991.1 GT3RS failures
#151
The .1 engines don't have hydraulic lifters. They use hydaulic elements the alter the positions of the finger followers. The hydraulic elements don't add mass to the moving parts in the valvetrain. The design is for sure more compplex than the completely fixed version. And porsche can run other cam timings (efficiency) and save on the parts (less tight tolerances).
But thats not the question. The question is, are the proposed band aids with destroying the DLC coating of the cams are better than the factory solution. If we see a comparison of 2 engines with 100k miles on the dyno each, then we can judge ;D
But thats not the question. The question is, are the proposed band aids with destroying the DLC coating of the cams are better than the factory solution. If we see a comparison of 2 engines with 100k miles on the dyno each, then we can judge ;D
Someone posted a photo of a horizontal line across the backside of the finger. This is from the finger contacting the base circle of the cam lobe all the time. Same contact stress the finger follower sees from the same cause.
This conversion is not for all. Some will stick with what they have, some will decide to swap out for same new parts. Some will change over to solid. Its all about what you decide.
Choices.
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Indyxc (08-19-2024)
#152
The .1 engines don't have hydraulic lifters. They use hydaulic elements the alter the positions of the finger followers. The hydraulic elements don't add mass to the moving parts in the valvetrain. The design is for sure more compplex than the completely fixed version. And porsche can run other cam timings (efficiency) and save on the parts (less tight tolerances).
But thats not the question. The question is, are the proposed band aids with destroying the DLC coating of the cams are better than the factory solution. If we see a comparison of 2 engines with 100k miles on the dyno each, then we can judge ;D
But thats not the question. The question is, are the proposed band aids with destroying the DLC coating of the cams are better than the factory solution. If we see a comparison of 2 engines with 100k miles on the dyno each, then we can judge ;D
#153
Ah, you re-coat them. Interesting. That makes sense. Can you also run more powerful cam timings when re-cutting anyway?
The basic difference to a classic hydraulic lifter design is, that porsches construction doesn't move the hydraulic elements. And thats a gigantic difference compared to a classic hydraulic lash adjuster. Call it how you want, I'm not used to english tech-vocabulare. But in fact the MA175/MA176s valvetrain design is completely different compared to that of a 9A1 Carrera engine and the lash adjusters of the GT3 might kill the lash/clearance as you said. But argumenting with moving masses is just wrong.
The basic difference to a classic hydraulic lifter design is, that porsches construction doesn't move the hydraulic elements. And thats a gigantic difference compared to a classic hydraulic lash adjuster. Call it how you want, I'm not used to english tech-vocabulare. But in fact the MA175/MA176s valvetrain design is completely different compared to that of a 9A1 Carrera engine and the lash adjusters of the GT3 might kill the lash/clearance as you said. But argumenting with moving masses is just wrong.
The following users liked this post:
Flo89 (08-21-2024)
#154
Ah, you re-coat them. Interesting. That makes sense. Can you also run more powerful cam timings when re-cutting anyway?
The basic difference to a classic hydraulic lifter design is, that porsches construction doesn't move the hydraulic elements. And thats a gigantic difference compared to a classic hydraulic lash adjuster. Call it how you want, I'm not used to english tech-vocabulare. But in fact the MA175/MA176s valvetrain design is completely different compared to that of a 9A1 Carrera engine and the lash adjusters of the GT3 might kill the lash/clearance as you said. But argumenting with moving masses is just wrong.
The basic difference to a classic hydraulic lifter design is, that porsches construction doesn't move the hydraulic elements. And thats a gigantic difference compared to a classic hydraulic lash adjuster. Call it how you want, I'm not used to english tech-vocabulare. But in fact the MA175/MA176s valvetrain design is completely different compared to that of a 9A1 Carrera engine and the lash adjusters of the GT3 might kill the lash/clearance as you said. But argumenting with moving masses is just wrong.
Indeed, maybe the translation to your language makes the description different. There are 3 parts to the Lifter. An inner that when filled with oil pushes against the bottom part of the outer. This then pushes the middle section that the finger pivots off, upwards stopping the whole assy from collapsing.
#155
.. and in a normal car engines valvetrain, that whole thing would sit somewhere inbetween the cam lobe and the cam and would move on every rotation cycle, creating a lot off moving masses. Not so in the GT3, where it just sits in its mount and alters the finger followers position. The original design idea is smart... just to ambitious.
Is it a standard hydraulic element? The interesting thing is, that they drilled oil sprayers into the top cap.
Is it a standard hydraulic element? The interesting thing is, that they drilled oil sprayers into the top cap.