Stan Weiss wrote: ↑Thu May 17, 2018 10:30 amJoe,joe 90 wrote: ↑Thu May 17, 2018 5:28 am I like the title of this one.
"Cam data from well developed engines".
It's so easy, everyone can do it themselves (yes, I have) without having to ask any questions.
Just go find yourself a "well developed engine" at your local junkyard.
Turn the flywheel into a degree wheel.
Adjust the valve lash so it's zero or negative.
Use a dial gauge to measurevalve lift every X crank degrees.
Pull the cam, measure base circle and max cam lift.
4 important numbers, IO, OC, EO, EC.
ICL, ECL, LSA, overlap, they're nothing more than different combinations of those 4 numbers.
Once you've done that, you'll be asking even more questions, like.......... why isn't max lift half way between open and close?
How would you know if you've never made the effort to measure?
A flow bench is OK but full of limitations.
28 inches water, that's about 1 PSI.
Atmospheric pressure is more like 14.5 PSI so it's 1/14.5 away from reality at best.
A flow bench that works at atmospheric pressure drop would be a good upgrade.
Making more vac than 28 inches isn't really practical either.
Even a 2000W electric vac motor struggles to make 28 inch vac at max head flow, well it won't.
So you'd need other methods, like a turbo converted to a jet engine.
Really?
NOT! I am sure you understand pressure deferential. To see the full 14.69 psi you would need absolute zero pressure / psi in the cylinder.
Also just what is the atmospheric pressure in the room when you are flowing the heads?
What does the pressure deferential on a running look like fro IVO to IVC and how does it change with an increase in RPM?
Stan
Cam Data from Well-Developed Engines
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Re: Cam Data from Well-Developed Engines
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http://www.magneticlynx.com/carfor/carfor.htm
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http://www.magneticlynx.com/DV
Re: Cam Data from Well-Developed Engines
I don't, duration more effect where the peaks happen than total rpm for the most part.SchmidtMotorWorks wrote: ↑Thu May 17, 2018 9:50 amHow do you use RPM to determine lift, duration and centerlines?
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Re: Cam Data from Well-Developed Engines
Moving the installed center line does not change the distance between center lines... I am well aware that different lobes on the same Lobe "separation" angle will effect valve motion by a few degrees.Orr89rocz wrote: ↑Thu May 17, 2018 8:12 amBecause LSA is just half the sum of the ICL and ECL.
106 lsa can have the same cam lobes but on different centerlines and behave rather differently
106 lsa. 100 intake centerline. 112 exhaust centerline
106 lsa. 110 intake centerline. 102 exhaust centerline
You think those cams will behave same in the same motor?
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Re: Cam Data from Well-Developed Engines
So if you want to move the RPM of the peaks up what direction do you move the following:?GARY C wrote: ↑Thu May 17, 2018 12:00 pmI don't, duration more effect where the peaks happen than total rpm for the most part.SchmidtMotorWorks wrote: ↑Thu May 17, 2018 9:50 amHow do you use RPM to determine lift, duration and centerlines?
Lift
Duration
LSA
Index
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Re: Cam Data from Well-Developed Engines
Depends on where start from, they can all have an effect as they increase or decrease overlap, exhaust scavenging or window area to draw on the intake port.SchmidtMotorWorks wrote: ↑Thu May 17, 2018 12:44 pmSo if you want to move the RPM of the peaks up what direction do you move the following:?GARY C wrote: ↑Thu May 17, 2018 12:00 pmI don't, duration more effect where the peaks happen than total rpm for the most part.SchmidtMotorWorks wrote: ↑Thu May 17, 2018 9:50 am
How do you use RPM to determine lift, duration and centerlines?
Lift
Duration
LSA
Index
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 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!
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Re: Cam Data from Well-Developed Engines
Looks like this thread is nothing but one continuous pop quiz. Has anyone got it correct yet?
While it is OK to ask questions of others, some people really need to learn that they also have to answer questions ask of them.
Stan
While it is OK to ask questions of others, some people really need to learn that they also have to answer questions ask of them.
Stan
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Offering Performance Software Since 1987
http://www.magneticlynx.com/carfor/carfor.htm
David Vizard & Stan Weiss' IOP / Flow / Induction Optimization Software
http://www.magneticlynx.com/DV
Offering Performance Software Since 1987
http://www.magneticlynx.com/carfor/carfor.htm
David Vizard & Stan Weiss' IOP / Flow / Induction Optimization Software
http://www.magneticlynx.com/DV
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Re: Cam Data from Well-Developed Engines
Stan Weiss wrote: ↑Thu May 17, 2018 1:06 pm Looks like this thread is nothing but one continuous pop quiz. Has anyone got it correct yet?
While it is OK to ask questions of others, some people really need to learn that they also have to answer questions ask of them.
Stan
And there is the issue. Lots of question askers but no one will answer anything because it's all top secret shit.
Re: Cam Data from Well-Developed Engines
Most people here know that will never happen but it's fun watching people dig a hole.Stan Weiss wrote: ↑Thu May 17, 2018 1:06 pm Looks like this thread is nothing but one continuous pop quiz. Has anyone got it correct yet?
While it is OK to ask questions of others, some people really need to learn that they also have to answer questions ask of them.
Stan
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 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!
- Stan Weiss
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Re: Cam Data from Well-Developed Engines
Let me add telling someone that something does not work is not a technical answer.
Thomas A. Edison "I have not failed. I've just found 10,000 ways that won't work"
Stan
Thomas A. Edison "I have not failed. I've just found 10,000 ways that won't work"
Stan
Stan Weiss/World Wide Enterprises
Offering Performance Software Since 1987
http://www.magneticlynx.com/carfor/carfor.htm
David Vizard & Stan Weiss' IOP / Flow / Induction Optimization Software
http://www.magneticlynx.com/DV
Offering Performance Software Since 1987
http://www.magneticlynx.com/carfor/carfor.htm
David Vizard & Stan Weiss' IOP / Flow / Induction Optimization Software
http://www.magneticlynx.com/DV
Re: Cam Data from Well-Developed Engines
Over the years, studying the effects of cam positioning on my own and others dyno tests has led me to looking at valve events on a more individual basis rather than Lobe Separation...or at least trying to. Post's from ST members that were and are involved with DOHC engines doing positioning tests was also very inciteful to me.
There are some very interesting things being done with the Coyote engine...and others I'm sure, as far as playing with the camshaft actuators via software, in relation to rpm etc. as well. Want a lumpy idle in your Coyote? No problem..how does an instant 96 LSA at idle only sound to ya. There is definitely not one set of centerlines that are ideal through a broad rpm range.
There are some very interesting things being done with the Coyote engine...and others I'm sure, as far as playing with the camshaft actuators via software, in relation to rpm etc. as well. Want a lumpy idle in your Coyote? No problem..how does an instant 96 LSA at idle only sound to ya. There is definitely not one set of centerlines that are ideal through a broad rpm range.
Re: Cam Data from Well-Developed Engines
Too many adjustments for my brain to deal with, it would probably get me in trouble.CGT wrote: ↑Thu May 17, 2018 2:11 pm Over the years, studying the effects of cam positioning on my own and others dyno tests has led me to looking at valve events on a more individual basis rather than Lobe Separation...or at least trying to. Post's from ST members that were and are involved with DOHC engines doing positioning tests was also very inciteful to me.
There are some very interesting things being done with the Coyote engine...and others I'm sure, as far as playing with the camshaft actuators via software, in relation to rpm etc. as well. Want a lumpy idle in your Coyote? No problem..how does an instant 96 LSA at idle only sound to ya. There is definitely not one set of centerlines that are ideal through a broad rpm range.
If memory serves me right the one I saw ran a 106 through the meat of the pull moving to a 109 and ending with a 113... It might have been Jon that posted it years ago.
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 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!
Re: Cam Data from Well-Developed Engines
One such engine I know has the ICL at 70 at 2500rpm and at ICL 125 at 7500rpm. Cam is about 230-235@0.050" if I recall. The exhaust cam doesn't move around as much though
Take a more typical fixed cam setup. Run the same overlap (ie fix evc and Ivo ) but change the evo and ivc it massively changes both topend and bottom end. Then investigate constant evo and ivc but vary the overlap. I've done this in engmod4t. Then do a sensitivity study on each event one at a time. Do it fir a bunch of different engine.
Take a more typical fixed cam setup. Run the same overlap (ie fix evc and Ivo ) but change the evo and ivc it massively changes both topend and bottom end. Then investigate constant evo and ivc but vary the overlap. I've done this in engmod4t. Then do a sensitivity study on each event one at a time. Do it fir a bunch of different engine.
Re: Cam Data from Well-Developed Engines
I could quite easily go one or 2 steps further when I say I use turbos?Stan Weiss wrote: ↑Thu May 17, 2018 10:32 amStan Weiss wrote: ↑Thu May 17, 2018 10:30 amJoe,joe 90 wrote: ↑Thu May 17, 2018 5:28 am I like the title of this one.
"Cam data from well developed engines".
It's so easy, everyone can do it themselves (yes, I have) without having to ask any questions.
Just go find yourself a "well developed engine" at your local junkyard.
Turn the flywheel into a degree wheel.
Adjust the valve lash so it's zero or negative.
Use a dial gauge to measurevalve lift every X crank degrees.
Pull the cam, measure base circle and max cam lift.
4 important numbers, IO, OC, EO, EC.
ICL, ECL, LSA, overlap, they're nothing more than different combinations of those 4 numbers.
Once you've done that, you'll be asking even more questions, like.......... why isn't max lift half way between open and close?
How would you know if you've never made the effort to measure?
A flow bench is OK but full of limitations.
28 inches water, that's about 1 PSI.
Atmospheric pressure is more like 14.5 PSI so it's 1/14.5 away from reality at best.
A flow bench that works at atmospheric pressure drop would be a good upgrade.
Making more vac than 28 inches isn't really practical either.
Even a 2000W electric vac motor struggles to make 28 inch vac at max head flow, well it won't.
So you'd need other methods, like a turbo converted to a jet engine.
Really?
NOT! I am sure you understand pressure deferential. To see the full 14.69 psi you would need absolute zero pressure / psi in the cylinder.
Also just what is the atmospheric pressure in the room when you are flowing the heads?
What does the pressure deferential on a running look like fro IVO to IVC and how does it change with an increase in RPM?
Stan
1 bar boost?
2 bar boost
Or more?
How much pressure differential is that?
If you've made the effort to measure all 4 events of the cam on cylinder 1, repeat with the opposite cylinder.
Are the events the same?
Should they be?
What about all the other cylinders?
They'll always measure a bit different.
Re: Cam Data from Well-Developed Engines
I really thought a lot of the factory engines would have moved away from cams by now but I guess the technology didn't advance as was predicted.digger wrote: ↑Thu May 17, 2018 5:21 pm One such engine I know has the ICL at 70 at 2500rpm and at ICL 125 at 7500rpm. Cam is about 230-235@0.050" if I recall. The exhaust cam doesn't move around as much though
Take a more typical fixed cam setup. Run the same overlap (ie fix evc and Ivo ) but change the evo and ivc it massively changes both topend and bottom end. Then investigate constant evo and ivc but vary the overlap. I've done this in engmod4t. Then do a sensitivity study on each event one at a time. Do it fir a bunch of different engine.
Have you ever found engmod4t's predictions to match dyno results?
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 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!
Re: Cam Data from Well-Developed Engines
I met a guy at the Sonoma CA track in 1986 who was working on solenoid-operated valves. He figured his system would be fully operational in about two years. The plates on his Thunderbird read "EVA", for Electronic Valve Actuation...
Felix, qui potuit rerum cognscere causas.
Happy is he who can discover the cause of things.
Happy is he who can discover the cause of things.