Not sure how far to go?

[mhurwitz]

I’m pulling the motor/trans on my 71 911E mainly to fix the 2nd gear syncro. I’m giving the trans to my mechanic to do. I’ll have him do everything it needs while he’s in there.
My question is what to do with the motor that has 140,000 on it. It’s not a daily driver. I’ve owned the car since 1979 and have driven it about 40,000 miles. It was recently checked out by a mechanic (not my mechanic), for a ppi and he discovered some oil leaks. The good thing is the leak down test was good ….0%-5% on all cylinders. My goal is to fix all the leaks and have a strong safe engine.
I’m I looking a a complete rebuild?
Should I just do the top end?
Should I just fix the oil leaks?
(The mechanic thought that oil was leaking from the flywheel seal, rear pulley seal, both banks, liners and heads and the timing chain housings.
The leaks are very very slow. I may have 1-2 drops of oil in 3 different places after a drive.
Should I replace the chain tensioners (they were replaced in the early 80’s), but I’m guessing there are better ones now?
Just not sure if I should do anything now, or wait until the engine is rebuilt?
As always,
Thanks in advance. I really value the opinions of the people on this forum.
Mark

[911obgyn]

Fix the leaks, clean it up, replace fuel and vacuum lines

[356911930]

Fix the oil leaks and replace the tensioners. The sounds good to go!

Rahl

[porschedude996]

Go all the way if it’s affordable for you. Do everything to seal it properly. Special sealant on case, rocker shaft seals, viton rear crank seal, good valve stem seals, turbo lower valve covers, etc. In 1986 my 1972 911T with 150,000 miles on it, had .0025 cylinder taper (Maximum Tolerance for rebuilding) and I couldn’t afford to replace pistons and cylinders. I drove it daily for 125,000 miles and never a problem. The crankshaft was still within new spec at that time. Typical of horizontal opposed engines with so many main bearings.

[Discseven]

Mark... 140k with the leak levels you indicate suggest the engine has not / is not being beat to pizz. Is likely but not guaranteed that the engine has many miles still to go before the investment in a rebuild is required.

My take is to treat the engine to a reseal, adjust the valves, replace the plugs and ignition wires if they're old, replace distrib cap & rotor, degrease/clean engine to max out it's thermal performance, replace engine mounts and all rubber hoses (oil, air, fuel), replace filters, opening up the chain covers I'd put hydraulic tensioners in if not there already, measure clutch parts (disk, flywheel, pressure plate) and address as called for, replace throw out (clutch release) bearing, clean the CV joints/check bearings & races & boots... I suggest this being standard stuff with the engine down and I assume gear box and engine will be separated. Can surly be a few more things others will add.

Beautiful, clean 911 you roll!

.

[Tremelune]

Take the airbox and intake off and eyeball the engine for where there's grime forming. The Triangle of Death tends to seep, and it just coats the whole engine over time...It's probably worth replacing those seals and gaskets, and "resurfacing" the breather cover with sandpaper on a hard, flat surface (kitchen counter).

[mhurwitz]

Originally Posted by Tremelune

Take the airbox and intake off and eyeball the engine for where there's grime forming. The Triangle of Death tends to seep, and it just coats the whole engine over time...It's probably worth replacing those seals and gaskets, and "resurfacing" the breather cover with sandpaper on a hard, flat surface (kitchen counter).

Thank you Tremelune, I did the Triangle of death a few months ago.

[Trackrash]

It's hard to believe the original valve guides are still good, amazing. But with those leakdown numbers, yeah fix the leaks and drive it. The leaks between the heads and cam housing can be a problem....

The chain tensioners can and should be rebuilt. Not hard and usually works well.

The trans?

[lateapex911]

yea, you're living the good life ! (I used to live in NB in the 90s, loved driving my 911 there, great place for a 911)

If the leakdown numbers are really that good, (Those are REALLY good, regardless of miles!) don't screw with it! Just gaskets and seals while the trans is out and other perishable things, like fuel lines! (Cough, fire cough, ask me how I know!)

tensioners, because why not!? You've gotten the $$$ out of them, and...cheap insurance..
Valve adjust as mentioned, can't hurt.

And keep on doing what you're doing.