| View previous topic :: View next topic |
| Author |
Message |
kondzi
Joined: 02 Jul 2018
Posts: 485
Location: Poland/EU
|
 Posted: Wed Feb 08, 2023 7:33 am Post subject: |
 |
|
I think for this engine I’ll leave it as is.
But this itch…  Seems now it is not the valve/seat that limits the flow, but the port itself.
High lift and no gain over stock there, right?
The 964RS and 993RS had the ports slightly bigger in diameter.
If I enlarge the port there (narrowest part) that should bring the flow up (not sure about the velocity though), at least for the high lift.
But would that hurt low lift? Hmmm…
_________________
---
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) |
|
| Back to top |
|
 |
Mike9311
Joined: 14 Dec 2004
Posts: 1678
Location: Chicago-ish
|
| Posted: Wed Feb 08, 2023 9:10 am Post subject: |
|
|
| kondzi wrote: | I think for this engine I’ll leave it as is.
But this itch… Seems now it is not the valve/seat that limits the flow, but the port itself.
High lift and no gain over stock there, right?
The 964RS and 993RS had the ports slightly bigger in diameter.
If I enlarge the port there (narrowest part) that should bring the flow up (not sure about the velocity though), at least for the high lift.
But would that hurt low lift? Hmmm… |
Oh man, I feel that itch too but it can bring you trouble. What you just wrote is exactly what I was thinking and in my case which I think is worse, I got major turbulence. Its a game and you have a nice port
When I did what you said I lost my nice jump at low lift. I am sad for the moment about this situation. Yesterday I worked a little bit on slowing things down and it helped me. Now is the time to stay calm and work the problem. Going to probe the turbulent section and areas leading to it. My thought is that needs more expansion in that area. Vel probe should help me along with the flow ball at the same time
Good luck but be careful! I like that area under the whole curve better than just high flow at peak lift. You get the high flowing middle sections of lift twice as valve goes up and down! Not just one peak number
_________________
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 |
|
|
kondzi
Joined: 02 Jul 2018
Posts: 485
Location: Poland/EU
|
| Posted: Wed Feb 08, 2023 6:05 pm Post subject: |
|
|
Numbers are good IMHO. To be honest I was not expecting that much change, as the port design is nice straight from the factory. I leave it as is and leave the unknown to theoretical thoughts
_________________
---
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) |
|
| Back to top |
|
|
safe
Joined: 18 Mar 2017
Posts: 588
Location: Sweden
|
| Posted: Wed Feb 08, 2023 7:12 pm Post subject: |
|
|
The 964 engine really comes alive with an aftermarket ECU so you can get rid of the flapper air meter and optimize it.
Head porting is icing on that cake!
FVD has cams that add 20-30 hp on top of that.
_________________
/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 |
|
|
kondzi
Joined: 02 Jul 2018
Posts: 485
Location: Poland/EU
|
| Posted: Wed Feb 08, 2023 10:03 pm Post subject: |
|
|
Yep. Cams, ECU and VarioRam. And exhaust. We’ll see in some time where this will bring me.
_________________
---
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) |
|
| Back to top |
|
|
kondzi
Joined: 02 Jul 2018
Posts: 485
Location: Poland/EU
|
| Posted: Wed Apr 05, 2023 11:42 pm Post subject: |
|
|
I'm queued for replicating the port to the remaining 5 heads on CNC, should happen by the end of April.
Anyway, they were curious if the flow bench results I got were correct, as their experience is that usually these heads get worse with bigger valves... I did not ask for this, but they flow benched my hand ported head. Same results as the other place, woohoo 
_________________
---
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) |
|
| Back to top |
|
|
Mike9311
Joined: 14 Dec 2004
Posts: 1678
Location: Chicago-ish
|
| Posted: Thu Apr 06, 2023 5:00 am Post subject: |
|
|
| kondzi wrote: | I'm queued for replicating the port to the remaining 5 heads on CNC, should happen by the end of April.
Anyway, they were curious if the flow bench results I got were correct, as their experience is that usually these heads get worse with bigger valves... I did not ask for this, but they flow benched my hand ported head. Same results as the other place, woohoo |
Yeah baby! Nice! Love it when something works out that way That is cool news when results can be confirmed in this way
_________________
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 |
|
|
kondzi
Joined: 02 Jul 2018
Posts: 485
Location: Poland/EU
|
| Posted: Thu Jun 22, 2023 6:20 am Post subject: |
|
|
A short update. Today I got my heads from the CNC shop. 2.5 months late and they included a price increase during the time not asking me if I agree to that :-/
Anyway I have them back.
They look cool 
As I was informed, due to the tooling, the 3D model had to be slightly different than my handported intake port.
This resulted in 3-4% differences in the flow. Got worse in low lift and better in higher lift.
I will use hot cams, so I expect this will be ok’ish for me.
Results here, top after CNC, bottom - hand ported.
What do you think?
_________________
---
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) |
|
| Back to top |
|
|
Mike9311
Joined: 14 Dec 2004
Posts: 1678
Location: Chicago-ish
|
| Posted: Thu Jun 22, 2023 7:28 am Post subject: |
|
|
Nice! Now you can do it again and again!
_________________
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 |
|
|
kondzi
Joined: 02 Jul 2018
Posts: 485
Location: Poland/EU
|
| Posted: Thu Jun 22, 2023 8:19 am Post subject: |
|
|
Yeah, it was 6 times already ha ha.
I think I will make a mold of this CNC’ed port to compare with the one I have from my hand ported port.
As my hand ported port did not give any more flow at full lift it seems the port diameter was a limiting factor, not the valve.
With CNC’ed port I have gains at full lift vs stock. Just curiosity, probably the CNC’ed port is wider in the narrowest area.
_________________
---
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) |
|
| Back to top |
|
|
Mike9311
Joined: 14 Dec 2004
Posts: 1678
Location: Chicago-ish
|
| Posted: Fri Jun 23, 2023 3:28 am Post subject: |
|
|
The cnc port should be creating a different boundary layer action due to milling lines vs a smooth polish. So all this is interesting indeed. Again, nicely done!
_________________
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 |
|
|
kondzi
Joined: 02 Jul 2018
Posts: 485
Location: Poland/EU
|
| Posted: Fri Jun 23, 2023 6:36 pm Post subject: |
|
|
| Mike9311 wrote: | | Again, nicely done! |
Thanks Mike!
I talked to them today about the low lift losses, and they told me I should not reference these paper notes of the operator. I found in my email SPAM this, from 2 days ago:
The graph out of the software uses corrections of pressure drops or so (that's what I heard) and I should look at the chart not at the notes on the paper...
What do you think?
[/list]
_________________
---
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) |
|
| Back to top |
|
|
Mike9311
Joined: 14 Dec 2004
Posts: 1678
Location: Chicago-ish
|
| Posted: Fri Jun 23, 2023 11:03 pm Post subject: |
|
|
I think it looks good and there is even some similar behavior at around .1" lift
What I like is that you didn't lose anything. For me this means you won't lose drive-ability. The car will drive normal until you want power. It should feel better all around really
As far as corrections go, I don't see an issue there either. It is very standard for everyone
_________________
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 |
|
|
kondzi
Joined: 02 Jul 2018
Posts: 485
Location: Poland/EU
|
| Posted: Tue Jul 11, 2023 4:13 am Post subject: |
|
|
I did take the mold of the CNC'ed port.
From top to down:
- stock
- hand ported
- CNC ported
Don't be mislead by the camera lens.These are all same in diameter in general.
As this last mold included the guide in place it was a bit challenging to remove it with corkscrew, but I managed to take it off in one piece
I need to make some measurements, but from what I see it’s almost exactly as my hand ported mold. The only difference is behind the guide on the long side radius. Mine had a fin, here it’s not present.
Not sure if this makes any difference for the flow though (but the bowl could be slightly bigger thanks to that though).
_________________
---
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) |
|
| Back to top |
|
|
Mike9311
Joined: 14 Dec 2004
Posts: 1678
Location: Chicago-ish
|
| Posted: Wed Jul 12, 2023 5:57 am Post subject: |
|
|
Nice! I know how that is with the pictures. Interesting too, like you pointed out, that the fin is removed. Must of just been easier for them on that side to machine the bowl. Probably affected it very little if at all
Cool, pics! Thanks for sharing
_________________
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 |
|
|
|
FAQ
Search
Memberlist
Usergroups
Register
Profile
Log in to check your private messages
Log in
924 FAQ (Technical)
