1977 911


I like Porsches. All Porsches. We've had 9 including 2 912, 2 Boxster, and 2 911. I found the following opportunity interesting.

The shop working on my 912 restoration project has a green 1977 911 that is for sale - as you can see the picture. The car is dirty as it has been sitting in the back lot for a while.
020708-1301 1977 was an interesting year for the 911. It was the first year of fully galvanized sheet metal and the last year for the 2.7 liter engines with the infamous magnesium case. The former has increased the resistance for rust to the point that very good examples are available. The latter almost destroyed Porsche's reputation as a reliable automobile. It is not uncommon for rebuilds of these engines to be required at 60 K mile intervals. Good body, bad engine. Starting in 1978 with the 3.0 liter engines, reliability and reputation was restored. There are example of the 3.0 liter engine that have gone more than 400K without a tear down. YMMV.
020708-1302 This green car has 190 K miles on the car and still has the original engine. The engine can actually be detuned enough to pass smog, although it is clearly getting tired and may die a catastrophic death if pushed hard. The rest of the car is in quite good shape and may even be turned into show car shape with out too much work. Much of the paint is original. There is a spot on the hood that needs to be spot painted, There are some places on the original paint that are getting a bit thin. The car is straight. The wheels have been reconditioned. The suspension has been looked after with many new parts.

For Sale

Here is the interesting part. They are asking $8.5K and will absolutely take less -there have been no takers at that price. The combination of tired original 2.7 engine and bright green color puts most buyers off. I actually like the color and would not hesitate.

A show car does not need much of an engine. I could imagine buying this, cleaning it all up - turning it into a garage queen and have significantly less invested than nearly any comparable 912. Clean it up the first year. Show it the second year. Mean while track down a 3.0 liter engine and rebuild it. Install the new 3.0 liter engine in year 3 and end up with a flat out gorgeous (although bright green) result that will turn heads that you can drive anywhere and could last for another 10-20 years depending on how much it is driven.

What is it worth?

Excellence suggests the '77 values:

 Poor 7859
 Good 8936
 Excellent 11963

The '78 was the first year with the 3.0 liter engine. Look at the jump in values:

 Poor 12031
 Good 13679
 Excellent 18313


 Curb Weight 2630 lb
 Displacement 2.7 l
 HP 157 SAE net
 0-100 KPH 7.8 sec
 Top Speed 134 mph
 Milage 24 mpg

Common Applicable Problem Areas

Of the top 15 problems found on early 911, the following might be applicable to a '77 911S.

  • Throttle linkage damper failures
  • Pulse type electric fuel pumps
  • Electrical grounds and connectors (early '77)
  • Chain Tensioners
  • Clutch designs and actuation systems (all years)
  • CIS air box breakage from backfires
  • CIS fuel pump relay failures
  • CIS warm-up regulators
  • Fuel system check valve failures

2.7 Engines

The 2.7 liter 911 engine was in the 'middle' years 1974-1977. These were not good years for 911 sales. There were only 23K Coupes built.

These were CIS (continuous injection system) fuel ingection cars which was the standard until the DME engines appeared in 1984.

Chain tensioner failure was common in 911 engines from 1966-84. The chain drives the camshafts, one on each side of the engine. Expansion is considerable between hot and hold conditions. The chain must hold tension over a wide range of rpm and temperature. The original tensioners had an internal oil cushioned piston which had a tendency to go soft which would cause slack in the chain causing a rattle below 3000 rpm. At worse the chain could come loose causing extensive valve and piston damage. In 1984, the factory introduced an oil fed tensioner which used pressurized oil off the main oil supply. This system could be retrofitted to the earlier cars except those that drove an air pump off the left rear camshaft.

Emission control was a problem and California cars from 1977-78 used a solution involving thermal reactors and an air pump. The thermal reactors are part of an EGR (exhaust gas recirculation) system which was designed to reduce the combustion temperature. They are now very difficult to find, but are required to pass the emission tests. They generate a lot of heat and are often removed. 1977 was a low point on emission controls. Some of these cars have been back dated to 1974 heat exchangers and a dual inlet muffler for some power gain and significantly cooler running.

All 1977 cars had the California emission controls.

The 1974 to 1977 cars had magnesium crank cases and aluminum heads. The thermal expansion caused the studs to pull out of the cases. Porsche designed special Dilavar studs to improve this problem. These were used on the 1977 engines with improvements in engine life.

This 1977 car has working thermal reactors.


The 915 transmission was used from 1972 through 1986. Shifting could occasionally become balky.

5 speed was standard in 1977.

Galvanized Metal Panels

Europe received galvanized bodies in 1976, but the U.S. cars did not recieve them until the mid 1977 time period.

The non-galvanized bodies often had grounding problems in their electrical system as well as general connectors due to corrosion. More and more relays were added during the '70s to help compensate for the large distances between the battery, switches and various components.

Miscelaneous Improvements in 1977

  • Door locks were modified by removing the door button.
  • More sound proofing.
  • Better carpeting.
  • Improved spring plates allowing easier ride height adjustments.
  • Some cars had cruise control.
  • Some cars had thermostatically controlled heaters.
Last modified: Mon, 08 Jul 2002


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