GTP Valve Cover

Talk and Tech about turbocharged 924/944/968 cars
michaelmount123
Posts: 299
Joined: Fri Jul 09, 2021 7:51 am
Has thanked: 26 times
Been thanked: 179 times
Tom wrote: Thu Feb 20, 2025 7:13 pm I've been experimenting with Bambu's PPA-CF, and am fairly sure it would hold up fine as an intake like that. Good to 440F degrees with a tensile strength that exceeds some aluminums, at least on paper. My first few prints with it suggest it's the real deal in terms of printer-to-engine-bay parts. That said, even though Porsche put a plastic oil pan on my 992 :shock: :shock: I still wouldn't want a valve cover in plastic. I assume that GTP valve cover has machined bearing races, with oil galleys, etc.?
Oh my, Tom. Your response is music to my ears. The 4V cover is simply a cover; there are no oil passages, and no bearing races. This makes it relatively simple, I would imagine. You mentioned you wouldn't want a plastic valve cover. Why not? If it's got the heat tolerance, I don't see an issue. What am I missing? I'm VERY happy to continue this discussion!
M.

#21

User avatar
Tom
Site Admin
Posts: 8992
Joined: Fri Jun 25, 2021 2:04 pm
Location: Silicon Valley, CA
Has thanked: 947 times
Been thanked: 4040 times
Contact:
michaelmount123 wrote: Thu Feb 20, 2025 7:28 pm
Tom wrote: Thu Feb 20, 2025 7:13 pm I've been experimenting with Bambu's PPA-CF, and am fairly sure it would hold up fine as an intake like that. Good to 440F degrees with a tensile strength that exceeds some aluminums, at least on paper. My first few prints with it suggest it's the real deal in terms of printer-to-engine-bay parts. That said, even though Porsche put a plastic oil pan on my 992 :shock: :shock: I still wouldn't want a valve cover in plastic. I assume that GTP valve cover has machined bearing races, with oil galleys, etc.?
Oh my, Tom. Your response is music to my ears. The 4V cover is simply a cover; there are no oil passages, and no bearing races. This makes it relatively simple, I would imagine. You mentioned you wouldn't want a plastic valve cover. Why not? If it's got the heat tolerance, I don't see an issue. What am I missing? I'm VERY happy to continue this discussion!
M.
Ah, just a cover, well that's much different. I was thinking it was part of the internally lubricated portion of the engine. If it's really just a cover, then it's a good candidate for 3D printing. Its size would require a commercial printer, which opens up a world of material possibilities (including metal). Or, it could be printed in sections at home, which may or may not look ok.... It all starts with a CAD model though. Anyone have leads on a file? Or, if anyone had an original, we could 3D-scan it to make the model...

#22

User avatar
333pg333
Posts: 238
Joined: Sat Jul 03, 2021 8:24 pm
Has thanked: 90 times
Been thanked: 49 times
That sounds pretty exciting Tom & Michael. Love the idea of printing so many parts for our cars. As Michael says, one offs are really not chased by any manufacturers. Unless you're stupid like me and pay #krazy! money for a one off billet intake!
Heck, they're printing houses nowadays so surely we can so some smaller detailed parts. It's the new materials that can be used which are becoming more and more advanced. Soon they'll be printing off complicated exhaust headers. Pretty sure Koenigsegg prints parts of turbo chargers...Amazing! The guy doing the new aero kit for me is going to print some of the parts. Perhaps just to act as a mold but it shouldn't be long until it will just be the complete piece.

#23

User avatar
blueline
Moderator
Posts: 6139
Joined: Mon Sep 26, 2022 12:22 pm
Location: Middle Tennessee
Has thanked: 4487 times
Been thanked: 2436 times
Regarding advanced 3D printing, @Stormy_Monday posted this short YouTube video a few weeks ago showing what Porsche is doing. It's incredible, at least to me.

https://www.carpokes.com/viewtopic.php?p=41502#p41499


A bit of the YouTube synopsis from the Porsche-Trumpf-Mahle collaboration:

"Three-dimensional printing is transforming the automotive industry, and Porsche is at the forefront of this exciting evolution. By blending cutting-edge technology with engineering expertise, the company is paving the way for a future where vehicle components are more efficient, customizable, and accessible than ever before. This is just the beginning of a journey that promises to reshape how cars are designed, built, and experienced."

"In just a few decades, three-dimensional printing, also referred to as additive manufacturing, has revolutionized the way we create objects. Beginning in the 1980s with the production of basic polymer items, the technology has advanced to the point where almost anything can be fabricated—from automobiles and human organs to components for advanced space exploration equipment like SpaceX's Falcon 9 rocket. Now, Porsche is pushing the boundaries of this innovation with groundbreaking three-dimensional printed pistons."

"Yes, pistons—those high-stress, precision-engineered components found in engines—are being successfully produced using three-dimensional printing. Collaborating with its partners Mahle and Trumpf, Porsche has developed a process to create these critical parts. To test the feasibility of their creation, Porsche installed a set of prototype pistons in the engine of a 911 GT2 RS and subjected them to 200 hours of high-speed operation. The results were extraordinary. Not only did the pistons withstand the rigorous conditions, but they also delivered improved efficiency and performance compared to traditionally manufactured counterparts."


The YouTube vid:


Tim
Current:
'26 911 Carrera S - PTS Verde British Racing Green
'24 Cayenne S - Algarve Blue Metallic
'21 718 Cayman GTS - Black
'22 911 Turbo S - Carmine Red
'21 718 Cayman GT4 - White
'11 GMC 1500 Quad Cab 4x4 - Black

Musik-Stadt Region

#24

User avatar
333pg333
Posts: 238
Joined: Sat Jul 03, 2021 8:24 pm
Has thanked: 90 times
Been thanked: 49 times
WoW!!!

#25

cda951
Posts: 180
Joined: Sun Jul 04, 2021 8:55 pm
Location: Santa Barbara, CA
Has thanked: 136 times
Been thanked: 81 times
The issue with plastic valve covers in my experience is they tend to "warp" or deform with age and use, which leads to external oil leaks.

This experience is entirely derived from my 20 years as a technician at a Porsche/BMW shop, with the leaking plastic valve covers being a BMW thing. Years ago we initially tried replacing the rubber profile gaskets only, but after several warranty repairs the entire valve cover was deemed as the necessary repair. This became doubly important once the crankcase pressure regulating valves and/or the check valves were built into the valve cover per typical BMW "wisdom."

Anyway, I'm not an engineer, but my experience with valve covers leads me to believe that the designer also needs to consider clamping loads at all the bolt locations, profile gasket material and thickness, etc.
Chris A.
---'86 944 Turbo track rat
---'90 944S2 Cab daily/touring car
---'73 BMW 2002tii road rally car
---'81 Alfa Romeo GTV6 GT car/Copart special
---'99 BMW Z3 Coupe daily driver/dog car
---'74 Jensen-Healey roadster
---other stuff

#26

User avatar
Tom
Site Admin
Posts: 8992
Joined: Fri Jun 25, 2021 2:04 pm
Location: Silicon Valley, CA
Has thanked: 947 times
Been thanked: 4040 times
Contact:
cda951 wrote: Sat Feb 22, 2025 12:15 am The issue with plastic valve covers in my experience is they tend to "warp" or deform with age and use, which leads to external oil leaks.

This experience is entirely derived from my 20 years as a technician at a Porsche/BMW shop, with the leaking plastic valve covers being a BMW thing. Years ago we initially tried replacing the rubber profile gaskets only, but after several warranty repairs the entire valve cover was deemed as the necessary repair. This became doubly important once the crankcase pressure regulating valves and/or the check valves were built into the valve cover per typical BMW "wisdom."

Anyway, I'm not an engineer, but my experience with valve covers leads me to believe that the designer also needs to consider clamping loads at all the bolt locations, profile gasket material and thickness, etc.
That would certainly be my worry with anything intended to contain engine oil. That, and with FDM 3D printing, most plastics have a porosity that might absorb oil and become saturated all the way through over time. Other forms of 3D printing can solve the porosity issue though.

#27

ROB III
Moderator
Posts: 609
Joined: Fri Mar 25, 2022 2:47 pm
Location: Nashville
Has thanked: 521 times
Been thanked: 266 times
333pg333 wrote: Thu Feb 20, 2025 10:37 pm That sounds pretty exciting Tom & Michael. Love the idea of printing so many parts for our cars. As Michael says, one offs are really not chased by any manufacturers. Unless you're stupid like me and pay #krazy! money for a one off billet intake!
Heck, they're printing houses nowadays so surely we can so some smaller detailed parts. It's the new materials that can be used which are becoming more and more advanced. Soon they'll be printing off complicated exhaust headers. Pretty sure Koenigsegg prints parts of turbo chargers...Amazing! The guy doing the new aero kit for me is going to print some of the parts. Perhaps just to act as a mold but it shouldn't be long until it will just be the complete piece.
Here is a video from Papadakis Racing in SoCal that runs a Toyota in GT racing. They print in Inconel which I understand to be more durable than titanium.
https://www.bing.com/videos/riverview/r ... ORM=VRDGAR
Rob
89 944 Turbo
Musik-Stadt Region

#28

User avatar
333pg333
Posts: 238
Joined: Sat Jul 03, 2021 8:24 pm
Has thanked: 90 times
Been thanked: 49 times
$ounds $pendy!!

#29

ROB III
Moderator
Posts: 609
Joined: Fri Mar 25, 2022 2:47 pm
Location: Nashville
Has thanked: 521 times
Been thanked: 266 times
No question there! Not for the average hobbyist or even the well funded hobbyist I'd assume, but for a frontline funded race team, it's interesting to me to see what can be done in the technically advanced world of 3D printing.
Rob
89 944 Turbo
Musik-Stadt Region

#30

Post Reply