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kondzi
Joined: 02 Jul 2018
Posts: 485
Location: Poland/EU
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 Posted: Mon Dec 12, 2022 1:27 am Post subject: |
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So I made it! 
Measured the diameters here and there.
Good reference for different head types is here by Bill Verbung:
| Quote: | 964 3.8RS used the same port sizes as the rest of the 964 series but got the larger 51.5/43.5mm valves that were later used on 993RS.
here's a run down
964 all 41.5/38mm ports & 49/42.5mm valves w/ peak torque /hp @4800/6100, except 964 3.8RS & 964RSR which used 41.5/38 & 51.5/43.5 @5250/6500 and 46/42 & 51.5/43.5 @5500/6900 respectively
993nvr 43/39 & 49/42.5 @5000/6100
995vram 43/39 & 50/43.5 5250/6100
993RS & Cup & RSR 46/42 & 51.5/43.5 @5400/6500 @5500/6200 @5500/7000
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I measured also not that much accurately the smallest dimension between top and bottom of the port where the valve guide stem is - this is around 28mm.
I'm thinking whether should I cut this mold into few pieces and scan them to calculate the cut-through area, or just don't bother that much (which I may choose in the end).
As you can see below the casting is not perfect. Especially when it meets the machining below the valve seat. The transition from the car to machined part is far from ideal IMHO.
Although in the first look the port looks symmetric, it's not. There are slight differences here and there.
Anyway it seems that doing a finishing touch on the transitions and working on the lip for the bigger seat will be thing I will do first. Then I'll check how it's flowing - if it's good, I'll leave it that way (but will make another mold "After").
Please share your comments 
_________________
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Konrad
'89 951 US
'88 Mustang 5.0 LX Convertible (factory specs)
'84 911 Carrera 3.2 RoW (factory specs)
'81 931 RoW (TBD)
'81 Ford Capri 2.8i (factory specs)
'79 Ford Capri 2.9 (heavily modded) |
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Mike9311
Joined: 14 Dec 2004
Posts: 1678
Location: Chicago-ish
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| Posted: Tue Dec 13, 2022 12:24 am Post subject: |
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Should come out surprisingly easy. I was surprised the first time I did it and I didn't use a lube. I would now though
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1980 931 since 1989
1981 Ideola 931 Club Sport
1982 931 Entwicklungsfahrzeug
1979 924 NA ohne 650 mit 471
1982 931 Red Resurrection - 951 IC
1982 931 parts car / resurrection?
1980 924 NA (R&D lightweight)
1982 931 wana-be GTR race car |
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Mike9311
Joined: 14 Dec 2004
Posts: 1678
Location: Chicago-ish
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| Posted: Tue Dec 13, 2022 12:42 am Post subject: |
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That is a nice looking port. No wonder they said it flowed nicely
_________________
1980 931 since 1989
1981 Ideola 931 Club Sport
1982 931 Entwicklungsfahrzeug
1979 924 NA ohne 650 mit 471
1982 931 Red Resurrection - 951 IC
1982 931 parts car / resurrection?
1980 924 NA (R&D lightweight)
1982 931 wana-be GTR race car |
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safe
Joined: 18 Mar 2017
Posts: 591
Location: Sweden
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| Posted: Tue Dec 13, 2022 1:27 am Post subject: |
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| Mike9311 wrote: | | That is a nice looking port. No wonder they said it flowed nicely |
Amazing what 25 years of evolution can do to a head design!
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/Magnus, Stockholm Sweden
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Porsche 924 -79 NA, EFI and Turbo.
Porsche 931 -79
Porsche 911 -77, 3.2 Targa
Porsche 911 -69, 3.6, Coupe |
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kondzi
Joined: 02 Jul 2018
Posts: 485
Location: Poland/EU
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| Posted: Mon Jan 09, 2023 9:26 am Post subject: |
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First in first out. Hope I did not make it wrong 
Checked a LOT of photos of the ports from well known and reputable head porters, read and watched a lot prior.
Looking’ good. Hope it will flow good as well. Should bring it to the shop for flow benching this week.
Keep fingers crossed
_________________
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Konrad
'89 951 US
'88 Mustang 5.0 LX Convertible (factory specs)
'84 911 Carrera 3.2 RoW (factory specs)
'81 931 RoW (TBD)
'81 Ford Capri 2.8i (factory specs)
'79 Ford Capri 2.9 (heavily modded) |
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Mike9311
Joined: 14 Dec 2004
Posts: 1678
Location: Chicago-ish
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| Posted: Tue Jan 10, 2023 4:32 am Post subject: |
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Looks great! Nice job
_________________
1980 931 since 1989
1981 Ideola 931 Club Sport
1982 931 Entwicklungsfahrzeug
1979 924 NA ohne 650 mit 471
1982 931 Red Resurrection - 951 IC
1982 931 parts car / resurrection?
1980 924 NA (R&D lightweight)
1982 931 wana-be GTR race car |
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kondzi
Joined: 02 Jul 2018
Posts: 485
Location: Poland/EU
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| Posted: Mon Jan 16, 2023 9:33 am Post subject: |
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I'm beginning to like making these molds. Cork screw is your friend
_________________
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Konrad
'89 951 US
'88 Mustang 5.0 LX Convertible (factory specs)
'84 911 Carrera 3.2 RoW (factory specs)
'81 931 RoW (TBD)
'81 Ford Capri 2.8i (factory specs)
'79 Ford Capri 2.9 (heavily modded) |
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Mike9311
Joined: 14 Dec 2004
Posts: 1678
Location: Chicago-ish
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| Posted: Mon Jan 16, 2023 10:07 am Post subject: |
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I like it! Nicely done
It is fun. You don't think it will work because you think it won't come out. Then it just does
_________________
1980 931 since 1989
1981 Ideola 931 Club Sport
1982 931 Entwicklungsfahrzeug
1979 924 NA ohne 650 mit 471
1982 931 Red Resurrection - 951 IC
1982 931 parts car / resurrection?
1980 924 NA (R&D lightweight)
1982 931 wana-be GTR race car |
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kondzi
Joined: 02 Jul 2018
Posts: 485
Location: Poland/EU
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| Posted: Tue Feb 07, 2023 11:56 pm Post subject: |
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_________________
---
Konrad
'89 951 US
'88 Mustang 5.0 LX Convertible (factory specs)
'84 911 Carrera 3.2 RoW (factory specs)
'81 931 RoW (TBD)
'81 Ford Capri 2.8i (factory specs)
'79 Ford Capri 2.9 (heavily modded) |
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Mike9311
Joined: 14 Dec 2004
Posts: 1678
Location: Chicago-ish
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| Posted: Wed Feb 08, 2023 12:23 am Post subject: |
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What a nice fattening of that curve/area! What I am most jealous about is that .104" figure. As well as how much you get with those low lift numbers
Great job!
_________________
1980 931 since 1989
1981 Ideola 931 Club Sport
1982 931 Entwicklungsfahrzeug
1979 924 NA ohne 650 mit 471
1982 931 Red Resurrection - 951 IC
1982 931 parts car / resurrection?
1980 924 NA (R&D lightweight)
1982 931 wana-be GTR race car |
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| Back to top |
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kondzi
Joined: 02 Jul 2018
Posts: 485
Location: Poland/EU
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| Posted: Wed Feb 08, 2023 12:46 am Post subject: |
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| Mike9311 wrote: | What a nice fattening of that curve/area! What I am most jealous about is that .104" figure. As well as how much you get with those low lift numbers
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Beginners luck
I still wonder how this will end up on the dyno. Time will tell, but at least that chart made my day today.
The plan was to get more for a daily. This seems to be a achieved. The limit at full lift is the port diameter in narrowest part if I read that correctly.
_________________
---
Konrad
'89 951 US
'88 Mustang 5.0 LX Convertible (factory specs)
'84 911 Carrera 3.2 RoW (factory specs)
'81 931 RoW (TBD)
'81 Ford Capri 2.8i (factory specs)
'79 Ford Capri 2.9 (heavily modded) |
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safe
Joined: 18 Mar 2017
Posts: 591
Location: Sweden
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| Posted: Wed Feb 08, 2023 1:04 am Post subject: |
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Basically this was just a "cleanup" with smoothing of transitions, right?
_________________
/Magnus, Stockholm Sweden
=======================
Porsche 924 -79 NA, EFI and Turbo.
Porsche 931 -79
Porsche 911 -77, 3.2 Targa
Porsche 911 -69, 3.6, Coupe |
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kondzi
Joined: 02 Jul 2018
Posts: 485
Location: Poland/EU
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| Posted: Wed Feb 08, 2023 1:25 am Post subject: |
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Kind of… bowl around valve guide slightly enlarged to slow down velocity. Short side radius almost untouched.
_________________
---
Konrad
'89 951 US
'88 Mustang 5.0 LX Convertible (factory specs)
'84 911 Carrera 3.2 RoW (factory specs)
'81 931 RoW (TBD)
'81 Ford Capri 2.8i (factory specs)
'79 Ford Capri 2.9 (heavily modded) |
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safe
Joined: 18 Mar 2017
Posts: 591
Location: Sweden
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| Posted: Wed Feb 08, 2023 1:29 am Post subject: |
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I think it will perform really nice.
_________________
/Magnus, Stockholm Sweden
=======================
Porsche 924 -79 NA, EFI and Turbo.
Porsche 931 -79
Porsche 911 -77, 3.2 Targa
Porsche 911 -69, 3.6, Coupe |
|
| Back to top |
|
|
Mike9311
Joined: 14 Dec 2004
Posts: 1678
Location: Chicago-ish
|
| Posted: Wed Feb 08, 2023 6:42 am Post subject: |
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| safe wrote: | | I think it will perform really nice. |
I agree
_________________
1980 931 since 1989
1981 Ideola 931 Club Sport
1982 931 Entwicklungsfahrzeug
1979 924 NA ohne 650 mit 471
1982 931 Red Resurrection - 951 IC
1982 931 parts car / resurrection?
1980 924 NA (R&D lightweight)
1982 931 wana-be GTR race car |
|
| Back to top |
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