RSR crankcase breather
10-30-2005, 07:38 PM
#46
Instructor
Join Date: Nov 2003
Location: Wilton, CT USA
Posts: 239
Likes: 0
Received 0 Likes
on
0 Posts
i heard it explained that you either want pressure or a vaccum, not neutral. this way, the o-rings are better seated, and the engine produces more power (holds better compression). dragsters use a vaccum principal. rsr, pressure
10-31-2005, 11:34 AM
#47
Rennlist Member
A data point of interest.
A friend had the RMS on his GT3 begin to leak and the dealer replaced it with the 996.102.264.92 RSR part number without any special request from my friend.
In fact, my friend asked if he could supply an RSR seal for them to use and was told they were already going to use one.
So, it appears from my friends experience that Porsche is using the RSR seal in leak repair orders.
A friend had the RMS on his GT3 begin to leak and the dealer replaced it with the 996.102.264.92 RSR part number without any special request from my friend.
In fact, my friend asked if he could supply an RSR seal for them to use and was told they were already going to use one.
So, it appears from my friends experience that Porsche is using the RSR seal in leak repair orders.
Last edited by Cupcar; 10-31-2005 at 12:03 PM.
10-31-2005, 06:18 PM
#48
Originally Posted by healeyg
i heard it explained that you either want pressure or a vaccum, not neutral. this way, the o-rings are better seated, and the engine produces more power (holds better compression). dragsters use a vaccum principal. rsr, pressure
Any other theories? Increasing the partial vacuum in the c/c makes sense incresing the pressure will blow out all seals, I lost a set of 3.8 cylinder base seals that way.
11-01-2005, 04:33 PM
#49
Three Wheelin'
My guess is the RSR breather allows additional vacuum which puts added stress on the stock seal. The RSR seal is stiffer & more resistant to the flexing caused by the extra vacuum ie; the stock seal would flex in/out often enough with the extra vacuum, weakening the seal & causing it to eventually begin leaking when the car was stationary. What do you guys think?
11-01-2005, 05:45 PM
#50
Originally Posted by JW in Texas
My guess is the RSR breather allows additional vacuum which puts added stress on the stock seal. The RSR seal is stiffer & more resistant to the flexing caused by the extra vacuum ie; the stock seal would flex in/out often enough with the extra vacuum, weakening the seal & causing it to eventually begin leaking when the car was stationary. What do you guys think?
11-01-2005, 06:50 PM
#51
Rennlist Member
I think it is a problem only when the engine stops and the oil pressure goes to zero and there is residual vacuum in the crankcase. The lip of the seal is lifted by the vacuum and the full oil galleries above burp oil out past the seal.
The oil pressure behind the seal is what normally makes the seal work, and it is hard to imagine there could be enough vacuum generated to make a difference in seal pressure while the engine is running.
The oil pressure behind the seal is what normally makes the seal work, and it is hard to imagine there could be enough vacuum generated to make a difference in seal pressure while the engine is running.
11-06-2005, 05:24 PM
#54
Technical Guru
Rennlist Member
Rennlist Member
Originally Posted by Cupcar#12
you should also use the Front main seal from the RS/RSR 996.102.264.92 advailable via PMSNA
11-07-2005, 09:29 PM
#56
Technical Guru
Rennlist Member
Rennlist Member
Thanks Cupcar! Feebie(?) at PMNA confirmed that the FMS is exactly the same on all the cars (964/993/GT3/996CUP/996RSR) so we only need to replace the RMS and not the FMS if we install the crankcase breather.
Last edited by JasonAndreas; 11-11-2005 at 04:07 AM. Reason: further info from PMNA
03-13-2010, 07:44 AM
#57
Three Wheelin'
Interesting coming back to this thread after all this time. The 7GT3 runs the lower crankcase pressure and its the apparent cause of all the RMS leaks owners constantly battle with. Still for a free 8bhp seems a nice mod. What is the current thinking on the optimal RMS to use? Presumably the 7RS one? (leaky as it is)
03-13-2010, 05:30 PM
#58
Rennlist Member
I've done quite a bit of research on the subject and have not been able to find the elusive RSR RMS part number, I'm pretty certain that the RSR uses the old 996 TT/GT3/Cup seal (with inner spring). I have a crankcase breather installed and although I did see a bit of oil seepage around the seal (old 996 version), it never actually leaked onto the ground. I've since had two of the newer 997 seals installed and just like clockwork they both began to drip (onto the ground) within thirty days of installation. I plan to have the old 996 seal (999.113.426.41) installed when I have some money to burn.
03-13-2010, 10:04 PM
#59
Rennlist Member
Jmla- seems like alot to do just to get 8hp. I imagine mite be a good mod if car was leaking and thusly necessary parts to put in for crankcase breather. Mike
