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Mike9311
Joined: 14 Dec 2004
Posts: 1678
Location: Chicago-ish
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 Posted: Wed Apr 19, 2023 9:40 am Post subject: |
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Oh man, the port is liking what I am doing (thank you Vizard!)
I actually was able, if I went slow, to get all the way to .5" lift stable. Technically it really wants to go turbulent now at .45" which is just below max lift!
.400" @184 cfm
.430" @ 189 cfm
.450" @ 192.7 cfm
....but then Intake "sigh". Still decent numbers. Trumpet kills some flow at the higher lift (turbulent) and the Intake more so.
However the mods appear to have fattened up the lower end yet again. I was checking for leaks like crazy just to be sure but these are the results. There was 5-6 cfm picked up at .1 and .2 of lift. Topping out at 179 with intake or turbulent version no intake still 179. I still have to apply a low lift trick with a valve back cut which I was going to do at the end of the project
I kept the 'No Intake' top end at its turbulent level so graph wouldn't auto scale. It easily made it into the 190's today on its own (no intake). This is baguette level  Yes, its sensitive but this is a good day! All I did was apply the original premise of treating this head like a 2 valve American head and the first idea that the offset would allow for bias modifications. Pulled out the carbide burr and went at it
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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: Wed Apr 19, 2023 11:51 am Post subject: |
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22% gain in area under the curve with Intake. Remember my % before was without Intake
_________________
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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Cedric
Joined: 27 Aug 2004
Posts: 2610
Location: Sweden
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| Posted: Wed Apr 19, 2023 11:46 pm Post subject: |
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Whats the goal for this stage before moving on (even though its a fun process ), to get it more stable for turbulence? And who knows what the turbulence with twice the density will look like when its actually on the engine
Have you started on the exhaust port yet? Its not an an uninportant part for a turbo engine to get good turbine response/energy transfer from the cylinder to the turbine.
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1980 924 Turbo
www.instagram.com/garagecedric/ |
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Mike9311
Joined: 14 Dec 2004
Posts: 1678
Location: Chicago-ish
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| Posted: Thu Apr 20, 2023 3:52 am Post subject: |
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| Cedric wrote: | Whats the goal for this stage before moving on (even though its a fun process ), to get it more stable for turbulence? And who knows what the turbulence with twice the density will look like when its actually on the engine
Have you started on the exhaust port yet? Its not an an unimportant part for a turbo engine to get good turbine response/energy transfer from the cylinder to the turbine. |
That just it, I am having too much fun lately  I was trying to get stable flow even though I know full well it will be crazy turbulent who-knows-what when running. If the Intake didn't have such an influence I would keep going to break 200 consistently for fun (it would be easy because I have seen 199). Now the Intake is becoming a project on to itself. So maybe its time to wind this part down and get going on everything else.
Other than choosing a 38mm for the super alloy, I am not doing anything that the previous owner didn't already do. I have to fix the exhaust manifold sleeve situation because he ported too high. Not a big deal, just work. Obviously I will blend the new 38mm seat to the port but leave the rest alone. Not going to chase anything that wastes time here
I need to cut the intake seat slightly and I was going to 30deg back cut the valve (don't have to I guess but just wondering if it helps low lift)
Then I need to create a CAD model of the port to recreate in the other 3 ports via cnc. That will be some work but it also could be used to continue this testing on the side. I could cut the port and chamber in any old block of aluminum and flow that  but there is so much more to do in the car in general. FrankenCIS etc. I never mentioned I also modified the stock CIS to accept a Merc 6Cyl head to work with the FrankenCIS. Did that over a year ago. I did it only to save setup time vs v8 head. Will see how much it can support I guess if this all works positively power wise.
Need to cut loose and move on for this year. You see it and maybe its the push I need
_________________
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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fblade
Joined: 06 Dec 2020
Posts: 38
Location: UK
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| Posted: Thu Apr 20, 2023 9:42 pm Post subject: |
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| Mike9311 wrote: |
keep going to break 200 consistently for fun (it would be easy because I have seen 199)
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Perhaps that is your goal right there as you have been doing so well.. |
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Mike9311
Joined: 14 Dec 2004
Posts: 1678
Location: Chicago-ish
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| Posted: Thu Apr 20, 2023 11:42 pm Post subject: |
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| fblade wrote: | | Mike9311 wrote: |
keep going to break 200 consistently for fun (it would be easy because I have seen 199)
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Perhaps that is your goal right there as you have been doing so well.. |
Yeah that was said sort of jokingly especially since the intake ruined the fun.
Although I did put a vane/baguette in there last night to test with the Trumpet / velocity stack but got interrupted for testing. There is this nagging suspicion that the vane may work with the trumpet even though it doesn't with the actual Intake
If it does, a GTR / GTS Intake may be the ticket with a vane
A realization from the last few days of research: The vane finally makes sense to me even though its use by porters is to atomize wet flow fuel, not the way I am using it so much. The reason the fuel requires the extra atomization help is that the short side radius (SSR) gets laid back too far to increase dry flow during porting. When this happens the wet flow no longer has the velocity at the SSR and falls out of suspension. Then it doesn't turn with the SSR and straight-lines into the back wall (long side of the seat) resulting in more problems (Cedric touches on this). Some Port SSR's are designed to have some controlled turbulence (vortices) to help wet flow. This is more of a Carb issue (wet flow) than with injection. Credit for this is a mix of info, primarily D. Morgan, so I hope I do it justice and don't lead anyone astray since I am drawing conclusions from all the info)
_________________
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: Fri Apr 21, 2023 7:28 am Post subject: |
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Tested with a quick clay vane (baguette) and now the trumpet / velocity stack performs
Original CS ported stock intake is still performing different but a straight velocity stack with Vane (Baguette) is the ticket for flow throughout lift curve. Wonder what the trumpet would do once enclosed in an intake? Ahhh, I need to move on
_________________
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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lildude4life
Joined: 27 Apr 2015
Posts: 60
Location: Milwaukee WI
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| Posted: Tue Apr 25, 2023 12:15 am Post subject: |
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Hey Mike9311,,
Got anymore of those,,, updates?
Its been like 4 days. and an entire weekend.
Dying overhere..
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"931 EFR" 81 931 S2 w/ EFR 6258 turbo, EFI, Haltech Elite ECU, 240whp |
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Mike9311
Joined: 14 Dec 2004
Posts: 1678
Location: Chicago-ish
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| Posted: Tue Apr 25, 2023 4:20 am Post subject: |
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| lildude4life wrote: | Hey Mike9311,,
Got anymore of those,,, updates?
Its been like 4 days. and an entire weekend.
Dying overhere.. |
I lil'one I suppose I have been playing with the CAD to get a feel for creating the port surface so it can be readied for CAM simulation and machining. So far I have been using the mid process port shape you see in this thread so it won't be valid but its a good warmup. What amazed me was the port size of 71cc. I am so used to see US V8 sizes so this was almost funny. Really don't see velocity as an issue here
In the immediate to-do are two items. Back cut the valve and re-finish valve seat. Then test. Hoping it continues to fatten the lower area under the curve and gets the mass of air moving sooner. Then I need to make another mold and continue the process in the first paragraph above
Longer term would be intake development. It dawned on me that if the TMIC is kept in place, one could develop a shorter runner intake and just bring the TMIC output down and around. This thought though just came to me this morning. If a front mount IC was used it would be nice to have a GTR style with proper port sizing. Not GTS. That already has curves / bends.
I wasn't able to work on the actual head this weekend as kids sports have begun. Friday I cleaned up the port a bit in preparation for mold making.
As far as the "ultimate" 931 head as has been asked for previously. I think this will become at least 2 part process. Build this first one and test on running car. Then just keep moving on a second head and full engine build
_________________
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 Apr 25, 2023 6:42 pm Post subject: |
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GTR intake is so nice. I took part in the Transaxle League this weekend in Poland. This motivates me to move forward with my 931 IC/Turbo/EFI works and try some track racing with that car (never been on track in a 924).
Just remember this damn alternator is colliding with anything you try to do in the intake area
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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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Cedric
Joined: 27 Aug 2004
Posts: 2610
Location: Sweden
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| Posted: Tue Apr 25, 2023 7:32 pm Post subject: |
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The GTR runners are really short though, so it will hurt the mid and lower end of the power curve, which might not be the best idea. But if you have a really responsive turbo charger it could of course be compensated for it a bit. But no one in here is building a max hp high rpm drag car Dont forget that its a system, and it has to be thought of as such
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1980 924 Turbo
www.instagram.com/garagecedric/ |
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fblade
Joined: 06 Dec 2020
Posts: 38
Location: UK
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| Posted: Tue Apr 25, 2023 8:04 pm Post subject: |
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| Cedric wrote: | | The GTR runners are really short though, so it will hurt the mid and lower end of the power curve, which might not be the best idea. But if you have a really responsive turbo charger it could of course be compensated for it a bit. But no one in here is building a max hp high rpm drag car Dont forget that its a system, and it has to be thought of as such |
I am building a high HP car(very slowly at the moment  ) depending on your definition of high HP of course and yes not a drag car.
Sent you a PM Cedrid btw |
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Mike9311
Joined: 14 Dec 2004
Posts: 1678
Location: Chicago-ish
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| Posted: Tue Apr 25, 2023 11:51 pm Post subject: |
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Maybe the runners could be made in a GTR fashion but longer? The idea being straight into the port. This is what throwing me as far as system development. Its that other bend or "hook" into the head port that seems to cause all the issues with flow loss. I can see the bulge in the hood now for an intake
Also for us, we are at the low end of the lift spectrum. According to the Vizard software (this .25D rule with D=Valve diameter) we are at .413 lift where this flow cross over occurs. This means it is seat and valve work below this lift point that is most important. Wasn't really paying attention to this before the last few days. Its why I want to move to a valve back cut and final seat cut test. This can't be entirely true however since low lift flow improved with careful port work just this last time. Maybe careful isn't the word but paranoid
Also looking at calculated port velocity which seems high but I am researching further before reaching any conclusion.
I feel like I need to work with what I got for now. Intake and all. Knowing that a straight, or at least no bend into the port from below, with the same head will flow much more without me having to adjust the head in any way with the way it is currently. Get it running and develop an intake to test might be the idea
Sorry I am a bit all over the place with this post. Ran in two directions at once
_________________
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: Wed Apr 26, 2023 12:08 am Post subject: |
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Mike, I think you did all the checks without the injectors, right? Or I missed something? You know I want to adapter-fit the VW 1.8T intake, which has it's own injector ports (that way I need to blank either these ones in 1.8T intake or the ones in 931 head). I'w wondering which would harm flow less.
_________________
---
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 Apr 26, 2023 9:28 am Post subject: |
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| kondzi wrote: | | Mike, I think you did all the checks without the injectors, right? Or I missed something? You know I want to adapter-fit the VW 1.8T intake, which has it's own injector ports (that way I need to blank either these ones in 1.8T intake or the ones in 931 head). I'w wondering which would harm flow less. |
All posted results are without injectors because they made a difference. As soon as the injector protruded or stuck out into the port is when it mattered. My plan is to make adapters to lift them up a bit so the still spray on the valve but don't stick out into the port. In your case we don't want fuel falling out of suspension with it being farther away but I think turbulence will keep it all mixed up
_________________
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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