Well-Developed Engines

Post by digger » Wed May 16, 2018 5:12 pm

GARY C wrote:
Wed May 16, 2018 11:25 am
digger wrote:
Wed May 16, 2018 2:57 am
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 ?

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Re: Cam Data from Well-Developed Engines

Post by David Redszus » Wed May 16, 2018 6:26 pm

digger wrote:
Wed May 16, 2018 5:12 pm
GARY C wrote:
Wed May 16, 2018 11:25 am
digger wrote:
Wed May 16, 2018 2:57 am


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.

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Re: Cam Data from Well-Developed Engines

Post by GARY C » Wed May 16, 2018 6:55 pm

digger wrote:
Wed May 16, 2018 5:12 pm
GARY C wrote:
Wed May 16, 2018 11:25 am
digger wrote:
Wed May 16, 2018 2:57 am


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 MEMBER AND SHOULD BE VIEWED AS ENTERTAINMENT ONLY...Thanks, The Management!

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Re: Cam Data from Well-Developed Engines

Post by GARY C » Wed May 16, 2018 7:00 pm

hoffman900 wrote:
Wed May 16, 2018 12:32 pm
GARY C wrote:
Wed May 16, 2018 11:25 am
digger wrote:
Wed May 16, 2018 2:57 am


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 MEMBER AND SHOULD BE VIEWED AS ENTERTAINMENT ONLY...Thanks, The Management!

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Re: Cam Data from Well-Developed Engines

Post by B Original » Wed May 16, 2018 7:29 pm

GARY C wrote:
Wed May 16, 2018 7:00 pm
hoffman900 wrote:
Wed May 16, 2018 12:32 pm
GARY C wrote:
Wed May 16, 2018 11:25 am


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....

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Re: Cam Data from Well-Developed Engines

Post by digger » Wed May 16, 2018 7:36 pm

GARY C wrote:
Wed May 16, 2018 6:55 pm
digger wrote:
Wed May 16, 2018 5:12 pm
GARY C wrote:
Wed May 16, 2018 11:25 am


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 ?

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Re: Cam Data from Well-Developed Engines

Post by GARY C » Wed May 16, 2018 7:55 pm

digger wrote:
Wed May 16, 2018 7:36 pm
GARY C wrote:
Wed May 16, 2018 6:55 pm
digger wrote:
Wed May 16, 2018 5:12 pm


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 MEMBER AND SHOULD BE VIEWED AS ENTERTAINMENT ONLY...Thanks, The Management!

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Re: Cam Data from Well-Developed Engines

Post by Headguy » Wed May 16, 2018 8:03 pm

What is this thread about? #-o

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Re: Cam Data from Well-Developed Engines

Post by Stan Weiss » Wed May 16, 2018 8:11 pm

WAG

How chromosomes - XX or XY relate to camshaft selection. :lol:

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Re: Cam Data from Well-Developed Engines

Post by Headguy » Wed May 16, 2018 8:14 pm

Stan Weiss wrote:
Wed May 16, 2018 8:11 pm
WAG

How chromosomes - XX or XY relate to camshaft selection. :lol:

Stan
Oh wow. We have advanced that far since I took a nap? How long was I gone? Lol

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Re: Cam Data from Well-Developed Engines

Post by carzngunz » Wed May 16, 2018 8:47 pm

I hardly ever post on here but after reading through this I've got to say, this is some funny s**t! :lol:

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