Re: Ported Dart 215's with port energy discussion 3.0

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groberts101
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Re: Ported Dart 215's with port energy discussion 3.0

Post by groberts101 » Sat Apr 14, 2018 8:21 pm

Carnut1 wrote:
Sat Apr 14, 2018 8:10 pm
Resized_20180414_200544.jpegHaving trouble getting a decent pic. I am thinking this is about the final bowl shape I will make the rest. Any input to help someone with no experience? Thanks, Charlie
No experience? Lol.. you might not be a big time pro headporter.. but you're sure as hell getting pretty good at grinding out cylinder head ports, Charlie.

Looks damned good in the picture but tough to say anything about the overall design by looking at it. Short side and cross section is where most of the magic happens to equalize the velocity profile, IMO.

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Re: Ported Dart 215's with port energy discussion 3.0

Post by Carnut1 » Sun Apr 15, 2018 8:59 am

Thanks Greg, if you check out the previous pic you can tell the ssr is in pretty good shape. Sometime you can see things in pics you miss looking at the head. For those interested this bowl was finished with an older straight blade aggresive single cut burr.
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Re: Ported Dart 215's with port energy discussion 3.0

Post by Carnut1 » Mon Apr 16, 2018 6:41 pm

0416181830a.jpg
Anyone else this twisted? I like the bowl the same shape on each port. (as close as possible anyway) The bowl is usually not centered but each straight wall will be the same distance from the valve stem. The distance from valve stem to pushrod wall as well. This seems to make a big difference in a similar swirl profile throughout the lift curve. Helps equalize the port cc a bit as well. Thanks, Charlie
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Re: Ported Dart 215's with port energy discussion 3.0

Post by Carnut1 » Sat Apr 21, 2018 9:15 am

Question answered on Larry's ssr thread.
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Re: Ported Dart 215's with port energy discussion 3.0

Post by Carnut1 » Sun Apr 22, 2018 12:21 pm

20180422_091035_2.jpg
I took this pic yesterday and thought it was interesting. You can really see how the floor fin is aimed a bit off from the valve stem. When I designed it I had two thoughts, on junk head the string followed this shape without the fin. So a floor fin might not fight the flow but better organize the mass flow in the direction it wants to go. My other thought was to lose a bit of swirl which the floor fin did, If I wanted higher swirl progression through the lift curve I could have aimed the floor fin right at the valve stem. You can also see how the apex is hand sanded smooth. Input welcome. Thanks, Charlie
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Re: Ported Dart 215's with port energy discussion 3.0

Post by Carnut1 » Sun Apr 22, 2018 12:26 pm

Resized_20180422_091614_2.jpeg
It is interesting how sometimes you can see things different in a picture. Notice how choppy the transition on the right side of the bowl to valve job is. This is the same bowl as previous floor fin pic. Input welcome. Thanks, Charlie
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Re: Ported Dart 215's with port energy discussion 3.0

Post by Carnut1 » Sun Apr 29, 2018 3:49 pm

Ok guys doing some flowing at 35" what am I looking for? Seems the finned wonder actually likes the higher depression. Smooth throughout the lift range where at 28 I get a bit of noise at a certain lift. Seems the air starts to actually use the damn bowl at the 35". Input welcome. Thanks, Charlie
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Re: Ported Dart 215's with port energy discussion 3.0

Post by Headguy » Sun Apr 29, 2018 3:58 pm

Carnut1 wrote:
Sun Apr 29, 2018 3:49 pm
Ok guys doing some flowing at 35" what am I looking for? Seems the finned wonder actually likes the higher depression. Smooth throughout the lift range where at 28 I get a bit of noise at a certain lift. Seems the air starts to actually use the damn bowl at the 35". Input welcome. Thanks, Charlie
Make a change, flow it at 28, write it down, now 35, write it down. Did it impact more at 35 than 28. Etc

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Re: Ported Dart 215's with port energy discussion 3.0

Post by Carnut1 » Sun Apr 29, 2018 4:06 pm

Headguy wrote:
Sun Apr 29, 2018 3:58 pm
Carnut1 wrote:
Sun Apr 29, 2018 3:49 pm
Ok guys doing some flowing at 35" what am I looking for? Seems the finned wonder actually likes the higher depression. Smooth throughout the lift range where at 28 I get a bit of noise at a certain lift. Seems the air starts to actually use the damn bowl at the 35". Input welcome. Thanks, Charlie
Make a change, flow it at 28, write it down, now 35, write it down. Did it impact more at 35 than 28. Etc
Ok, I can do that. I was expecting that noisy turbulence at 28" to be worse but it vanished. Thanks, Charlie
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Re: Ported Dart 215's with port energy discussion 3.0

Post by statsystems » Sun Apr 29, 2018 4:35 pm

Now go back and flow it at 10 inches. Then flow it backwards at all those depressions and spend several hours ruminating the results.

I also convert the numbers and see how much gain or loss I get from the change in depression.

For example, if you flow at 25 and then again at 28 you would multiply the 25 flow number by 1.06.

200 at 25 SHOULD be 212 at 28.

You'll have a bunch of data to evaluate.

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Re: Ported Dart 215's with port energy discussion 3.0

Post by Carnut1 » Tue May 01, 2018 8:37 pm

0430181956b.jpg
Since Stats overloaded me to near breakdown I decided to grab my early 90's Vic jr. Tall with 1204 match and very minor porting and see how bad it is with my nearly finished Dart 215's.
Head with radius flowed 315 cfm .7" lift 2351 rpm swirl.
90's ported Vic jr. Tall, 1204 match with 770 cfm Holley, flow radius, flow @ .7" lift, 289.2 cfm and 825 rpm swirl.
Modern porting Vic jr. Tall 1206 match, with 770 cfm Holley, flow radius, flow @.7" 311 cfm 1300 rpm swirl. This one port did not take 10 min. I took a good amount out of the top of the runner as it enters the plenum. I worked on the taper but didn't go nuts. Overall I am pretty happy with what the old manifold with some work can do. Thanks, Charlie
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Re: Ported Dart 215's with port energy discussion 3.0

Post by Headguy » Tue May 01, 2018 8:38 pm

Carnut1 wrote:
Tue May 01, 2018 8:37 pm
0430181956b.jpg Since Stats overloaded me to near breakdown I decided to grab my early 90's Vic jr. Tall with 1204 match and very minor porting and see how bad it is with my nearly finished Dart 215's.
Head with radius flowed 315 cfm .7" lift 2351 rpm swirl.
90's ported Vic jr. Tall, 1204 match with 770 cfm Holley, flow radius, flow @ .7" lift, 289.2 cfm and 825 rpm swirl.
Modern porting Vic jr. Tall 1206 match, with 770 cfm Holley, flow radius, flow @.7" 311 cfm 1300 rpm swirl. This one port did not take 10 min. I took a good amount out of the top of the runner as it enters the plenum. I worked on the taper but didn't go nuts. Overall I am pretty happy with what the old manifold with some work can do. Thanks, Charlie
Shouldn't the the throttle be open? :wink:

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Re: Ported Dart 215's with port energy discussion 3.0

Post by Carnut1 » Tue May 01, 2018 8:39 pm

Only when the bench is running!
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Re: Ported Dart 215's with port energy discussion 3.0

Post by Carnut1 » Thu May 03, 2018 5:11 pm

Resized_20180503_152333.jpeg
I should include first flows with manifold was cylinder #2. Cylinder #4 flowed 300 cfm @ .7" which has a shorter runner. This was basic rough out porting. I will most likely rough them all out and see where I am then do some taper and csa work. Input welcome. Thanks, Charlie
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Re: Ported Dart 215's with port energy discussion 3.0

Post by GARY C » Thu May 03, 2018 5:34 pm

I am guessing you blocked off all the other ports?

I had a set of Pro 1's flowing 317 and with ported Super Victor it was 307, then I had a long conversation with the main porter at Wilson manifolds that told me it would probably show good top end power at high rpm on the dyno but would probably suffer from shift recovery on the track, he was correct.

He went into great detail about how and why Cup teams will develop 3 or so Intake Spiders at the shop for track testing and how what show best on the dyne my not return the best track times and can even vary from track to track.

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