Exactly how much oil can leak past the cylinder base "O" rings?
02-17-2013, 10:20 AM
#1
Pro
Thread Starter
Exactly how much oil can leak past the cylinder base "O" rings?
Hi There
I rebuilt the top end of my 993 last year (car is in the UK). I used a Wrightwood racing gasket set that came with green "O" rings for the cylinder bases. The engine was then successfully started and I then had to go and work in Asia. My brother put the exhaust back on and the car went for and passed its MOT. The car then seems to have developed what my brother describes as a major oil leak from 4 of the cylinder bases, plus some minor ones from he cam covers just for luck. The cam covers have been off and the head nuts seem tight.
I am hoping against hope that the cylinder bases are not leaking and that it is in fact something else. I have not seen the leak personally but I am told it is bad. The cardboard sheet under the car is soaked through with oil.
Does anyone know just how much oil can leak past the cylinder bases? Especially when the car is not being run.
Where else can the oil be leaking from?
How much oil sits around the cylinder bases when the car is level and the engine is not running?
Also if the bases are leaking is there some sort of short term fix?
I ask because I was hoping to fly back and take the car for a weekend drive in about a months time, hence the desire for a short term fix.
One last thing, although the engine was rebuilt very carefully I think the cylinder base gaskets must have got twisted on install. Also I used a smear of Hylomar blue on them.
Many thanks
Berni
I rebuilt the top end of my 993 last year (car is in the UK). I used a Wrightwood racing gasket set that came with green "O" rings for the cylinder bases. The engine was then successfully started and I then had to go and work in Asia. My brother put the exhaust back on and the car went for and passed its MOT. The car then seems to have developed what my brother describes as a major oil leak from 4 of the cylinder bases, plus some minor ones from he cam covers just for luck. The cam covers have been off and the head nuts seem tight.
I am hoping against hope that the cylinder bases are not leaking and that it is in fact something else. I have not seen the leak personally but I am told it is bad. The cardboard sheet under the car is soaked through with oil.
Does anyone know just how much oil can leak past the cylinder bases? Especially when the car is not being run.
Where else can the oil be leaking from?
How much oil sits around the cylinder bases when the car is level and the engine is not running?
Also if the bases are leaking is there some sort of short term fix?
I ask because I was hoping to fly back and take the car for a weekend drive in about a months time, hence the desire for a short term fix.
One last thing, although the engine was rebuilt very carefully I think the cylinder base gaskets must have got twisted on install. Also I used a smear of Hylomar blue on them.
Many thanks
Berni
Last edited by berni29; 02-17-2013 at 11:07 AM.
02-18-2013, 05:33 AM
#2
Rennlist Member
Berni how are you ? hope you are well....
As much as I sound old and dumb in my threads, sometimes I unintentionally write something important
due to experience (past mistakes), and not knowledge....
You have used the superb wrightwood racing gasket kit, but the kit has 102mm cylinder gaskets.
I have written in your thread whilst rebuilding your engine about regarding these seals, and that they differ from
the 3.6 version, and should be acquired ' au lieu' of the wrightwood kit seals
here is the thread:
https://rennlist.com/forums/993-foru...o-replace.html
tell me you purchased the good dimension seals, please
As much as I sound old and dumb in my threads, sometimes I unintentionally write something important
due to experience (past mistakes), and not knowledge....
You have used the superb wrightwood racing gasket kit, but the kit has 102mm cylinder gaskets.
I have written in your thread whilst rebuilding your engine about regarding these seals, and that they differ from
the 3.6 version, and should be acquired ' au lieu' of the wrightwood kit seals
here is the thread:
https://rennlist.com/forums/993-foru...o-replace.html
tell me you purchased the good dimension seals, please
02-18-2013, 09:57 AM
#3
Pro
Thread Starter
Hi Geolab
Thank you for taking the time to reply. Yes not too bad thank you. I am taking a spur of the moment trip back to the UK for 2 weeks later this week. I hope things are good with you also.
I ordered the set from Supertec and told them it was for a 993, so I had assumed that they were standard. Now of course I am not so sure
I will call Supertec and ask as soon as I can. From memory they were not loose on fitting, but neither were they particularly tight. I am almost hoping that they are wrong, so that I can be sure that changing them will fix the problem, rather than it being something else.
I will be back with the car later this week. I really hope that the leak is not as bad as it sounds and I can at least drive the car with some cat litter in the under tray. In the summer I can drop the engine. I do not fancy all that again right now given the likely weather and my garage situation.
All the best
Berni
Thank you for taking the time to reply. Yes not too bad thank you. I am taking a spur of the moment trip back to the UK for 2 weeks later this week. I hope things are good with you also.
I ordered the set from Supertec and told them it was for a 993, so I had assumed that they were standard. Now of course I am not so sure
I will call Supertec and ask as soon as I can. From memory they were not loose on fitting, but neither were they particularly tight. I am almost hoping that they are wrong, so that I can be sure that changing them will fix the problem, rather than it being something else.I will be back with the car later this week. I really hope that the leak is not as bad as it sounds and I can at least drive the car with some cat litter in the under tray. In the summer I can drop the engine. I do not fancy all that again right now given the likely weather and my garage situation.
All the best
Berni
02-18-2013, 12:23 PM
#4
Geolab is correct in that the 102mm RS/RSR cylinders used a different base gasket than the 100mm normals.
The RS/RSR also have a groove machined in both the cyl and the cc to accommodate the bigger seals
normal 3.6 seals are 102x2mm w/ no cc groove
RS/RSR are 110.72x3.53mm w/ both cyl and cc grooves
I doesn't hurt to also use additional sealer on the cylinder bases.
The RS/RSR also have a groove machined in both the cyl and the cc to accommodate the bigger seals
normal 3.6 seals are 102x2mm w/ no cc groove
RS/RSR are 110.72x3.53mm w/ both cyl and cc grooves
I doesn't hurt to also use additional sealer on the cylinder bases.
02-19-2013, 07:49 AM
#5
Instructor
Berni,
I used the wrightwood kit, purchased from Steve W. I had a bad leak at cylinder 2 and ended up tearing down to fix it; at the time I posted here and there was no mention of the cylinder gasket issue. Even withbeverything apart I couldnt find what was causing the leak. For insurance I used a sealant the second time around and have had no more leaks after 3k miles.
I used the wrightwood kit, purchased from Steve W. I had a bad leak at cylinder 2 and ended up tearing down to fix it; at the time I posted here and there was no mention of the cylinder gasket issue. Even withbeverything apart I couldnt find what was causing the leak. For insurance I used a sealant the second time around and have had no more leaks after 3k miles.
02-19-2013, 10:41 AM
#6
Pro
Thread Starter
Hi Don
I am sad to hear you had to do that! I will be doing the same I think. Which sealant did you use along with the standard porsche gaskets? Also did you buy new cylinder head sealing rings, or is it possible to get each bank of three off the pistons (and as importantly back on) without removing the cam towers and cams?
I am glad you fixed the problem!
Berni
I am sad to hear you had to do that! I will be doing the same I think. Which sealant did you use along with the standard porsche gaskets? Also did you buy new cylinder head sealing rings, or is it possible to get each bank of three off the pistons (and as importantly back on) without removing the cam towers and cams?
I am glad you fixed the problem!
Berni
