Fiat 806: research and scratchbuilds

[harveyb258]

Hi chaps.

 

I'm somewhat sceptical about a shortened tank, tbh. The car was designed and built to race the 500km....and it was only a "late" decision to do the two 50km because of steering vibration, so I seriously doubt the Fiat fabricators would have altered the oil tank, when part-filling it would have sufficed.

 

Regarding the oil-rad....I think it would probably make more sense for it to have been a pair of pipes with the "grille" between, but, as always, I guess we'll never know for sure.

 

Cheers, H

[NickD]

Maybe - though the implication from Drawing 2 is that there was not a lot of mechanism at the bottom. There would also need to have been a by-pass unless it went through the the n-shaped pipe. Who knows.

[harveyb258]

I simply cannot believe that ALL of us have missed a MAJOR detail of this car....look very closely at photos 4a-4b-7d-8b-10 and 24...………………………………..NO FLOOR-SCOOP on left side!!!!!!!!

 

Cheers, H

[Hannes]

I had similar suspicions as well but the poor quality of the left side´s photos  didn´t allow a final proof imho . Was the scoop on the right side only a support for the driver´s feet ? As it seems our research is not over  yet ! I always hoped that  Massimino´s private photo album will show up one day !  Hannes

[NickD]

To be fair:

 

1. All the pictures of the left hand side are dark and indistinct - i.e. crap
2. Only people who have read all 199 pages are likely to be trying to extract new information - and there are only 3 of us leftt

 

Outstanding spot by the way...

 

Now to work out what it is for. Could it just be to cool the driver? Seems unlikely - it would have made the cockpit very breezy and very wet at 100+ mph.

[Black Knight]

Is it a 'scoop' or is it just the floor at the driver's feet extending forwards? It would not be needed on the left side

[NickD]

Looking at Photo 2, there is a thin vertical line across the entry to the "scoop". Maybe a stone catcher or grill?

 

Maybe it was just a floor.

 

There is a feature forward of the scoop that I have never been able to work out. It is visble in Photo 2 and Photo 3. In Photo 3 it hangs down as if it is broken. It looks like a bent piece of sheet. But what it is I have never managed to work out.

Nick

[NickD]

sorry Black Knight. I mispoke there are more than 3 of us left.

[harveyb258]

28 minutes ago, Hannes said:

. Was the scoop on the right side only a support for the driver´s feet ?

 

Most likely, yes!! Which also leads me to another suspicion.....as the lowest part of the tank is below the plane of the floor, maybe there's no floor at all on left side up to the fuel tank..... the "grille" could just be a mesh stone-guard.

 

4 minutes ago, NickD said:

There is a feature forward of the scoop that I have never been able to work out.

 

Most likely extra foot protection. I think I mentioned this many moons ago.

Edited July 19, 2018 by harveyb258
Forgot summat!

[Black Knight]

Combination? Floor extending forward and the vertical front enclosed by a mesh grill to allow some air flow over the driver's feet and up his legs?

The legs and feet gets mighty hot down there, even at 40 to 50 mph in an Austin 7. Previous owners of my car had hacked a big hole in the vertical face of the body tub at the driver's feet area. It was actually to facilitate quick gear-box changes. I never closed it off as it allowed in very welcome cooling air.

I'll see if I have photo - just to amuse you.

[Hannes]

Drawing 1 becomes more important if we discuss the issues regarding a floor imho . Did you notice these odd parts below the floor on the back view ? 

There´s a Greek (? ) company which owns the copyright of drawing 1  . Maybe we should ask them for a better version of this important drawing .  Hannes

[Black Knight]

8 minutes ago, NickD said:

sorry Black Knight. I mispoke there are more than 3 of us left.

S'ok. I just keep an eye on things here and drop in occasionally

[Hannes]

It´s only my own theory but I believe that only the region below the tank and the region around the driver´s feet was protected by a sheet and for the rest some wooden planks were mounted . Maybe the Protar designers learned about  it by someone who knew this circumstance and realized  a fake floor in their model .

But - as I said - it´s just theoretical .   Hannes

[NickD]

On the bent plate behind the chassis brace - looking again at Photo 2 there appears to be a bent sheet in front of the "floor" that extends inboard to a point where there is a sliver of light showing in the photo. Not clear how it is mounted, or why it is there. It does not have an obvious relationship with the "floor" and has a very strong curve - why is not obvious.

[Black Knight]

52 minutes ago, Black Knight said:

Combination? Floor extending forward and the vertical front enclosed by a mesh grill to allow some air flow over the driver's feet and up his legs?

The legs and feet gets mighty hot down there, even at 40 to 50 mph in an Austin 7. Previous owners of my car had hacked a big hole in the vertical face of the body tub at the driver's feet area. It was actually to facilitate quick gear-box changes. I never closed it off as it allowed in very welcome cooling air.

I'll see if I have photo - just to amuse you.

Sorry these are poor photos. They were taken some years ago

Number 1. View towards the front. Through the hole you can see the rear end of another Austin 7 we used to have;

Bottom left of the yellow oval line is where the gear box gear stick comes up

 

Number 2. From the engine side. The body tub should be as the right side, right across

[Hannes]

Harvey´s important discovery requires new considerations . In my opinion there was a bottom sheet on the left side which corresponds with the downside of the chassis rail . It´s also a logical support for the frontal additional tank .

In combination with a firewall it should protect some important parts like brake booster , oil tank , gear change system , pipelines  and so on .

Contrary to the right side stones and other dangerous parts  could not get sucked in so easily . A stone through the open scoop on the right side would " only " hit the driver and no precious technical parts !😄 Maybe the odd part in this region - spotted by Nick - is a protection sheet to prevent that the driver will get killed in action ...

 

I will alter my construction accordingly and will show some pics after that . The heat in the last days prevented  a progress and I start to like the idea of a cooling sytem !

Many greetings !   Hannes

[NickD]

On 19/07/2018 at 13:27, harveyb258 said:

 

I'm somewhat sceptical about a shortened tank, tbh. The car was designed and built to race the 500km....and it was only a "late" decision to do the two 50km because of steering vibration, so I seriously doubt the Fiat fabricators would have altered the oil tank, when part-filling it would have sufficed.

 

Regarding the oil-rad....I think it would probably make more sense for it to have been a pair of pipes with the "grille" between, but, as always, I guess we'll never know for sure.

Hi Harvey,

 

I missed your post above for some reason. Your points are well made. Perhaps the following modified logic works

 

Moving the n-pipe forward implies the tank was smaller in the built car than the Drawing 2 version. Why?

 

The oil tank would be sized for the expected endurance. (in line with your comment above). We know the oil consumption was very high. Perhaps it was higher than expected. For a short race the tank would work (part filled) but for a longer race a bigger tank would be required.

 

Does that make more sense?

 

Nick

 

[Hannes]

One of the last sources of information are the 3 pages of the test drive report imho  . They were published in the Rogliatti article and were only partial translated when they  were  published here  as far as  I remember . For example : At the 8/24 of 1927 there was a temperature  on the Monza circuit of 26-29 degrees Celsius . The water temperature during the test drives  was 89 degrees and the oil temperature 79 degrees Celsius .

The water consumption was 2,1 litres / 100 km .

Informations like this could help to unravel some questions if we consider the context of all protocols .

If there is an interest for  translating the Italian text I could post these documents again .

Many greetings !  Hannes

[NickD]

That's a good idea. I will go and root out a copy though Italian is not one of my languages (which are limited to English and family-embarrassing standards in French, German and Japanese).

[harveyb258]

Yes please, Hannes!  My only languages are English and Jibberish!!

[Hannes]

[Hannes]

This  is the Rosetta stone ! Unfortunately some passages are hard to read . But I think a native Italian could unravel the whole text . If someone who reads this  could translate , please help !   Hannes

[Hannes]

An important information ! Although our documentary  cannot get accessed directly anymore , it´s still possible to watch this movie by visiting the Instituto LUCE .( Esplora-archivio cinematografico - vedi tutti collezione - page 11 ) 

Here we have the opportunity to freeze the movie and watch important passages picture by picture .

That´s a great progress  for us even this is not the best version available . Roy possesses a better and  purchased version . But for the rest of us this feature will help as well .

Regarding the 3 pages above :  I´m dissapointed that noone is willing to help us . I guess I will have to find a student or another German with Italian background who could translate this text .   Hannes

[NickD]

On translation - It may be slow by DIY translation with no knowledge of Italian is possible. The first section of page 1 reads:

 

"1 ° CAR 504 WITH 406 MOTOR – Bridge(?) 10/49 - Tires 29x5,25

 

-1-      

  

21/8/927

 

In order to improve road-holding during curves, the front and rear of the chassis were re-enforced.

 

Engine No 3 was fitted with the new cylinder design that had given good results both in terms of power and thermal balance during in-house testing.

 

During the first laps it was immediately found that the frame reinforcement had improved the road holding so that there are no longer strong oscillations in turns

 

However it is worth noting that the race track may be too slow to trigger the oscillations that require steering correction.

 

47 very fast test laps were performed during the day, looking at different parts of the set up, with the best done by Salamano in 3'32 "3/5.

"

Not in german I'm afraid and a bit rough round the edges but even this snippet is interesting.

 

The frame stiffening for instance. Is it the frame itself or a reference to the bars that cross under the chassis. They have always looked a bit of an anomaly to to me and the aren't on drawing 2. Maybe they were additions what were engineered in the workshop rather than the drawing office.

I plan to plod through the rest. I'll let you know what I turn up.

 

Regards

Nick

 

 

 

[Hannes]

Thanks a lot , dear Nick ! Regarding the crossed members : If we consider drawing 1 as an early plan of the 406 version , these struts are already visible .In my opinion they belonged to the engine suspension system .

I guess some reinforcement sheets were welded to the inside of the chassis rails . The jumping left front wheel is not yet directly mentioned !

I believe that Agnelli was informed regarding the problems with vibrations and of course he expected a solution asap .

As we all know today the explanation for this problem was the U-shaped frontal axis in combination with the steering rods . I don´t think that the reinforcement of the chassis was very effective but the weight of the car increased of course . The successor was supposed to be 40 kg lighter and that´s a lot !

Many greetings !  Hannes