rufrob

Hi everyone.

A simple cam seal oil leak repair has turned into a full overhaul. It turns out No1 piston top ring cracked and floated around doubling up and each other thus widening the gap, and scratching the cylinder wall very lightly. And No1 cylinder also has a piece missing for the Nikasil coating right at the edge of the combustion chamber. Some of the other pistons show signs of detonation. And the clearance for the bottom oil ring is really tight. Should I be concerned?
I am on shoestring budget so just want to spend as little as possible.
Do I need all pistons and cylinders or can I just change to some JE pistons?
My mechanic showed me a set of 100mm 3.5 Andial pistons and cylinders. He said they came out of a 3.3l 964 turbo but they wont slide into my 81-911 turbo. If I decide to use them will I need to machine them or my case or should they be able to slide in with some cleave use of heat and cold?
Thanks for all your advice.

Geoffrey

A 3.3 964 engine and your 81 930 engine are fundamentally the same (minor changes). If I were you, I'd install a new 98mm kit and move on.

jwasbury

The cylinder spigot bores in the case must be machined in order to accept those 100mm jugs. That machining operation will require that you split your case, so unless you need to do that anyway, the 100mm P&Cs don't really fit into your shoestring budget concept very well.

rufrob

thanks for the input. I managed to find a set of 3.3s on Ebay and a set of 3.4s here in Japan. The price is double for the 3.4. I will check them out this weekend.

here are some pics:
https://picasaweb.google.com/T3Japan...Pept4Tg88agXw#

rufrob

update. I went with a set of 3.4 pistons and cylinders. I then measured the spring rate on all new valve springs, measured their height and installed them. Today I will install the Pistons and Cylinders. I will have to wait for head gaskets since I didnt know I needed them. Now I have to decide whether to go with SC cams or put the originals in. Most people recommend the SC cams but I noticed in the Porsche specs. book the valve seat heights are slightly different. Is that a problem and how easy is it to time SC cams vs the original turbo cams?
https://picasaweb.google.com/T3Japan...Pept4Tg88agXw#