Calculating CFM used from Dyno sheet ?

[hoffman900]

Thanks for the full picture. It is what I believed. 0 to 720 / 2 full crank rev / one complete cylinder cycle. So 640 would be BDC. 630 = 10 BDDC 624 = 16 BBDC

Stan

Stan,

That's my graph. Let me know what you want to see I can I pull up some. Numbers, wave directions, etc.

Also, It doesn't always cross zero at the same point.

Bob,
At what RPM is that and what RPM is Peak HP?

Stan

Stan, 7000rpm and 7000rpm

[n2xlr8n]

I think the pulse thing may be a joke

Pulses are a Joke ??

I had one that had a dip at 7000 rpm. A few cams, a couple intakes with work on them more than once, 3 sets of heads on it, 2-3 collectors on the headers,..lots of dyno pulls over 8-10 dyno sessions, a few carb spacers, 3-4 different carbs. That stubborn power dip stayed there.

Then switched out my headers for a set the dyno shop had hangin on the wall,.... and power dip gone.
Same primary pipe diameter.

What did away with the dip if it wasn't waves ?

Randy

Rhetorical statement, I know.

But to the OP, pressure waves are certainly not a joke.

Most of my career has been focused on waves of some sort.

I used to show these vids to students having trouble with the function:

https://www.youtube.com/watch?v=BWraEDaVXZM

[Warp Speed]

I think the pulse thing may be a joke

Pulses are a Joke ??

I had one that had a dip at 7000 rpm. A few cams, a couple intakes with work on them more than once, 3 sets of heads on it, 2-3 collectors on the headers,..lots of dyno pulls over 8-10 dyno sessions, a few carb spacers, 3-4 different carbs. That stubborn power dip stayed there.

Then switched out my headers for a set the dyno shop had hangin on the wall,.... and power dip gone.
Same primary pipe diameter.

What did away with the dip if it wasn't waves ?

Randy

Rhetorical statement, I know.

But to the OP, pressure waves are certainly not a joke.

Most of my career has been focused on waves of some sort.

I used to show these vids to students having trouble with the function:

https://www.youtube.com/watch?v=BWraEDaVXZM

Pretty cool vid!

[groberts101]

I think the pulse thing may be a joke

Pulses are a Joke ??

I had one that had a dip at 7000 rpm. A few cams, a couple intakes with work on them more than once, 3 sets of heads on it, 2-3 collectors on the headers,..lots of dyno pulls over 8-10 dyno sessions, a few carb spacers, 3-4 different carbs. That stubborn power dip stayed there.

Then switched out my headers for a set the dyno shop had hangin on the wall,.... and power dip gone.
Same primary pipe diameter.

What did away with the dip if it wasn't waves ?

Randy

Rhetorical statement, I know.

But to the OP, pressure waves are certainly not a joke.

Most of my career has been focused on waves of some sort.

I used to show these vids to students having trouble with the function:

https://www.youtube.com/watch?v=BWraEDaVXZM

What I don't understand is how someone could be so well versed in engine theory and design yet not believe in wave tuning? Seems highly counter-intuitive in the scheme of what goes on inside a constantly moving uni-directional mass and exploding combustion engine.

Ever see fuel standoff above a carb or injector trumpet? The power of multi-directional waves combining to create standing waves can easily levitate those small droplets of fuel.

So even testing same tube diameter headers.. subtle changes in bend radius and number of bends along with slight length variations can cause different reflected wave tuned results that Randy is pointing towards here. Very real phenomena and extremely well studied for the last hundred years or so.

Tons of vid's out there showing sound wave levitation capabilities over solid objects much heavier than air. I had a few good ones saved on my other downed hard drive but I will see if I can recollect their names and post them up here.

EDIT: Turns out my memory is horrible.. been too long and search parameters are obviously everything when it comes to finding things on the net. Here's a couple of decent ones though.

Since everybody loves slo-mo vids... https://www.youtube.com/watch?v=0K8zs-KSitc

Another using smoke to show half length standing waves... https://www.youtube.com/watch?v=XpNbyfxxkWE

[swampbuggy]

Uni-directional-----i can not for the life of me believe other than, at 9000 RPM's the air/fuel mixture is moving "MOSTLY" one direction----towards the cylinder. ???????? Mark H.

[DrillDawg]

The pulse or wave just provides a low pressure area at the valve when timed right just like in the exhaust.

[n2xlr8n]

Rhetorical statement, I know.

But to the OP, pressure waves are certainly not a joke.

Most of my career has been focused on waves of some sort.

I used to show these vids to students having trouble with the function:

https://www.youtube.com/watch?v=BWraEDaVXZM

What I don't understand is how someone could be so well versed in engine theory and design yet not believe in wave tuning? Seems highly counter-intuitive in the scheme of what goes on inside a constantly moving uni-directional mass and exploding combustion engine.

Ever see fuel standoff above a carb or injector trumpet? The power of multi-directional waves combining to create standing waves can easily levitate those small droplets of fuel.

So even testing same tube diameter headers.. subtle changes in bend radius and number of bends along with slight length variations can cause different reflected wave tuned results that Randy is pointing towards here. Very real phenomena and extremely well studied for the last hundred years or so.

Tons of vid's out there showing sound wave levitation capabilities over solid objects much heavier than air. I had a few good ones saved on my other downed hard drive but I will see if I can recollect their names and post them up here.

Or the pulses exiting the zoomies on a TF FC at night....the pulsed RF waves (with E and H fields) accelerating an electron to 99.997% of the speed of light...two sound sources out of phase, algebraically cancelling or adding a phase shift to the sound our brains register, etc.

Waves are cool

[Stan Weiss]

Stan,

That's my graph. Let me know what you want to see I can I pull up some. Numbers, wave directions, etc.

Also, It doesn't always cross zero at the same point.

Bob,
At what RPM is that and what RPM is Peak HP?

Stan

Stan, 7000rpm and 7000rpm

Bob,
Thanks. If it is not a lot of work can you produce another one of those at what will be the RPM you shift at?

Stan

[hoffman900]

Uni-directional-----i can not for the life of me believe other than, at 9000 RPM's the air/fuel mixture is moving "MOSTLY" one direction----towards the cylinder. ???????? Mark H.

I'll post lots of graphs later on at both peak hp and peak torque. Have stuff to do..

In the meantime..

Jon Kaase's clear manifold:
https://www.youtube.com/watch?v=7Iq1B-2paCs

Renault Formula One engine dyno (circa 2006):
https://www.youtube.com/watch?v=y2iBbwocYZw

Harley horsepower shootout winner:
https://www.youtube.com/watch?v=pvECwI7ODwE

Bob,
At what RPM is that and what RPM is Peak HP?

Stan

Stan, 7000rpm and 7000rpm

Bob,
Thanks. If it is not a lot of work can you produce another one of those at what will be the RPM you shift at?

Stan

Stan, I accidentally overwrote that file, but I produced a new file (slightly different exhaust) while eating breakfast this morning. Does peak hp and peak torque work? I have most of them saved, just need some time to post them up and type a key.

[groberts101]

Or the pulses exiting the zoomies on a TF FC at night....the pulsed RF waves (with E and H fields) accelerating an electron to 99.997% of the speed of light...two sound sources out of phase, algebraically cancelling or adding a phase shift to the sound our brains register, etc.

Waves are cool

Yep.. almost mentioned those too but my posts tend to get long enough as it is.

What about shock wave diamonds too!

https://goo.gl/images/H5tpKv

https://www.youtube.com/watch?v=swoCdEwbFRc

I love this kinda stuff too.

PS.. sorry for the tangent but if you think hard enough about its potential effects.. this stuff can surely affect "CFM used from the dyno sheet".

[Stan Weiss]

Uni-directional-----i can not for the life of me believe other than, at 9000 RPM's the air/fuel mixture is moving "MOSTLY" one direction----towards the cylinder. ???????? Mark H.

I'll post lots of graphs later on at both peak hp and peak torque. Have stuff to do..

In the meantime..

Jon Kaase's clear manifold:
https://www.youtube.com/watch?v=7Iq1B-2paCs

Renault Formula One engine dyno (circa 2006):
https://www.youtube.com/watch?v=y2iBbwocYZw

Harley horsepower shootout winner:
https://www.youtube.com/watch?v=pvECwI7ODwE

Stan, 7000rpm and 7000rpm

Bob,
Thanks. If it is not a lot of work can you produce another one of those at what will be the RPM you shift at?

Stan

Stan, I accidentally overwrote that file, but I produced a new file (slightly different exhaust) while eating breakfast this morning. Does peak hp and peak torque work? I have most of them saved, just need some time to post them up and type a key.

Bob,
Yes, that should work.

You need a better data back up system. I have an external hard drive that I can hookup and use about once a month. But I always have a USB thumb drive plugged in and back what I am working on to there at least one a day.

Stan

[Scotthatch]

Wow you guys take one little comment a guy makes and go screaming off into right field .......

I was not talking about any of the stuff you guys posted but now I guess we have three subjects being discussed in this thread....

My problem is with this page from the superflow manual

15267463087920.jpg

In a lot of ways this conflicts with the ram effect page that I made work

If you looked back at my posts you will see I did have the reflective wave listed in what is going on in the runner and like anyone that has work on motors a long time I have seen standoff above the carb .. my problem is in pinning down HP produced by this that is not also in the ram effect calculation

[Scotthatch]

In my current view of how it all works I think there is a standing wave in the runner created by the opening and closing of the intake valve and the frequency is dependent on the rpm and this standing wave moves with the column of air fuel into the cylinder following the basic ram effect calculation ... if you look at the video of the running cylinder you can see the pulsing because I think the fuel somewhat sits in the waves like the balls ...

The other thing to note is as a runner gets longer if you don't leave the valve open latter the standoff gets worse which suggests that the energy that is generated by ram effect is higher as the runner gets longer and so the reflective wave is stronger unless you use the energy to fill the cylinder....

[DrillDawg]

2nd pulse is the strongest, but the longest, 4th the weakest, but the sbortest, each time it gets weaker.

[Warp Speed]

Wow you guys take one little comment a guy makes and go screaming off into right field .......

I was not talking about any of the stuff you guys posted but now I guess we have three subjects being discussed in this thread....

My problem is with this page from the superflow manual

15267463087920.jpg



In a lot of ways this conflicts with the ram effect page that I made work

If you looked back at my posts you will see I did have the reflective wave listed in what is going on in the runner and like anyone that has work on motors a long time I have seen standoff above the carb .. my problem is in pinning down HP produced by this that is not also in the ram effect calculation

It IS the ram effect!