PreA 1500S registry?

[SplitPersonality]

The hottest Porsche in pre-Carrera times: The 1500S Coupe

How many have survived and is there a registry for such cars?

In terms of Registry-activity it is sort of squeezed between the Split Windows and the Carreras....has anybody reserached these competition Coupes specifically?

[James Davies]

Joining the 356 Registry is your best bet, though their database is far from complete.

I've been researching these cars myself. I count at least 85 coupes and 28 cabriolets existing from my own database, but this list is definitely incomplete. All these were originally delivered with the Type 528 (1500 Super) motor. And of course there were 1500S Speedsters plus the Competition Roadsters, though all of those are accounted for I think.

I'll add that most 1500S cars were not sold to be raced. Many were sold as road-going, high-performance cars. There was the USA de Luxe model of 1953-54 that included all the bells and whistles and a 1500S motor. See this Competition Motors brochure from 1953 or 1954.

The price was $4400 for the USA de Luxe 1500S coupe in 1954. The Speedster that same year was $3000. The USA de Luxe 1500S cabriolet was $4700.

Originally it was Porsche's intention to only include the 528 motor in cars for racing customers. But I suspect when they saw the demand for a higher-powered car in the US, and that people would pay an absurd premium for the more powerful car with more accessories, they decided to put them into series production.

It was not a great idea to put 1500S engines in road cars, as most of these motors had serious problems when used in normal traffic. The 25hp VW cases were being asked to handle 75hp, and those early Hirth crankshafts whipped like a jump rope, not helping matters. There were and are many cracked 528 blocks due to this. The crack occurs at the center main rib generally. Eventually in mid-'53 they put some through bolts through the case to beef it up. And at the end of '53 they switched to the 36hp VW case, which was stronger. But the solution was to build their own crankcase. The 528/2 using the new crankcase was a much stronger engine, and I think it was rare for that case to crack.

The Hirth crankshafts still had issues, but they eventually solved most of those. The Hirth crankshafts on the 1500S engines had rod journals separable from the counter weights, allowing flex. Eventually they moved to a one-piece forging for these parts, and the cranks were much stronger and didn't whip as much. These later cranks were used in the 1600S engines through 1957.

Of course the Hirths still used roller bearings, which was an issue for cars used in normal street driving. Stop-start driving and dropping the clutch wore out the bearings, and once those seized, you had a rod through the side of the case or worse.

It would be interesting to learn more about the development of these engines from an engineering standpoint, from the point of view of Porsche's troubleshooting these motors.