Piston Ring Gaps
06-06-2005, 05:53 PM
#16
Rennlist Member
Thread Starter
944 n/a rings: 944 103 902 82
944 Turbo rings: 951 103 901 02
I bought a set of the Goetze 951 rings from EBS, but I believe that Paragon now carries them also (within the past month).
I looked for any 928 that uses a 951 part number for the rings and did not find any. So still not sure why the Goetze box identifies the possible application for a 928 with the 951 103 901 02 ring set. Think anyone on the 928 board might know?
Im also not sure what the benefit of the chrome plating would be in regards to preventing the rings from cracking. It would depend on what the failure mechanism is that causes the cracking. More heat, pressure, etc? Is it a brittle fracture?
I believe that the chrome plating is normally done to increase surface hardness and/or wear resistance of a material. Not sure what effect it would have on heat disipation.
Its such a small area of the top ring that is plated. Pretty much just the cylinder wall edge. The top of the ring is basically unplated, with just a tiny strip along the outer edge. Hard to tell if this is intentional or just some overplating from the chroming process.
944 Turbo rings: 951 103 901 02
I bought a set of the Goetze 951 rings from EBS, but I believe that Paragon now carries them also (within the past month).
I looked for any 928 that uses a 951 part number for the rings and did not find any. So still not sure why the Goetze box identifies the possible application for a 928 with the 951 103 901 02 ring set. Think anyone on the 928 board might know?
Im also not sure what the benefit of the chrome plating would be in regards to preventing the rings from cracking. It would depend on what the failure mechanism is that causes the cracking. More heat, pressure, etc? Is it a brittle fracture?
I believe that the chrome plating is normally done to increase surface hardness and/or wear resistance of a material. Not sure what effect it would have on heat disipation.
Its such a small area of the top ring that is plated. Pretty much just the cylinder wall edge. The top of the ring is basically unplated, with just a tiny strip along the outer edge. Hard to tell if this is intentional or just some overplating from the chroming process.
06-07-2005, 04:04 PM
#17
I think the issue with them being chrome on the outside indicates thier actual meterial makup in relation to the black rings. This is conjecture.
All I know about the 928 rings for the 100mm bore before the GTS is that the 928 part numbers have been superceded by 944 part numbers, and we can no longer get the 928 ones. It may be a 944 part number, but I think the idea may be to actually get the 951 ones if we know whats good for us under boost.
All I know about the 928 rings for the 100mm bore before the GTS is that the 928 part numbers have been superceded by 944 part numbers, and we can no longer get the 928 ones. It may be a 944 part number, but I think the idea may be to actually get the 951 ones if we know whats good for us under boost.
