more info on my questions about the 3.0L mod
First, I want to thank Wayne for the quick response and the wonderful book. I rebuit a 911n engine in the 1980s and it was a bear without Wayne's book, even with a brother who is a Porsche mechanic and my adviser. It is a huge undertaking for a backyarder like me and a gamble since if you screw it up, you could be looking at an $8 grand loss. I think Wayne's book will be the catalyst for many more attempts. The Porsche shops won't like Wayne for this. Also must thank him for this Forum where people like us who the world thinks is nuts can communicate.
My car is a street car and maybe will see some PCA track events. It is a 1977 911 with an '82 SC motor. In my state it qualifies as a "historic car" and thus is exempt from all mechanical isnpections and smog tests. That gets my imagination whirling.
Some questions I have about the modifications:
1)I would use the JE 95mm pistons. Their website isn't helpful at getting info on them, but I assume that a simple phone call would do. How about cylinders? My guess is that I would tear down my engine and then inspect the ones in there. If they are alusil, then I scrap them and find a new set. If they are nikasil, I mic them and if they are within spec, I can use those. Do I have those contingencies right? If I have to replace the cylinders, are they hard to come by without buying the pistons with them?
2) Compresion ratio-- Wayne's book has it at 10:1 which is pushing the limit of street gas and avoidance of a dual plug ignition which would add $2500 to the project. But Wayne's 10:1 is only his best estimate. Machining of the case, etc. can change that. I am thinking if I can measure the CR in a dry assembly, I can then set the CR at a tolerable level by changing the copper gaskets between the cylinder and the case. Am I thinking down the right road here?
3) The S Cams. Do I regrind my SC cams to S specs or get early S cams? Am I right to think that I can't use the early S cams because they will have 3 bearings whereas my cam housing will have 4? The picture in Wayne's book on pg. 64 seems to show that I could use the early cam which would ride on 3 of the 4 bearing journals. Not sure about this issue.
4) distributor issues. Do I simply ship my distributor out to a reputable shop to be re-curved? How do they know what to do with it, since my engine is not stock and will be sitting on my engine stand in my garage?
5) estimated ball park cost: If I squirrel away $10 grand (my wife will love that!), can I cover the costs? The carbs and manifold add about $3K from Wayne's $8k estimate, but his estimate has a lot of case work that you need for a 2.7L which I avoid because I have the 3.0L aluminum case. Am I in the ball park here?
Sorry for the lengthy reply, but you have to get the planning right at the beginning or you will have headaches down the road.
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77 911, 3.0L
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