Camdesign transparency !

[MadBill]

<Hi-Jack Alert!>
I always thought I'd like a custom license plate reading dv/dt (acceleration) and one for my brother-in-law: da/dt (jerk)...

[GARY C]

CSZ lobe!

Do you have a L,V,A,J graph of it?

I would trust Comp to let me know if this lobe would work and then I would run it...I'm not scared.
If you had that info what would you do with it?

Jon, You dance well!...Makes me think of an Elton John song.

[Rick360]

You only can come to some basic good rules of thumb when you are a master in what you are doing.
People can tell me lots of things but not that DV does not know what he is talking about.
How do you think E=mc² came along.
JS

I think its a stretch comparing DV to Einstein.

New physics "rule of thumb" ...

E=128-mc²



Rick

[hoffman900]

Jon, You dance well!...Makes me think of an Elton John song.

And the biggest troll on both ST and YB goes to..
http://www.yellowbullet.com/forum/showp ... stcount=57

You!

You only can come to some basic good rules of thumb when you are a master in what you are doing.
People can tell me lots of things but not that DV does not know what he is talking about.
How do you think E=mc² came along.
JS

I think its a stretch comparing DV to Einstein.

New physics "rule of thumb" ...

E=128-mc²



Rick

[digger]

Maybe some will find some interesting things here.

Area under the curve.
viewtopic.php?t=1148

Stan

Thats a pretty good thread although I find it shocking that Larry came would blame low lift flow for loss of tq when trying to run a cam in excess of 270@.050 below it's intended rpm range.

Larry has mentioned many times that in his opinion backed up by the dyno that increasing low lift flow acts the same or similar to a slight increase of duration and thus makes perfect sense that below peak tq there is a loss with no cam change.

[hoffman900]

Maybe some will find some interesting things here.

Area under the curve.
viewtopic.php?t=1148

Stan

Thats a pretty good thread although I find it shocking that Larry came would blame low lift flow for loss of tq when trying to run a cam in excess of 270@.050 below it's intended rpm range.

Larry has mentioned many times that in his opinion backed up by the dyno that increasing low lift flow acts the same or similar to a slight increase of duration and thus makes perfect sense that below peak tq there is a loss with no cam change.

It's also well understood by anyone who plays with hemispherical type combustion chambers...

Here is a Calvin Elston quote which approaches the same issue from another angle...

If you keep dropping the pressure in the header, and that is not hard, you will eventually get to the condition which you are seeing which is overscavaging. Changing the camshaft around is effectual only to the degree that it was too large or too tight in the beginning. Lets try stepping back further from the situation. There is a basic amount of duration you need to get to a certain rpm and power level with a given engine combo. There is a wall there that you hit when your just dropping header pressure and correspondingly reducing exh duration and overlap, (and all the other tricks there are). It does not allow you to really make too much more power with the same size intake valve. It is a diminishing return. The adjustment is to reduce the size of the exhaust valve. This allows you to keep the duration or cam timing where it really wants to be and still exhaust well enough. The smaller exhaust valve allows most engines to use a larger intake valve and this is the ultimate purpose in using a properly tuned header. The well tuned exhaust side allows a larger intake valve which is the easier way to move more air into the cylinders than sucking from the back door. If your header is not functioning well, you will not be able to get there. Very few engine people get this. I believe if you look at PS type 2valve engine development over the last 10 years, you will see a very large increase in power and rpm, but exh valves are the same or smaller in diameter and the intakes are larger.The merged collector and corresponding header and valve sizing has been a important factor.

[SchmidtMotorWorks]

CSZ lobe!

Do you have a L,V,A,J graph of it?

I would trust Comp to let me know if this lobe would work and then I would run it...I'm not scared.
If you had that info what would you do with it?

Jon, You dance well!...Makes me think of an Elton John song.

The L,V,A,J graph tells you how aggressive the lobe design is in numbers (not marketing), how hard it is on the parts, how much is left on the table, it gives you some insight as to what kind of springs and push-rods are needed.

If you are interested in cams, this is essential stuff to understand.

If enough people are interested, I can start a new thread explaining how to read a chart with Lift, Velocity, Acceleration and Jerk curves on it.
We could also get into other valuable things to consider such as contact stress, and oil entrainment.

You really can''t make an informed decision about a cam without understanding these things.

[GARY C]

You only can come to some basic good rules of thumb when you are a master in what you are doing.
People can tell me lots of things but not that DV does not know what he is talking about.
How do you think E=mc² came along.
JS

I think its a stretch comparing DV to Einstein.

New physics "rule of thumb" ...

E=128-mc²



Rick

That may work better now that we know the speed of light and time do not remain constant!

[af2]

Jon, You dance well!...Makes me think of an Elton John song.

And the biggest troll on both ST and YB goes to..
http://www.yellowbullet.com/forum/showp ... stcount=57

You!


I think its a stretch comparing DV to Einstein.

New physics "rule of thumb" ...

E=128-mc²



Rick

[/quote]

[/quote]


Wow I was wondering??

[GARY C]

Jon, You dance well!...Makes me think of an Elton John song.

And the biggest troll on both ST and YB goes to..
http://www.yellowbullet.com/forum/showp ... stcount=57

You!


I think its a stretch comparing DV to Einstein.

New physics "rule of thumb" ...

E=128-mc²



Rick

[/quote]


Wow I was wondering??[/quote]
Hoffman, I think you have the ST award...I stated clearly to Warped where I stand, he and I have a future together... but it will not be here! I am not sure what that has to do with a cam thread though?

[Rick360]

The L,V,A,J graph tells you how aggressive the lobe design is in numbers (not marketing), how hard it is on the parts, how much is left on the table, it gives you some insight as to what kind of springs and push-rods are needed.

If you are interested in cams, this is essential stuff to understand.

If enough people are interested, I can start a new thread explaining how to read a chart with Lift, Velocity, Acceleration and Jerk curves on it.
We could also get into other valuable things to consider such as contact stress, and oil entrainment.

You really can''t make an informed decision about a cam without understanding these things.

Do cam companies have this info available for their lobes? Will they show it to customers? COMP has more info than most companies. I've never thought to ask but assumed it was proprietary. They do a pretty good job describing their lobe families in their catalog.

But, I would be interested in how to read a L,V,A,J graph, especially if we had a real graph from a real lobe. This needs to be design numbers, not from a cam doctor type device measuring what the lobe measures, correct.

Rick

[GARY C]

The L,V,A,J graph tells you how aggressive the lobe design is in numbers (not marketing), how hard it is on the parts, how much is left on the table, it gives you some insight as to what kind of springs and push-rods are needed.

If you are interested in cams, this is essential stuff to understand.

If enough people are interested, I can start a new thread explaining how to read a chart with Lift, Velocity, Acceleration and Jerk curves on it.
We could also get into other valuable things to consider such as contact stress, and oil entrainment.

You really can''t make an informed decision about a cam without understanding these things.

Do cam companies have this info available for their lobes? Will they show it to customers? COMP has more info than most companies. I've never thought to ask but assumed it was proprietary. They do a pretty good job describing their lobe families in their catalog.

But, I would be interested in how to read a L,V,A,J graph, especially if we had a real graph from a real lobe. This needs to be design numbers, not from a cam doctor type device measuring what the lobe measures, correct.

Rick

Would Cam Dr not show this?

[SchmidtMotorWorks]

The L,V,A,J graph tells you how aggressive the lobe design is in numbers (not marketing), how hard it is on the parts, how much is left on the table, it gives you some insight as to what kind of springs and push-rods are needed.

If you are interested in cams, this is essential stuff to understand.

If enough people are interested, I can start a new thread explaining how to read a chart with Lift, Velocity, Acceleration and Jerk curves on it.
We could also get into other valuable things to consider such as contact stress, and oil entrainment.

You really can''t make an informed decision about a cam without understanding these things.

Do cam companies have this info available for their lobes? Will they show it to customers? COMP has more info than most companies. I've never thought to ask but assumed it was proprietary. They do a pretty good job describing their lobe families in their catalog.

But, I would be interested in how to read a L,V,A,J graph, especially if we had a real graph from a real lobe. This needs to be design numbers, not from a cam doctor type device measuring what the lobe measures, correct.

Rick

Cam companies rarely if ever post those graphs.
It is a shame because that information is really necessary to make an informed buying choice.
Right, a Cam doctor chart is better than nothing but the acceleration chart only graphs smoothly if the measuring machine is super accurate or the curve is smoothed a lot, in which case the shape is not really representative of the design anymore.

I will give some thought on the best way to explain it and maybe start a thread on it.

[SchmidtMotorWorks]

Would Cam Dr not show this?

Not very well, unless you have super accurate equipment the shape of the acceleration and jerk curve will be sloppy and not very meaningful.

[CamKing]

morons