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 Post subject: Re: AutoRail engines
PostPosted: Wed Jan 20, 2010 7:51 am 
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Greg Morgan wrote:
Getting back to the original topic of this old thread, about Bugatti ever installing a spark plug on opposite sides of the cylinder block, I was very surprised to discover something interesting on page 102 of Barrie Price's book on the type 46 and 50.
If you look at the upper picture (I would have posted the image if I had the slightest idea what I was doing), you see a photo of the Type 46 prototype engine. Notice that it has only one spark plug per cylinder, unlike the twin spark production version. But- when you look at the distributor it has dual ignition and then when you look harder you notice that the other eight HT leads are all fed down a tube to a set of plugs on the other sideof the engine.
I have been studying the very earliest factory drawing of the Type 41 engine overview and I now believe that at some early stage of the prototype Royales life it also had this plug arrangment. Most of the part numbers are for the Type 34 and it really indicates where the design came from. One thing that is for sure though, the story of the prototype having a larger engine capacity than its production offspring is a load of nonsense, every drawing held at the Bugatti trust has the 130mm stroke.

The trust do not have every prewar drawing, and in any event, I would not regard that as evidence that a larger capacity Royale engine was not built.There are some interesting Railcar blocks at the Schlumph museum,including the entire Diesel conversion.I am sure that the Bugatti engines would run better were there plugs on both sides of the block like the Bentley and other engines.


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 Post subject: Re: AutoRail engines
PostPosted: Wed Jan 20, 2010 8:50 am 
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Even the new Kruta - Hucke book pictures two T41 engine drawings with ignition on both sides of the block.

If this is so, it seems logical that at least the prototype T41 had ignition on both sides. Does anybody have under-bonnet pictures of the first Royale? I remember having seen pictures of the bare chassis (with the typical test drive configuration of a loose bench and a wooden box) somewhere as well.

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 Post subject: Re: AutoRail engines
PostPosted: Wed Jan 20, 2010 9:59 am 
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It is true that the Trust do not have every single drawing in their archives but they have some very early drawings of the royale engine and every one shows the stroke as being 130 mm. The only reason that the legend of the bigger engine in the prototype came about because of the articles written by Bradley at the time. I proved without a doubt that the prototype did not have a longer wheelbase than the production car, in fact the chassis rails were 80 mm shorter (see my article in the latest Bugatti Trust newsletter).
The only photo of the prototype engine that I have managed to find can be seen on the Bugatti Trust website (and strangley enough it found its way into the Kruta book, Thanks for the credit). It shows the usual plug arrangment, the most notable difference from the other engines is the narrow gearbox driving the camshaft. From studying the old drawings the reason for this has become clear, the two bevel gears driving the camshaft were taken straight from the Type 34 design and were significantly beefed up in the production engines- hence the wider casing we see on the cars today.
Also, Bugatti played about with the railcar engines because a diesel was badly needed.
What point was there in making the Royale engine any smaller? rationality?


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 Post subject: Re: AutoRail engines
PostPosted: Wed Jan 20, 2010 10:52 am 
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Getting back to the very first point of this thread, if you look at the photo in the Kruta book of the railcar engine, sure enough it has double ignition.


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 Post subject: Re: AutoRail engines
PostPosted: Tue May 11, 2010 8:12 am 
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Hi Greg.

Ever since you first alerted me to the fact that the prototype was the same length as the other 5 I have been playing around with tracings and overlays and I am convinced you are right - only if the prototype had bigger wheels and a higher radiator can it perhaps be a bit longer, and that is unlikely.

Correct me if I'm wrong but isn't Bradley the originator of both the longer chassis and the bigger engine theory and am I further correct in believing these theories has never been corroborated? In all probability the engine and chassis of the Coupe Napoleon is the engine and chassis which Ettore crashed and Ettore crashed the prototype.

Mind you I always believed the Aerolithe had a standard T57 chassis and then Richard Day wrote a superbly compelling article more or less convincing me that I was wrong. I now believe the Aerolithe to have been fitted with an early flat radiator, 'gondola' chassis. So my opinions cannot be relied on much, but I really think you've proved your point Greg ; the Royale was never bigger.

You questioned facts accepted as truth by Hugh Conway and proved the Grand Master of Bugatti historians wrong. Now that's one hell of an achievement.

With Admiration
Johan


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 Post subject: Re: AutoRail engines
PostPosted: Tue May 11, 2010 8:24 am 
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Greg Morgan wrote:
Getting back to the very first point of this thread, if you look at the photo in the Kruta book of the railcar engine, sure enough it has double ignition.

Thanks for pointing me to this picture, it is the first proof I have seen that Ettore actually used the remaining engines of the batch manufactured for the Royale in AutoRails!

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 Post subject: Re: AutoRail engines
PostPosted: Wed May 12, 2010 7:57 pm 
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What I can tell you as a definate fact is that the prototype Royale chassis was not longer than the production chassis- it was actually 80 mm shorter. The wheelbase was the same as the subsequent cars, but the distance ahead of the front axle proved to be too short to provide an adequate length for the front springs. A modification was made to the prototype chassis towards the end of 1927 which extended this distance to make it the same length as the production cars.
The engine for the prototype was also unique to this car, it did not have the elaborate camshaft clutch/bevel gear arrangement we see on the cars today and because of this, the front tower for the camshaft drive is more compact. Because of this the engine sump was some 50 mm shorter than on the production cars.
As for the bore and stroke of the first engine, it was identical to the later cars- the 14.7 litres that Bradley spoke of in 1926 was rubbish.
These are a couple of points that I have discovered after obtaining all the Type 41 factory drawings from the Trust.
Another thing that I have discovered is that on the Type 46 (the nearest thing Bugatti made to the Royale), if you look closely at the photo on page 102 of the Barry Price book on the big Bugattis, you can see that the prototype engine had double ignition, with eight plugs on each side of the engine in the manner that Jaap is talking about with the drawings in the Hucke/Kruta book, not 2 plugs next to each other as in the production Type 46 (and Royale).
One thing I can also say-there were seven Royales. The prototype was not the car we see today as the Napoleon. I dont even believe it carried the same chassis number.


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 Post subject: Re: AutoRail engines
PostPosted: Wed May 12, 2010 8:31 pm 
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Greg;
you can the drawings copieeren for the forum of the Trust :?: :|


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 Post subject: Re: AutoRail engines
PostPosted: Wed May 12, 2010 9:01 pm 
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Sorry buddy- not allowed to.


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 Post subject: Re: AutoRail engines
PostPosted: Wed May 12, 2010 9:31 pm 
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That had presumption I already.
But it is try worth. :(
I asked it also because my interest assumes particularly for models goes by train. :wink:


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 Post subject: Re: AutoRail engines
PostPosted: Thu May 13, 2010 11:09 am 
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Greg Morgan wrote:
What I can tell you as a definate fact is that the prototype Royale chassis was not longer than the production chassis- it was actually 80 mm shorter. The wheelbase was the same as the subsequent cars, but the distance ahead of the front axle proved to be too short to provide an adequate length for the front springs. A modification was made to the prototype chassis towards the end of 1927 which extended this distance to make it the same length as the production cars.
The engine for the prototype was also unique to this car, it did not have the elaborate camshaft clutch/bevel gear arrangement we see on the cars today and because of this, the front tower for the camshaft drive is more compact. Because of this the engine sump was some 50 mm shorter than on the production cars.
As for the bore and stroke of the first engine, it was identical to the later cars- the 14.7 litres that Bradley spoke of in 1926 was rubbish.
These are a couple of points that I have discovered after obtaining all the Type 41 factory drawings from the Trust.
Another thing that I have discovered is that on the Type 46 (the nearest thing Bugatti made to the Royale), if you look closely at the photo on page 102 of the Barry Price book on the big Bugattis, you can see that the prototype engine had double ignition, with eight plugs on each side of the engine in the manner that Jaap is talking about with the drawings in the Hucke/Kruta book, not 2 plugs next to each other as in the production Type 46 (and Royale).
One thing I can also say-there were seven Royales. The prototype was not the car we see today as the Napoleon. I dont even believe it carried the same chassis number.


On the pictures in Barry Price's Bug Bugattis book, it is very difficult to actually see the spark plugs on the exhaust side. There is single ignition on the inlet side, and there is a distributor with 16 leads, half of them going to the other side; your conclusion is logical. The picture of page 103 does not show spark plugs on the exhaust side, but this may be a different engine. Strange that Barry did not see this himself.

Thanks for your explanations on the differences between the prototype and the later Royale. I have a document from the 60's, where it is claimed that this prototype has been found.

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 Post subject: Re: AutoRail engines
PostPosted: Fri May 14, 2010 7:40 am 
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This document is now on-line; go to http://www.bugattirevue.com/revue41/henry.htm

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 Post subject: Re: AutoRail engines
PostPosted: Fri May 14, 2010 10:32 am 
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OK, a very nice document.

Would it be possible to go through the list of cars mentioned, and check history for each of them. The claims Mr. Cesari makes could then have a tag:

-true
-plausible
-not plausible
-untrue

If we can trace a good portion as being true, the Royale story, which at this moment cannot be verified, can at least be tagged "plausible". And the big question then: Where dit it go?

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 Post subject: Re: AutoRail engines
PostPosted: Fri May 14, 2010 11:31 am 
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Herman,

In those days, with Bugattis being priced at less than an average new car, there was not much need to lie about such things.

All of the statements therefore are at least plausible, and for those cars that I know, they are true.

Finally the myth of the 7th Royale becomes close to reality!

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 Post subject: Re: AutoRail engines
PostPosted: Fri May 14, 2010 5:36 pm 
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Herman wrote:
OK, a very nice document.

Would it be possible to go through the list of cars mentioned, and check history for each of them. The claims Mr. Cesari makes could then have a tag:

-true
-plausible
-not plausible
-untrue

If we can trace a good portion as being true, the Royale story, which at this moment cannot be verified, can at least be tagged "plausible". And the big question then: Where dit it go?

To Mr Harrah apparently.


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