www.QV500.com - Porsche 356 Part 2: 356 (1951 - '54)
 
The first upgrades introduced by Porsche on the 356 came in March 1951 when a 1.3-litre engine was added to the line up. Designated Typ 506, the capacity increase to 1286cc was facilitated by stretching the bore to 80mm (up from 73.5mm) whilst stroke remained unaltered at 64mm. Other interesting enhancements included light alloy cylinder barrels and Mahle pistons, output rising to 44bhp at 4200rpm (4bhp up on the 1100). Compression was dropped to 6.5:1 and although the pair of Solex downdraught carburettors were still 32 PBI's, they were set up slightly differently. Performance was improved, top speed moving up to 85mph, 0-60 requiring 17 seconds.
   

These gains were at some cost to refinement with the Typ 506 engine being a good deal noisier than its smaller capacity counterpart. The very next month (April 1951), Porsche switched from lever type rear shock absorbers to telescopic dampers and also made some minor switchgear alterations along with introducing opening three-quarter windows. Soon afterwards came one of Porsche’s most significant racing results when in June 1951, a hot rod alloy-bodied ‘Gmund’ 356 won the 1100cc class at Le Mans. This cemented the 356’s reputation as a competition car par excellence, the winning car featuring enclosed wheel spats, a tuned 100mph engine, Lockheed hydraulic drum brakes from Ate and tubular shock absorbers. Following the April changes, further developments came six months later in October 1951 when a 1.5-litre roller bearing engine was introduced. Displacement of the new Typ 527 engine was 1488cc thanks to a bore and stroke of 80 x 74mm respectively, the latter being stretched 10mm over the 1.3 Typ 506. This big stroke increase was facilitated by the use of flat top pistons whilst roller bearing rod journals allowed the inclusion of a one-piece connecting rod that saw the engine run a lower oil pressure at a higher rpm than a plain bearing crank engine. Compression was set at 7.0:1 and with bigger downdraught Solex 40 PBIC carburettors, output jumped to 60bhp at 5000rpm, endowing the new flagship 356 with a 92mph top speed and 0-60 time of around 14 seconds.
 
There were three alternative engines for the 1952 model year, the 1.1-litre Typ 369 for which demand was unsurprisingly dwindling, the 1.3-litre Typ 506 and the 1.5-litre Typ 527 roller bearing unit. 1952 saw right-hand drive examples produced in significant numbers for the first time and more changes were on their way that April. New vented wheels were lighter and wider than before whilst louvred alloys were an expensive option and remain exceedingly rare today. Visually there was a one-piece windshield with two plane sections meeting a vertical fold in the centre of the screen. All cars were fitted with fully reclining seats, plastic driver and passenger sun visors, a folding rear seat and had their wooden door inserts replaced by painted trim. More changes followed in June when the grooved bumpers were repositioned away from the body and fitted with black rubber inserts. The spare wheel was also repositioned and the battery moved further back in the storage compartment. September 1952 saw the Typ 527 1.5-litre engine replaced by the Typ 546, this downgraded 1500 motor producing 55bhp at 4400rpm and featuring two Solex 32 PBI downdraught carburettors as used on the 1100 and 1300 units.
   
However, the loss of the 60bhp 1.5 was more than compensated for with the arrival of the new 1500 S with its Typ 528 roller bearing crankshaft engine. Despite retaining the same 1488cc displacement as other 1.5-litre versions, the 1500 S incorporated the larger Solex 40 PBIC carburettors from the now defunct Typ 527. With an 8.2:1 compression it produced 70bhp at 5000rpm. Transmission was via a new Porsche Getrag gearbox with patented split-ring synchromesh. A top speed of around 100mph and 0-60 in 14 seconds made it the most potent production 356 yet. Universal changes were made to every 356 at the same time, the most important of which were new light alloy brake drums fitted as standard. Aesthetic revisions saw more substantial bumpers set even further away from the body, the front indicators being moved to directly underneath the headlamps and twin roundel rear lights introduced. The interior was treated to additional soundproofing and a VDM two-spoke steering wheel. October 1953 saw a roller-bearing engined 1.3 introduced, the 1300 S bowing at the Paris Salon prior to going into production that November for the 1954 model year. Designated Typ 589, displacement was increased to 1290cc (4cc up on the plain bearing Typ 506) by reducing the bore from 80 to 74.5mm and increasing stoke from 64 to 74mm. Thanks also to an increased compression of 8.2:1, output rose to 60bhp at 5500rpm and the 1300 S continued Porsche’s winning ways on road and track.