Jump to content

Fiat 806gp full-scratchbuild 1:12


Recommended Posts

Your construction looks great , dear HarveyĀ  , but IĀ“m not sure if there were similar sheets in the real car . A firewall at the front - yesĀ  but sheets at that place prevent an easy access to the differential case and the fuel supply as well . They also reduce the cooling effectĀ  for the gasoline . The fact that the two gaps under the bonnets were not closed shows the need of cooling air imho.

In my opinion there were some stiffening structures welded on the tank and connected with the rear bodywork . We can see rivets where the rear 15-numbers are situated . If the tank was firmly connected with the bodyworkĀ  a simple support frame should suffice imhoĀ 

Many greetings !Ā  Hannes

  • Like 1
Link to comment
Share on other sites

As regards the lighting holes, of course nobody knows for sure as the car was unfortunately scrapped in 1928. Some thoughts on the subject though:

Ā 

* It's true that the Delage 15-S-8 had very similar holes as depicted by Harvey, although I have no idea where you found that (or if you simply guessed it right). I don't recall having seen any photo online on which that structure is shown. This is what you see in the car:Ā 

Ā 

25673773318_f35113b0a3_k.jpg

Ā 

38835294874_243248023f_k.jpg

Ā 

These are my own photos. There's anotherĀ photo taken during restoration of a DelageĀ showingĀ that behind the seat back rest there are at least five roundĀ holes just like the big ones in Harvey's own version. Unfortunately I'm not allowed to share that photo.Ā 

Ā 

* Everywhere on the Delage evidence can be found of weight reduction. Already 90 years ago they really took this matter very seriously. On the other hand, getting these cars as close as possible toĀ the minimum weight of 650 kilograms for these 1,5 litre cars, as announced in 1926, generally didn't work out as well as was generally expected. I'll quote from pages 51-52 of 'The Grand Prix Car' by Laurence Pomeroy, 1st edition 1949:Ā 

Ā 

[Nearing the yearĀ 1927...] Everyone was agreed that the existing 2-litre cars were too lightly constructed and the prospect of a reduction in weight, coupled with a maintenance of speed due to enhanced engine efficiency, led to predictions of dire disaster. Indeed, responsible persons claimed that less than half a dozen drivers could take full advantage of the existing 2-litre cars and they considered that new, and lighter, 1,5-litre models would be even more difficult to handle. These criticisms were based on the assumption that designers would do all in their power to reach the minimum weight figure. In point of fact they did no such thing, practically all the cars scaling between 2 and 3 cwts. over the minimum which, in any event, was raised to 13.76 cwt. in 1927.

Ā 

If I had to guess, I'd think there's a more than reasonable chance that Fiat, trying to minimise the weight of their car (and, at the start of the season not knowing whether their competitors had been able to build lighter cars, and therefore perhaps feeling a bit anxious), did exactly the same thing as Delage did on their own car: remove as much metal (=weight) as they deemed opportune strength-wise vs. weight-wise.Ā 

Ā 

But as said, we'll never know for sure now and I'd say that in themselves Hannes' thoughts are valid too. As there's no certainty I guess it would be fair to sayĀ each depiction of the car should be considered equally acceptable.

  • Like 5
Link to comment
Share on other sites

Many thanks Roy! It must have been a good guess, I suppose. I just got inspired by the side panels. Quite a lot of "artistic-licence" will have to be employed in this project, because there's still so much unknown, but, I think that by using the Delage as reference/inspiration, I won't be that far off the probable truth!! I'm thoroughly enjoying myself!!!:D

Ā 

Great pics and info btw.

Ā 

Cheers, H

  • Like 1
Link to comment
Share on other sites

The same topic seen by another source ( Cyril Posthumus , 1980 )

" Four years was thought long enough for the 2-litre rules of the 1922-25 "Golden Age" . Early in 1925 the AIACR already gave hints that for 1926-1927 Grand Prix engine size would be cut to 1,5 litres , with or without superchargers , bodies would require only one seat , and minimum weight would be down to 550 kg .

This precipitated a great fuss to the effect that such cars would be too light and too fast for even the finest drivers to cope with ; so the AIACR had to rethink , and in July their Sporting Commission ( CSI ) announced that in fact bodies with two seats and 31 inches wide , as used in 1925 , would be retained, although no mechanic would occupy the second seat , while the proposed minimum weight was raised to 700 kg "

AccordingĀ  Massimino the weight of our 806 was 740 kgĀ  and it should get lowered to 700 kg for the Brooklands race ( drawing 2 .)

Many greetings !Ā  Hannes

PS : AIACRĀ  Ā“sĀ  name today is FIA ( 1946 ) , CSIĀ“s name was FISAĀ  (Ā  motorsport issues ,separated from AIACR in 1922 , united with FIA again since 1990 )

  • Like 1
Link to comment
Share on other sites

  • 4 weeks later...

Dear Harvey , this virtual model is very interesting and it shows an improved compressor . But itĀ“s not completely correct .Ā  The photo above shows the last remaining 406 engine part . ItĀ“s possibly still in possession of the Massimino family . As you can see thereĀ“s a steel core inside the cylinders . Besides itĀ“s technical advantagesĀ 

this core tends to get deformed very quickly and the engines had a very short lifetime for this reason .

These racing cars ( 801 - 806 ) could not get sold into private handsĀ  because they were not reliable at all .Bugatti sold his racing cars to everybody who was interested . If Agnelli had done the same , the reputation of his company would have been damaged .

I also doubt the tube adaption on the right engine front . We cannot see a construction like this on drawing 2 . Most likely the virtual designer was influenced by the Protar engine .

Besides these critic points this virtual drawing will be very helpful for us in the future . Great discovery ! Ā  Hannes

  • Like 1
Link to comment
Share on other sites

The photo on the right side shows the famous drawing of Massimino regarding the improvement of the frontal steering system .Cavalli said : "Ā  ItĀ“s too late " when Massimino showed him this drawing which he made during his vacancies . ItĀ“s interesting for us because it shows the exact lenght of the steering cross-memberĀ 

( 1121 mm )

Many greetings !Ā  Hannes

  • Like 1
Link to comment
Share on other sites

  • 2 weeks later...

Good afternoon, chaps! I hope all is well with you all!

Ā 

So then, time for an update on the proceedings! As previously seen, the chassis was becoming rather too weathered and needed completely stripping to sand, polish and protect with a couple of coats of clear metal primer. Next, I painted the cross-beams and engine-brace hangers matt black, then gave the middle 2 a light coat of AK xtreme metal metallic smoke for a bit of contrast. It was then assembly time.

Ā 

Whilst assembling I made the leaf-spring hangers for the rear from 0,3mm tin and 1,2mm brass tube. The frontal hanger supports were made from the brass pin of an old plug.

Ā 

38434040670_569220912e_h.jpg

Ā 

38434039010_986fabb903_h.jpg

Ā 

39346856155_9e5462a99b_h.jpg

Ā 

38434036750_75cee8c47b_h.jpg

Ā 

Ā  38434036070_827544905e_h.jpg

Ā 

38434035230_1abe01cebe_h.jpg

Ā 

38434034530_1cd52d16f5_h.jpg

Ā 

38434033830_b21c5007d3_h.jpg

Ā 

38434033010_f09aa071ab_h.jpg

Ā 

38434031540_1a0539bd5b_h.jpg

Ā 

Well that's all for now folks, I hope you enjoy. Leaf-springs next!

Ā 

Thanks for following guys!

Ā 

Cheers, H

Ā 

Ā 

  • Like 5
Link to comment
Share on other sites

Very convincing and neat ,dear Harvey ! As I can see you want to represent all 4 struts for the engine brace hangers .ThatĀ“s very realisticĀ  and a great improvement .

I hope I can show my improved bodywork soon . Ā 

Great work !Ā  Hannes

  • Thanks 1
Link to comment
Share on other sites

Thanks for your kind comments, chaps. Much appreciated!

Ā 

I haven't fixed the fuel-tank support yet, because it may need modifying and it's a bitch to bolt up. I'll know more when I start on the coachwork in that area, then it can be finalised.

Ā 

Cheers, H

  • Like 1
Link to comment
Share on other sites

Good evening gents!

Ā 

Leaf springs....I started off with a coil of 5mm x 0,5mm brass strip from ebay (3m for about 7 or 8 quid), then proceeded to cut to the required length. Since the brass came in coil form, it saved the task of having roll it to the desired curvature. Bargain!!

Ā 

Next step was to form the end loops. Unfortunately, I didn't take any pics of that stage, or my little jig, so I will take step-by-step pics and do a little "how-to" when I do the front springs tomorrow.

Ā 

Once that was done, the strip needed to be reduced by 0,5mm, soĀ I drilled the centres to take an M1 bolt and bolted the leaves together firmly. This made the task of getting all the leaves the same width a whole lot easier. I then removed the bolt and replaced it with a 1mm brass rod. A small dab of solder then holds the assembly together very firmly.

Ā 

The hanger assy's are made from nickel sheet and brass tube.

Ā 

Ā 

26391559588_3bce34bbc8_h.jpgDSCF1782 by Harvey Brennan, on Flickr

Ā 

38434030020_77a69cafe3_h.jpgDSCF1781 by Harvey Brennan, on Flickr

Ā 

26391560478_fc5745ad86_h.jpgDSCF1783 by Harvey Brennan, on Flickr

Ā 

26391566398_7d5052105a_h.jpgDSCF1785 by Harvey Brennan, on Flickr

Ā 

26391572418_a7c231edbc_h.jpgDSCF1788 by Harvey Brennan, on Flickr

Ā 

That's all for now, folks....stay tooned!:D

Ā 

Cheers, H

Ā 

Ā 

  • Like 5
Link to comment
Share on other sites

Great work again , dear Harvey ! When I made my first version of the leaf springs I bought fire bronce strips fromĀ  the german Hartmann company and used chinese jewellery pliers for bending the loops . ItĀ“s not easy , I know... I really like how you constructed the the connection with the axis .Great progress !

Many greetings ! Ā  Hannes

  • Like 1
  • Thanks 1
Link to comment
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
×
×
  • Create New...