997 gen 2 cupcar engine/piston failure
04-25-2017, 08:22 AM
#1
3rd Gear
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997 gen 2 cupcar engine/piston failure
Seeking advice here
This weekend piston number 4 of my 2014 997.2 caupcar melted in race conditions and our team are trying to work out why.
I run the Holinger shiftek system which has also been troublesome this weekend and not always downshifting so I have had to over rule it a couple of times via a switch on the steering wheel (could that have caused an over rev). The problem there seems to be the system thinks its on more than 12% throttle when I am off it and that condition only happens after about 15 mins or racing. Any thoughts there please on a fix?
Have people experienced piston melt before like this, I now need a new crank case, head, pistons etc which is an expensive solution. What could have caused this? The valves are still in place more or less although the plug was damaged in the process of course
All feedback and thoughts appreciated on my first post with Rennlist
David
UK member in London
This weekend piston number 4 of my 2014 997.2 caupcar melted in race conditions and our team are trying to work out why.
I run the Holinger shiftek system which has also been troublesome this weekend and not always downshifting so I have had to over rule it a couple of times via a switch on the steering wheel (could that have caused an over rev). The problem there seems to be the system thinks its on more than 12% throttle when I am off it and that condition only happens after about 15 mins or racing. Any thoughts there please on a fix?
Have people experienced piston melt before like this, I now need a new crank case, head, pistons etc which is an expensive solution. What could have caused this? The valves are still in place more or less although the plug was damaged in the process of course
All feedback and thoughts appreciated on my first post with Rennlist
David
UK member in London
04-25-2017, 01:53 PM
#3
If you melted a piston then you had a lean condition which caused the combustion temperatures spike. I don't see how an overrev would cause this. Check with the boys in the Cup forum.
05-01-2017, 11:31 AM
#4
Rennlist Member
Cups switched over to the 991 platform from MY2013 onwards. There is no such thing as a 2014 997.2 Cup... That said, whether you have a 997.2 or a 991.1, they are fundamentally the same non-variocam Mezger engine.
Do you have a picture of your "melted" piston? There are really too many variables here... a failed oil squirter, blocked coolant circuit, faulty injector, trippy ECU... you see there are many paths...
The throttle signal of 12% is interesting. When my Bosch MS3.1 ECU was on its way out, it reported all kinds of implausible throttle levels and it dumped way too much fuel into the cylinders. Better swap into your car a known ECU and test when you've sorted out the mechanicals.
Lastly, as others said, post details incl. pictures on the Cup forum--there are some knowledgeable guys over there.
Do you have a picture of your "melted" piston? There are really too many variables here... a failed oil squirter, blocked coolant circuit, faulty injector, trippy ECU... you see there are many paths...
The throttle signal of 12% is interesting. When my Bosch MS3.1 ECU was on its way out, it reported all kinds of implausible throttle levels and it dumped way too much fuel into the cylinders. Better swap into your car a known ECU and test when you've sorted out the mechanicals.
Lastly, as others said, post details incl. pictures on the Cup forum--there are some knowledgeable guys over there.