Fiat 806: research and scratchbuilds

[Hannes]

Chapter 2

After the right number ( 504 ) was known it was easy to find the plans in old files which were situated between the plans for the passenger coaches 503 and 505 .

But who changed the name ?

The name 806 was established at a later time because the precessors names were the 804 and 805 .

At the time of the Monza race this car was named " Fiat 1500 " or " Fiat 1500  12 cylinders "

The car had an very unusual 12 cylinders 4 strokes engine with two vertical 6 cylindres blocks.

Both rows had a common crankshaft case made out of aluminium but each row had their own crankshaft .

The V - situated valves were operated by 3 ohc ´s.

The center camshaft operated the inlet valves the other two the outlet valves .

This engine was developed by the Zerbi team .

Cavalli was responsible for the chassis and the rest of the car .

The minimal weight for formula 1,5 litres cars of that time was 700 kg , the minimal width of the body was 800 mm , because no second passenger had to be on board anymore in 1927 .

The exactly dated documents of Massimino shows the development of the car :

At the 4. of July 1925 the general design was established ( with a left-hand output drive , so the driver´s position could be very low )

In September Massimino constructed the suspension of the rear axis .

In December he calculated the clutch adviced by Cavalli :

In January 1926 he was busy with designing the body and numerous detais .

The chassis was an usual construction of that time .

 

Under Zerbi´s control 2 versions of an engine were developed in the beginning :

" tipo 451 " ,also called 151 and " tipo 406 ".

Even if " tpo 451 " was never used in a car it was a very interesting construction : It was a 2 stroke engine with a compressor .

At this time it was believed a 2 stoke engine with a compressor could develop more power compared with a 4 stroke engine .

But problems with overheating and a lot of other difficulties made an end for this construction and only " tipo 406 " was developed further :

 

The car and it´s engine were completed in May 1927.

The car´s weight was about 50 kg more as the desired 690 kg .

The engine´s weight including clutch , magnetos and compressor was about 200 kg .

With 170 kg of liquids and the  driver this new construction `s weight was approximately 980 kg at the beginning of the race :

 

End of chapter 2   will be continued...  Hannes

[sharknose156]

Amazing information... if we can rebuild as close a model as possible, we have to imagine that Eng. Massimino, Eng. Zerbi and Me Cavalli would be very emotional... in their graves RIP.

in memory of their great ingenuosity and creativity. 

 

Imagine Massimino finding the reason for the cursed vibrations, running to his boss's office and Me Cavalli telling him "too late".

 

Great efforts Olivier and Hannes !!  Thank you a mil. !

Edited January 18, 2017 by sharknose156

[Hannes]

Dear Sam ,he found out , but too late ! The whole story is more amazing  as any thriller ! Liebe Grüsse !  Hannes

[Roy vd M.]

Read in this document during the Delage research:

 

Quote

[Bugatti] were the first Grand Prix cars to be supplied for sale new to private customers as well as used by the works team. Presumably they made a profit for Bugatti. Other makers and also Bugatti previously had sold ex-works cars, eg Peugeot even before WW1, although FIAT always scrapped theirs when no longer required.

 

So according to this source at Fiat it was common practice to scrap their Grand Prix cars. It's yet another possibility. 

[Hannes]

Dear Roy these are very interesting documents ! I´ll read them later , because this will take some time .And I want to finish my today´s translation works first :

The rest of this very interesting article will be published tomorrow :

 

Chapter 3

At a late evening on an old military compound near Torino and in presence of Fiat General Director engineer Rossi and other technicans Pietro Bordino was the first who was driving test runs.

After only two rounds around that compound the clutch lost one of it´s steel discs and the car had to be repaired in the factory .

In June of 1927 the car was driven on a non-public road several times .

To prevent curious eyes from looking these runs were made early in the morning and on every crossing a watcher was posted .

Because the testings needed a lot of time it was not possible to build more than one car even 3 or 4 engines existed :

The chances to win the race on the 4. of September with only a single car in it´s first race were considered as very very low .

 

There were more test runs on the Monza race track on the 12. and 13. and between the 21. and 25. of August :

An exact record about these test runs was made by engineer Rossi , mainly written by hand :

This record shows- besides the usual difficulties with a new racing car - a mysterious shaking and jumping of the left front wheel which could not get fixed :

The engineers tried  to strenghten the leaf springs and to stiffen the frame but these efforts were in vain :

The engine was powerful , but only had a short lifetime .

 

Therefore an agreement was made with the officials of the Grand Prix :

Two different races should be held :The Grand Prix of Italy over 50 Monza - rounds ( or 500 km ) and the Grand Prix of Milano over just 5 rounds ( or 50 km )

Fiat only participated the second race , Delage decided to drive the Grand Prix of Italy :

This way both competitors won their race :

 

End of chapter 3 , to be continued tomorrow  , there are still a lot of surprising informations !  Hannes

[Roy vd M.]

Chapter 3 is very interesting indeed. The previous two chapters contained little 'novelties' but this third one does. 

 

Thank you Hannes for taking the trouble of translating this all. 

[Hannes]

You´re welcome dear Roy and the rest is the best , like the icing on the cake when you showed us this amazing film document !  Many greetings !  Hannes

[Totally Mad Olivier]

Translation of p. 1 of "Fiat Ufficio tecnico" :

 

Title: 504 car with 406 engine. Bridge (deck?) 10/49   Tyres 29 x 5,25

 

Monza trials from the 21/8 to the 25/8/1927

 

21/8/1927: the car was reinforced at the front as at the back of the frame, in order to improve the driving stability when cornering. On the car was set the engine n°3 (?) with new cylinders that, in the room test, gave good results as well in term of power than about the thermal balance.

From the first laps, we immediately found that the reinforcement of the frame had improved the driving stability in curve. We can see however that, on this circuit, the car has a too short wheelbase, so that she wags the tail during the necessary steering corrections. 

47 laps test during the day, very fast, are done, for the development of the different parts, and the best lap time is got by Salamano, in 3'32"3/5.

 

Observations:

1) the fuel pressure valve must be of at least 10 mm, of light (??) and must be set on a connection of the piping and easily registrable.

2) the magnets tend to give some misfirings at the maximum number of laps; and the necessary will be done so that Bosch will check that.

The .... Bosch thinks it is necessary to do a modif ... to all magnets. They provide ... with the agreement  that the remaining will be modified at Milano or Torino with the brought pieces from Stuttgart about the 25/8.

3) The ... of the crankcase at the central box .... but the engine goes on losing a little oil .... the collars from the lateral distribution box, and this oil ...  the servobrake that we have to protect with plates and felts.

4) The deck under the engine on the right side produces an accumulation of hot air that affects the conduction, for which we decide to remove it, and this action still improves the refreshing of the radiator. (ndlr: is it question here of the lower part of the bonnet on right side, 3G part on the kit, for which Hannes was wondering if it was still present on photo 9 or not?)

5) the tyres that are still at test session don't last more than 15 laps at a fast pace; we pray the officials from Pirelli so that we can get the definitive tyres.

6) we can see that the inside of the fuel tank, after a few laps, grow to 47°C, and, to avoid that, we create refreshing louvres on the body (ndlr: the left ones, just openings, behind the cockpit, on photo 4?)

7) A star on the drive pivots of Hartford shock absorbers was broken.

8) the clip of the oil .... was not improved: it would be necessary to make transversal bulheads in the same tank to prevent the oil accumulation during the braking.

9) there are still misfirings of sparkplugs N2 by craking ...

10) The ... of the sparkplugs have a weak spring that must be replaced.

11) the central electrodes of 2 plugs were covered by a coat of carbon.

12) the distilled water in the radiator makes a lot of sediment of a fine mush that flocks together on the cap (transl. not sure...)

Edited January 19, 2017 by Olivier de St Raph
correction

[Totally Mad Olivier]

10 hours ago, Hannes said:

At the 4. of July 1925 the general design was established ( with a left-hand output drive , so the driver´s position could be very low )

About the low profile chassis, Sebastien says in his book, p. 149, speaking about the 806 chassis:

" it is a low profile chassis. The rails pass over the front axle and then come down to pass below the rear axle. This configuration was seen from 1922 on the Rolland-Pilain Grand Prix."

 

P.S: Thank you Hannes, very interesting german article, with new details... including through others a very precise creation schedule of the car, that confirms - with still more precisions - what Massimino said in the interview...

 

Edited January 19, 2017 by Olivier de St Raph
add

[Totally Mad Olivier]

Let's come back to the build, with a question I am wondering about the frame lenght:

I recall the frame was, according to drawing 2 (I go on thinking Drawing 2 is nearly right for the frame lenght), around 7-8 mm too long (I thought 10 to 12, but I have changed my mind)

I made a mistake cutting it at the cockpit level, removing the same 7 mm that needed to be cut on the body at the same level.

So, the question now, is:

where should I cut my frame?

The frame can be considered as made of 3 parts:

1) Rear part, nearly horizontal, coming from the rear leaf spring stand rod (10B on the kit) to the curve, at the 8B level (on step 1 of the instruction sheet)

2) Middle part, in which the frame goes up to pass over the front axle (from 8B to 5 mm before the triangle at the front cross engine stand 108 and 109D level, step 4)

3) front part, nearly horizontal, from this last mark, to the front leaf spring rod stand 9B (step 1).

 

I do think, following drawing 2 but also photo 1, that the part to remove on the kit's frame is essentially situated on the middle part. more precisely at the front part of this middle part.

 

 

 

 

I will be careful, and keep the portion removed, just in case. But, after all these "surgeries", and as I have to paint again my frame (fiammante rosso!), I must first cut it, to avoid filling, sanding and painting again later, after floor and engine placement....

Before I do that (I become careful...), I will wait your points of view, especially Hannes one! (I suppose he won't agree with any frame decrease ).

Edited January 19, 2017 by Olivier de St Raph
add

[Hannes]

Chapter 4

In the last days before the race the test-runs were continued .

Bordino was very fast with 3,326 min per round but the engine by overcharging .

In a hurry a new engine was installed but the main problem - the shaking front wheel - still existed .

But somehow Bordino managed to deal with this problem :

 

After the race the press was enthusiastic and foresaw an appearance of Fiat with 3 cars for the Grand Prix in Brooklands at the 1. of October.

But inside of Fiat they knew better .

It´s reported , old Agnelli , who was never a fan of racing sports , was very angry after the victory

He called Cavalli and blamed him for not having solved the issues with the car :

As a consequence Cavalli  gave notice of termination for the next month :

 

In the meantime Massimino had some free days after months of struggling and preparation works

He was still mulling over the the shaking wheel and one day he found the solution.

It was the frontal axle which was a construction of 3 parts screwed together .

For security reasons the twisting of this axle was limited but due it´s special form these twistings  had an influence on the steering rods .

 

Massimino made a quick scetch and hurried to Cavalli .

Cavalli just looked at him and told him , his improvement was a good solution , but unfortunately it was too late .

 

At the 14. of January 1928 engineer Fornaca died due cancer , who was the most eager defender of racing sports .

This date was the total end :

All racing cars were destroyed to prevent any strugglings for racing activities for all times .

But not everything was destroyed ...

 

End of chapter 4 , to be continued  Hannes

[Hannes]

Sorry Bordino wrecked the engine by overcharging :senior moments perhaps ... Hannes

[sharknose156]

@Olivier de St Raph

 

as for the place of cutting, i think you and Hannes have become such experts... lets see what the blueprints from Miami will say ? may be it is a 'dud' and may be it is not ! and it will help tilt your decision.

 

@Hannes

 

Excellent translation, one can feel the nostalgia and regrets in the tone of the writer.

 

How sad is the death of Eng. Fornaca and the resignation of Me Cavalli... 

 

The perseverance and determination of Massimino reminds me of this thread... he could have easily been part of our group ! 

 

i am trying to understand the anger of Sen. Agnelli.

 

Perhaps he knew that to be credible the 806 had to also win in the forthcoming UK and Spanish GP's etc, outside of Monza, which is Fiat's turf where many exceptions can be made to favor the rossos ( to this day ).

 

 we know from Hannes's translation that in Monza, Fiat was able to make this deal entering in the small race only and leaving Benoist/ Delage to win in the main race... and the world championship soon after.

 

so, IMHO Agnelli knew that IF they could NOT resolve the front wheel vibration, they would fail at longer races/  Grand Prix' ... so better stop at the top than lose to competition...

so his anger

so the fateful decision... "stop and destroy", so it is irreversible... out of racing... and nobody can copy.

 

and then.... we have Massimino's tenacity to resolve the issue suceeding but... too late... and Cavalli had resigned ... then Fornaca dies a few months later... how sad.

 

grrrrrrrr... for the beloved 806

 

Edited January 19, 2017 by sharknose156

[Totally Mad Olivier]

 

1 hour ago, Hannes said:

But not everything was destroyed ...

 

End of chapter 4 , to be continued  Hannes

As in the best soap operas, the story is stopped at the most critical moment! 

Hannes, tell us further!! 

Seriously, thank you again for that great translation job my friend.... I spent myself this morning 1h20 just to translate the p.1 of the Monza trials. While I would have a lot of work to do on my build... and few time! 

So, it seems - but let's wait the end of Hannes story - that all race cars were destroyed from the 14/01/1928...

If it is confirmed that it is so, the good version would be the Massimino one in the interview, and D. Giacosa was wrong situating the Agnelli's order after Bordino's death...

 

Edited January 19, 2017 by Olivier de St Raph
add

[Totally Mad Olivier]

20 minutes ago, sharknose156 said:

lets see what the blueprints from Miami will say ? may be it is a 'dud' and may be it is not ! and it will help tilt your decision.

I really hope the blueprints will be the one of the car BEFORE the race, but, honestly, I don't think so. It would be too extraordinary to discover these blueprints 90 years after, in the Rev's library, while only the ones after the race were published everywhere... It is much more probable that it will be a "dud", pity... and I will have to refer to Drawing 2 as the only reference available... But one more time, I am quite sure OUR ONE BLUEPRINTS (drawing 2 modified) , made from Roy and Nick work, are at least 95% right now. And I think we can be proud of the work done together.

When I think the Centro Storico did not yet reply to our many requests to dig in their archives, while we would deserve all a Fiat gold medal... GRR...

Edited January 19, 2017 by Olivier de St Raph
add

[Totally Mad Olivier]

23 minutes ago, sharknose156 said:

How sad is the death of Eng. Fornaca and the resignation of Me Cavalli... 

 

The perseverance and determination of Massimino reminds me of this thread... he could have easily been part of our group ! 

 

Dear Sam, I share with you these feelings... Massimino had ever moved me with his interview, while he felt guilty, 40 years after, of this dramatic end, and while he did his best to solve the issues... Cruel destiny for these men, for these cars, and a mission, a duty for us... That is also why, reading Sebastien's book, I decided to represent Pietro Bordino. Building just the car was for me unfair vis à vis these men. Of course, Bordino was just one of them, but one of the most important, who had been risking his life for many years, all that for the success of Fiat, and representing him, I represent in fact all these guys, engineers, technicians, who took part to that amazing story.

[Roy vd M.]

16 minutes ago, Olivier de St Raph said:

When I think the Centro Storico did not yet reply to our many requests to dig in their archives, while we would deserve all a Fiat gold medal... GRR...

 

It doesn't feel right, I agree. They didn't come back to me. I wonder what they would think if they saw all documents and info gathered in this thread.

 

As promised here are scans of the book Trent'Anni di Corsa by Severo Boschi, which book arrived today. As far as I have been able to check the holder of copyrights doesn't exist anymore (the book is from 1966) but if anyone has better information about that then please let me know and I will delete all pages at once. I do not intend to make copyright infringements. 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

A beautiful 3 page fold out version of Drawing 5:

 

 

 

 

 

 

 

For Olivier, a good photo of Bordino in 1922:

 

 

 

 

For Sam, a good photo of the Mefistofele:

 

[Hannes]

Dear Olivier , wait and see !

 

Short chapter 5

I met a man who already owns one of the 2 cylinder blocks ( the engine was constructed by adding 6 of these 2 - cylinder blocks )

There´s no doubt this was a part of the 406 engine :

Till today the story of this car was told in a different way .

Carlo Salamano , once test driver for Fiat told his version to Richard von Frankenberg , published in the summer edition of " Motor-Revue "  1960

Salamano also drove this car in Monza and was almost as fast as Bordino .But he didn´t know too much about the preparation works :

!960 only the construction drawings of the engine were known:

 

Today the author of this article has clear evidences because he owns copies of all construction drawings , Massimino´s scetches , his calculations regarding the power of the car and an exact reconstruction of the events which led to an end of all racing activities of Fiat.

 

End of short chapter 5

 

Unfortunately  " the author " is Mr. Gianni Roglatti in the year 1967 and not    Hannes

 

[Hannes]

Sorry not already, still ! another senior moment perhaps !  If Mr Rogliatti is still alive , he must be very old !  Hannes

[Totally Mad Olivier]

Thank you Roy, very good Bordino portrait!

[Hannes]

Dear Olivier regarding the shortening of the frame : I.m also not yet completely sure how much ,where :and if : I trust my eyes most of the time and something irritates me if I compare drawing 2 with the photos of our car : Maybe only the radiator case `s dimensions were altered or the frame : If  changes were made on the original car with only a few cm or mm for instance , this would be almost nothing in our scale . Therefore I´m cautious and try to unravel the photos of the real car .Of course it will be necessary to shorten or even elongating the frame , but I ´ll wait with these measures , till parts of the model are in such  a state I can see them in a complex : And of course the model´s  frame´s height is way too low ! This angle which goes upwards where the handbrake is situated also seems to be a slightly different one compared with the original .The only advice I can give you : Look at the original car !  Hannes

[Hannes]

Last chapter

 Regarding the hp of the 406 engine 187 hp are a bit overestimated .

It was measured :

124 hp at 5500 rpm

156 hp at 7500 rpm

160 hp at 8000 rpm

 

It´s very likely one of the engines had

161 hp at 6500 rpm

187 hp at 8000 rpm

It´s not sure if this one was the Monza engine.

 

At the test runs in Monza the car had a high speed of 219 km / h by 158 hp and 7750 rpm

 

Calculations of that time led to an improved version .This car should start in Brooklands , 1. of October :

The new version had less weight ( 700 kg empty and 940 kg at the start ) and a smaller frontal space (from 0,89 to 0, 84 square meters )

The calculations also showed : This improved car would have been 235 km / h fast by 168 hp at it´s flywheel.

 

End of article , written about 1967  by the author Gianni Rogliatti 1929 - 2012 RIP   Hannes

[harveyb258]

Hi lads.

 

This story is so moving. It would make a mega-bucks blockbuster book/movie......and it's all true!

Thank you once again Sir Hannes and Sir Olivier for your incredible dedication in the quest for our Holy Grail!

 

Cheers, H

[Roy vd M.]

1 hour ago, Hannes said:

 Regarding the hp of the 406 engine 187 hp are a bit overestimated .

It was measured :

124 hp at 5500 rpm

156 hp at 7500 rpm

160 hp at 8000 rpm

 

It´s very likely one of the engines had

161 hp at 6500 rpm

187 hp at 8000 rpm

It´s not sure if this one was the Monza engine.

 

At the test runs in Monza the car had a high speed of 219 km / h by 158 hp and 7750 rpm

 

According to this article, again a comparison with the Delage (those cars will probably ever be compared to one another) the Fiat had 160 HP at 8,000 RPM. This was a test result. 

[Hannes]

I wonder how to reduce the cars weight in only 4 weeks by 40 or 50 kg ! Now we possibly  know  Bordino´s weight was about 70 kg if  the liquids weight at the start was about170 kg