high oil warning
06-10-2012, 12:45 PM
#1
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high oil warning
I read that most 944 racers run the oil just above full line to help with the starvation of the #2 bearing. I'm not sure if this is a coincidence but i decided to do this and within a week my cam tower gasket blew a hole right above the exhaust port for cylinder #1
-85.5 944 na
-head and all gaskets replaced less than 5k ago
-valvoline vr1 20w50 non synthetic
i don't know if this simple over filling can be the cause of this but its really aggravating knowing that i will have to retention the timing belt.
-85.5 944 na
-head and all gaskets replaced less than 5k ago
-valvoline vr1 20w50 non synthetic
i don't know if this simple over filling can be the cause of this but its really aggravating knowing that i will have to retention the timing belt.
06-10-2012, 05:28 PM
#3
Rennlist Member
Running with a high oil level probably contributes to rod bearing failure...Cavitation and oil foaming can occur if you run the oil too high in any engine...not a good idea IMHO.
06-10-2012, 08:34 PM
#6
Drifting
The most common area for a Cam Tower / Cam Box gasket leak with old age only ( 15 years +) on the single cam 2.5 & 2.7 L 944 engines is adjacent to oil pressure gallery hole in this gasket which naturally is above No 4 exhaust manifold which is at the other end of the engine.
The Cam Tower/ Cam Box gasket is not subject to oil pressure ( except at the small area described above ), however the Cam Tower / Cam Box gasket is just a thin paper gasket & the two metal surfaces ( top of head & bottom of Cam Tower/Cam Box)must be completely flat , the slightest warpage of one surface will cause a leak with minutes, days or weeks after reassemble, depending on the amount of warpage , plus noting that a warped head will often just get machined at the traditional machining surface ( the head gasket surface ) , leaving the cam box surface still warped slightly or more . ( have seen this quite a few times over the decades)
Next comes the crankcase ventilation over pressurisation when one takes a 944 ( particularly single cam) to a track , this is because the standard (street) ventilation system was only just good enough for normal street work when new , but 26 years later it needs a bit of help .
Remember , once the crankcase ventilation increases dramatically as it does with these on the track , all that one gets is a huge increase in crankcase pressure , this will now put much more strain on all the gaskets / seals / O rings , for example it often pushes the sump gasket out in many places causing leaks & even this Cam Tower / Cam Box gasket on you're engine will be subject to a huge increase of pressure in an outwards direction , so as we know the Cam Tower / Cam Box is absolutely full of oil at high RPM , but now its heavily pressurised with way too much crankcase pressure as well .
We usually double the amount of ventilation to a custom oil catch can mounted up as high as possible
The Cam Tower/ Cam Box gasket is not subject to oil pressure ( except at the small area described above ), however the Cam Tower / Cam Box gasket is just a thin paper gasket & the two metal surfaces ( top of head & bottom of Cam Tower/Cam Box)must be completely flat , the slightest warpage of one surface will cause a leak with minutes, days or weeks after reassemble, depending on the amount of warpage , plus noting that a warped head will often just get machined at the traditional machining surface ( the head gasket surface ) , leaving the cam box surface still warped slightly or more . ( have seen this quite a few times over the decades)
Next comes the crankcase ventilation over pressurisation when one takes a 944 ( particularly single cam) to a track , this is because the standard (street) ventilation system was only just good enough for normal street work when new , but 26 years later it needs a bit of help .
Remember , once the crankcase ventilation increases dramatically as it does with these on the track , all that one gets is a huge increase in crankcase pressure , this will now put much more strain on all the gaskets / seals / O rings , for example it often pushes the sump gasket out in many places causing leaks & even this Cam Tower / Cam Box gasket on you're engine will be subject to a huge increase of pressure in an outwards direction , so as we know the Cam Tower / Cam Box is absolutely full of oil at high RPM , but now its heavily pressurised with way too much crankcase pressure as well .
We usually double the amount of ventilation to a custom oil catch can mounted up as high as possible
06-10-2012, 08:44 PM
#7
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wow! that was awesome, my greatest appriciation for that information. so since this is soon going to be a weekend car, i guess i ll make a catch can and replace the gasket. so final question** should i run oil just above the full line or keep it in the normal operating zone?
