How to make the most of a Porsche 911 SC

Photograph Courtesy Porsche

[Editor's Note: This article originally appeared in the March 2018 issue of Classic Motorsports.]

The Porsche 911 SC added fender flares and an aluminum-case, 3.0-liter engine to the standard 911 package. Stoddard Authentic Parts caters to this model as well as the rest of the Porsche lineup.

Expert: Per Schroeder

Stoddard Authentic Parts

The 1978–’83 911 SC is somewhat of an in-betweener: better than the early cars, but without the torque or small refinements of the Carreras.

Make sure the car is in good running condition before you go off half-cocked and get crazy with the performance stuff. These cars have had three or more decades’ worth of previous owners who may have made them worse.

There are several very good short-shift mechanisms on the market that will help the 911 SC’s 915 gearbox shift better. The 915 feels more modern than the previous 901 box, but there are still plenty of improvements to be had.

The 911 has a reputation for trailing-throttle oversteer. This can be tuned out somewhat with a larger front anti-roll bar and adjustable shock absorbers, but there’s still a lot of weight behind the rear wheels. Physics will eventually leave its mark.

A proper pre-purchase inspection will include pulling the valve covers and inspecting for broken head studs. By now, most cars will come with either a few pulled studs or (hopefully) receipts for fixing them. Even the later Dilivar studs can break or pull out of the case. When replacing them, source new pieces from ARP or Raceware. You can also use the latest Porsche 993 parts supersession.

Porsche started fully galvanizing the cars by the mid-1970s, but the potential for rust still exists. Look at the bottom rear of the doorjamb as well as the rocker and torsion housing. You can also find it at the tops of the front fenders and around the rear window.

The pedal cluster, one of the iconic throwbacks of the air-cooled 911, is a bottom-hinged affair that would seem more at home in an old VW. Rebuilding the cluster is a must for most high-mileage cars. A leaking windshield seal can leave a rusty mess here, too.

There are plenty of replacement rubber seals and weatherstripping options available for 911 SCs in both reproduction and Porsche OE form, but hard trim pieces are typically only available from Porsche.

Right now, the best replacement fenders for the 911 are from the factory. The aftermarket pieces have some fit issues. However, these cars were finished with leading from the factory, so even a Porsche fender will require some work to ensure proper panel gaps.

Dropping the engine in an air-cooled 911 isn’t that difficult. Jack up the rear of the car and set it on tall jack stands under the torsion bar housings. Use an ATV jack to support the engine properly and lower it out of the car. You can gain clearance by removing the rear valance panel so that the top of the airbox clears on the way out.

A small, one-way pop-off valve is a common modification for the CIS fuel injection’s airbox. Otherwise, small intake backfires can crack the expensive plastic air filter housing.

The SCs had the last of the non-oil-pressure-fed timing chain tensioners. You can either update to the Carrera-style tensioners and oil feed lines or use the last supersession of the non-pressure-fed tensioners. If you choose the latter, don’t forget a pair of inexpensive locking collars to prevent total collapse. Both paths have their pluses and minuses–the pressure-fed versions can fail, too, contrary to widespread belief.

Most 911 SCs should have had their rubber-centered clutches replaced with more typical spring-type units. The rubber-centered versions can fail and cause collateral damage. Check, and replace if necessary.

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