Fiat 806: research and scratchbuilds

[Hannes]

My theory is as follows : The improved version with less weight and an altered body form according the calculations is represented in drawing 2 .Because this drawing was made after the Brookland race it might have been the pattern for a new car if Agnelli would have changed his mind and had given his agreement for further racing activities   Many greetings !  Hannes

[Hannes]

Another interesting aspect is the destruction of the racing cars after Fornaca´s death : Maybe Agnelli knew his engineer had only a short time to live and did not want this man to die in the conciousness that all his struggle was in vain . Even if Agnelli was a hard man , this cruelty also possibly  would have caused deep aversions in  some of his employees.

And I guess , he was not interested in loosing more of his good engineers :  Hannes

[Hannes]

http://www.grandprixhistory.org/fiat.htm

 

 

This link could be of interest  Hannes

[Totally Mad Olivier]

I have translated as I could the p. 2. The problem is that even for an italian, it wouldn't be easy, because of the bad quality of the document, typewritten.

I must say, reading all the issues Fiat had with this car just a few days before the race:

1) that I am not surprised they were not optimistic at all about the race

2) it is obvious that the car couldn't take part to a long race, as the Italian G.P

3) I can understand Agnelli's impatience. 

 

Indeed, it would have been much faster to write what was OK with that car during these trials. I admit I was taken by a giggle by rereading  this list of problems (I recall it is the p.2, the p.1 was ever full of worrying issues! And there is a p. 3 in which I suppose I will find the engine break... ). 

Sorry, I translate in french for now (ever uneasy...):

 

13) Le compte-tours tombe en panne et doit être remplacé. Le nouveau ne marque pas les tours au delà de 7200 t/mn, alors que le moteur monte à 8000.

14) le pied gauche du pilote se brûle au contact du carter. Il faut mettre une protection: de même, sur la pédale d'accélérateur, il faut mettre du matériau isolant.

15) les bougies avec les masses protégées exécutées par OCS chauffent beaucoup: le siège conique de l'étoile est mal fait et laisse passer la compression au point que l'une d'elle ........ (?)

16) les bougies KIG 348 donnent aussi des ratés.

17) la coiffe du radiateur se déchire à gauche au niveau de l'attaque ...... (?) Il faut la renforcer à ce niveau. Il faut en outre l'élargir à l'embouchure de l'air pour augmenter l'efficacité du radiateur car, quand la t° extérieure atteint . 8°C, l'eau approche elle les 90°C...

18) les temps signés par Bordino ont été:

3'40 - 3'35 - 3'44 - 3'50 - 3'40 - etc.

et ceux de Salamano 3'42 - 3'38 - 3'34 etc.

Nombre total de tours de la journée: 35 dont 4 à basse vitesse pour chauffer le moteur.

Consommation carburant: 35 l/ 100 kms      T° maxi eau: 87°

conso huile moteur: 3,2 l/ 100 kms       T° ext: 27°

conso eau de refroidissement: 2,1l/ 100 kms

 

 

22/8/1927: 

 

19) Il faut arrêter les essais à 2 reprises à cause de pneus qui ont tendance à déchapper, faisant faire à la voiture d'inquiétantes embardées, et ce après seulement 6 tours à vitesse élevée.

20) On a perdu le bouchon de la valve de pression d'huile... de même de la valve et du ressort (?) On n'a pas pu le retrouver et il n'en existe pas d'autres provisoires. Il est nécessaire que tous les écrous et les bouchons, tant au niveau du moteur que de la voiture, aient des attaches sûres et faciles à substituer.

21) Certaines roues (?) ne bloquent pas sur le cône de l'écrou parce que leur moyeu touche d'abord le bas-fond de l'écrou. Il faut abaisser la partie antérieure du moyeu de ces roues (??)

22) Les bougies RP (?) d'origine sont celles qui fonctionnent le mieux. Il faudra faire le tri avant la course.

23) Un pneu arrière gauche a "déchappé" nettement: les représentants de Pirelli assurent qu'il s'agit d'un cas sans précédent.

24) La pression de l'huile tombe à 4 atm. On vérifie le filtre qui se trouve .... ..... ..., .... différents rapports dans les carters et les tubulures. Il faut apporter plus de soin au montage.

25) La carène conique de la transmission (?) se déforme sur une portion importante et les pignons sautent. Il faut la renforcer particulièrement dans la partie sous les pignons jusqu'aux boulons de fixation. Il faudra vérifier aussi le matériel et le traitement parce qu'elle fait un bruit différent des autres.

 

 

In french, we would say it is "un inventaire à la Prévert...".

 

Edited January 21, 2017 by Olivier de St Raph
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[Totally Mad Olivier]

Translation (still in french, sorry...) of p. 3:

 

26) Faire le bouchon de la cuve d'eau au moteur (vase d'expansion?) plus grand et à démontage rapide

27) ..... le bouchon du radiateur pour pouvoir le visser plus rapidement

28) Faire la bague de cuivre qui fixe les demi bagues à ras .... à sphère antérieure (?) arbre de transmission en fer et avec une fixation plus rapide

29) Les freins arrière ont les segments complètement usés, mais ils ont déjà fait beaucoup plus qu'une course.

30) Temps sur le tour complet signés par Bordino: 3'39 - 3'37 - 3'34 etc.

et par Salamano ....

32 tours pour cette journée

Conso carburant 33l/ 100   T° max eau: 89°  conso huile: 3,5l/ 100   T° ext. 28,5°    conso eau moteur: 1,2l/100   T° huile: 78°

31) Les fenêtres ouvertes dans la carrosserie pour rafraîchir le réservoir d'essence ont permis d'abaisser la t° à l'intérieur de celui-ci de 47° à 36°. On pourrait encore améliorer ce refroidissement avec des fenêtres dans le tablier  ou du côté droit de la carrosserie. Il semble que ce refroidissement ait un effet positif sur la carburation et sur le comportement des bougies.

32) Le rapport 10/49 du pont est celui indiqué pour ce circuit comme le rapport total de la 3ème vitesse de boîte (0,83)...... dernières formes il serait bon de l'augmenter encore un peu pour empêcher qu'avant d'arriver au virage rehaussé, le moteur dépasse les 8000 t/mn.

 

 

23/8:

Cette journée a été consacrée au remplacement de la couronne dentée du pont arrière ou du pignon avec double roulement. Pour faciliter ce montage, il serait bon qu'il soit exécuté ..... d'épaisseur variée pour ajuster les .....

33) La couronne dentée demandée de .... échange n'a pas les .... pour les têtes des boulons d'union (?)

 

 

24/8:

On essaye à nouveau la voiture avec le pont renforcé en montant à gauche 2 pneus du type définitif pour course et s'ensuivent 20 tours avec résultat assez satisfaisant. L'essai est interrompu par l'obscurité et en raison de l'usure complète des freins arrière. Bougie R2 OK.

34) Le tube caoutchouc pour l'huile au manomètre .... (pression 9 1/2 atm.) et inonde le pilote Bordino d'huile dans les jambes, produisant diverses brûlures (poor Bordino!).

Salamano reprend qui fait les temps suivants: ......

 

 

2 comments:

1) the tests had to last until the 25/8, and we know the engine broke during these trials. I suppose the engine broke on the last day, the 25, and the last page must have been lost... or destroyed.

2) the point 31) confirms if I am right that certainly the openings on the left side were not present at the beginning and were added to refresh the fuel tank. Pity, on photo 1, 2 and 3, we can't see this left side, but I suppose the openings were not yet done.

Edited January 20, 2017 by Olivier de St Raph
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[NickD]

Sounds like the drivers were earning their money!

[Totally Mad Olivier]

On 19/01/2017 at 8:10 PM, Hannes said:

And of course the model´s  frame´s height is way too low !

I heard you, Hannes, and decided to increase the frame's height where it is really too low. I will soon post a topic on this...

[Hannes]

Dear Olivier , if you change the frame´s height at it´s upper side , the body must get lowered the same amount !  I hope I can send pictures soon of my altered radiator case :

I´ll also will fix it to the  (not yet altered ) frame so I can judge distances and ratios :  Many greetings !  Hannes

[Totally Mad Olivier]

No, dear Hannes, I will increase the frame (not everywhere, only on the front part, I'll show that soon...) at its lower side, of around 0,9 mm...

[Hannes]

Dear Olivier , but the frame itself has a different height too , where the body is situated ! Only the thick bottom - sheet gives an illusion the height was OK ! Many greetings !  Hannes

[Hannes]

 

 

 

 

 

 

 

 

 

Here´s looking at you , kit !  Hannes

 

 

 

 

 

 

 

 

[Hannes]

Of course the frame is not yet altered , the body not yet lowered and so on . But it shows the direction , where I want to go with my constuction  Many greetings !  Hannes

[sharknose156]

@Hannes

Well done Humphrey 

 

It is a little difficult to see the final shape and exact length but the overall harmony is there

 

It is less shrimpy for sure more grenouille

Edited January 21, 2017 by sharknose156

[Totally Mad Olivier]

Very nice and useful, Hannes. What I don't understand is that, on the photo with the grille, you radiator case seems to have the same height than the kit's grille, while it should be around 5 mm shorter. 

2 other questions, about the bonnets: looking at your photos, it seems that you will make them longer (they seem to be a bit short in lenght):

1) is it your intention to increase the bonnets' lenght?

2) As your radiator case is wider, logically, your bonnets should be enlarged too. On the photos, however, they seem to be nearly OK. How do you explain that?

 

About me, I cut the frame where I said, but, carefully, of 5 mm only... I am quite sure it was too long, and I needed to make that modif before going on, as I explained above. I will try to get back on my feet...

 

I have allowed myself to use one of your photos to show where I will increase the frame's height (green line). Indeed, IMHO, it is on that front portion that it needs to be increased the most.

Edited January 21, 2017 by Olivier de St Raph
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[Hannes]

Dear Olivier , as I said some time ago , I´m not working in exact ! /12 scale , but in a bit larger scale . That´s the reason why some measurements are different . Of course I can still alter heights lenghts and so on if I see it´s necessary . We are both pioneers so sometimes trial and error actions make sense : It´s my system to let options be opened till I´m convinced :

Regarding your questions : 1 ) yes I intend to do  the bonnet´s elongation ( about 3 -4  mm )  The bonnets can get adapted even if the radiator case is about 8 mm wider now .A small gap between the bonnets , a elongation of the bonnets height ( necessary anyway ) maybe bending a bit and doing the usual adaption works with strips and filler will do .

2 ) I shortened the case´s height about 2 mm under the mounting points ( hard to see on the photo ) elongated the case 3 mm before and 1,5 mm  behind the mounting points .

The width was elongated 8 mm .

The bodywork will be lowered at least 2mm maybe more depending on where I will alter the frame´s height :

The tails end also will be made shorter ( between 5 and 10 mm , not yet sure )

Next actions  will be alterings of the frame . If i see than , maybe the bonnets don´t need to get elongated or less , I can still can delay the mounting points :And of course  the radiator case itself could still get altered if necessary :   Many greetings !  Hannes

[Hannes]

Dear Olivier regarding the bonnets : The exhaust pipes need to get involved when adapting the bonnets ! That´s very important ! Some pages ago I gave you some advices regarding the pipes :  Many greetings !  Hannes

[Totally Mad Olivier]

The comparisons with the photos (1, 2, 3 in particular) show many corrections necessary on the frame. Through others:

- in the front part, the chassis is too low in height. Evergreen 0,82 mm thick has been cemented and with Mr Surfacer will get invisible.

- the slots to set 108 and 109D do not exist in reality. They will be removed.

- the fixing pin for the rear leaf spring front side is totally wrong and will need to be scratch builded.

 

Furthermore, the photo shows my work with Evergreen 0,82 mm and Mr Surfacer to make disappear the portion added (I had removed it by mistake, see above).

And it shows too my cutting on this frame, not yet filled. I have removed 5 mm lenght. I could not put a label for this by lack of space.

 

 

 

 

 

 

 

Edited January 22, 2017 by Olivier de St Raph
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[Hannes]

Dear Olivier these are very good observations ! And it´s very clever to use the thick bottoim plate as a part of the frame !

Regarding the fixing pin for the rear spring : It does not only has the wrong shape , it´s also situated at the wrong place ! It should get delayed about 5 mm into the backward direction .

Same goes for the support part behind it :

The parts which should  set parts 108 and 109 also have a different shape in reality so I think about removing at least the two rear parts and replace them with a scratchbuild.

Unfortunately these parts are hidden in the shadow on most of our photos :  Many greetings !  Hannes

[Hannes]

Drawings 3 and 6 show possible solutions for this construction . The construction of the master model ( gangshow ) is way better too compared with the kit´s snap -in solution  Hannes

[Totally Mad Olivier]

2 hours ago, Hannes said:

Dear Olivier these are very good observations ! And it´s very clever to use the thick bottoim plate as a part of the frame !

Thank you Hannes. You played your role of prickle marvelously, suggesting the necessity to increase the chassis height! About the bottom plate, that is a part from the underbody 1G on the kit, we can see on photos 1, 2 and 3 that there is in fact a continuity on the frame, so it was necessary to fill the limit between both parts (1G and 1A/ 2A). And indeed doing that allow to get a correct height, but only up to the front limit of 1G. My idea was to extend this plate with Evergreen 0,82 mm after that limit, on the front part of the chassis. I think it should be OK after the filling/ sanding step.

Edited January 22, 2017 by Olivier de St Raph
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[Totally Mad Olivier]

2 hours ago, Hannes said:

Regarding the fixing pin for the rear spring : It does not only has the wrong shape , it´s also situated at the wrong place ! It should get delayed about 5 mm into the backward direction .

Same goes for the support part behind it

I am a bit surprised by this observation. I have checked with my body on and, on my set frame/ body, the support part is at the right place, as in photo 2, under the rear cockpit fairing. And the fixing pin should maybe be a bit delayed, but not more than 2 mm IMHO (I repeat on my build, that is maybe a bit different than yours).

[Hannes]

Dear Olivier , take one of your wheels and hold it to the right place and compare with photos 1 and 2 ! ( right angle is importtant) : you will see , the pin  should be situated to the left more than 2 mm !You also can compare it with the fairing for the seat !  Hannes

[Totally Mad Olivier]

7 hours ago, Hannes said:

You also can compare it with the fairing for the seat ! 

Dear Hannes, that's precisely what I did... and, as I said above, it is OK on my build. I didn't check with the wheels, but I don't think it would change anything. But as I said, maybe you have something different on your own build...

Notice that I have completely removed the fixing pin.

I redid the line of rivets with Evergreen 0,13 mm thick card and Rivets maker RP Toolz 0,9 mm diameter. 

I was not very glad with my rim fairing, that did not go up to the limit body/ bonnets, so I removed it and did it again. Not very glad too with my rivets on this rim, I will do these very small rivets differently, probably after painting, with very small points, unless I decide finally not to represent them...

Another comment I wanted to make: this comparison photo shows I was right cutting my body in height (I had removed about 5 mm). On this comparison, it even seems that I should have removed a little more than that, no?

 

 

Edited January 22, 2017 by Olivier de St Raph
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[Hannes]

Dear Olivier , look at that photo of my model you showed above It´s almost the same angle as photo 1 . compare it with photo 1 . As I can see we both have about the same dimensions of body and frame :This cramp construction under the bottom sheet needs to get delayed backwards too !

To make comparisons always the same angle of view is necessary ! It´s also a good idea to use a wheel as comparison :  In my firm opinion the plate for the suspension pin on the frame and this cramp construction need to get delayed backwards  ( about 5 mm ). Of course the leaf spring needs to get shortened too .  Many greetings !  Hannes

[Hannes]

4mm will do  Hannes