Flow bench results

[paulzig]

Define flow quality please.

Flowz energy...

[Scotthatch]

Define flow quality please.

Flowz energy...

If your talking David's deal your not even close

[randy331]

What it shows is the potential of the engine power you can be lower if things are not correct ....

I posted lots of dyno tests where the HP was dead on

Mine is higher 60-70 HP higher than your math,
cgarb is lower.

Both were dyno tuned.


When engines that similar don't line up with a formula, it's the formula.

Have you ever went to a bigger cam and made less power ?
Have you ever seen a head that flowZ more cfm, make less power ?
Examples are out there of both, which means the math would be flawed if your using CFM and IVC to determine HP.

But if it always matches your engines, use it.

Randy

[user-30563]

It has ALWAYS been about the quality of flow, period. And you can look at a flow curve and have a better than average idea what is going on. Becuase it's all about .25, especially for those who don't like low flow.

[Warp Speed]

Define flow quality please.

Right

[Warp Speed]

What it shows is the potential of the engine power you can be lower if things are not correct ....

I posted lots of dyno tests where the HP was dead on

Mine is higher 60-70 HP higher than your math,
cgarb is lower.

Both were dyno tuned.


When engines that similar don't line up with a formula, it's the formula.

Have you ever went to a bigger cam and made less power ?
Have you ever seen a head that flowZ more cfm, make less power ?
Examples are out there of both, which means the math would be flawed if your using CFM and IVC to determine HP.

But if it always matches your engines, use it.

Randy

[paulzig]

Mine is higher 60-70 HP higher than your math,
cgarb is lower.



But if it always matches your engines, use it.

Randy

Your 383 was 290CFM and 690HP wasnt it?

So nearly 2.4CFM per HP... Can I use your formula?

[digger]

one indicator of flow quality would surely be the BSFC, another might be the velocity gradients

[Rimmo]

Define flow quality please.

How about cfm per sqin at the maximum velocity that will allow the intake charge to move cleanly through said port and it's changes in CSA and direction without causing choke, separation or turbulence.

Can we agree on that and move on with the discussion? I think most here know it's not just the CFM number.

[cjperformance]

Define flow quality please.

How about cfm per sqin at the maximum velocity that will allow the intake charge to move cleanly through said port and it's changes in CSA and direction without causing choke, separation or turbulence.

Can we agree on that and move on with the discussion? I think most here know it's not just the CFM number.

Hang on , but now we need chart to indicate sq"/cfm, something like , Poor, Fair , Good, Average, Great and Yes we're on!
Just had to throw that on you as you were ready to move on !

[Warp Speed]

... if I need more HP I can up the cfm or move the closing point of the intake valve out more ... now this just deals with peak HP

Wish it was as easy as you make it sound.


Randy

Everyone that has pulled heads and ported them to gain power is doing so to up the cfm flow not to change some wave characteristic .... when you add high ratio rockers and gain power why is it helping? More flow from peak lift? Changing cam specs? Or did it change the waveform?

You guys are so hung up on the cool idea of how to refine a engine you have forgotten the bread and butter of how it works most of the time .....

Not really, you start with the basics (bread and butter as you mention) then add the rest to over achieve!
Scott, most of your views are based purely on the data supplied in the Superflow manual and inertia-supercharging effect. Being as you do not believe in the resonant pulses /waves and their effects on the intake tract, did you skip page 31 9.0, or just don't believe it?

[Rimmo]

Define flow quality please.

How about cfm per sqin at the maximum velocity that will allow the intake charge to move cleanly through said port and it's changes in CSA and direction without causing choke, separation or turbulence.

Can we agree on that and move on with the discussion? I think most here know it's not just the CFM number.

Hang on , but now we need chart to indicate sq"/cfm, something like , Poor, Fair , Good, Average, Great and Yes we're on!
Just had to throw that on you as you were ready to move on !

ahhhh....yes...but you already know what Good CFM is, so the chart would only be a distraction
I would however be open to a chart like that defining Good/Fair/Poor resonant waves in an intake tract, what say you

[CGT]

What it shows is the potential of the engine power you can be lower if things are not correct ....

I posted lots of dyno tests where the HP was dead on

Mine is higher 60-70 HP higher than your math,
cgarb is lower.

Both were dyno tuned.


When engines that similar don't line up with a formula, it's the formula.

Have you ever went to a bigger cam and made less power ?
Have you ever seen a head that flowZ more cfm, make less power ?
Examples are out there of both, which means the math would be flawed if your using CFM and IVC to determine HP.

But if it always matches your engines, use it.

Randy

So a later IVC is always worth more peak power?... that seems ridiculous. ..I've noticed the more developed higher power stuff that the IVC seems to get earlier than what youd expect.. Especially when looking at high output NA 4V stuff. So now its flow bench flowz and IVC run the show. I see.

[Scotthatch]

What it shows is the potential of the engine power you can be lower if things are not correct ....

I posted lots of dyno tests where the HP was dead on

Mine is higher 60-70 HP higher than your math,
cgarb is lower.

Both were dyno tuned.


When engines that similar don't line up with a formula, it's the formula.

Have you ever went to a bigger cam and made less power ?
Have you ever seen a head that flowZ more cfm, make less power ?
Examples are out there of both, which means the math would be flawed if your using CFM and IVC to determine HP.

But if it always matches your engines, use it.

Randy

No the math looks dead on for your motor too ...

You did not give a lot of information on your build but you did say 290 cfm , intake duration about the same at 272 on 109 but you have more aggressive ramp and .100 more lift . So since I have specs for his cam I will go with it or a Z of 1.09 from the chart

At 2.46 HP per cfm and 290 cfm you made 713.4 HP

So 290cfm x 1.09 Z x .257 HP per cfm x 8 cylinders x 1.1 for running alcohol = 714.8

You do know alcohol is a power adder ......

As for his engine yes it should be higher ... one thing to note is as you go past 100 % port efficiency things have to be right ... in your case you have a groomed port With a moved pinch point and would guess good stortside and different valve angle ... all this helped you get to the number you did ..... lower there are problems to fix ..higher and you need more cfm or cam ....

Now if you wave tuned this engine how did you pick the induction events ? Or change the intake runner length and to what rpm did you tune to and how wide is that band? ...not talking exhaust side as I have already agreed there is power there that I am ignoring by choice... induction tuning is what I am asking

[Scotthatch]

Wish it was as easy as you make it sound.


Randy

Everyone that has pulled heads and ported them to gain power is doing so to up the cfm flow not to change some wave characteristic .... when you add high ratio rockers and gain power why is it helping? More flow from peak lift? Changing cam specs? Or did it change the waveform?

You guys are so hung up on the cool idea of how to refine a engine you have forgotten the bread and butter of how it works most of the time .....

Not really, you start with the basics (bread and butter as you mention) then add the rest to over achieve!
Scott, most of your views are based purely on the data supplied in the Superflow manual and inertia-supercharging effect. Being as you do not believe in the resonant pulses /waves and their effects on the intake tract, did you skip page 31 9.0, or just don't believe it?

I addressed it in the thread link below

.https://www.speed-talk.com/forum/viewtopic. ... tart=180