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What would be the purpose of installing an O-ring where Porsche deemed it not necessary? I'm sure they took the slight internal pump leak into consideration, so maybe installing the O-ring (if possible) could raise oil pressure more than optimal? Not that the engineers always get things right, but with so many years of development on this 9A1 engine, I'd guess that's not an issue at all. But yes, I've seen car manufacturers skimp on pennies before, so always possible. Will be following this thread out of engineering curiosity;).
 

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Interesting article in 911 & Porsche World (May 2017 issue) regarding bore scoring in MA1 engines. The reporter outlined the analysis done by Barry Hart, the boss of Hartech who are the main Porsche engine rebuild specialists in the UK. Barry believes, based on an admittedly small sample of failed engines, that inbuilt stresses in the crankcase halves microscopically squeeze the bores in a vertical axis and reduce piston clearances. This only causes a problem if people push the car too hard before it is fully warmed up - the pistons warm up faster than the bores, the clearance reduces to zero and there is scoring on both the bore and piston.

I would emphasise that this is not a significant problem - we are talking about a very small number of engines - but it is the first report I have read that suggests that the MA1 engine is not totally bombproof. The moral, as if we didn't know already, is to make sure the oil is fully up to operating temperature before working the car at all hard.
 

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I'm sorry if I have missed that. I did try to use search but had no luck.
Was this procedure posted on this forum?
V6 has been off the forum for some time. I believe he was having some health issues. I tried to contact him a few months back and got no response. Hoping for the best, but the silence isn't a great sign. He was a frequent contributor.
 

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Oh, I'm sorry to hear that. I hope he is doing alright. His contributions are indeed very thorough.
Thank you for your response. Would you care to explain more about Cobb Stage 1 tune? We can move to another thread since this is not strictly topic related.
 

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Would you care to explain more about Cobb Stage 1 tune? We can move to another thread since this is not strictly topic related.
Sure. Fire one up and I'll chime in based on my experiences.
 

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Thank you. I will send you a private message so this thread can follow the original topic.
 
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