A 24h winner is the heart of your 718
Did you know that the very heart of the WEC-reigning Porsche 919 Hybrid also powers the new entry-level 718?
As you can obviously guess from the name of this tribe I am quite attracted to amazing engineering. That is why I was no big friend of the fact that Porsche would dump the wonderful flat six in their small Boxsters and Caymans.
If you ever had the chance to drive one of those massive machines in those tiny cars, you’ll understand. So much of the driving pleasure came directly from behind your ears. The growling, the punch, the torque – and even the surprisingly low fuel consumption – those S, GTS and of course the GT4 and Spyder Models were absolut peaches.
The change to the smaller flat-four units was inevitable though. Political as well as strategic: those 3.8 liter 981s came to close to the mighty 911, some even said, that they were the better driving machines.
Porsche did the best they could: changing the name of their entry-level cars to 718. The famous racecar of the late 50s and early 60s featured a wonderful, yet extremely complex 4-cam flat-four, should be the best advert that a four pot could be sexy.
Marketingwise this was a very clever move, because no one could hate on a 718 - they simply are the most pretty Porsches ever and bathe in the heritage of very successful racing.
So, where does this leave us now? A bit uninterested if I’m honest. Why bothering with a marketing trick, when you could get the “full-fat” flat sixes in the classifieds – see what I mean?
But then came the day, when Porsche invited me to a test day of their 919 Hybrid LMP1 racer. If you are only the slightest bit in to engineering, machining, lightweight materials and of course racing, then those Le Mans racecars of the modern era are just eye-wateringly spectacular. Compare them to the Turbo-F1 from today and you’ll have a very good laugh.
Things got really interesting, when they lifted the bonnet and I could catch a glimpse on the engine. The offset of the cylinder banks just seemed a bit too big for a conventional V4. The press release also noted that the 919 features the same cylinder distance as the 718 Boxster engine – would there be the chance, that those to machines are closer together, than we would have thought?
No. It’s not a “Boxer”-engine, but a 90 degree-V4. The press release did not leave any room for speculation. But on the other hand: same cylinder distance, same injectors, same stroke? Then there were the vibration issues they had, when the 919 first came out in 2014. They had to change the firing order to sort things out and prevent the rear chassis subframe from falling apart due to the heavy shaking.
Thing is, a V4 does not leave many room for changes in firing order. You have either a 360° crank or a 180° crank. You may know them as the “big bang” or the “screamer” if you are a bit into motorcycles. The 360° crank could have been an interesting choice for an endurance racer, as it gives the tyre some time to breathe between the power strokes, but it definitely would add vibrations.
That was what I asked the press department in Stuttgart: whether they tried the 360° crank and changed that to the more familiar 180° one. As it was clear that the would not answer this one directly I asked some more questions and wrote some generally admiring things of the 919. The reply came fast and it took him several lectures on engine construction as well, said the press guy. Since he still was not a hundred percent sure which crank their Motorsport department in Weissach was really using, he promised me to ask them directly.
Then, the unbelievable happened: I got a reply from Alex Hitzinger, the technical director of the LMP1 project. It is a flat-four crank with a cylinder angle of 90°.
The 718 Boxster features the exact same crankshaft as the 919 Hybrid.
Time to explore this new small engine a little deeper. Thanks to Porsche they agreed and lent me one for some thorough inspection. It was a Boxster S with the 2.5 litre-unit mated to the 7-speed PDK gearbox. I drove him over 3000km through the south of Europe and will explain him next week here on DRIVETRIBE.