Fiat 806: research and scratchbuilds

[CrazyCrank]

Anyone here who knew this photo ?

 

 

 

It's probably the kit Italeri, because of the spokes, but i'm struck by this fact: we can see throught the grill ot radiator  by holes

 

 

And there is a lot of spokes on the front grille

 

Last Edit: Ok, I've found.....I apologize, guys, this is a kit !!! 

Edited November 12, 2016 by CrazyCrank

[Roy vd M.]

Again, very interesting new info. 

 

CC I am not convinced by your indication of the water pump or crank hole though, at least if the water pump is an extension of the left crankshaft (because then the left crankshaft would be too far to the left). I must admit however that the crankshafts are most likely not to be considered as extensions of the supercharger shafts (because then those shafts would be too far toward the center of the engine).

 

Compare with Bugatti M-engine.

 

 

 

I will think about this for a bit more.

 

 

Edit: ..... or..... maybe you're right after all. Of course it's only a 1,5 liter engine so the cilinders are probably tiny. Now I see some hints in the drawing that may lead to you being (partly) correct after all.

Edited November 12, 2016 by Roy vd M.
Or maybe...

[NickD]

This thread is insane. Respect to all who have contributed so far.

 

OK, so I think the tech might be finally catching up with VTs iPhone. It is a long way from right, but as you will see I think some caution is required before anyone enthusiastically butchers bodyshells. I have three photos. A bit less rough than last time but I have still only looked at one photo, which is not really enough to do things properly.

I love this photo. It appears to be with a very long lens. But one concern is that a pre-war camera is likely to have all sorts of quality issues more modern cameras don't suffer.  Anyway, key to alignment was the front red chassis tube. and getting all the tyres level. Those 5 features seem to line up quite well. Maybe the front still needs a very minor adjustment. I started with Drawing 2 geometry including wheels. Funky colours chosen to give some contrast.  The lines do not have the curve of the windscreen cowl or the cylinder head blisters etc.Had to rescale the tyres. Scaled the fronts and used at the rear. Old tyre is shown for comparison. Increasing diameter means the ride height on the drawings is possibly too low. To get the right alignment had to move the wheels back a little. Not happy that is real. I'll come back to that. As we will see in a minute the bodywork had to be raised to match the photo. So Drawing 1 is too high and drawing 2 is too low. Chassis looks to be quite close.

Drawing 1 really is rubbish. Wheels are very out of round. Not just a linear stretch in one direction. Bodywork is too high everywhere. Chassis not far off. Position of front edge of the cockpit is quite good. Ignor the lefthandside of the cockpit. I have not done that yet. The rear of the cockpit bothers me a bit because its a big difference and is similar to the wheelbase error. I fear photo 1 may have some sort of residual distortion at the edge of the photo which might be a bit difficult to spot.

This photo refers to Drawing 2 lines. Where the red shows through Drawing 2 is too high and where it is green the drawing is too low. So it is low at the front and high at the rear. Cockpit position on Drawing 2 is similar to Drawing 1, so the concern for me is that the photo alignment above is not valid at the back. Other photos will need to be checked before it can be confirmed one way or the other.

 

The other concern is directed to Olivier. The above analysis is only really good enough to urge caution. At the moment none of the lines for the body seem right so be cautious everyone who has scapel, saw and dremel in hand. I don't mind being wrong but I would hate to deliver bad news at some point that is right.

[Roy vd M.]

Where are my other 9 likes for that post!

 

Excellent work Nick and I must say your conclusions (last image) are exactly as I thought they would be, except for the middle red section which I hadn't noticed. I'll have a look at that. But the green part is also where I saw a match between Drawing 2 and the photos. The rear section I had noticed to be different (Drawing 2 differing from the photos) after Hannes gave that remark. 

 

Indeed drawing 2 could represent a further development model for 1928 (never finished) where 90% of the body lines are similar to the 1927 version.

 

Great work!

[Hannes]

Dear Crazy Crank, that´s the Protar Version with different tires : This was builldt oob like I did a Long time ago,when no Internet existed to get precious informations like we share today.

Dear Nick,what an amazing work!  Hannes

[NickD]

Chaps, Thanks. But I have been playing with this sort of thing for a long time. As I have noted elsewhere, the quality of the tool is the really cool bit. I love it when/ if it works.

 

Glad it seems to be consistent.

[Roy vd M.]

I'm stuck it seems.

 

Looking at the 5th picture here of Andi's engine it's clear that Protar says the crank should be in what we think is the right side compressor drive shaft (=on the picture: left side). But then the two 'crankshafts' would, in my opinion, be too close to one another. 

 

So I went on to research CrazyCrank's theory. I edited the engine drawing in Inkscape:

 

 

 

and I'm lost. I'm trying to prove that the 'circle with the 6 bolts' that CrazyCrank deemed to be the water pump, is (next to probably being a water pump) the left crank shaft. In itself that would have been possible although there is only limited height to the top of the engine. The reason is, that each cilinder only had a displacement of 125cc. That is this:

 

 

Really very little. So the cilinder doesn't have to be long and it doesn't have to be wide.

 

The problem I see is that the exhaust camshafts were placed at an angle, almost diagonally. Therefore the valves would not be at the top of each cilinder (which is standard) but at the side of each cilinder. When on the last of four strokes (the exhaust stroke) occurs, the piston will not be able to push out all gasses. In fact, the piston would seal off the valve opening and unless any other opening were in place, the engine would most probably explode or break down after 2 seconds. I'm sure that's not what happened in 1927. 

 

Another problem is that the 'cams' would have to be inverted, because the valves driven by the cams would have to be placed externally, as seen in my drawing. Placing them internally is impossible, as the pistons would crash into them. 

 

This is from the Wikipedia article Crankshaft quoted:

 

A single shared centrally mounted camshaft, patented by Guido Fornaca,^[6] operated the induction valves which were on the inside of each cylinder bank; two camshafts mounted outboard drove the exhaust valves. 

 

So what are the other options? In my view it's illogical if the valves are not at the top of each cilinder. How could this have been in the real engine? 

 

My only remaining theory would be that the cilinder ceiling is much lower than on the drawing. Then both intake and exhaust valves would be positioned just on top of the cilinder. Judging by the size of the spark plugs it may have been possible (those were then LOOOONG spark plugs!) but there would be very very little room for displacement... again, IF CrazyCrank's theory is correct. 

 

Probably I'm overseeing something and I'm being very stupid. I'm looking forward to your thoughts.

 

 

[Hannes]

Dear Roy, have to mull over too... All that I know, is that at this time horizontal valve constructions (all in a row!) were made like the Horch V 12,1933. Many greetings!  Hannes

[Hannes]

Dear Roy ,lok at the Bordino Fiat Monza side (Big scale models) The second small Picture on the right side. Maybe this could be helpful!  Hannes

[Roy vd M.]

This is not an easy post... hope you will be able to follow my thoughts here and I hope you'll have a bit of patience reading this post.

 

 

This could be what the cilinders and valves looked like. The pink thing is the piston. Obviously the cilinder and valve etc. should be mirrored on the opposite side of the engine.

 

The drawing would still imply that the crank isn't extended to either of both 'crankshafts'. It would still implies that there are internal gears (or a chain) transmitting the manual cranking motion to the 'crankshafts'. I see no problem with that though. I'll comment the Wikipedia quote to examine if my drawing and theory could be correct. 

 

Starting in 1925, FIAT began preparing an engine and car for the new 1926 1.5 litre racing formula, adopted in both Europe and the USA.^[5] For the engine, designated the 'type 406', FIAT chose to mount two 750 cc six-cylinder banks side by side...

 

Check and confirm, see drawing.

 

...on a common aluminium crankcase, with their crankshafts geared to a common output shaft.

 

Check the 4th picture in this post of Andi's: the output shaft is set (according to Protar (who I'm 99,999999% sure had a side drawing of the engine at their disposal) very low to the ground, at the rear of the engine entering the gearbox. Suppose for a second that gears were used in the engine internally. Then the central wheel could look like gear wheel 'B' in the next drawing.

 

 

How to 'read' the drawing, seen from the front of the car (in other words, seen as it was drawn):

 

- Gear wheel A turns clockwise. It is on the manual crank shaft as well as on the compressor drive shaft. This is supported by Protar's kit and Drawing 2, as pointed out before.

- Gear wheel B turns counterclockwise. When cranking manually, it is driven by gear wheel A. This is the output shaft, as named by Wikipedia.

- Gear wheel C turns counterclockwise. It is on the same shaft as gear wheel B. As said, this is the output shaft. 

- Gear wheel D turns clockwise. It is the right engine half 'crankshaft' as we call it nowadays.

- Gear wheel E turns clockwise. It is the left engine half 'crankshaft' as we call it nowadays. 

 

To educatedly theorize further, I reckon there was another gear wheel centrally above Gear Wheel C. From there most probably the three cam shafts were driven using one chains. See in the hereunder drawing gear wheel F, turning clockwise. It's on the same shaft as chain wheel G. Through chains, chain wheel G drives the three camshafts. Each of these three shafts would have turned clockwise.

 

 

A single Roots-type supercharger driven from the nose of the right-hand crankshaft

 

Now it gets a bit tricky. If by 'the nose of the right-hand crankshaft' the author meant the manual crankshaft (in my drawing: 'A'), which is situated on the same shaft as the supercharger drive shaft, being on the right side of the engine, then Drawing 2, Protar and my rudimentary theory are correct. Provided that the Wikipedia author is correct, of course.

 

Another, probably better, interpretation of the quote would be that the right 'camshaft' would directly drive the supercharger driveshaft (being, according to Drawing 2 and Protar, also the manual crank shaft). The 'nose' of the right-hand crankshaft could mean a chain wheel mounted at the very front of the right-hand crankshaft (on my drawing: wheel D). That would mean that while manually cranking the car, the right-hand 'crankshaft' D would not only have a gear wheel (to drive gear wheel C) but would also contain a chain wheel. Through a chain it would drive chain wheel D, the right 'crankshaft'. In that situation, gear wheel B would not exist. It could look like this:

 

 

This theory appeals to me more, because of the contents of the remainder of the Wikipedia quote:

 

delivered mixture to a pair of intake manifolds located between the cylinder blocks at 13 psi boost. The left-hand crankshaft drove the single water pump.

 

If by 'left-hand crankshaft' the author meant the opposite of 'right-hand crankshaft' (=wheel D), which would point to the shaft of wheel E, then the water pump could be seen drawn into the drawing of the engine. Just like CrazyCrank says. This would make most sense to me. The alternative would be that the author meant wheel E when using the term 'left-hand crankshaft' and wheel A when using the term 'the nose of the right-hand crankshaft'. That seems very unlikely to me. So I think my last engine drawing (which leaves out gear wheel B ) comes closer to the truth. 

 

A single shared centrally mounted camshaft, patented by Guido Fornaca,^[6] operated the induction valves which were on the inside of each cylinder bank

 

Out of the three top shafts driven by chains, this induction valve camshaft is the middle one. 

 

two camshafts mounted outboard drove the exhaust valves.

 

Those are the top shafts to the left and to the right.  

 

Twin Bosch magnetos were driven from the tail of the central camshaft.

 

We cannot check that in this drawing. 

 

The engine weighed 381 lbs, not excessive for the time. On test the unit delivered 187 bhp at 8,500 rpm at maximum boost "

 

Now to quote CrazyCrank (whose name could not have been better chosen):

 

So there were two  crankshafts in a unique crankcase on this engine, and by a set of gears, these two crankshafts came out on a common output shaft, probably situated at the lower part of the crankcase. This common shaft drove the engine flywheel at the back of the engine,

 

Correct according to my theory.

 

This common shaft (...) was probably connectable on the front of the car to the starting crank

 

I disagree here, as do Drawing 2 and Protar's engineers. The reason to not use that position for manual cranking: it would be too high (radiator would be in the way). I don't say your theory is incorrect though... just saying that more research is welcome. But as the cards are at the moment, I'd say that your theory is questionable in this respect. 

 

The case in front of the engine is the supercharger, driven by right crankshaft. Above it, the water pump, driven by the left crankshaft

 

Correct according to my theory.

 

And at the upper middle of the supercharger, there is a hole where to put the crank !

 IMHO

 

In my theory, that would be the output shaft (wheel C) to which the crank would not be connected. 

 

So.... hopefully you'll all have survived this extensive theorization lol 

[Roy vd M.]

2 hours ago, Hannes said:

Dear Roy ,lok at the Bordino Fiat Monza side (Big scale models) The second small Picture on the right side. Maybe this could be helpful!  Hannes

 

Good one! I looked it up and found a better version here. 

 

(Copyright Saga55, educational purposes only, picture will be deleted upon first request)

 

That also shows that Drawing 2 might be from a book featuring that same drawing. Unfortunately the (French) text isn't scanned optimally so I can't read most of it. 

 

Before I forget it, during my websurfing activities I also found scans of Protar's instructions and perhaps, in this same post, another photo of the car (see second image of that post). Regarding the instructions, Photo 5 featured on the first page seems to be a better scan than the one I found online. And the scan isn't even that great. Does anybody have an original copy of the Protar instructions? And if so, would he be so kind as to scan that page, using the best possible scanner settings? I'd be much obliged... 

 

Anyway, a few things I conclude from the technical drawing of the engine's inner works as I copied above:

 

- To start with the positive, I was right that all three cam shafts turn clockwise. That supports my theory that they were all chain-driven by one wheel (in my drawing: chain wheel G).

- I was wrong to put the 'crankshafts' so high. They should be placed quite a bit lower.

- I was wrong to use a flat cilinder top. It turns out to have the shape of an upside-down 'V'.

- I put the water pump in the correct place. However it wasn't lined up as an extension of the left 'crankshaft' but was in fact driven by it from below (!).

- The 'crankshafts' appear to have driven the supercharger shafts directly. They did use gears for that, most probably behind the supercharger. Which makes sense if you take a look at pictures of the finished engine model.

- The two supercharger shafts were also connected to each other by gear wheels. It makes sense, really, now I come to think of it. I'll come back to that hereunder.

- When the left engine half turns clockwise, the right engine half turns counterclockwise (and vice versa).

- There's no doubt now that what we thought was the supercharger is exactly that ("asse compressore" -> supercharger axle). 

- Logically, the supercharger air comes from below ("aspirazione" -> breathe).

- With engine halves turning oppositely and the both exhaust valve camshafts turning in the same direction, the outer cam shafts were probably mirrored. 

- In the drawing I see no central gear wheel for the output shaft. I therefore can't know where it was. 

 

But most importantly, by studying this drawing it has become almost clear and without doubt to me that shaft A in my drawings was in fact the manual crank shaft. 

 

Why? Because the drawing makes clear that all gear wheels (mounted on both 'crankshafts', the water pump shaft and both supercharger shafts) were linked. I had not thought about it being necessary for the two supercharger wheels, but of course, thinking of it now, they need to stay relatively synchronized at all time. The supercharger mechanism in itself isn't reliable to do that and it would furthermore be damaged and worn if there were no gear wheels to connect both drive and driven axles to one another. That having established, the drawing makes clear that both supercharger gear wheels are in connection with the 'crankshaft' wheels. In this situation in principle it should make little difference technically as to which of the gear wheels is actuated by the manual crank shaft. If I were the engineer, I would pick the lowest (=radiator height) and rightmost (=toward car center) shaft. To reduce the risk of gear wheel torque I'd preferably not use either wheels at the end. 

 

The only situation in which this theory is -very maybe- wrong is that of the output shaft being placed slightly above and centrally in between the two supercharger shafts, as mentioned by CrazyCrank. But I see no evidence of that whatsoever. The newly discovered technical drawing doesn't make it clear. Protar clearly chose my theory and the same applies to the artist responsible for Drawing 2. 

 

Another possible reason for not using the output shaft (which may be the circle referred to by CrazyCrank) is that -unlike a regular crankshaft- it probably was not the strongest link. The reason why I think that is that the output shaft was either driven by ONE 'crankshaft' either by chain or by gear wheel... in which case the drive shaft would have been the end of the series of gear wheels. It cannot be driven by two equally large gear wheels driven by both 'crankshafts', because they rotate in opposite directions. In this situation, the drive shaft gear wheel would be easier 'torqued' upon cranking the car up, because it wasn't enclosed by two wheels, one at each side. Remember, this was a car from 1927 and a race car at that, so reduction of engine weight would have been important for the engineers. Not claiming it would have been a flimsy engine (not even claiming that because it's a Fiat), I personally would have opted for a manual crank shaft gear wheel put between two other gear wheels. 

 

Suppose a chain was used to drive the output shaft, then these arguments apply even more strongly, because a chain is generally weaker than a gear wheel. It's perfectly okay to use driving the rear wheels (see also the Mefistofele), but not so much to put pressure on all engine shafts. 

 

Third option would be if the drive shaft were 'fed' from both sides, in other words from both 'crankshafts'. One side would be driven by only one gear wheel driven by the one 'crankshaft', the other by two gear wheels in a row (to 'synchronize' the direction of the wheels) driven by the other 'crankshaft'. This would seem improbable to me, because two extra gear wheels would mean extra weight, plus.. the more gear wheels the more friction, the slower the car will be.

 

Checking the Wikipedia quote again with this new information, everything seems to be in order. 

 

And one final thing, as I mentioned in my previous post I'm almost certain Protar had a side drawing of the 406 engine. Take another look at Andi's finished engine. Why would Protar make such a... let's say unmistakably present and protruding connection hub for the manual crank shaft? I don't think they made that up.  

 

Further support for this theory:

 

- Drawing 3 also features the large protruding hub (?) and it seems aligned to the manual crank shaft. I'm not so convinced about the value of Drawing 3 but I'm a hypocritical human being haha

- In Drawing 2, not only does the engine center not line up (horizontally) with the manual crank shaft, the same applies with the cardan shaft.

- Finally, in Drawing 2 it becomes clear that the crank shaft is situated considerably below wheel center level and thus below cardan shaft and differential. 

 

 

although... and this may also be something newly discovered... do you see that dotted line starting at the rear wheel centre and leading to the front of the car? That might just be the real cardan shaft (especially as the dotted line starts (or ends) there... now why would that be. Not sure what Protar did with that information, if they had it available.  

 

Here is that line but now in red. For my conclusions above it's relevant to note that also the red line doesn't extend to the manual crank shaft. 

 

Note that below the steering wheel there is the 'bend'. Did anyone notice a bend like that in their kit parts? Or maybe a cross-joint?

 

 

Anyway, if Drawing 2 is correct in this respect (although I think Drawing 2 is a very trustworthy source in many aspects I'll always have my reservations given the nature of this project) I advise you to take a look at the cardan shaft in your Italeri kit. It just might need correction... (what's new)

 

I sure hope everyone survived all of this text. Now I'll try to get some sleep finally. It's an addictive project this. 

Edited November 13, 2016 by Roy vd M.

[Totally Mad Olivier]

Hello guys, 

I am impressed by all infos going on this thread! Can't follow!! Ok, I'm gonna sell my cabinet to devote myself to the project. (I joke)

Well, I have not read yet all your posts, and I change a little the subject.

As I am working now on the 17th step, I asked CC to give me his feelings about a photo of this step on a model.

(I precise this is NOT my work)

 

He sent me this (sorry, tuto in french):

 

and that (sorry, in french too):

 

On my side, I found this on the Mef (but I suppose it is not the original piece):

 

 

Thanks so much for this help, Thierry! Now, I wonder if I should reproduce the Hartford shock absorbers Thierry sent, with the inscriptions, or the Mef ones, all black... My Fiat is supposed to be placed in the time a few days before the race... 

I will be confident on Protar and let the 2 rebound clips, just getting a better shape, as suggested by CC.

Suggestions? 

 

What I liked the most on the photos CC found: Posted 8 hours ago is the escape traces. I will try to do the same, very nice and realistic.

Edited November 13, 2016 by Olivier de St Raph
Correction

[Totally Mad Olivier]

P.S: I think this important doc (thanks to John and Rich) was missing on our thread, so I add it:

 

 

 

[Totally Mad Olivier]

 

I could not resist making an enlargement and posting this detail which I referred above... Good weathering!

Edited November 13, 2016 by Olivier de St Raph
Correction

[Totally Mad Olivier]

11 hours ago, CrazyCrank said:

there is a lot of spokes on the front grille

on this photo, it is the kit's grille with its 32 spokes, but the weathering is good, and this makes think there are more. In fact, there are 52 spokes on the grille...

[Totally Mad Olivier]

 

Enlargement of the Torino museum showing the Mef's shock absorbers and leaf springs:

1) the shock absorbers are the same than the one we saw just above on another Mef, gloss black and with a shape slightly different from CC Hartford photo. We can suppose the 806 ones were close from the Mef ones...

2) The leaf springs have only 2 rebound clips, we can imagine it was the same for the 806, and Protar made them so.

3) Notice the adhesive strips probably used to attach the springs together...

4) Notice the brown aspect of the leaf springs, that seem to be rolled in leather or something like that. Rest to know if on the 806, leaf springs were rolled like that or not, which changes very much the aspect. Your opinion?

Thierry sent me a tuto in french on PM about leaf springs, I can post it but I know the thread is supposed to be mostly in english (Julien recalled that). I think it would be useful for everyone, tell me if you mind.

 

All the best, waiting for comments...

 

Have a nice and peaceful sunday

 

Olivier

[Hannes]

Dear Roy,there´s nothing in the Protar´s instruction  ,That we don´t know already.The black and White Picture of the master model is the same as I was posting some weeks ago.

I also believe, that Protar did not use another sideview than shown in drawing 2.

But there are some important differences!  If I look at my Protar engine and compare it with drawing 2,I can see that the cooling ribs of the roots blower are much more Extended in the vertical direction(about 3 mm!)

The first Fixing Point for the engine could be a Little bit too high (ca.1mm) but I see it now as a reference Point.

The crank´s line on drawing 2 lies under this Fixing Point and the Protar´s solution very slghtly too.

The Point for the crank´s hole as we consider as right lies over our Fixing Point!

We should not Forget,that the grill and it´s Radiator case in drawing 2  were altered compared to our car (bottom line!),so there´s further Research required.  Many greetings !  Hannes

[Roy vd M.]

8 hours ago, Olivier de St Raph said:

I am impressed by all infos going on this thread! Can't follow!!

 

You are right, I reasonably should have included a summary of my findings. I'll give it here: I have been trying to replicate and theorize about the internal construction of the Fiat's U-engine. The reason to do that is not that we'll ever need to rebuild it, but to check whether the manual crank shaft should be connected to the hole where Protar indicates it should be. My conclusion, after much research, is that Protar (and the artists who drew Drawing 2 and Drawing 3) were most probably correct. 

 

8 hours ago, Olivier de St Raph said:

[Pictures with French texts]

 

Now, I wonder if I should reproduce the Hartford shock absorbers Thierry sent, with the inscriptions, or the Mef ones, all black... My Fiat is supposed to be placed in the time a few days before the race... 

I will be confident on Protar and let the 2 rebound clips, just getting a better shape, as suggested by CC.

Suggestions? 

 

What I liked the most on the photos CC found: Posted 8 hours ago is the escape traces. I will try to do the same, very nice and realistic.

 

I'll study this subject and its French texts more closely when I'll focus on this subject (the shock absorbers), hopefully you won't mind. My limited technical French does not allow me to study this quickly at the moment. 

 

8 hours ago, Olivier de St Raph said:

P.S: I think this important doc (thanks to John and Rich) was missing on our thread, so I add it:

[photogrammetry]

 

You're right there. I will add that to the first post.

 

8 hours ago, Olivier de St Raph said:

 

I could not resist making an enlargement and posting this detail which I referred above... Good weathering!

 

Indeed nice weathering. I think it was inspired by photo 3 (although the exhaust in that photo is lower). I'd like to note thought that the exhaust pipe may not have been square but circular, see photo 8. But maybe photo 8 was altered. Photo 7 makes it seem like the exhaust end was square indeed. More research required

 

4 hours ago, Olivier de St Raph said:

Enlargement of the Torino museum showing the Mef's shock absorbers and leaf springs:

1) the shock absorbers are the same than the one we saw just above on another Mef, gloss black and with a shape slightly different from CC Hartford photo. We can suppose the 806 ones were close from the Mef ones...

2) The leaf springs have only 2 rebound clips, we can imagine it was the same for the 806, and Protar made them so.

3) Notice the adhesive strips probably used to attach the springs together...

4) Notice the brown aspect of the leaf springs, that seem to be rolled in leather or something like that. Rest to know if on the 806, leaf springs were rolled like that or not, which changes very much the aspect. Your opinion?

Thierry sent me a tuto in french on PM about leaf springs, I can post it but I know the thread is supposed to be mostly in english (Julien recalled that). I think it would be useful for everyone, tell me if you mind.

 

Re. last point: I'd welcome any information in this thread, in French or in English. When the time is right (=when I'll start working on the leaf springs) I'll translate the text as well as I can. 

Re. points 1) to 4), it would be my tactic to use as many details as seen on the Mefistofele on my 806 build insofar there is no other information available. I'll decide on that after finalizing my research. Meanwhile I'm happy that you are sharing these wonderful insights, which we will most probably need for our build. 

 

38 minutes ago, Hannes said:

Dear Roy,there´s nothing in the Protar´s instruction  ,That we don´t know already.The black and White Picture of the master model is the same as I was posting some weeks ago.

 

Ok thanks for checking.

 

38 minutes ago, Hannes said:

I also believe, that Protar did not use another sideview than shown in drawing 2.

 

I reckon you mean Drawing 1. Or perhaps you mean "Protar DID use another sideview than that shown in Drawing 2".

 

38 minutes ago, Hannes said:

But there are some important differences!  If I look at my Protar engine and compare it with drawing 2,I can see that the cooling ribs of the roots blower are much more Extended in the vertical direction(about 3 mm!)

The first Fixing Point for the engine could be a Little bit too high (ca.1mm) but I see it now as a reference Point.

The crank´s line on drawing 2 lies under this Fixing Point and the Protar´s solution very slghtly too.

The Point for the crank´s hole as we consider as right lies over our Fixing Point!

 

To be clear about this, I am fully convinced that Protar used the correct fixing point (=right hand supercharger shaft) for the manual crank shaft. 

 

Thank you for your other notes. 

 

 

##########

 

 

Friends I just wanted to speak out that I feel very fortunate and proud to be able to contribute to a topic that is fed by very intelligent and knowledgable people. Whenever I thought I saw someone contribute a valuable thing, I saw someone else contribute something possibly even more remarkable. Rarely have I encountered this level of insight and smartness in any other thread and I do feel at home here. I enjoy all the research and over-the-top scratchbuilding and it seems I have met a bunch of soul mates. Your contributions are what led me to purchase the kit.

 

Coming back one more second to the split up from the Gangshow thread (r.i.p.), I think one of the differences in approach between most of the original posts / builders and the current contributors to this thread is that we probably love the research part as much as we do the building part. We seem to get a lot of joy from this 'quest' full of surprises around each corner. I know I do. It's like a labyrinth that you might or might not finish in the center. But we know for sure that we are approaching the labyrinth's center with every new insight and every new finding. It would not shock me to learn if you guys are all interested in history and its mysteries, and that you often watch History Channel, Discovery Channel or National Geographic Channel. 

 

In my view, this is what drives us, this is what separates us from those who prefer to keep themselves to modeling. They just want to get on with the build are here specially for the joy of building and watching others build. I understand that difference and as I said before, no view is better than the other. 

[Hannes]

How did you know my favorite channels? Of Course I am very interested in history culture ,arts philosophy,astronomy and science. I think all These Things can be described as human curiosity. Many greetings! Hannes

[vontrips]

46 minutes ago, Roy vd M. said:

It would not shock me to learn if you guys are all interested in history and its mysteries, and that you often watch History Channel, Discovery Channel or National Geographic Channel. 

 

LOL...spent most of my career working for The History Channel and freelance for Discovery and Nat Geo!

[CrazyCrank]

There is 3 TVS sets at home...

I quite never look at them, because always another urgent or most important thing to do....very occasionally, one of my TV looks at me 

 

But you're right Roy, when I had time to  watch TV, my favourite shows were: National Geographics, Thalassa, Faut pas rêver, Discovery etc.

 

To talk about most serious things: you definetly convinced me with your last analysis  of the U engine working, and, right, the crank connect very very probably but indirectly to common crankshaft via the right shaft or the blower...I warmly congratulate and thank you !

WE ARE fortunate to have  such an expert like you with us

 

 

 

Edited November 13, 2016 by CrazyCrank

[NickD]

Chaps, a couple of questions, well 3 actually.

 

Olivier - did you note my earlier post on caution about using either of the drawings as a reference for the lines. It won't be a surprise as the Roy and VT had covered most of it. I will post updates if and when I have them. On springs, the various Mefistofele threads cover springs in a lot of detail. Full-size uses cord I think. The white stripes are presumably tape.

 

Roy - I didn't notice in your comprehensive engine analysis but it may have been covered, did you think about whether your conclusions were consisent with the action of turning the starter handle. Presumably the handle to engine revs gearing is appropriate?

 

Nick

[Roy vd M.]

11 minutes ago, NickD said:

did you think about whether your conclusions were consisent with the action of turning the starter handle. Presumably the handle to engine revs gearing is appropriate?

 

If you're talking about the timing of the four gear wheels it can be concluded that the timing is most probably correct. 

 

 

 

Take a look at the two 'crankshaft' gear wheels. The left wheel (on the drawing: right hand) is not seen in the drawing, safe for a small part of it. What you see in the drawing is the smaller gear wheel that drives the water pump. That smaller gear wheel is on the same shaft as the larger gear wheel driving the left compressor gear wheel. The larger gear wheel (a bit of curvature is shown in the drawing) has the same diameter as the three other low gear wheels.

 

That means that if the compressor wheels are at 60% speed and are at 60% compressing capacity, the gear wheels of both 'crankshafts' are also running at 60% speed. The amount of air being compressed is therefore linear to the speed of the 'crankshafts' being turned and therefore linear to the amount of fuel needed. 

 

So that shows me that the timing as seen in the drawing is correct. 

 

Whether the manual crank was connected to either of the four lower shafts would have made no difference in drive shaft RPM. 

 

I hope this answers your question.

[Hannes]

I found another description of the 406  engine in a book about racing cars,dated 1990.I don´t trust These descriptions,but maybe some truth can be found.

It says,that the camshafts were driven by a (!) crankshaft over gears. 2(!) roots blowers were supposed to press air into the carbouretors.(I can see two of them,maybe one blower for one carbouretor and 6 cylinders?)

Because there´s a nice drawing too,I´ll send the german description together with another drawing I found today or tomorrow (dont know,how Long my sister Needs her Office-pc today)

Nothing new,but interesting...  Hannes

[Hannes]

Dear Nick,dear Olivier,these White spots are not tape,this only shows parts,where the strings were  renewed.Look at my Mef´s construction and you will see,what I mean (Fiat Mefistofele Protar+Italeri Wettringer modellbauforum.de)I did not Show the diagonal strings,because they are tied together with very ugly knots .Hannes