297K miles on original unopened engine ???

[nicfranc]

I recently purchased a 1980 911sc from a friend who was the original owner.
The engine has never been opened and has not had any major work done to it.

It never has had a broken head stud nor does it have a Pop-Off valve.
It has the original chain tensioners as opposed to the pressure fed tensioners.

So my question to you is:
is this car and its engine just an anomaly ?

The car has had regular maintenance for 33 years and has managed to survive without a pop-off valve or pressure fed chain tensioners so why would I add them now ?

Why not just rebuild or replace the existing tensioners and add collar clamps as protection against catastrophic failure ?

I have replaced the CAT with an M&K Pre Muffler and replaced the stock muffler with an M&K single in single out Sport muffler.

The car had the O2 sensor disconnected years ago.

The car starts right up and runs great. It does not burn oil.
I have tuned it up and plan on checking the existing chain tensioners and ramps in the upcoming weeks.

Note:
Carerra pressure fed chain tensioners are $1,214.
Would the Pop off valve introduce possible vacuum leaks as Peter Zimmermman has mentioned in his book.

Your thoughts ?

[mlfox]

If it ain't broke, don't fix it.

[CountD]

..I wouldn't mess with it, other than the tensioners (do check those)...Seriously, leave it be as there is mojo working inside that case and doing anything drastic might release those spirits...and it may unravel.

Post some pics.

[porschetub]

Originally Posted by CountD

..I wouldn't mess with it, other than the tensioners (do check those)...Seriously, leave it be as there is mojo working inside that case and doing anything drastic might release those spirits...and it may unravel.

Post some pics.

Bruce Anderson (RIP legend) talked in Excellance about valve guides failing,or head studs pulling,remember he said they don't all do it and he had seen those motors with HUGE mileage ,so cool this is one,put chain savers on the tentioners and drive it and enjoy,don't touch it.

[lateapex911]

Yea, Bruce loved the SCs. They can really run for miles and likes. (Nice change from the 76s etc.)
Put the tensioners on it, and get some compression numbers as a benchmark.

[Dodge Man]

I have a friend that rode his super cherry 78 SC until it dropped a valve after he spent $3000 removing door dings and getting 8" rims for the rear. The high mileage is cool but valve train components are where the real wear happens. You have a clean numbers car so make sure that you do not ruin the case. It is a defensive strategy but at 297K is it worth a risk? M2CW Research a good shop to do the top end and freshen up the trans (syncros, etc...) if you plan to keep the car long term. Nice buy.

[RWebb]

it IS an anomaly in the sense that not many go that far without being crashed, hot-rodded or just sitting in a garage all the time w/o getting that many miles

I've heard of a few with 400k on them, so it is not a high mark

[nicfranc]

I've heard of a few with 400k on them, so it is not a high mark



400K ! I would sign up for that right now.
I also read that someone had a car with 475 K on the original engine.

I will plan on a total rebuild in the future but in the meantime it runs great
and I love driving it.

[Justin@Athens]

The highest mileage car I have seen on Pelican was a 964 with 521k. The engine had been rebuilt at least twice, with many aux. components replaced 3 or 4 times, and given a 10k repaint. It was in the classifieds either last year, or the year before. Just thought I'd share.

[fbarrett]

Not an anomaly: A friend from the Pacific Northwest put well over 300,000 miles on his SC (bought new) without engine work, and that was at least 20 years ago, so it would have more on it today.

Frank ('65 912, 180,000 mi; '95 MB E320, 197,000 mi)

[Chuck.H]

I have 350k on my unopened 3.2 engine - only 'wear' I know of is the timing chains are stretching and this is letting the tensioner idler pulleys move closer to the engine case. I'm going to try cutting off the chains and spinning in new ones this summer.

Chuck.H
'89 TurboLookTarga, 352k miles