SBC gen1 porcupine heads.
Moderator: Team
SBC gen1 porcupine heads.
Just a general interest question, why the BBC and SBF heads with canted valves were successful while SBC versions withered on the vine. I know GM played with some prototypes for the DZ and Trans Am racing and Trick Flow had their own in the mid 90's. TF had some quality issues with springs, limited cam compatibility, spring pocket machining issues, probably a poorly informed customer base. With 30 years of refinement the inline valve heads have blossomed- but I wonder if the Twisted Wedge ever had a chance....
-
- Guru
- Posts: 6353
- Joined: Tue Jul 24, 2012 11:15 am
- Location: Roseville, Michigan (just north of Detroit)
- Contact:
Re: SBC gen1 porcupine heads.
GM ran those heads on several engines in racing vehicles during the early 90's ... the winning car I remember distinctly was the GTP car "Intrepid".dfarr67 wrote: ↑Thu Feb 02, 2023 6:37 pm Just a general interest question, why the BBC and SBF heads with canted valves were successful while SBC versions withered on the vine. I know GM played with some prototypes for the DZ and Trans Am racing and Trick Flow had their own in the mid 90's. TF had some quality issues with springs, limited cam compatibility, spring pocket machining issues, probably a poorly informed customer base. With 30 years of refinement the inline valve heads have blossomed- but I wonder if the Twisted Wedge ever had a chance....
Although, I know most people on here don't have a clue about road racing or endurance racing.
http://www.rmcompetition.com
Specialty engine building at its finest.
Specialty engine building at its finest.
Re: SBC gen1 porcupine heads.
More potential than inline valves, but geez there's some good inline valve motors still.
This one?
You do not have the required permissions to view the files attached to this post.
Ignorance leads to confidence more often than knowledge does.
Nah, I'm not leaving myself out of the ignorant brigade....at times.
Nah, I'm not leaving myself out of the ignorant brigade....at times.
Re: SBC gen1 porcupine heads.
If Trickflow had have done more field testing and proving before release of the G1 head they may well have been developed further over the years and the premise adopted without copyright infringements by other cylinder head companies.
I still use the pair I purchased back in ‘98. Short 5.2” intake length, 2.02 valve that only comes as close as .200” to the combustion chamber wall and flow a tad over 270 cfm @ .500”. Some quick measurements 89% throat, mcsa hxw 2.3 sq" but I haven't measured the radius to subtract yet and bowl around 106%. Intake cc's 197cc. I’ll have them flowed again soon and if necessary tweaked to see what more they have in them. They are not world beaters for sure but no company has put the r&d into them like has been done to highly developed similar size 23* heads as stated over the past 20-30 years. Maybe no one wants something of a similar ilk in competition with their own highly invested 23* midrange head? The G2 had real potential flowing 254cfm @ .500” out of the box not needing as much special care to set up that the G1 did. I’d love to get my hands on a pair of G2 but they are scarce so I’ll have to stick with the G1.
I still use the pair I purchased back in ‘98. Short 5.2” intake length, 2.02 valve that only comes as close as .200” to the combustion chamber wall and flow a tad over 270 cfm @ .500”. Some quick measurements 89% throat, mcsa hxw 2.3 sq" but I haven't measured the radius to subtract yet and bowl around 106%. Intake cc's 197cc. I’ll have them flowed again soon and if necessary tweaked to see what more they have in them. They are not world beaters for sure but no company has put the r&d into them like has been done to highly developed similar size 23* heads as stated over the past 20-30 years. Maybe no one wants something of a similar ilk in competition with their own highly invested 23* midrange head? The G2 had real potential flowing 254cfm @ .500” out of the box not needing as much special care to set up that the G1 did. I’d love to get my hands on a pair of G2 but they are scarce so I’ll have to stick with the G1.
I’m a Street/Strip guy..... like to think outside the quadrilateral parallelogram.
-
- Guru
- Posts: 4584
- Joined: Sun Sep 18, 2011 11:31 am
- Location: Heading for a bang up with Andromeda as we all are.
Re: SBC gen1 porcupine heads.
For those who where doing a total rebuild you could purchase a set of the Brodix CV heads but with the runners not CNCed and with no intake valve seats.
You could then step down to a 2.05” valve from a 2.200” valve and still likely get 330 cfm at far less the the heads out of the box norm of 265 CCs.
These heads do have spread port exh though.
You could then step down to a 2.05” valve from a 2.200” valve and still likely get 330 cfm at far less the the heads out of the box norm of 265 CCs.
These heads do have spread port exh though.
You can cut a man's tongue from his mouth, but that does not mean he’s a liar, it just shows that you fear the truth he might speak about you!
-
- Guru
- Posts: 4584
- Joined: Sun Sep 18, 2011 11:31 am
- Location: Heading for a bang up with Andromeda as we all are.
Re: SBC gen1 porcupine heads.
Whatever happed to the 4 valve Aris head that was around like 15 years ago.
I think I recall that being a bolt on 150 hp.
I think I recall that being a bolt on 150 hp.
You can cut a man's tongue from his mouth, but that does not mean he’s a liar, it just shows that you fear the truth he might speak about you!
Re: SBC gen1 porcupine heads.
Not the heads I was thinking about- late 60's, they were deemed too expensive to mass produce I think or the output didn't justify further development. Last year there was an article about a recent restoration and since the heads are so rare the owner just broke it in on the dyno and didn't even do a full power pull.Walter R. Malik wrote: ↑Thu Feb 02, 2023 6:42 pmGM ran those heads on several engines in racing vehicles during the early 90's ... the winning car I remember distinctly was the GTP car "Intrepid".dfarr67 wrote: ↑Thu Feb 02, 2023 6:37 pm Just a general interest question, why the BBC and SBF heads with canted valves were successful while SBC versions withered on the vine. I know GM played with some prototypes for the DZ and Trans Am racing and Trick Flow had their own in the mid 90's. TF had some quality issues with springs, limited cam compatibility, spring pocket machining issues, probably a poorly informed customer base. With 30 years of refinement the inline valve heads have blossomed- but I wonder if the Twisted Wedge ever had a chance....
Although, I know most people on here don't have a clue about road racing or endurance racing.
Re: SBC gen1 porcupine heads.
Most but not all!Walter R. Malik wrote: ↑Thu Feb 02, 2023 6:42 pm Although, I know most people on here don't have a clue about road racing or endurance racing.
Loved the endurance racing of the late 60's/early 70's as a young spectator.
CanAm in the mid-70's at my home track Mosport Park.
F1 for as long as I can remember.
The opportunity to race actively never presented itself though despite my high school and college friend receiving a national sponsorship for some level of GT racing through the 80's and 90's.
Drag racing is an relatively easy entry level sport.
Kevin
Re: SBC gen1 porcupine heads.
The general valve layout of:
1. parallel valves
2. angled with respect to the bore axis
3. operated by pushrods
4. in a closed chamber
5. with quench
...which we find in the LS, was first introduced in the 1949 Cadillac 331 and Oldsmobile 303.
There's nothing wrong with it (used by every mfg.), just needed more tweaking.
1. parallel valves
2. angled with respect to the bore axis
3. operated by pushrods
4. in a closed chamber
5. with quench
...which we find in the LS, was first introduced in the 1949 Cadillac 331 and Oldsmobile 303.
There's nothing wrong with it (used by every mfg.), just needed more tweaking.
Re: SBC gen1 porcupine heads.
There was a time when you could win a F1 World championship with an inline two valve V8.
You do not have the required permissions to view the files attached to this post.
Ignorance leads to confidence more often than knowledge does.
Nah, I'm not leaving myself out of the ignorant brigade....at times.
Nah, I'm not leaving myself out of the ignorant brigade....at times.
Re: SBC gen1 porcupine heads.
"Quality" is like buying oats. You can pay a fair price for it and get some good quality oats,
or you can get it a hell of a lot cheaper, when it's already been through the horse.
Nil Satis Nisi Optimum
Ed Curtis - www.FlowTechInduction.com
or you can get it a hell of a lot cheaper, when it's already been through the horse.
Nil Satis Nisi Optimum
Ed Curtis - www.FlowTechInduction.com
-
- HotPass
- Posts: 1858
- Joined: Sun Mar 01, 2009 2:42 am
- Location: The Seasonally Frozen Wastelands
Re: SBC gen1 porcupine heads.
The original Twisted Wedge heads for SBC did not have "canted" valves in the sense of the BBC and Cleveland and 385-series Fords.
The original Twisted Wedge heads had the standard, ordinary exhaust valve location, but the intake was shifted in one plane, to a more-upright angle. Neither valve was "canted". The Twisted Wedge head was more like the Polyspherical Mopar than a BBC.
I don't know about the Gen 2 version, except that both valves had altered angles. I think there was no cant to either valve.
Did Arias make a 4-valve head? I remember the DOHC Moser 4-valve heads, but not Arias
The original Twisted Wedge heads had the standard, ordinary exhaust valve location, but the intake was shifted in one plane, to a more-upright angle. Neither valve was "canted". The Twisted Wedge head was more like the Polyspherical Mopar than a BBC.
I don't know about the Gen 2 version, except that both valves had altered angles. I think there was no cant to either valve.
Did Arias make a 4-valve head? I remember the DOHC Moser 4-valve heads, but not Arias
Re: SBC gen1 porcupine heads.
An inline valve head from Oz back in the day.
I have a set of Duggan ported fuelies.
I have a set of Duggan ported fuelies.
You do not have the required permissions to view the files attached to this post.
Ignorance leads to confidence more often than knowledge does.
Nah, I'm not leaving myself out of the ignorant brigade....at times.
Nah, I'm not leaving myself out of the ignorant brigade....at times.
Re: SBC gen1 porcupine heads.
Yep, often miss understood as canted. Intake is stood up to 13* but the valve seats did not stay in the same location or move in a line perpendicular and toward the intake face. Instead the valve seats were moved backward toward the intake face and inward toward bore centerline - hence twisted and the .200” min shrouding to combustion chamber with a 2.02. Valve stem remains parallel to bore wall.Schurkey wrote: ↑Sat Feb 04, 2023 2:12 am The original Twisted Wedge heads for SBC did not have "canted" valves in the sense of the BBC and Cleveland and 385-series Fords.
The original Twisted Wedge heads had the standard, ordinary exhaust valve location, but the intake was shifted in one plane, to a more-upright angle. Neither valve was "canted". The Twisted Wedge head was more like the Polyspherical Mopar than a BBC.
I don't know about the Gen 2 version, except that both valves had altered angles. I think there was no cant to either valve.
Did Arias make a 4-valve head? I remember the DOHC Moser 4-valve heads, but not Arias
G2 went for 16* intake and 18* exhaust, no cant, larger intake port.
I’m a Street/Strip guy..... like to think outside the quadrilateral parallelogram.