Fiat 806: research and scratchbuilds

[NickD]

OK - understand now - seems an eminently sensible course of action

 

ATB

 

Nick

[Hannes]

Yes it is , but I knew that before I decided to build the model  in this scale .   But all problems are solvable .  and I have enough space for my engine  , gearbox and blower case .

If you build the model in exact 1.12 it will be very hard  because you have to calculate with tenth of mm  , for my construction tolerances of 1 mm are sufficient regarding engine-gearbox and case unit  in relation with bodywork and bonnets.

 

Many greetings !  Hannes

Edited July 3, 2017 by Hannes

[Totally Mad Olivier]

Dear Hannes,

there is something wrong in this drawing imho: the wide movement to the outside. What I see is just a marked curvature at the 9th louvre level, and this personal observation is confirmed by the top view of Drawing 1, quite right regarding the exhaust shape (the exhaust is missing on the Drawing 2):

 

 

 

 

 

What is obvious too for me is that the parts 148 and 149D are much too short (contrarly to the rear exhaust that was much too long) in their rear part (the part connecting with the rear exhaust). I had to add around 16 mm lenght. It will be adjusted to the good lenght and will be finally around 14 mm.

 

 

This photo shows on right side the 148D part before the deep modif I did. As Hannes said, it would have been probably faster to full scratchbuild, but, in the idea of writing my article, I try to use as far as possible the kit's part... 

 

P.S: Even if I am much closer from truth with this part now, I don't consider it is over. Some improvements are still to bring, basing on all our documents. And still opened to suggestions and comments. About that, I wonder how to manage the wrapping on this part. Did the wrapping concern all pipes, including the ones just coming from the engine, at the exhaust birth? 

 

 

 

Edited July 4, 2017 by Olivier de St Raph

[Totally Mad Olivier]

I found these photos of an Amilcar (I had them in my library and probably ever posted them), showing the matt ivory wrapping I wanted to look at. Well, this a probably not asbestos (the photos are recent) but it doesn't matter, I suppose the look was nearly the same. It is interesting too for the wrapping weathering (a bit more brown at the bottoms) and for the traces of exhaust gas on the rear body. Very inspiring!

 

 

Edited July 4, 2017 by Olivier de St Raph

[Totally Mad Olivier]

As I did before for other parts of the car, I publish here a synthesis of enlargements of the front exhaust area on some of our docs. Every doc brings something and looking at all of them gives a quite good idea of what the reality was...

 

Edited July 4, 2017 by Olivier de St Raph

[Totally Mad Olivier]

Continuation of the synthesis, with photos 4, 9 and 12:

 

[Totally Mad Olivier]

The instruction sheet doesn't give any information on where the 3 wires coming from the bezels should go, after the hole in the body. Help! I need somebody help... on this technical question.

 

[Black Knight]

What are the three instruments?

I assume

1. one is oil pressure

2. one is revolution counter

3. one might be ammeter

 

1 goes to engine crankcase high up, not the cylinder bore section

2. rev counter usually runs off the engine, one of the cam shafts or if electrical from a magneto

3. ammeter runs into electric circuit which gets engine electic power [for sparking plugs] from the magnetos - this tells the driver that the electrical energy to the sparkplugs is correct or failing - in other cars it also tells the driver that the battery is charging, but this car does not have a battery ignition system

 

It is fairly common that such racing cars do not have speedometers - the driver does not need to know how fast he is going, but he does need to know the engine revs so he can change gear at the right point. A good driver will know by the revs what mph/kph he is driving at, eg at 2150 rpm on my red Austin in top gear I am at approx 30mph

[Hannes]

Dear Olivier the 3 cables refer to cables A B and C of step 29 , I´ll answer the questions regarding the pipes later on :

Many greetings !  Hannes

[Hannes]

Dear Olivier forget drawing 1 regarding the pipes ! The most interesting photos of the left pipe are 4 , 7 and 8 B ( not wrong retouched 8 A ). They all show imho that the rear left pipe is tight to the bodywork and the bends have to bend backwards to reach that rear pipe .Similar for the right side as we can see on photo 9 in my opinion.,but maybe the arch is wider .If you elongate the bends on photo 9 into it´s ( invisible ) frontal direction under the bonnets you will see the shape

The ´bends start under the bonnets as we can see on photo 3 for instance , beyond  that point they are outside the bonnets and some of the short pipes can be seen and they have to  get back to the rear pipes

which are tight to the bodywork . Of course my drawing is only schematic and the real arch could look somewhat different  and a bit more straight  at the transition to the rear pipe ( right pipe ) but I wanted to show the principle .

The kit´s bends are way too straight imho and it´s very hard to transform them into a good shape  .The easiest way to find out  is to compare straight and arched bends on the model with the different photos . It should be sufficient if you bend plastic plates and  compare the shapes by " connecting "  them with the rear pipes .Instead of the kit´s  bonnets you could use a tensioned piece of tape to simulate the bonnets downside limits .

Many greetings !  Hannes

Edited July 4, 2017 by Hannes

[Totally Mad Olivier]

5 hours ago, Black Knight said:

What are the three instruments?

I assume

1. one is oil pressure

2. one is revolution counter

3. one might be ammeter

 

1 goes to engine crankcase high up, not the cylinder bore section

2. rev counter usually runs off the engine, one of the cam shafts or if electrical from a magneto

3. ammeter runs into electric circuit which gets engine electic power [for sparking plugs] from the magnetos - this tells the driver that the electrical energy to the sparkplugs is correct or failing - in other cars it also tells the driver that the battery is charging, but this car does not have a battery ignition system

 

It is fairly common that such racing cars do not have speedometers - the driver does not need to know how fast he is going, but he does need to know the engine revs so he can change gear at the right point. A good driver will know by the revs what mph/kph he is driving at, eg at 2150 rpm on my red Austin in top gear I am at approx 30mph

Thanks Fred, I will try to put the wires at the good place...

 

4 hours ago, Hannes said:

The kit´s bends are way too straight imho

Dear Hannes, no bend at all on the kit's parts. There is something curious with these front exhausts left and right. I will come-back on that later...

[Hannes]

Dear Olivier " bends " is the name for the frontal part of the exhaust pipes. That´s what I found in my dictionary . In French : collecteur d´echappement  Please read my post again in this context .    Hannes

Edited July 4, 2017 by Hannes

[Black Knight]

Olivier; are there markings on the circles for the instrument faces, or are there decals for them?

Given a choice I would have;

from the right;

Rev counter

Oil pressure

Ammeter on the left

[Totally Mad Olivier]

38 minutes ago, Hannes said:

Dear Olivier " bends " is the name for the frontal part of the exhaust pipes. That´s what I found in my dictionary . In French : collecteur d´echappement  Please read my post again in this context .    Hannes

Ah O.K Hannes, I understand better. This shows how our different languages can create misunderstandings. I would have said exhaust manifolds or exhaust collectors for these parts.

[Hannes]

In german it´s called Krümmer . "krumm " means " bent " or" crooked " In french it´s different .The collector is the bigger tube where the small tubes get united Because every cylinder has it´s own outlet tube we can name it fan-shaped bends . I hope , it´s correct

Many greetings !    Hannes

Edited July 4, 2017 by Hannes

[Black Knight]

And to me the whole piece is the manifold, the individual pipes to the engine are the 'branches', 

[Hannes]

I´ll burn my dictionary !  Hannes

[Hannes]

I want to share some deliberations regarding drawing 1 . As you all know it is my conviction that this drawing shows an early stage of our car´s development and was kept by Massimino.

One important indication for me is the shape of the engine´s downside , this means the oil-pan under the crankshaft case . On drawing 1 only a straight line can be seen in this region , the shape of the 406 engine´s pan is stepped .

What does this mean ? In my opinion the draughtsman did not yet know about the engine´s shape or the 2-stroke engine was provided for the car with a flat oil-pan .

Most likely the engine 406 was not yet developed  when these  plans were made  and the 2-stroke-engine  had a different lenght . This could be the reason why drawing 1 looks twisted for us .

The development of the 2-stroke engine was a failure as we all know  and the 406 engine was further  developed instead ..

A different engine could require different proportions like longer bonnets , different radiator , a different chassis ( 806 ) and this also could explain  our confusion regarding this drawing .

Of course the exhaust system was only  shown in a schematic way and is not relevant  for us .

Many greetings !   Hannes

Edited July 5, 2017 by Hannes

[Totally Mad Olivier]

Fred, here is the dashboard with its dials. Does this confirm your assumptions about them?

Edited July 5, 2017 by Olivier de St Raph

[Hannes]

After a comparatively easy start my construction now becomes more complicated for me .The engine unit is too small and I have to adjust it by altering engine , gearbox and blower case .

Fortunately I own two engines and I can use both for achieving my goals .Nevertheless it is a very delicate issue as Nick already pointed out .

Of course it is a no-go to add plates between the single elements for elongation purposes . This would look awful and could destroy the characteristics of the engine unit .

More elegant solutions are required and I´m about to find and realize them .

My three main goals are :

1 ) The gearbox should be at the right place regarding it´s rear part , this means I will elongate it .A correct height is necessary too !

2 ) The oil- pan should be at it´s correct height sreen from the side . An vertcal elongation below the chassis is required for that .

3 ) The beginning of the manifold should be at it´s correct spot . This is the most difficult task and I´m not yet completely throughh with my plans .

 

The downside of the blower case is wrong in every scale as we can see on engine drawing 4 , the cooling ribs should be situated much lower  and this should get altered in every construction .

 As you can see it´s not easy to create a convincing model ! But all problems can get solved .

A careful planning is required for all of these measures .

I want to give you an example : I want to create the frontal part of my bottom plate with it´s openings . To do that I need the exact location of the gearbox  and it´s correct lenght and height .

This means : I have to do the alterings on gearbox and engine first before I can construct my bottom plate .

If I do these alterings I have to consider the height of the crossed struts -system under the engine .

That´s the reason why I will have to start with this construction !

 

Once a good solution is found it´s easier for others to do the same or even better but pioneer´s work lasts a longer time very often . A percentage of 98 per cent deliberations and plannings is not unusual for these processes !  The realisation itself  does not take long usually .

Some members may think I´m a slow builder and that´s not very entertaining . But I guess I´m not slower than most of the other members if I had to build a good model oob.

But this is a different challenge .And I enjoy it even if some of my hairs start to get grey by that 

Many greetings !  Hannes

Edited July 5, 2017 by Hannes

[Black Knight]

8 hours ago, Olivier de St Raph said:

Fred, here is the dashboard with its dials. Does this confirm your assumptions about them?

Looks like

from right

Speedometer

Rev counter [as indicated by the red line at the 3 o'clock position]

oil pressure

 

[Hannes]

The speedometer only shows 210 km/h That´s not the maximum speed ! Monza is a high-speed track till today . And I doubt in Italy the speedometer shows miles per hour .

Many greetings !  Hannes

Edited July 5, 2017 by Hannes

[Totally Mad Olivier]

Thanks Fred and Hannes, for your comments about the dashboard. Hannes, even if Monza is a high speed track, I am not sure the 806 was able to go much faster than 210 km/h in straight portions. The medium speed was about 160 km/h, if I remember. I recall the engineers had to decrease the power of the engine that was initially, with 187 ch at 8700 r/mn, allowing a max speed of 240 km/h, but the engine broke and the next engine was "only" 160/ 165 ch at 8000r/mn. Anyway, even if the speedometer is wrong, what we will never know, I won't change it, of course. Notice that, once in place, with the steering wheel just in front, it is difficult to read the inscriptions on the dials...

 

I come-back on the exhaust manifolds and branches, that required a lot of job and patience (and it is not over) to get something acceptable. Indeed, I had to move and modify angles of some of the branches, a lot of surgery here, and to add portions of plastic card to increase the lenght of the branches.

I used then double sided tape to make a dry fit assembly, right and left side. Phew! right side, it is acceptable, but left side, the most frontal branches, ever lenghtened of several mm, will have to be more, because for now, the horizontal manifold is too internal. And the added portion of plastic card is a bit too long and also is going to the inside... What a challenge, these exhausts! But if I keep the idea not to place the bonnets, they will be very visible and so, no compromise possible... That said, I am aware even with these many corrections, the result will be just acceptable but not perfect. 

 

 

 

 

Edited July 5, 2017 by Olivier de St Raph

[Totally Mad Olivier]

3 hours ago, Hannes said:

But this is a different challenge .And I enjoy it even if some of my hairs start to get grey by that 

Hannes, happily, mine are ever silver!

[Black Knight]

2 hours ago, Hannes said:

The speedometer only shows 210 km/h That´s not the maximum speed ! Monza is a high-speed track till today . And I doubt in Italy the speedometer shows miles per hour .

Many greetings !  Hannes

I think, like a lot of this model, that the instruments are representative and not true to real

 

Olivier; remember, if you see faults, others, even those who work on such cars will look at your model and just say 'Wow!'