Changing Intake ports to a D shape for better flow.

OK there's bad news and VERY VERY goods . Bad news is due to Atlantas congested traffic jams and accidents I arrived late and wasn't able to
correct any port CFM differences,it was getting very late and was just so fatigued from the dive and running around trying to squeeze everything in with
what little time we had left. On the right port there are apparently some minor differences in the short turn radius and bowl along the long side. I'm
in the process of making molds of the good port for comparison,will make adjustments and then it's back to Dallas for more flow testing .
Good news is the left port excelled above my expectations and the contributors would be the valves, seat work and the port with absolutely no
resistance,none,real smooth running port and the #s back this up. In comparison to the first D port flowed, 100 lift picked up 13.5 CFM,200 lift picked
up 18.5 CFM,300 lift picked up 21CFM,400 lift picked up 15.5 CFM,Wasn't able to flow higher than 400 cuz stupid me took the wrong spring retainers.
Although I wasn't able to bias max flow at 300 lift,I was able to bring max flow at 400 lift down to 300 lift and still managed to increase flow at 400.
Waiting for the molds to harden so I can get back to working the right port. Took a view videos but am lost has how to up load from phone.
 
Here's the head on the bench
d port flowing.jpg
 
Unfortunately I have extremely little time this week, a lot to do at work and with the family... Dear Jack, what a bummer the ride was so turbulent. I am glad that the head has come out so good!

Can you please explain what you mean with:
Now here's Chris's head
Left port and right port down 1,12,18,18 CFM

Is the handwritten chart you postet above of your first ported head and taken with the same flow bench? And was it also an DPort?

I can´t see a file in your link. If you like you can send me the video via https://wetransfer.com/, I will put it here!

Aller beste Grüße and a big thx!
 
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Unfortunately I have extremely little time this week, a lot to do at work and with the family... Dear Jack, what a bummer the ride was so turbulent. I am glad that the head has come out so good!

Can you please explain what you mean with:


Is the handwritten chart you postet above of your first ported head and taken with the same flow bench? And was it also an DPort?

I can´t see a file in your link. If you like you can send me the video via https://wetransfer.com/, I will put it here!

Aller beste Grüße and a big thx!
The right port was down on flow, the port dimensions are with in spec but I overlooked a small hump at the inner bottom corner of the wall near the short turn, which I filed down, lowered the corners of the short turn just a hair more and slightly rolled them over plus worked the guide boss some more. Also worked the long side of the bowl leading up to the seat smoothing the transition by straightening it out a hair more These small imperfections can upset flow by slowing it down and it doesn't take much to speed air flow back up. Will be going back down to Dallas next Saturday to re-flow the head, hopefully it'll be a positive test.
All the heads where flowed on the same bench and no the first one was not a D port
 
Thanks for clarifying, interpreting english language is sometimes not so easy for me:)
If I see it right, the flow in the lower and middle lift areas has gone up till a plus of 40cfm at 300 lift! (in compare to the stock head as your old chart says)
And in my understanding the low lift gains benifits not only in the lower till middle rpm range but over the hole rpm range, and so I could have a torque monster:love: (by way of reference to an usually XS;)

Also, the E/I ratio is usually well over or near 70%. I have read that everything over 60% is good, 70% plus = high performance, 80% plus = top racing. So I like it very much and it promises more torque in the lower and middle range, if the other components play along (and i try as best as i can to catch this) nice :cheers::rock:

And last but not least I must say wow, you optimesed the E Ports to a very fine plus over the hole lift range.(in compare to the stock head as your old chart says). I think optimising the E Port to such extend is awesome!

cfm stock I:
lift - I cfm - E cfm - E/I flow ratio

100 - 76 - 67 - 88%
200 - 118 - 96 - 81%
300 - 162 - 115 - 71%
400 - 181 - 122 - 67%
440 - 190 - 121 - 64%

work in progress head
:
lift - I cfm - E cfm - E/I flow ratio
100 - 93,6 - 91,7 - 98,0%
200 - 137,5 - 119 - 86,6%
300 - 202,3 - 132 - 65,2%
400 - 216,5- 143 - 66,1%
440 - with the right retainers - next weekend:whistle:


In anticipation of the coming weekend:D I wish you that this time the journey goes well!:bike:

p.s. what did you do with your first modified head, that the exhaust have such great gains? Did you test wise epoxied it up, or was it voodo magic?


 
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spungle
Jack
If I see it right, the flow in the lower and middle lift areas has gone up till a plus of 40cfm at 300 lift! (in compare to the stock head as your old chart says)
And in my understanding the low lift gains benifits not only in the lower till middle rpm range but over the hole rpm range, and so I could have a torque monster:love: (by way of reference to an usually XS;)
Yes having stronger low to mid flow will produce more power in that area of the flow curve but the over all bigger picture is that every time the valve events opening and closing the port is moving more air in total than a port with peak numbers and what this achieves is a torque curve that hangs on longer producing more peak power. The flow curve of this D port was a total surprise for sure as I wasn't expecting that much of a flow shift in the 300 lift range and 400 lift range disrupting the targeted flow ratio I was after. Depending on how the right port flows,I might have to make some flow changes to the left port to level out the cylinder pressures.

Also, the E/I ratio is usually well over or near 70%. I have read that everything over 60% is good, 70% plus = high performance, 80% plus = top racing. So I like it very much and it promises more torque in the lower and middle range, if the other components play along (and i try as best as i can to catch this) nice :cheers::rock:
Don't to get to fixated on flow ratios and flow numbers,it all depends on the engine combination and yours being a long rod,this changes some what do to pumping loses through the ports. The numbers will change by drag loses through the carb,manifold,air filter and air quality. Exhaust changes with exhaust system. On a long rod motor you want very high velocity,high flowing ports to over come the pumping loses from TDC to 90 degree stroke and at BDC as the piston dwells it allows the flow inertia to pack the cylinders tighter.


And last but not least I must say wow, you optimesed the E Ports to a very fine plus over the hole lift range.(in compare to the stock head as your old chart says). I think optimising the E Port to such extend is awesome!
You have to be careful not to over scavenge,the 100 to 200 lift range still eludes me,one day I'll get it.


cfm stock I:
lift - I cfm - E cfm - E/I flow ratio

100 - 76 - 67 - 88%
200 - 118 - 96 - 81%
300 - 162 - 115 - 71%
400 - 181 - 122 - 67%
440 - 190 - 121 - 64%

work in progress head
:
lift - I cfm - E cfm - E/I flow ratio
100 - 93,6 - 91,7 - 98,0%
200 - 137,5 - 119 - 86,6%
300 - 202,3 - 132 - 65,2%
400 - 216,5- 143 - 66,1%
440 - with the right retainers - next weekend:whistle:

:D There might be some more flow in that lift.
In anticipation of the coming weekend:D I wish you that this time the journey goes well!:bike:

p.s. what did you do with your first modified head, that the exhaust have such great gains? Did you test wise epoxied it up, or was it voodo magic?
It was all "FINGER VOODOO" and very hard to duplicate how i twisted the inner port
wall and roof,it has to be dead nuts correct to reduce the flow resistance as it turns.
 
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