Type 170 revisited

Does this look like a stationary engine or a boat motor to you? Despite common belief it seems as the supercharged type 170 was a stationary engine for high altitude rather than a Sturmboot motor.

Before continuing with Porsches post war development I want to go back in time to 1943 as new information has came to my attention.

A consultant at my workplace, and fellow vintage Porsche fan, did hand me a book a week ago. It was "Driving in its purest form" by Conradt. He had found an interview with Ferry Porsche from 1989 in the book that he wanted me to see.

In the interview Ferry mentions a project for a stationary engine for high altitude using a Roots compressor to compensate for the power loss due to the low air pressure. He also mentions that such an engine later was installed in his private kdf cabrio (as pictured in the "origin of the species" book by Ludwigsen).

As I see it, it's clearly the type 170 Ferry refers to. It all makes sense: The weight was too high for a Sturmboot application and the engine canopy (as seen above) did make it feel like a stationary engine.

Part of the document in which type 170 is (faulty?) categorized as a Sturmboot motor

If all this is true the 170 was not part of the Sturmboot program, despite what it's said on the typewrited copies I got (that originates from the Porsche archives). Or, could it be so that the first version, with the supercharger on top, was for the Sturmboot program? Perhaps when they realized it was too heavy they reused it for the high-altitude stationary motor request.

It's all goes to show that there are still things to discover in the early history of VW/kdf/Porsche engines and if something seems a bit strange you are probably missing a piece of the puzzle.

The 356 engine development, part 1 - introduction

The 34 hp 1131 cc Porsche type 366 engine used in the very first Gmünd Porsches was very similar in concept as the 1085 cc engines for the Berlin-Rome cars

When the war was over Porsche had re-located to Gmünd, Austria and plans for an own sports car started to take form. Almost all of Porsches work had been done for customers, thus they didn't possess much in terms of intellectual property to base their sports car on.

The whole Berlin-Rome program, including the type 115 engine, was designed with Volkswagen Werk as customer and the Sturmboot program was done for the German military forces. Thus, Porsche did not own these designs.

The lack of own intellectual property was a problem already before the war as Porsche was not allowed to use kdf-designs as a base for any private sports car project. Thus Porsches stillborn attempt of a sports car in 1938 (type 114) had to be designed from scratch.

After the war the situation was a bit different. Volkswagen Werk was now run by the British forces who heavily relied on Porsche knowledge to keep developing the beetle. Also there were some overlap in the staffing. Gustav Vogelsang, the chief engineer for engine development at Volkswagen in the 40's, seems to have worked in parallel also for the Porsche company. According to the book "Porsche - Origin of the species" by Ludwigsen, Vogelsang fled from Germany to join Porsche in Gmünd late 1944, but seems to have re-located to Fallersleben, and his position as head of the engine development at Volkswagen,  some years later.

So when it came to re-use Volkswagen parts Porsche had a friendly counter part to negotiate with. But when it came to the  re-use of wartime designs I imagine the situation was more tricky. This is only my speculations, but having Ferdinand prisoned in France for war time crime was probably not a good starting point for negotiations to re-use military designs for commercial purposes.

But, as they had the knowledge, the easiest way was probably to do new drawings using new project numbers. It might not be a coincident that the first attempts to develop a new Porsche sports car engine looks more or less like a re-make of the Sturmboot program.

Stay tuned for part 2 and I'll explain more!

The origin of VW tuning – Type 174A, 1942-1943

The Type 174A engine. From this angle it looks like a pretty normal kdf engine with dual carbs.

The last in the row of Sturmboot prototypes is the 174A. In the specifications I have seen it is said to be a normal kdf-engine, but with higher compression, larger intake valves and dual carburetors. But, was there perhaps something else done?

I want you to put yourself in the shoes of the Chief Engineer for the Sturmboot engine program. Your first attempt, 170, was a rather simple execution: Slap a Roots supercharger on to an existing engine. Simple, but in the end too heavy for the application.

Your next try, 171: An engine that is totally re-designed only to be able to get hemispherical combustion chambers. A nice solution from a design point of view, but tooling up for a entirely new engine, aimed for a very narrow application, would have been insane.

So, what to do next? Obviously there is a resistance in increasing the cylinder volume* and there is also a belief that hemispherical combustion chambers is the way to increase power in a normally aspirated engine (perhaps it was also deemed as a necessary measure to be able to raise the compression with the war-time fuel). On top of that, the new engine must reuse as many kdf parts as possible.

If only there was a way of tilting the valves while still retaining the overall lay-out of the kdf engine. Hmmm…. Wait a minute! If I tilt the valves in the other direction? Never mind the intake valves, perhaps only tilting the exhaust ones would be sufficient to get a much better combustion chamber? If we can find a way to get the pushrods on the exhaust side to work despite the angled valves, we can have a nice high compression engine, reusing most of the kdf parts. Then we only need tooling for new heads and we don't even need to touch the casting of the case! While we're at it we can add dual ports on the intake side for better flow, much like the early E60 engines from the 1930's.

This, ladies and gentlemen, describe the design principles of the type 369 head, a design that would follow Porsches pushrod engines in all 356 and 912 up until the late 60's.

Viewed from this side we see that this is not normal kdf-heads. They have dual ports and very different valve covers (I did the yellow high-lightning for illustrative purposes).

Look at the picture above of the type 174A. I have highlighted the shape of the valve cover and the dual port intake. Then compare it with the very early type 369 engine found at the Prototyp museum in Hamburg. I think the similarities are striking.

An early type 369 engine from the Prototyp museum. Compare this to the previous picture. To me it seems as the type 174A was the true father of the Porsche 356 heads.

Could it be that the 369 engine launched by Porsche in the late 40's was a carry over from the war time type 174A? Phil Carney (356 Registry vol 32, nr 6) writes that it's "quite possible" that the type 369 heads "were initially designed during the war". Not exactly heavy evidence, but I can't find any information that goes against my theory that the type 174A and 369 heads are closely related.

Again, any additional information that can support, or destroy, my theory is very welcome. To me the sketch of the type 174A is a good indicator that the Porsche 356 pushrod engine had its origin in the Sturmboot motor type 174A from 1942/1943.

*The cylinder volume was already increased a bit from 998cc to 1131cc, but I see no attempt in going further.

The origin of VW tuning – Type 174, 1942-1943

This is the only type 174 picture I have seen. Not a 100% normal kdf-engine as you can see.

As said before the type 174/174A is somewhat of a mystery. In this post I'll try to cover the first one, the type 174.

Looking at the technical data it looks like your normal post-war 1131 cc with 25 hp and a 5,8:1 compression ratio. But the only picture  of a 174 I have found show some strange things.

First there is a bulky device where the distributor should be, which seems to be some kind of magneto device. "Normal" kdf-stationary engines did have a bulky magneto device somewhat similar to this one on the type 174, while the type 171 had a Scintilla device of the type used on post-war stationaries. I guess they tried out different types during the war before they settled for the Scintilla type.

Technical data of the type 174/174A.

The second thing is the carburetor that looks a bit different from other ones from that time. It it's a Solex 26vfi II with dual float bowls that was also tested on the Schwimwagens*. Perhaps it was an attempt to try out a carburetor more suitable for use in a boat application? 

And that's all for the type 174. I have no more at this point in time. Next up is the 174A.

*Edit note: I did update this blogpost with additional information from Dieter and Lucian. Thank you!

The origin of VW tuning – Type 170, part 2

The first version of the type 170 featured a top mounted Roots supercharger, the photo was taken in March 1943.

This blogpost was supposed to be about Sturmboot prototypes type 174/174A, but when asking my source some follow up questions I received some more very interesting information. So until this new information is digested I will wait with the174/174A post, but until then I have some new findings related to type 170 I want to share.

As it turns out, type 170 were built in two versions: One with the Roots supercharger on top of the engine and one were it's axial mounted in line with the crankshaft. The first one is labelled version one and the photo is dated March 1943. The latter does only say type 170 and 1943, with no further details.

The new photo material of Sturmboot prototypes I got show different versions of prototypes and even complete units that appear ready for the sea. This put my statement in earlier blogposts in a new light. Probably no one knows for sure anymore how many prototypes were made.

The second version had an axial mounted Roots supercharger. Could this have been the engine that ended up in Ferry's kdf cabrio? To me it seems like the earlier version above would have been more practical...

The origin of VW tuning – Type 171, 1942-1943

A prototype of the type 171 Sturmboot engine dated 1943

Next in line for the air-cooled Sturmboot project was project 171. This time a normally aspirated 1131cc pushrod engine with hemisphearical combustion chambers. The inspiration of the heads seems to origin from the pre-war SOHC type 115, but this time a bit more conventional using pushrods from a centrally placed camshaft.

To me it's a mystery why they did chose to go to this rather complicated design instead of increasing the cylinder volume, a solution that would have required less amount of new parts. Somehow I have the feeling Porsche took this military order as an opportunity to make designs that could be useful in future projects after the war. According to my source document this rather novel design was scrapped due to the cost (and probably time) it would take to put it into production. Not many details remained unchanged from the original kdf-design.

As can be seen not many parts are interchangeable with the original kdf-engine. A fact that was to be the fall of this concept.

But how far did the development of this engine go before it got stopped? Both the document I have access to and Chris Barbers book "Birth of the Beetle" indicates that of the different air-cooled Sturmboot designs only type 174 was ever tested in a the real application. However, from the picture above we can assume that a prototype of the 171 was made. According to one of the worlds leading kdf-experts only one prototype of each (170, 171, 174) were made and they were all later scrapped in Linz/Donau in 1960. 

Some believe that 171 heads were used by Kurt Khunke in his VLK (Vollstromlinien-Leichtbau-Konstruktion) in which he won the 1947 Braunschweig Autobahnrennen (first ever victory for a kdf/VW based vehicle). This has not been confirmed and if only one prototype of a complete 171 was ever made this seems highly unlikely. From the design it is obvious that these heads can not be used on a kdf engine as the case is very different. My conclusion is that we can probably rule out that the 171heads were ever used in racing applications (I welcome any fact that can strengthen my theory, or destroy it).

In some current litterature the V-heads in Peter Max Mullers race car, displayed at the Prototyp museum in Hamburg, are referred to as Sturmboot heads. Looking at this picture, showing one single valve cover for two cylinders, I think we can safely rule out that connection.

If anyone has more information, please contact me! If new information surfaces I will share it on this very blog.

The origin of VW tuning – Type 170, 1942-1943

Basic data for the type 170 engine dated 1943. As can be seen the original compression ratio of 5.8 was retained despite the use of a supercharger (Gebl.).

In 1942 three new project numbers aimed for the same purpose saw the light of day at the Porsche Designbureau: 170, 171 and 174. The background was a problem with the Sturmboots (a kind of simple motor boat with a very long propeller shaft) in which dirty water did clog the cooling system. The idea was to replace it with an air-cooled engine, but the only one in production, the kdf, was not powerful enough. Thus, Porsche  Designbureau was consulted to fix the power issue.

In this blogpost I will focus on the first one, type 170. It was a pretty normal 1131cc kdf engine, but with a Roots type supercharger mounted axially behind the crankshaft. Remember my reference in the last blogpost to Barbers book "Birth of the Beetle"? What he claims to be a type 115 engine looks very much like a type 170 mounted in a car. Also looking at the timeline it makes sense. According to Barber, the first version of a kdf engine with axial Roots compressor was completed in September 1942 which is more in line with project number 170 than 115 that is dated to 1939.

This is the only picture I have found on the type 170, I have chosen to zoom in on the axial mounted Roots type super charger (the rest of the picture was of poor quality anyway)

From a business point of view my belief is that the type 170 should have been killed already before the drawing stage. The engine was far to heavy for its purpose due to all the parts surrounding the supercharger. But, perhaps Porsche did proceed with the project just so he could put the high power engine in Ferry Porsches private kdf-cabrio? Who knows…

The origin of VW tuning – Type 115, 1939

Cut-away of the cylinder and head of the type 115. As can be seen it has a single overhead camshaft with a 74 mm bore and 40 mm intake valves. The bore size, with a 64 mm kdf crank makes 1101 cc. A rather odd displacement for a conpetition engine.

In the list of Porsche design numbers we can read that type 115 was a kdf based 1,1 litre engine with overhead cams, hemispherical combustion chambers and supercharger. Thus, a pretty advanced engine for its time, and as such a very interesting one for this blog! Perhaps it can also be seen as the grandfather of the Carrera engine?

Cut away drawing in which we can see the bevel gears and the shafts driving the over head cams. Even though the Carrera engine has twin cams per head the drive principle of the type 115 is not too far off.

But what was the background? Was it even intended for a kdf type car? Did it ever really exist?

Reading Chris Barber’s excellent book “The Birth of the Beetle” it is easy to believe it was a running prototype as a picture of what is supposed to be a type 115 engine in a kdf-wagen is published. However, looking closer at the picture we see a supercharged kdf engine with normal cylinder tin and what appears to be a standard case. For once the otherwise very correct Mr Barber seems to be wrong. What we see on the picture is a "normal" kdf-engine with a Roots type supercharger. As far as I know there are no known pictures of a completed type 115 engine.

The background why the project 115 was started I know very little about. My source has been able to measure the original engine block (yes it still exist) and confirms that if fits on a kdf-type transmission. He further claims that the case is very similar to its kdf sibling aside from the rear of the engine where the cam drive is. Thus it seems reasonable to believe that the type 115 was somehow connected to the kdf (race car) program rather than Porsches private sports car project (As the kdf-program was state owned Porsche was not allowed to use such parts in his own endeavors).

The supercharger is of a centrifugal type throwing out air in one pipe for each cylinder bank.

Another view of the rather unusual supercharger

The assembly drawings I have access to are dated 28.8.1939 and 1.9.1939, only weeks before the Berlin-Rome event. My immediate conclusion was that the engine must have been aimed for a future race after the famous one. But, my source who has interviewed mr. Kaes, cousin of Ferry Porsche, claims that the documentation sometimes were made afterwards, thus the date doesn't mean that much. In any case my guess is that the Type 64 needed a more "normal" kdf-engine for Berlin-Rome due to propaganda reasons and that type 115 was aimed for a future race.

If there ever was a running engine, or even a complete one, I don’t know. But, it seems that most of the parts were manufactured at least. According to my source, Otto Mathé saved the parts when he emptied Porsche’s shelves of old prototype stuff in the 40’s. It would be a thrill to see those parts come alive one day!

The first page of the drawing lot that this blogpost was based upon.

The origin of VW tuning – Introduction

 Together for the first time in a long-long while! In 2015 the Berlin-Rome car IIIA0701 (ex. Mathé) was finally re-united with its original engine 38/43, a mildly tuned E60 kdf engine.

A little over a year ago I did write about the origin of the ”V-heads”, that is the very special cylinder heads used on the type 367 Porsche prototype as well as on one of Peter Max Müllers race cars. Since then I have come in contact with a long time kdf-collector based in Central Europe who have provided me with very interesting information.

As it seems, my expression “V-heads” was not a good one. What I thought was basically versions of the same head proved to be three very different designs. But my guess that the design principles of a V-headed VW/kdf-engine stems from the time of the Berlin-Rome Wagen seems to be correct though.

Reading in books and articles there are a lot of confusing and sometimes contradictive information related to this mythic car and the race that never happened. Some state very detailed information that, upon a closer investigation, turns out to be totally wrong.  However, I will focus on the engines only and try my best to avoid using unreliable sources.

All VW/Porsche history writers tends to agree that the engine that in the end made it to the sleek Berlin-Rome car was a tuned version of the normal kdf engine using dual carbs. A qualified guess is that the engine needed to be recognized as a kdf-one for propaganda/marketing purposes. The Berlin-Rome Wagen needed to be perceived as a sports version of the peoples car rather than an exotica.

A teaser for the next blog post in which the technical specifications of the Type 115 will be revealed.

But, it's doubtful if this whole race car program was started for just one single race. Most likely they had future events in mind. In parallel with the preparation for the September 1939 Berlin-Rome race Porsche did develop a far more exotic engine based on the kdf platform. This project, type 115, will be the topic for my next blog post. Stay tuned.

*Images courtesy of my anonymous Central European contact

The blog will soon re-open!

Thanks to a generous blog-reader in Central Europe I have come across some very interesting material related to the early attempts of making high performance versions of the kdf/VW engine. Thus I find it's now time for me to re-open the blog!

Above is a teaser. It's a part of an engine drawing from Porsche dated 1 September 1939, the very same day as German did invade Poland. In upcoming blog posts I will tell you the story behind this drawing and how the off-springs of this design did affect the post-war racing scene.

To be continued

Okrasa and the Karmann Ghia

1956 installation of the Okrasa kit in a Karmann Ghia

Already in the 1950's it was obvious that there was a gap between appearance and performance in the Karman Ghia coupé. One of the ways to close this gap was to add an Okrasa performance kit to the flat four in the back. In this blog post we will look closer to the installation of such kits in the Ghia.

The picture above, from the 1956 test in Auto Motor und Sport, shows what is probably a very early installation. The engine seems to be a pre-August-1955 unit so if it's the original engine of the car, this is a very very early Ghia. But, the engine could of course have been swapped.

A couple of things differ from later installations:

- The equalizer tube between the intakes runs in front of the fan shroud.

- The air filters are of the Knecht brand, just as for the "original" Okrasa kit.

- The oil filter is placed in a tilted position in front of the fan shroud.
- The ignition cables seems to have no support

1958 installation

If we move to 1958 and a test of the TSV 1300 kit in the same magazine the equalizer tube have now moved to the back of the fan shroud. Also, the original cable conduits are being used. The air filters are now of the brand Mann, probably because Okrasa wanted as light weight air filters as possible to avoid problems running on bumpy roads with the swan neck air filter fittings.

Fitting instructions from the early 60's

The last picture comes from a fitting instructions from the early 60's. It looks similar to the 1958 installation, but now the oil filter is on its own stands to the left of the engine. A much better solution for cooling and serviceability,

In all three installations the stock distributor with combined mechanical and centrifugal advance is used.  It was only with the introduction of the Okrasa kit for the 34/40 hp engines that all centrifugal distributors were used.

EDIT Aug 2015: I have collected all Okrasa/Ghia installations under one label, see: http://lowlightkaizen.blogspot.se/search/label/Okrasa_in_Ghia

Importfrossa

I slutet av 50-talet hade Europeiska importbilar, med Volkswagen i spetsen, gett Detroit skrämselhicka. Alla de tre stora skissade därför på mer kompakta modeller att lansera vid decennieskiftet.

Som bekant vade Chevrolet att gå ett steg längre än sina övriga landsmän och själva prova konceptet med luftkyld boxer i aktern. Resultatet blev Corvair en, för amerikanska mått mätt, kompakt bil med plattsexa i baken. För att gå all-in valde de att till modellåret 1961 dessutom lägga till kommersiella modeller, precis som VW gjort med typ 2. Modellserien fick namnet Corvair 95.

Men, samtidigt lanserade Ford sin Econoline i precis samma segment. Den var konventionellt byggd, billigare att köpa, billigare att köra och, skulle det visa sig, spenderade mindre tid stillastående på en verkstad. För att göra en lång historia kort: Corvair 95 blev aldrig någon storsäljare.

Pic-up:en på bilden, fotad utanför en välkänd VW verkstad utanför Södertälje, är därför faktiskt den ovanligaste av alla Corvair modeller. Synd, för den är ganska snygg tycker jag.

Okrasa för bastarden

Bilden ovan visar något mycket ovanligt, en Okrasa topp till den unika motor som fanns i VW Transporter från början av maj 1959 till slutet av maj 1960. Att Okrasa hann göra en topp till denna "udda" motor var en nyhet för mig. Men, tänker man efter så var det ingen som trodde det var en uddamotor när den kom. Den allmänna uppfattningen var nog att detta var VW's framtid.

Bakgrunden var att VW under slutet av 50-talet tyckte det var dags för en större uppdatering av sin drivkälla. Gissningsvis stod driftsäkerhet och tillverkningskostnad i fokus. Till exempel ökades avståndet mellan cylindrarna för att möjliggöra en starkare vev. Vidare flyttades bränslepumpen till en position mellan fördelaren och generatortornet. Det sistnämnda var nu dessutom skruvat, istället för gjutet, vilket troligtvis sänkte produktionskostnaden. Topparna var nya, cylindrar och kolvar likaså. Lyftarna var separerade från stötstängerna och ventilerna vinklade i toppen, Men, slagvolym och effekt förblev detsamma, likaså bibehölls den mekaniska choken.

Förutom vevaxelns förstärkning hade principen för dess axiallagring ändrats. Men, konstruktionsändringarna som skulle lösa VW's kvalitetsproblem med brustna vevaxlar kom att göra situationen etter värre. Vevaxlarna brast på löpande band. I januari 1960, ett halvår efter lanseringen, hade motorn konstruerats om så att principen för axiallagringen återigen var som den gamla 50-tals motorn. Dessutom instruerades VW verkstäderna att modifiera kundmotorer från 1959 på samma sätt.

Redan i juni 1960 fick VW Transporter ännu en nykonstruerad motor, nu på 34 hästar. Inte många delar var utbytbara mot den gamla motorn, trots att de var ganska lika. Cylindrar, kolvar och toppar var nykonstruerade och dimensionerna på vevlagen ökade*. I augusti 1960 hamnade samma motor i VW typ 1 och kom efter det att bli företagets smör-och-bröd motor under lång tid.

Eftersom en helt nykonstruerad motor lanserades bara 13 månader efter den misslyckade innebär det att VW visste att det var en usel motor redan innan produktionsstart. Det finns ingen chans att VW skulle ha hunnit få feedback, konstruerat en ny motor, beställt nya gjutverktyg och anpassat hela produktionslinan på den tiden.

Att ett stort företag inte lyckas att samla sig för att stoppa en dålig idé är ingen nyhet, speciellt inte i den tyska ingenjörshierarkin där man ogärna ifrågasätter chefens beslut. Många gånger försöker organisationen lappa och laga för att få produkten på banan igen, med varierad framgång. Men, hos Volkswagen var det någon som vågade fatta ett djärvt beslut: Skit i den nya motorn vi håller på att lansera. Låt oss konstruera en helt ny istället! Detta beslut räddade nog VW. Hade de fortsatt in i 60-talet med en motor med lägre tillförlitlighet än den gamla hade VW's konkurs kommit snabbare än någon hunnit säga Volkswagen 411.

Det finns källor på nätet som hävdar att samtliga dessa bastardmotorer blev återkallade. Jag finner det osannolikt att man skulle gjort så. Instruktionena till verkstäderna tyder på att motorerna tillverkade under 1959 modifierades med den nygamla axiallagren. jag hittar inga säkra källor att motorerna från 1960 blev återkallade.

Knappast många av bastardmotorerna kan ha utsatts för en Okrasakonvertering. Toppen på bilden är i skrivande stund till salu på thesamba.com. Säljaren har dessvärre bara en. Frågan är var man hittar en till…

*Rättelse (maj 2015): Ramlager av 34 hästarstyp introducerades i april 1960 på bastarden.

Gmündbilarna och dess motorer

Börjar man studera VW veterntrimning är det svårt att undvika Porsches tidiga historia. Efter det första sportbilsförsöket från Porsche, en öppen mittmotorprototyp, byggdes ett femtiotal bilar i aluminium 1948 - 1950. Detta var de så kallade Gmünd bilarna. De flesta av dem hade en typ 366 motor, vilket i praktiken var en VW motor med högre komp och dubbla förgasare.

Effekten angavs i marknadsmaterial till 40 hästar, men de flesta nutida Porsche historiker verkar överens om att den siffran var tämligen överdriven. Verklig effekt uppskattas till 28 - 35 hästar, beroende på vem man väljer att tro på.

Porsche typ 366. I princip en VW/kdf motor med dubbla förgasare och högre komp. Detta exemplar stod i Prototyp museets glasade verkstad. Från bilder på Facebook kan jag konstatera att en liknande (men inte samma) motor sitter i Gmünd coupén som visas längst upp i inägget.

Bristen på material efter kriget drabbade även Gmünd bilarna. Speciellt de tidiga bilarna använde sig av mycket begagnade delar från överblivet krigsmateriel. Många av de tidiga typ 366 motorerna var därför baserade på begagnade block. Porsche stansade in "P356" framför det vanliga motornumret på dessa. Man kan därför se om motorblocket ursprungligen var ämnat för Kdf, stationärmotor, Kübel- eller Schwimwagen.

Texten på museets skylt berättar att den här Porsche motorn från 1949 är den äldsta bevarade från Gmünd epoken*. Motorn har typ 369 toppar påhängda varför vi får förmoda att det är en sådan motor vi ser. Motornumret indikerar att den är baserad på ett begagnat block från en militär stationärmotor (om jag tolkat det rätt). 

Tittar man på sajten www.stasher.us så kan man gissa att Porsche gradvis gick över till nya block under 1949. Under samma år lanserades också den första "riktiga" Porsche motorn, typ 369**. Denna var först ut med de karaktäristiska topparna med snedställda avgasventiler.

Effekten angavs, precis som sin föregångare, till 40 hästar. Tack vare topparna hade man nog mer fog för sitt påstående i det här fallet. Förutom detta ändrades cylinderdiametern till 73,5 mm. På så sätt minskades motorvolymen från 1131cc till 1086cc vilket möjliggjorde tävlingar i 1,1 liter klassen.

Typ 366 dog ut med Gmündbilarna, men typ 369 kom att leva vidare ända till 1954. Man kan säga att det var den sista pusten från Gmünd-eran. Snart skulle den välkammade A-modellen äntra scenen och exporten till USA skjuta i höjden.

*Hade det stått "den äldsta typ 369 motorn" hade det känns mer trovärdigt, men nog måste det väl finnas någon äldre typ 366:a? Eller räknas inte det som en Porsche motor?

**Vissa källor anger 1948, andra 1949 och vissa 1950. Jag väljer att tro på 1949.

Stenhårda bromsar

Vi återvänder till Typ 597 Jagtwagen. Här en närbild på frambromsarna i Porsche 356A stil, men för fyrhjulsdrift. På bromsarna sitter 16" fälgar som jag misstänker är lite bredare än standard pre-A för att passa 6" breda C-däck. Rara delar.

Fotot taget på Prototyp museet i Hamburg

The V-Heads part 1: The Origin

The origin of the V-head: Part of the Berlin-Rome race car program, or a dead-end development for a sturmboot? (Photo by the author taken at the Prototyp museum in Hamburg)

Back in the 1940's VW hot rodders did not have that many choices to get a better breathing intake system. The Okrasa and Denzel heads would not be available until the 1950's and the Porsche head was not introduced until 1949.

But, a handful of prototype heads with better breathing capability did exist. I am talking about the famous so-called V-heads which had hemispherical combustions chambers with large valves placed in a V-position. They were used successfully by many racers in the late 40's: Petermax Müller, Kurt Kuhnke and Otto Mathé to name the most famous ones.

The Porsche Type 367 prototype from c:a 1948 using left-over V-heads. *This was one of three concepts for the Porsche engine, this one was deemed to be too expensive to manufacture. The type 367 prototype engine was sold to racer Otto Mathé together with the last remaining Type 64 Berlin-Rome car.

Most of the current literature use the term "Sturmboot" heads, probably stemming from statements made in Ludwigsens book Excellence was expected. However, according to Phil Carney in the 356 registry (Vol 32, No 6), the 1943 Sturmboot specification does not show such heads.

The British magazine Classic and Sports Cars (December 2007), takes a closer look at the restoration of one of the two existing engines (from Petermax Mullers race car). They mention that the gas welded valve covers and the machined pistons points at the fact that the parts were prototypes ones, rather than actual production parts. In my mind it strengthen the theory that the heads were not (production) Sturmboot heads.*

Looking at the list of Porsche design project number in Ludwigsens book I see two possible scenarios. One is that the heads were developed as part of the Berlin-Rome race car project in 1938-39. A couple of project numbers (64 and 115) could have had the heads as part deliveries. Carney promotes that theory pointing also at statements in the book Birth of the Beetle by Chris Barber regarding various experiment with a high performance KDF engine for the Berlin-Rome race car.

The other scenario is that the V-heads were designed for the Sturmboot, but never used. There are two project numbers for Sturmboot engine development (170 and 171, during 1942) followed by a final, number 174, with the title Sturmboot engine using normal kdf-engine. One could guess that the first two were more adventurous dead ends followed by a final simpler and more straight forward solution. The V-heads could theoretically come from the first two projects.

But, looking at designer logic I think the Berlin-Rome alternative makes the most sense. In a race car engine the rules of the race class sets the limitations, thus all parts need to be optimized with this in mind. In military applications the design criteria are different and there are no rules banning increased cylinder volume or super charging. I see it more logical that these advanced hemispherical heads stem from race car development rather than military applications. Until new facts surfaces I hold it as the most plausible theory.

The V-head engine in Petermax Mullers race car originally built by Gustav Vogelsang. More about the use of the V-heads in part 2.


*Edit November 2015: Since this post was written new material has surfaced. The type 367 heads are not same as the Sturmboot type 171 ones. Follow this blog for more information, I will tag all new posts on this subject with "V-heads"

NDIX:ens väg till Porsche

Nu är det snart förgasarnas tur i projektet. Givetvis förbereds detta med studier i teori och historik för den modell jag tänker mig använda. Vi börjar med det sistnämnda.

Zenith 32NDIX var en förgasare som i första hand utvecklades för terränggående fordon. Robusthet och en förmåga att klara stora lutningar och accelerationer i olika riktningar var ledord i konstruktionsarbetet. X:et i modellbeteckningen lär stå för att den är lämpad för dessa förhållanden.

Det var också på grund av sina terrängegenskaper firma Porsche kom i kontakt med förgasartypen i fråga. 1953 hade Porsche gett sig in i ett anbud gällande tillverkningen av lätta arméfordon för Bundeswehr i sitt projekt 597. För att få fram en lämplig drivkälla utgick de från sin nya motor med tredelat block som vid den här tidpunkten ännu var i prototypstadiet. De första bilarna hade 1,5 l motor, men när 356:an ökade till 1,6 l följde typ 597 efter.

Militären ställde lite andra krav på drivlinan än Porsches normala kunder. Bilen skulle kunna köras i en truppmarschfart på 2,8 km/h, samt klara 100 km/h på motorväg. Föga förvånande ställdes stora krav på extrem backtagningsförmåga samt möjligheten att köra den på lågoktanigt bränsle. Vissa justeringar behövdes därför.

Principen för fyrhjulsdriften lånades från krigets Kübelwagen och växellådan blev femväxlad med ettan som en ren klättringsväxel. Stora aluminumbromsar plockades från den vanliga 356:an. Motorn fick kompet sänkt till 6,5:1 samt en kam optimerad för lägre varvtal. Sist men inte minst tronade en ensam Zenith 32 NDIX på toppen av motorn istället för de vanliga dubbla Solexarna. 

1958 blev det klart att DKW Munga skulle få ordern vilket fick Porsche att lägga ned sitt projekt efter endast 70 tillverkade bilar. Trots detta kom Bundeswehr ändå i åtnjutande av den terrängvänliga Zenith 32 NDIX eftersom det var just en sådan som satt i Mungan.

DKW Mungas tvåtakts motor på tre cylindrar och en liter med NDIX förgasare. Munga tillverkades fram till 1967 då Bundeswehr gick över till VW typ 181 istället.

Det är inte orimligt att tro att projekt 597 spelade en viktig roll för att just dubbla Zenith 32NDIX valdes som ersättare för Solex PBIC förgasarna i Porsches motorsvagare modeller 1957 (60 resp. 75 DIN hp). Storleken var rätt och förmågan att klara hastiga accelerationer i olika riktningar är viktig för såväl sport- som terrängvagnar.

För Porsches vidkommande hängde Zenith NDIX med 356-serien ut. Tack vare förgasarens popularitet i olika fordon (i alltifrån Unimog till BMW 506) blev det en långlivad modell. Så sent som 2005 upphörde tillverkningen, lite drygt ett halvsekel efter introduktionen.

Fotnot 1:
För er som vill läsa mer om Typ 597 rekommenderas följande artikel: http://www.allrad-magazin.de/clubs_und_szene/klassik/Porsche/Typ597_Jagdwagen_01.php 

Fotnot 2:
Visst liknar baklysena på typ 597 väldigt mycket de som satt på Porsche 550?

Fotnot 3:
Goliath typ 31, den tredje kombattanten i striden om Bundeswehr ordern, försökte med insprutning, men föll på generell dålig driftsäkerhet på drivlinan. När de 1957 lanserade  typ 34, en uppföljare för civilt bruk, satt det givetvis en Zenith 32 NDIX förgasare på plats istället.

What if… The 1958 VW Karmann Ghia S

What if the VW marketing department had manage to convince the rigid VW CEO Heinrich Nordhoff to start making a Karmann Ghia with performance on par with the competition?

Of course, it couldn't be too fast to not upset the co-operation with Porsche. At the time the Ghia was launched the entry level Porsche was a 44 DIN hp 1300 cc (type 506). Thus, with the lower weight of the Ghia all attempts to increase horsepower would have given it similar performance to the Porsche 1300.

But during spring 1957 Porsche did drop the 1300 cc and the entry level was now the 1600N at 60 DIN hp. This would have opened up a possibility for VW to slide a model in-between the standard Ghia and the Porsche.

Looking at competition in Europe at the time 45-50 DIN hp would be needed to get performance in level with the middle class cars at the time. By aiming at the lower figure VW could keep a safe distance to the 1600N.

Sporty European Coupés anno 1957

With this power requirement a VW based engine similar to the Porsche type 506 would be suitable. VW would even have looked at what Okrasa did with the TSV1300, a VW based engine with the same power. Let's take a look component by component:

Case
For simplicity I guess VW would have stuck with the standard one to avoid creating a new partnumber. The case of the Porsche pre-A was similar, but had larger bore to accommodate the 80 mm cylinders.

Cylinder volume
Both engines we use as reference have a 1300cc displacement, it make sense for the S-Ghia to go the same route. To be able to use the same case, and avoid expansive Nicasil cylinders, I guess VW would have chosen a longer stroke crank to arrive at 1300 cc. Looking in the future, that's exactly what VW did eight years later when introducing the 40 DIN hp 1300 cc.

Cam
Both the Porsche 506 and the Okrasa TSV1300 did use the standard VW camshaft. It seems as if you are only looking at revs up to 4500 rpm the standard one is a good choice as you retain the good low to mid rpm properties of the VW engine. Thus it would have been a natural choice for the S-Ghia.

A Porsche 506 engine installed in a 1953 Type 1

Heads
As mentioned before in this blog the stock 30 DIN hp engine is dead above 3400 rpm due to the restrictive intake system. Both Porsche and Okrasa did make the extra effort to develop their own heads with improved flow, as well as going for dual ports instead of siamese as the original. Porsche did complicate things by tilting the exhaust valves. For the S-Ghia I guess VW would have chosen the Okrasa path with valves sitting in-line. Eight years later that's exactly what they did when dual port heads were introduced on the type 3 engine.

Carburators
Also on this point the 506 and the TSV1300 have a common solution: the Solex 32 PBIC carbutator. However if VW was to introduce a new model late 1957 this solution was already a bit old fashioned. That autumn Porsche did replace the PBIC with the Zenith 32 NDIX and it's possible that VW would have followed the same route to benefit from a more modern design. The smaller version of the NDIX did use 24 mm venturies, which puts it in the same size range as the 32 PBIC used in the 506 and the TSV1300.

Ignition system
Porsche did use the Zeniths without vacuum outlet. Thus the S-Ghia would need an all centrifugal distributor. Perhaps they would have used the one they had, the VJ4BR8 (019), from the transporter. Or, they could have spiced the curve up a bit to arrive at something like its 1959 replacement, the VJ4BR25 (010). The coil would probably have been a unit better suited for high compression engines, as the one Porsche did use at the time. Finally we could expect a change in heat range of the spark plugs from the standard 175 to the 225 Porsche was running.

As the observant blog reader probably already has noticed this is the route I am taking for my own Karmann Ghia. To build a replica of a car that never existed, The 1958 Karmann Ghia S. It will not be a sporty car by todays standard, but I hope it will drive, and feel like, a typical mid-class sporty coupé of its time.

The bulk of the content in this post has already been published earlier in this blog, but as I now have more international readers I thought it would be good to make a summary in English.

ZAZ Zaporozhets, källa till delar?

I senaste tidningen från 356-klubben står en notis om Vladimir Putins bilsamling och hans Zaporozhets från 1972. Där står också att dess luftkylda V4 motor var baserad på kopierade VW-delar och att kolvar, cylindrar och toppar skulle passa rätt av från 25- och 30-hästare. Givetvis något som denna blogg måste gå till botten med!

Bilden visar en Zaporozhets topp från 60-talet. Vid en snabb blick ser det ut att vara väldigt likt VW, tills man inser att tändstifthålen sitter på "fel" sida i förhållande till insuget. Dessutom var dessa tidiga motorer på mindre än 800 cc och hade betydligt mindre cylindrar än VW. Toppen är alltså rimligtvis mindre än vad vi är vana med. Motorn kom senare att få större volym, men så stora som 77 mm blev aldrig kolvarna.

Även om nu delarna inte är kompatibla med 30-hästaren så har den ändå en intressant historia. Ordern att utveckla denna Ukrainska folkbil kom i mitten på 50-talet. Enligt uppgift var det tydligt att VW och Fiat skulle vara förlagor. Resultatet, 965:an, kom att likna Fiat 600 på utsidan och VW typ 1 på insidan. Eftersom Sovjetiska verkstäder oftast hade jordgolv var det viktigt att så mycket service som möjligt kunde göras stående. Därav krånglet med att göra en V4 istället för en boxer.

Nästa generation, 966, kom att få NSU Prinz som förlaga och det är detta utseende man kanske mest förknippar med Zaporozhets. Dess vidareutveckling, 968:an kom att tillverkas fram ända till mitten av 90-talet. En intressant detalj är att dessa bilar nog är de enda som massproducerats i handikappanpassat utförande.

Bakgrunden finner vi i effekterna av andra världskriget. Aldrig någonsin i mänsklighetens historia har det funnits en så stor population invalidiserade människor som i Sovjet efter detta krig. Statsmakten gjorde sitt för att hjälpa, så om man saknade någon arm eller ben, kunde man gratis kvittera ut en Zaporozhets och efter några år kunde man, lika gratis, byta in den mot en ny. 

En annan toppnotering med gjutet generatortorn

På veteranbilsmarknader försöker jag alltid få hem minst en läsbar sak. På helgens Arosmarknad blev det tidningen Teknikens Värld 6/55, vars mest intressanta artikel var en test på Porsche 1500 Super. Det intressanta med just denna modell är att den, bortsett från rena tävlingsmotorer och specialbyggen, representerar det högsta effektuttaget ur det tidiga VW motorblocket.

I standardutförande gav 1500 Super (typ 528) 70 DIN hp vid 5000 rpm och till 550 Spydern kunde den specialbeställdas i en 100 hp version. Men, utvecklingen av denna motorkonstruktion hade nu nått vägs ände för Porsche. I tävlingssammanhang hade man redan börjat använda DOHC Carrera motorn och för gatbilarna skulle en stabilare nykonstruktion med tredelat block snart ta över.

Problemen med den gamla motorn hade eskalerat vartefter effekten ökats. Till exempel var pinnbultarna fortfarande  placerade med samma mönster som i VW-motorn. Detta begränsade utrymmet för de fina 80 mm Nicasil cylindrarna där de äntrade blocket. De blev helt enkelt lite för tunna och sprack därför gärna i botten.

En annan sak var Hirth vevaxeln med nållagrade vevstakar. Med den tidens smörjmedel var det nämligen inte lätt att få glidlager att hänga med när varvtalet ökade varför man lånade denna konstruktion från flyget. Men, trots att konstruktionen var beprövad där skulle det visa sig att den var mer problematisk i det lite stökigare livet som en bilmotor bjuder på. Det var dessutom dyrt och besvärligt att få dessa renoverade.

Jag gissar att det finns få typ 528 motorer kvar som fortfarande kör med ursprungsvevaxeln. Sedan Hirth slog igen1959 lär det vara svårt att få renoveringshjälp och med dagens oljor är det inga problem att nå samma varvtal med glidlagrade vevstakar.