2.7L Questions..

[yarin]

I've heard the 2.7L is the least desireable of the air cooled 6s. What do you guys have to say?

I'm toying with the idea of looking at a car with a 2.7L 6banger. So far all I know is that the motor has high compression JE P&Cs, eletromotive crankfire, G40 cams, race springs and retainers. Run on street gas.

Any comments? Good bad? Do these motors need to be rebuilt often? What are the major concerns? Any years to avoid? Factory design issues that could be solved during a rebuild? What kind of power can I expect out of it? (stock vs. modified)

I need a general list of questions to ask the seller and i'm not that familiar with these motors...

Thanks

[yarin]

I found this info on pelican:

Q4. So, what's all these problems I keep hearing about the 2.7 liter
911s?

A. It's a tragic story. Porsche increased the displacement of the
2.4 without providing enough cooling and, to add insult to injury,
the US models had thermal reactors (except for 1974) that got
REALLY hot. The result is, among other things, head studs that
pulled out of the crank case (due to thermal expansion of the
cylinders) and destroyed valve trains. All of this resulted in an
average engine life of about 50,000 miles (your mileage may vary --
HA! I was *waiting* to use that line).

So the natural follow-on question (so natural, in fact, that I'm not
breaking it out into its own question) is "can anything be done to
mitigate the design flaws of the 2.7?" The answer is:

- Have the case helicoiled or timeserted. These threaded inserts are installed in the crank case to hold the cylinder studs tightly and keep them from pulling.

- Use Dilivar or Raceware studs. These studs won't pull out because they expand with temperature at the same rate as the cylendars.

- Replace the 5-blade fan with an 11-blade fan.

- Add an extra oil cooler.

[Walter_Middie]

Yarin,

The 2.7 is a great engine - but a few things need to be done to ensure longevity. These engines are know for pulling the studs out of the magnesium blocks - particularly the head studs. As the engine heats and cools, expands and contracts, the studs can pull. What you need to know about any 2.7 that you are looking at is whether the block has been properly rebuilt with inserts to help hold the studs in place - that and the addition of an external oil cooler.

These engines have a bad reputation, and that can work in your favor when buying one, and work against you when it comes time to sell. Porsche's don't usually make good investments, so if you are just buying to drive and enjoy, you can get a great deal on a car with the correct upgrades. I love mine.

[dweymer]

I would ask for info on any machine work done during the rebuild. The set up you mention is not cheap.

Look for oil bypass mod, larger oil pump(sc, carrera, turbo), timecerts, helicoils, line bore. These are all good things to see on a rebuild.

[RoninLB]

i imagine a GE 40 is more peaky than an old s cam?

A 2.7 must be machined, rebuilt, and up-graded imo.

[2.7RACER]

All the bad news about 2.7's is old news. '75 to '77's are now how old? If this engine hasn't been upgraded in 30 years of operation what would lead you to believe a major failure is just around the corner?
Check it out just as you would any other old Porsche, compression, oil leaks, transaxle, etc.
My '76 has been a track car for the last ten years. In it's present configuration it'll run with SC's and Carrera's all day. No auxilary oil cooler, just the original on the motor.
Time serts were installed before I got the car along with Carrera tensioners and a 11 blade fan. Never saw the thermal reactors.
There isn't any reason if the car checks out to expect any more problems than with any other old 911.

[70SWT]

Originally posted by 2.7RACER
All the bad news about 2.7's is old news. '75 to '77's are now how old? If this engine hasn't been upgraded in 30 years of operation what would lead you to believe a major failure is just around the corner?

Damn well said. How many other cars from 1974-1977 are stilll running at all right now? Statistically, how bad could any of these cars be, right now in 2007, if bought in a reasonable running state and for relatively cheap?

If it seems OK, buy it and drive it like you stole it.

[GrantG]

The 2.7 (modified & rebuit) in my car is by far the best motor in any car I've ever owned (includes 6 Porsches and several other makes)...

Sounds like the 2.7 you're looking at is updated and modified too. If done well, it should be a sweetheart!

[kach22i]

Originally posted by yarin
So far all I know is that the motor has high compression JE P&Cs, eletromotive crankfire, G40 cams, race springs and retainers.

Sweet, all it needs is carb's in lieu of the CIS and it's perfect.

[yarin]

Thanks for all the info guys...

after a really great day autocrossing my megasquirted 4-banger I decided to hang onto it for a while. my car is setup really well as it is, i just can't sell it right now. plus all the maintinance is cheaper for a /4.

i'll have to wait for some power..