Some light holiday reading about early Porsche 8 cylinder engines

Here is something I wrote 4 or so years ago about early Porsche 8 cylinder engines } This is something that I find interesting ( Early Porsche engines ) and in this case 8 Cylinder , a lot of people do not know just how far back 8 cylinder Porsche engines go , most people think of air cooled flat 4 or flat 6 engines , but 8 cylinder ? There were two completely different 8 cylinder Porsche engines that Porsche made from 1960 , one engine type ( the first 8 cylinder engine ) had two important variations , it took all of 1960 & 1961 to get this engine's power up to a competitive level & was ready to race in 1962 The first 8 cylinder engine was the type 753 , it was a 1.5L( 1500cc) flat 8 (2 valve DOHC ) engine designed to go into Porsche's only ever "pure" Formula One car in 1962  ( car type 804 ) , it only raced a few Formula One races in 1962 & it even won the French Formula One race & that was the only time , Porsche withdrew from Formula One to concentrate on sports car racing Whats technically interesting about this 8 cylinder engine was the way it drove its DOHC ( double overhead camshafts ) via bevel drive shafts ( a bit like a 1960's/1970's Ducati motor cycle engine )& similar to Porsche's 4 cylinder Carrera "Fuhrmann " DOHC engines , so this means it was very time consuming to make & to get everything to stay together , everything had to be shimmed to get the correct preloads for the multiple bevel drive gears & their respective bearings & expected preloads & clearances ( cold & hot ), so there was a lay shaft driven by the crankshaft and this layshaft in the crankcase also drive the two ignition distributors & the crane drive ( take off ) for the large top mounted cooling fan , from this intermediate shaft ( centre / top of engine crankcase ) two of the bevel drive shafts went off at 90 degrees to the centre of the cam boxes to drive the inlet cams ( L & R ) with their respective bevel gears . shims / bearings & then from the inlet cams & going off al another 90 degrees , but this time straight down are two more bevel drive shafts going to the exhaust cams with their respective bevel gears / bearings / shims Magnificently complicated , but durable if all the clearances & preloads are massively time consumingly done This above 8 cylinder engine ( one year only raced as a 1.5L ) was modified over the next few years for use in sports car racing & had grown to 2.0L with mechanical fuel injection ( engine type 771 ) & then later as a 2.2 L engine ( engine type 771/1 ) , these 8 cylinder Porsche engines were used in sports car & hill climb & Targa Florio competitions & were very successful in Porsche car Types = 718 , 904 , 906 , 909 , 910 ,  One of the standouts for me is the  1967 Porsche 910/8 Bergspyder , this Porsche ( Hill climb special ) weighed in at 410KG( Total car weight) its 1,981cc 8 cylinder NA engine gave 270HP at 9,000RPM So these beautifully complicated 8 cylinder Porsche engines competed and won numerous sports car / hill climb events from 1962 to 1968 , the last hurrah for this engine was victory in the 1968 Sebring 12 hour & the Targa Florio in a Porsche 907 & then off to the Porsche museum for this engine & the last Porsche engine to use the bevel / shaft drive DOHC In 1968 came the 2nd new 8 cylinder Porsche engine , the 3.0 Litre 908 engine type 300HP to 360HP  in NA form , this was the a simpler chain drive to the DOHC ( much less expensive to make as compared to the type 771 ) and being air oil cooled it was still only 2 valves per cylinder , this engine went on being used in competition right up where this engine was eventually turbo charged ( like its big brother the 12 cylinder 917 engine ) which kept its ability to keep competing in events for years & years , a de tuned version of this 3.0L 8 Cylinder engine was installed into 2 separate Porsche 914's for evaluation purposes .    One 914/8 was built for Porsche's chief technician at the time Ferdinand Piech ( this one was not street registered as the engine was full race trim ), the other 914/8 was given to Dr Ferry Porsche for his 60th Birthday , this was more suitable for road conditions and was fitted with carby's & air-filters and produced 260HP Not surprisingly , in late 1968 Porsche experimented & developed water cooled 4 valve cylinder heads for the 8 cylinder 908 ( 3 litre engine ) , but at this stage in late 1968 Porsche was way too busy with the 12 cylinder 917 race car project , thats because the rules governing engine capacity for racing at ( Le Mans etc ) had changed from 3 liter  to 5 liter capacity & so the development of the 3 liter 908 engine was put on the back burner & the bigger 917 ( 12 cylinder ) engine now took precedence as a possible candidate for outright race wins My favorite 908 variant ( purely on looks & sound ) is the 1969 Porsche 908/02 Spyder , what a stunner Then there was a 928 transmission layout / design & shape link with the above as well , there were two very special Porsche's , one an hill climb experimental race car , the 1968   909 Bergspyder & the other the 1970 Porsche 908/03 Spyder (Targa Florio race car ) , both these race cars had their 8 cylinder engines pushed even further forward , naturally this meant the drivers legs / toes were well over the front axle line with a mid engined layout ( very dangerous but we are talking 1968 & 1969 / 1970 ) , this allowed an even better weight distribution so this meant for the first time Porsche had a new transmission built ( 5 speed with LSD ) where the diff was at the rear of the trans ( gearbox in front of the diff ) , in fact it looks very very similar to the later 928 5 speed manual transmission , even the end plate is extremely similar The above is just a condensed version of events in the history of Porsche 8 cylinder engines , so do not think that Porsche was going against the grain in building the 928 ( 8 cylinder) engine , the 928 was just the logical extension of what Porsche learnt about 8 cylinder engines in the decades before & the liquid cooling was the next logical step in to regards to emissions and mechanical noise control , much like how Porsche's famous racing 6 cylinder engines in the late 1970's had to go with water cooled cylinder heads( 934 & 935 ) & finally in the 962 Le Mans cars etc they received ( mid 1980's ) fully water cooled race engines & the water cooling enabled the use of 4 valves per cylinder because before that ( water cooled heads ) Porsche found in racing 4 valve per cylinder heads that were air cooled just could not cope with the heat ,plus you add emission controls & mechanical noise controls for road cars , hence why all Porsche from 1999 are water cooled The 928 was the beginning of the new era Regards Bruce Buchanan Buchanan Automotive

Bruce, I found this an interesting read: Project 928 (livedsl.nl) Probably better information regarding the development than Brian Long's 928 book.

A few years ago I purchased large coffee table size a book titled } " Porsche 917 Archive Works Catalogue 1968-1975 Edition Porsche Museum " written by Walter Naher , on page 467 there is a full page colour photo taken inside the Weissach Development / race dept ( Circa 1972 ) & the description mentions } The Victorious 917/10-003 from the Can Am back on the shop floor , next to it is the 917/015/035 and a Mercedes 350SL used for testing components in the early stages of development of the Porsche 928 Regards Bruce Buchanan Buchanan Automotive