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Alfa P3


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#51 Ray Bell

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Posted 18 July 2002 - 12:28

Actually, it wouldn't surprise me to learn that Jim Gullan modeled the new body on this one, he did much the same thing later when he built the Ballot Olds (a totally different car)... this he openly built along the basic lines of the ERA that Whitehead had raced here.

Just for interest's sake, here's a pic of that car (again)...



If you'd like to scan that pic, Richard, I'd be happy to post it.

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#52 Barry Lake

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Posted 18 July 2002 - 12:47

Originally posted by Vitesse2
That of course was the race where de Paolo's 4-wd Miller blew up so spectacularly ....



...and almost took out Adolf Hitler - despite the fact he was on the other side of the city at the time... :rotfl: :rotfl:

#53 Patrick Italiano

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Posted 18 July 2002 - 12:50

The streamlined Tipo B on the Alfa Club de France stand at Retromobile, coming from the Alfa museum, is indeed a replica made under Fusi's supervision during the 60s.

I add for those possibly interested in the "P3 transmission" issue that Doug Nye gave TNF his own conclusions, but in another thread, some not everybody has noticed it ( I did only recently )
http://www.atlasf1.c...&threadid=37444
Down page 1 .

#54 Vitesse2

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Posted 18 July 2002 - 12:50

Originally posted by Barry Lake



...and almost took out Adolf Hitler - despite the fact he was on the other side of the city at the time... :rotfl: :rotfl:


Never let the facts stand in the way of a good story Barry!! :rotfl: :rotfl:

I wondered who'd be the first to pick up on that.;)

#55 Ray Bell

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Posted 18 July 2002 - 13:30

Originally posted by Vitesse2
Never let the facts stand in the way of a good story Barry!!;)


I know I don't like to hear that sentence...

And I think Barry would have got sick of it too?

#56 dretceterini

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Posted 18 July 2002 - 16:03

I think that with 2 crown and pinion gears, closer to the ends of the axle, rather than one in the middle of the axle, there would be better torque control.

I would also think that the additional weight of 2 sets of ring and pinions rather than one would pretty much cancel out any benificial effect.

Although I agree IN GENERAL that lowering the seat by using 2 ring and pinions rather than 1 wouldn't have much effect, it would have SOME effect on the CG of the car, especially with the driver aboard.

Jano came up all the time with unusual designs to attempt to solve problems that appeared. The outboard petrol tanks on the Lancia D50...the Bugatti T251 GP car with it's "unusual" cross-tiebar (I don't really know what this oddball setup should be called) suspension...etc...

Stu

#57 Ray Bell

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Posted 18 July 2002 - 16:12

And I think, as outlined before, that he simply didn't understand why the Tipo A rear end worked so well.

This is effectively a copy of that rear end... but without what I believe was the beneficial component... contra-rotating driveshafts that cancel out the torque reaction of each other.

I still don't think the driver's seat height was reduced.

#58 dretceterini

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Posted 18 July 2002 - 17:20

Ray (and all) :

Are you sure the driveshafts wern't contra-rotating on a Tipo B (P3)?

Looking at from the car from the rear, maybe the right shaft rotated anti-clockwise and the left shaft rotated clockwise (or vice-versa)..

Did the teeth of the crown gears face outward (toward the wheels) or inward (toward each other)?



Stu

#59 Ray Bell

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Posted 18 July 2002 - 17:31

No, I explored that avenue...

Someone sent me diagrams of the differential layout and they were set up to spin in the same direction... seems to me that it was one of the great missed opportunities of all time.

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#60 Roger Clark

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Posted 18 July 2002 - 22:13

Originally posted by Vitesse2

In the race, Stuck sped away in the wet, building up a 1 minute lead by the end of lap 1,


Is this right - after one five-minute lap?

#61 Vitesse2

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Posted 18 July 2002 - 23:02

Roger - that figure is quoted in both Sheldon and Nixon. The start was VERY wet and in a picture in Nixon you can see an Auto Union starting very fast: this is presumably Stuck - only one car is ahead of him just seconds into the race.

Fastest lap was set by Momberger in 5min12.0sec - I'd guess Stuck's opening lap was substantially longer than that!

#62 Roger Clark

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Posted 19 July 2002 - 19:23

I still think a minute in a lap is a lot.

Sheldon gives Moll's race time over 15 laps as 1hr 26min 03 secs. This corresponds to an average lap time of 5min 44.2sec, so Stuck's opening lap can't have been very much slower.

#63 dretceterini

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Posted 20 July 2002 - 14:01

So the earlier Tipo A has contra-rotating shafts and the Topo B (P3) doesn't?? That seems like a HUGE oversight to me.

I'm sure that the swing axle set up was at least on the drawing board by 1934, and it works better anyway..

I also think that if Alfa had more money, the 12c 36s, 12c37s and 3 liter 312s would have been rather sucessful, and Jano would not have been booted out....but that is probibly a subject for another thread...

Stu

#64 Ray Bell

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Posted 20 July 2002 - 21:47

Indeed... a huge oversight... and while it might have been tremendously well balanced and all the other stuff, surely the self-cancelling of torque reactions would have given it more traction and thus made it a quicker car still.

I won't buy into the merits of the swing axle...

#65 VAR1016

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Posted 20 July 2002 - 22:16

First I would like to say how much I have enjoyed reading this thread.

Such a worthy subject too: the beautiful Tipo B ("P3").

I know from the first posting, that my point will be a little off-topic, but I am interested in the persistent rumour that lowering the seated height of the driver was either a) one of the objectives of the design or b) a fortuitous result (or not depending upon who you read!).

Last week at Goodwood I was studying the jewel-like 1927 straight-eight 1.5-litre Delage.

Now the driver sits very low in the Delage - much lower than in the Tipo B and although the Dealge's handling characteristics have been criticised, it does seem to have been a formidable achievement (especially as early as 1927) to arrange matters thus in a Grand Prix car (of course I am aware of how low Reid Railton's Rileys were at about the same time).

How was it done? no twin prop-shafts there!

VAR1016 :smoking:

#66 Ray Bell

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Posted 20 July 2002 - 22:54

Typical answers to this question were always along the lines:

a. offset the driveshaft.

b. offset the driver... or both

c. lower the driveline by some means, including by putting reduction gears below the differential input shaft (look at a Halibrand quickchange some day).

d. give the driver a rougher ride... one way or the other!

That Delage hasn't been modified, has it?

#67 VAR1016

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Posted 21 July 2002 - 08:26

Originally posted by Ray Bell
Typical answers to this question were always along the lines:

a. offset the driveshaft.

b. offset the driver... or both

c. lower the driveline by some means, including by putting reduction gears below the differential input shaft (look at a Halibrand quickchange some day).

d. give the driver a rougher ride... one way or the other!

That Delage hasn't been modified, has it?


Thanks for the reply. The Delage looked very standard - and it was pouring with rain so too miserable to go crawling on the floor!

I have a period photograph of Earl Howe sitting in his own Delage and it can be seen just how amazingly low it was.

VAR1016 :smoking:

#68 Kvadrat

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Posted 09 June 2005 - 10:46

Originally posted by Todd on 09-Dec-99 at 10:03
The twist of the differential is pressing on the left rear wheel under acceleration.


Why?

#69 Ray Bell

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Posted 09 June 2005 - 11:34

More to the point, it's trying to lift the right hand wheel off the ground...

That's the effect of the torque reaction between the pinion and crownwheel.

#70 Kvadrat

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Posted 10 June 2005 - 09:19

Thank you.

#71 Ray Bell

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Posted 10 June 2005 - 09:50

...which is a part of the case in favour of worm drive rear axles.

#72 Catalina Park

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Posted 10 June 2005 - 10:30

Originally posted by Ray Bell
...which is a part of the case in favour of worm drive rear axles.

Or transverse engines. ;)

#73 Ray Bell

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Posted 10 June 2005 - 10:44

Depending... if the gearbox is in the same oil as the engine, various factors change. For instance, animal clearance is totally negated...

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#74 Catalina Park

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Posted 10 June 2005 - 11:01

Originally posted by Ray Bell
....animal clearance is totally negated...

Which is another problem with worm drives.