Why is SC engine often referred to as bulletproof?
 

I bought an 82 SC RoW coupe for use as my daily driver. One of the many reasons I chose an SC is that it's engine is often referred to as "bullet proof".

What is it about that particular engine that warrants that term? Is it truly any more bullet proof than a later 3.2 or 3.6 ?

Because except for the occasional headstud problem it's a keep on running fool....

nope...just better design than the 2.7 however almost all of the pcar engines can be built better with the newer products.

My 1979 911SC had 190K miles on the clock. Was still quick, burned no oil, did not smoke on start-up and was taken to redline, often. No headstud problems, engine was never opened and it ran great! That's my definition of bullet-proof :)

My sc is working with similar results now at 200000k, but I can't believe it. The pesimist in me knows somthing will be broken soon. I take good care of it though.

The 2.7 in stock form gave troubles, so did the 3.2 with terrible valve guides on some engines. The 3.2 also has smaller rod bolts that may give earlier in an over rev situation. The early 3.6 had head to cylinder leakeage problems and the later 3.6 has air injection ports that clogg and get the check engine light to come on, leading to a top end job on fairly low mileage cars ...

So, compared to that stuff, the 3.0, even including head studs looks pretty darn good, once you put a pop off and address the tensioners. Note that the 3.2 has the same head stud problem than the 3.0. The 3.2 is newer and that many studs may have been changed already on the 3.2s, because the heads were off for valve guides! :D

George

With the 3.2, I think the key word here being 'SOME' (rather few) had a premature valve guide failure.

I have 4 pals with 3.2s. 3 of them had their valves redone. A couple of them under 100k miles. I know, 4 isn't a good statistical sample. Maybe the climate here adds to it, compared to sunny southern Sweden. ;) It is definitely not a few. I'd say 50% from what I see at my club. I don't know anyone with a 3.2 that has 200k with the top end untouched. I know a few SC owners that do have such cars.

George

Wow! That sounds ominous - to say the least. I would for sure trust your experience more than my own info solely based on what I have read in Porsche magazines and previously on this forum.

Is it at least close to the truth that those that did have valve guide issues seem to have turned up at rather short mileage - say already at 60-80k ? I think I read somewhere that there were a subgroup of engines that failed early, the rest being more or less SC quality in that department.

Inquiring since mine got almost 90k.. ;)

I have an SC with over 200k with an untouched top end "used and dirty, but running strong :)" - must be time to fit a turbo to that lump :D
http://forums.pelicanparts.com/uploa...1150792486.jpg

Thats a beautiful behind alright, Pål! SmileWavy

Not as nice as some of the engines I have seen on this site. I have decided that I will resist from removing and painting the engine and engine bay until the engine needs work, and then I will do all the usual "whilst you are in there" stuff as well :) I had been thinking about a 3.6 transplant, but I have been told that you get into lots of problems here in Sweden with the insurance and Vägverket when you do. Therefore I was thinking I would make more "not so visible" changes :)

Well except for failed head studs, blown airboxes and usual CIS problems it's quite reliable.

Frankly, I believe 930 engine is just a reliable (no exploded airboxes) if owners could stop fiddling with boost.

just keep in mind that like any engine, it needs to be taken care of.

I had to ditch a suppossely rebuilt engine last month because the PO has let the engine get so bad due to lack of "care" that the oil lines to the cam got clogged up with crud and the cam was toast and there was alo likely bottom end damage.

I'll let you know after another 100,000 miles or so. At 4,000 miles per year, that will be in 25 years. I have 123,000 on the engine now, I replaced all the lower dlivar headstuds with steel ones at 107, 000 miles. No machining was done, not even new rings, just new gaskets and put it back together. Cost $300 in parts, I did the work. Engine runs great with no issues.

Bulletproof (except for dilivar headstuds), time will tell.

At just over 100,000 miles I took apart my SC engine to replace the lower head studs with steel studs.
I found no measurable wear or damage, nada zip zilch.
The ring gaps were still within spec but I replaced the rings just because I had already bought a new set.
The valve guides, valves, and heads were in great shape and did not require any re-work.
I'd say that's bulletproof.
BTW, at the time I took it apart it had 2 years of running with a turbo on it so that confirmed that there was no damage due to boost.

190K miles, no valve guides issues, no head stud issues here. http://forums.pelicanparts.com/uploa...1150815230.jpg

Time to stand up for the 3.2.
How come everyone is saying the 3.0 is bullet proof after you do the 3.2 upgrades?
Come on. The 3.2 is what the 3.0 evolved into.
The 3.2 is everything the 3.0 wanted to be.
More of everything.
I'm 285,000 km and never opened.
Had to be said.

Another way to look at "bullet proof" is design development and for what reason. The 3.0 is the result of years of development since it is an evolution of the original 2.0L.
Porsche had plans to have a turbo car and they did not want to make a different engine for the turbo and none turbo cars so the case/ lower end on the 3.0 is very under stressed since it was designed for the HP of the turbo motor.
The 3.6 is a new design so there will be teething problems in the first years just like the 2.0L
The 3.2 is a stroked version of the 3.0 besides the longer distance the piston travels and the added stress that creates, smaller rod bolts were used in the 3.2 for clearance reason.
So the 3.0l is a sweet spot in Porsche air cooled engines.
The engine can be made even more trouble free with later development features such as the final evolution chain tensioner used on the Carrera. :rolleyes:

So they decided to make the lower end of the 3.2 weaker than the 3.0?
1 step forward, 2 steps back.
I can't see Porsche doing that.

Stop fiddling with the boost? come on where is the fun in that :) If we didnt have something to fiddle with we wouldn't have anything to do to the car other than drive it and look at it! LOL

Rod, Please do not misunderstand me, the 3.2 is a great engine and has design features that are better than the 3.0 like the aforementioned tensiners but when over spun the stock 3.2 rods will fail before the 3.0. Wayne Dempsey address this in his "How to rebuild 911 engine " book and Bruce Anderson discuses this in his book "Porsche 911 Performance Handbook" and if you ever talk to people who maintain these engines for racing they will tell you for high revving safety Porsche rod bolts are usally substitute with an after market fastener like an"ARP" product in the 3.2's. If you obey the red line the 3.2 will last fine, but the stock 3.0 can take more abuse in this department so it is more "bullet Proof" I belive this is a common undersatnding

I guess I'm just a little over protectve.
When I do a rebuilt can I make this improvement?

Yes you can upgrade to ARP rod bolts and head studs.

SmileWavy
Good stance, 911 Rod! I can't see Porsche doin' that either! My '86 Carrera doesn't have many miles on it (54K), but I'm adding to the total quickly enough, so we'll see eventually how well things go. That's assuming plenty of sunshine here in western Washington, of course! :D
I don't baby my Porsche, but then I don't try to see just how bullet proof it might be, either. Fast is fast is great stuff, tickets and accidents are something else entirely.
Targa! :cool:

Like the comment I read recently, "Do you know why I pulled you over?" :rolleyes: http://forums.pelicanparts.com/uploa...1150820068.jpg

163,000 miles+ on my 1987 Carrera 3.2 and the motor has never been touched.

I don't see how some of the earlier posters can dismiss blown up air boxes, broken head studs (that are apparently common on the SC), and the need to update chain tensioners to avoid a catastrophic piston into valve engine failure on the 3.0, yet focus in on some 3.2's that had early (under 80,000 miles) valve guide wear issues and rod bolts that may fail IF the motor is overreved. That makes for a pretty weak argument.

In the context of flat 6 Porsche motors, both the 3.0 and the 3.2 have proven to be remarkably reliable thus far. Perhaps if I owned the model that yields less horsepower, less torque, and is less fuel efficient I would better understand your argument.

Mike

FWIW, I honestly do not favor Carrera 3.2's over SC's at all. I would trade my Carrera 3.2 away for an SC in better condition in a New York minute. They are virtually identical cars with only subtle differences from one year to the next. In fact, the more I learn about the various vintages of air cooled 911's, the more I realize that ANY 911 (long hood, mid-year, SC/Carrera) can be sublime!

In the end they are all "our children".

Few more pointers:

The later 3.0 does not "need" the oil fed tensioner upgrade, as it already has the wider idler arms, with the bronze bushing, which took care of 90% of all chain tensioning problems.

The 3.2 has the SAME studs than the 3.0, they will start breaking and already are.

All mods to the 3.0 - minus the head studs - are external. Can't say that about 2.7 fixes, or 3.6 fixes, or even 3.2 valve guides.

George

I don't think mine is bulletproof. 123k and it needs a top end rebuild ... well, at least it is showing signs of valve guide wear and it uses 1.5qts of oil every 600 miles. Getting compression and leakdown tests done today.

The car was meticulously cared for by all POs based on the appearance and the paperwork. But I guess someone could have dogged it out.

I see bulletproof as a 200k mile engine ... there are TONS of engines that last to 150k (my dad's Jeep Cherokee for example).

Just my opinion ... don't get all mad at me ... my expectations are probably too high.

Well...as long as we're quoting personal examples

Recently retired 1990 Eagle Talon 2.0L ( aka "Mitsu" Eclipse).... 217,000 miles

Still active and strong 1993 Toyota Corolla 1.8L.... 245,000 miles ( and going !)

1994 Geo Prizm 1.6L..... 196,000 miles

...you can bet these "winter boots" don't get the TLC my 911 does !!!

- Wil

Your envy is starting to show, George.

185k, untouched, and rolling daily.

Wow....bad Karma. I just got a call from my wrench telling me that they found a broken head stud on my '80 SC with 109K.

DE schedule is now pushed back.....again.

I hope I do not fall victim to the "while I'm in there disease".

I hope I do not fall victim to the "while I'm in there disease". [/B][/QUOTE]

Disease or blessing in disguise?

It's certainly not the 3.2 I lust after, as my 3.0 does everything just as well. A 3.6 is a different story, I'd even pull the heads and flush out those air passes, before I drop it into my SC. ;)

George

When I had asked 3.2 owners with failed rod bolts to identify themselves I don't believe one did.

So, while they MAY fail under very extreme conditions I still don't think it's at all common.

Feel free to prove otherwise.

Maybe it's time for a poll.
One for engine failures,
and one for who is being honest.

:D

Just add a footnote to your poll page....

"* You must tell the truth to the best of your ability"

That should do it. ;)

I heard the 3.0 got the bulletproof rep because the fools that shot them didn't know where the engine was and only harmed the spare and the battery

In all fairness, the 3.0 also got the rep in comparison to the 2.7 and before the head studs started snapping. :D

George

I agree! I'm certainly banking on this, after a painstaking rebuild! I've already gotten grief about running a conservative .8 BAR spring instead of 1.0 or 1.2 BAR!

Sorry, I got off topic...