runner port volume / head CC measurements

General engine tech -- Drag Racing to Circle Track

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KnightEngines
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Re: runner port volume / head CC measurements

Post by KnightEngines » Wed Nov 01, 2017 6:11 pm

Not in every case. What if the port is smoking fast and you want to slow it down? Wouldn't then the goal be to increase cross section with minimal flow gains? If the case above happened, wouldn't the port still be smoking fast?
If you're a novice porter then that advice will serve well & stop you doing anything stupid!

But yeah, there are many reasons why you'd want a larger port even if the flow did not gain at the same rate as port volume - but those circumstances are a bit more advanced & you'll want to know what you're doing.

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Re: runner port volume / head CC measurements

Post by Frankshaft » Wed Nov 01, 2017 6:22 pm

KnightEngines wrote:
Wed Nov 01, 2017 6:11 pm
Not in every case. What if the port is smoking fast and you want to slow it down? Wouldn't then the goal be to increase cross section with minimal flow gains? If the case above happened, wouldn't the port still be smoking fast?
If you're a novice porter then that advice will serve well & stop you doing anything stupid!

But yeah, there are many reasons why you'd want a larger port even if the flow did not gain at the same rate as port volume - but those circumstances are a bit more advanced & you'll want to know what you're doing.
Right, I asked him that in a form of a question to get my point across. But then he clarified
Frankshaft wrote:
Wed Nov 01, 2017 10:18 am
mag2555 wrote:
Wed Nov 01, 2017 10:04 am
Quite true, but was referring to the novist who is just grinding and counting up CC's without the aid of a flow bench how are you going to know about have much you have changed the fps with your mod's
Good point.
Then I acknowledged his comment.

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Re: runner port volume / head CC measurements

Post by KnightEngines » Wed Nov 01, 2017 6:26 pm

Yep, but it never hurts to let guys know you're on the same page - sifting through advice on the net is easier if it's backed up a few times!

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Re: runner port volume / head CC measurements

Post by Caprimaniac » Sat Nov 04, 2017 8:42 am

mag2555 wrote:
Wed Nov 01, 2017 6:24 am
If you want a full picture of what going on , then when you send the heads out for flow testing spend the extra money for a added test done with the Intake bolted on.
I will. Am still unsure about intake runners- if they'll flow enough.... Have used 3 formulaes to calculate CSA, and getting 3 different numbers. But all 3 fit, most probably,the current runners. However, the may need tapering, and there seems to be limitations.

Understanding airflow Dynamics to a full extent; not my business. I just make Things og fast.....

Actually; I have NO official training in physics since... what do you Call it; high School(?) at age of 15. I have read lots of engine/ auto- related stuff, and some of it is useable and important to keep in mind. For the professional porter there sure are Things to consider that I won't try to challenge my mind With. However interesting....
How to turn GURU in an instant.....

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Re: runner port volume / head CC measurements

Post by David Vizard » Sun Nov 05, 2017 2:20 pm

mag2555 wrote:
Tue Oct 31, 2017 8:09 am
Yes, with the valves in place.

Use rubbing Alcohol to pour in.

The main factor in where a given head will peak rpm wise in power is the heads and or complete Intake systems minimum port area and not the overall port volume!
Two head of the same type and port volume can make there best power due to port area up to 1500 rpm apart from each other.

What you really want to know also is how much flow gain you are picking up per CC of port volume gain .
Your percent of flow gain should equal or exceed your percent of port volume increase, when this stops taking place if your a novist porter , then you had better stop grinding right then and there!
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Re: runner port volume / head CC measurements

Post by cspeier » Sun Nov 05, 2017 2:30 pm

In my World port volume is key because I think the average velocity of the entire runner is KING.

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Re: runner port volume / head CC measurements

Post by statsystems » Sun Nov 05, 2017 3:31 pm

cspeier wrote:
Sun Nov 05, 2017 2:30 pm
In my World port volume is key because I think the average velocity of the entire runner is KING.

And the management of said velocity.

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Re: runner port volume / head CC measurements

Post by mag2555 » Mon Nov 06, 2017 6:51 am

I agree on that , but on a highly developed port done by a pro who can track velocity every where in the Intake tract your able to use the overall port volume to get your best average port velocity , or maintain control of it as best you can, no?
This post was started by a novist!

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