I have a question after a bit of a long story... I bought a 1972 911T that was embroiled in a mechanic's lien situation, and had been sitting for about 18 years. When I found the car, it was outside and had no intake on then engine. It had been raining that day, and I noted that some water had been dripping into the intake ports. I stuck my finger into a port and found dirt and tree droppings inside. So, I figured that this was an engine that was hopeless as it was. I finally got the title to the car and had it flat-bedded home.
In the meantime, I bought another 1972 911T engine, complete with MFI, from a long-distance member of this forum (and the 356 registry too). The seller told me the engine had very good provenance and was "running sweet".
At this point, I have to say something... The Porsche community has been one in which I have been ripped off about 90% of the time. I'm a trusting type and , I guess, there are a lot of people out there who would rather get as much money from anyone at any cost. Zero integrity.
As you may have guessed, the "sweet running" engine has leakdown figures of under 10% on cylinders 1-4, a bit higher on cylinder 6, and 40% on cylinder 5. Long story short: This engine is no good. It basically has a dead cylinder and very little power. I know it was rebuilt, but has either a burnt or bent valve, or a broken ring. Oh well. Why am I not surprised. Why my ex-mechanic bothered to install this engine at all is a question I ask myself daily. That mechanic was German Auto Service of Jessup Maryland. He charged me through the nose to install a a crappy engine, put in a 914 fuel pump (I had to go buy another correct MFI electric fuel pump), charged to swap clutches, clean the fuel tank, and many other things, all of which he never did. I removed the fuel tank he had "cleaned" and it weighed about 50 pounds--all sludge. He never even removed the level sender. I know for a fact because when I tried to look inside for my self, the screws securing the sender were seized and snapped. Now, I have a solid and straight but limping 1972 911T sitting in my garage leaking oil, and the original engine dismantled and on an engine stand being rebuilt.
On to my question (finally), regarding the original engine (the one that had dirt and water in the intakes). I dismantled this engine, and it actually came apart quite easily, The PO had converted this engine to Webers, so the heads were plugged. I was pleasantly surprised to find that this engine had been rebuilt with 2.4 911S pistons and cylinders. The cylinders, particularly number 4 and 5 had a layer of rusty colored sludge (dirt and debris) on the bottom inside surface outside of the pistons. Question one: Can dirty S Nikasil cylinders be honed by a machine shop to clean them for reuse?
The heads are currently out being rebuilt by a pro. I have a new set of 911E cams. I have a choice of 2.2 911E pistons and cylinders, a second set of 2.4 911S pistons and cylinders, and the dirty 2.4 911S pistons and cylinders. I have a new set of Goetz piston rings to use on whatever pistons I go with. I also have a complete and good 2.2 911E MFI setup I want to use instead of the Webers.
Now, the main question... I split the case and found it surprisingly clean inside. I know for sure it as rebuilt because of the 911S P/Cs, and I know the engine can't have been run much because it sat since 1989. I am going to bring the case to a local machine shop to clean it up, verify tolerances, and ensure the mating surfaces are straight, and install case savers. The main bearings are STD with a date code of 5-82. The crank looks perfect to me. I see no scoring or pitting anywhere. Because I have been so ripped off and so bled of money by the extra engine seller and by German Auto Service, I want to spend as little as possible and come out with a strong and reliable engine. I'm wondering if it is absolutely necessary to remove the connecting rods, have them resized, have the crank micropolished, renew bearings, etc.? Obviously, I have to renew all of the gaskets and seals, I know.
My hope is to be able to not disturb the crank and rods setup, install all new seals and chains, re-mate the case halves, install a set of pistons and cylinders, install the rebuilt heads and E cams, and be done with it. Does this sound OK? Would it be false economy to neglect the crank and rods that have been sitting for almost two decades but not run much since the previous rebuild?
Finally, considering the price of gas today, would the use of the higher compression 2.2 E pistons be worthwhile over the lower compression 2.4 S pistons? I mean, with the S pistons, I could run any gas, I guess.
Thanks for reading this far. It's a long story and a lot of words, but I need some good advice, and appreciate it in advance. Thanks...