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Sat Nov 28, 2009 4:51 pm

The control arms are forged steel. Cast iron wouldn't be able to take the impact loading.

Sun Nov 29, 2009 12:32 am

kdfkid wrote: Hi PatterBon,

the engine is not correct for the the 38 it is from 1939 but at the moment i think i can not get closser ! :lol:
Christian

:) a 1939 engine in just as good in my books, and with you and your crews luck, with in a year or so of having it done, you'll have found enough parts to put together a 38' engine!

Sun Nov 29, 2009 1:35 am

kdfkid wrote:
PS : This is at the moment the only orginal arm known !

So, either the '38 vert has not original trailing arms?

Sun Nov 29, 2009 1:37 am

Hello,
no the 38 in the autostadt and the cabrio do not have these arms !

Christian

Sun Nov 29, 2009 7:34 am

axel struwe wrote: Hi Undis,

as Christian told me yesterday, the VW38 has no heather at all.
On the motor you can´t found any heatherboxes, only "J" pipes.
So, the restauration going to be cheaper... :lol:

Axel

You're right, I had the images of VW38/31 vert in my mind. It has the heater outlets under the rear seat.

Sun Nov 29, 2009 11:31 am

PatterBon wrote: kdfkid wrote: Hi PatterBon,

the engine is not correct for the the 38 it is from 1939 but at the moment i think i can not get closser ! :lol:
Christian

:) a 1939 engine in just as good in my books,
How do we know Professor Porsche didn't install a 39 engine in this car during testing when the car was a year old?

Sun Nov 29, 2009 11:59 am

Bruce wrote: PatterBon wrote: kdfkid wrote: Hi PatterBon,

the engine is not correct for the the 38 it is from 1939 but at the moment i think i can not get closser ! :lol:
Christian

:) a 1939 engine in just as good in my books,
How do we know Professor Porsche didn't install a 39 engine in this car during testing when the car was a year old?

Ahh good point! I wish the step by step things they did to these cars were all written down..personally I wouldn't have minded seeing it in running condition with all the Volga stuff on it. But that being said, I'd like to see it as it was in 1938 in running condition more so. We don't know even half the history of the car other than it was a prototype, and was a one point tried to be converted into a Volga.

Sun Nov 29, 2009 1:53 pm

It is truly amazing. Respect to the restoration team. I think it is really fascinating that more and more civilian prototype parts are being found under Kubelwagens. How different is the W30 suspension arm, out of interest?

Sun Nov 29, 2009 5:20 pm

Well, it's not often i'll read a topic that's over a few pages, but this story had me absolutely captivated from beginning to end last night. Amazing!

For me, the post of the whole thread (besides finding the car in the first place) has to be this one from page 58. Genius!

Such an amazing story. Well done to everyone involved!
Will deffo keep my eye on this. :D

Sun Nov 29, 2009 7:25 pm

Bruce wrote: The control arms are forged steel. Cast iron wouldn't be able to take the impact loading.
Can you verify this statement please?

Mon Nov 30, 2009 2:32 am

Crawl under any car you want. You will never find a cast iron suspension part from any factory on earth. Cast iron is very brittle, it has no ability to flex. Suspension parts are highly stressed and flex a lot, just ask the offroad guys. Try to flex a cast iron control arm, it'll just break. It doesn't work. They must be forged from steel.

Cast iron does fine for crankshafts because there isn't any sudden high impact loading on it.

There's a simple way to verify this. Christian can just touch the control arm on a grinding wheel for a microsecond. Orange sparks means cast iron, yellow sparks is steel.

Mon Nov 30, 2009 6:12 am

Bruce wrote: Crawl under any car you want. You will never find a cast iron suspension part from any factory on earth. Cast iron is very brittle, it has no ability to flex. Suspension parts are highly stressed and flex a lot, just ask the offroad guys. Try to flex a cast iron control arm, it'll just break. It doesn't work. They must be forged from steel.

Cast iron does fine for crankshafts because there isn't any sudden high impact loading on it.

There's a simple way to verify this. Christian can just touch the control arm on a grinding wheel for a microsecond. Orange sparks means cast iron, yellow sparks is steel.

With the VW prototypes, they even had trouble with cast crankshafts shattering so experimented with both forged and cast. Some of the prototype engines were a bit rough compare to the final E60 and exerted more force on the crank (particularly the sleeve valve designs).

Mon Nov 30, 2009 6:36 am

On the subject of suspension arms, it is interesting to point out that Porsche considered a single arm setup as opposed to the dual arm layout.

Mon Nov 30, 2009 8:21 am

Bruce wrote: Crawl under any car you want. You will never find a cast iron suspension part from any factory on earth. Cast iron is very brittle, it has no ability to flex. Suspension parts are highly stressed and flex a lot, just ask the offroad guys. Try to flex a cast iron control arm, it'll just break. It doesn't work. They must be forged from steel.

Cast iron does fine for crankshafts because there isn't any sudden high impact loading on it.

There's a simple way to verify this. Christian can just touch the control arm on a grinding wheel for a microsecond. Orange sparks means cast iron, yellow sparks is steel.
Just curious if they would have used the easier method of production since this is a prototype vehicle.

Mon Nov 30, 2009 10:09 am

MODIFIER wrote: Bruce wrote: Crawl under any car you want. You will never find a cast iron suspension part from any factory on earth. Cast iron is very brittle, it has no ability to flex. Suspension parts are highly stressed and flex a lot, just ask the offroad guys. Try to flex a cast iron control arm, it'll just break. It doesn't work. They must be forged from steel.

Cast iron does fine for crankshafts because there isn't any sudden high impact loading on it.

There's a simple way to verify this. Christian can just touch the control arm on a grinding wheel for a microsecond. Orange sparks means cast iron, yellow sparks is steel.
Just curious if they would have used the easier method of production since this is a prototype vehicle.

I design pressure vessels that see 5000psi using cast iron and depending on the grade it will definitely flex without breaking. It is definitely possible that this part could be cast. I hope Christian can shed some light on it"s composition. I'm curious if the metallurgy existed at that time to make this part out of a cast ductile iron. I used to design forging tooling and am curious if they went to the expense to forge this arm for a prototype. If they tooled the the prototype as a forging I would expect to see later models to be the same design. Bruce, I'm not disagreeing with you on whether later cars (all makes) would use forgings in suspension components.

Mon Nov 30, 2009 10:57 am

IIIA-0426 wrote: Bruce wrote: Cast iron does fine for crankshafts because there isn't any sudden high impact loading on it.

With the VW prototypes, they even had trouble with cast crankshafts shattering so experimented with both forged and cast. Some of the prototype engines were a bit rough compare to the final E60 and exerted more force on the crank (particularly the sleeve valve designs).

And in the end all the production crankshafts were forged precisely because cast iron didn't do fine for crankshafts. Even forged didn't do all that well because a lot of production crankshafts broke as well under higher-than-normal stresses (ask me how I know that! :wink: )

Mon Nov 30, 2009 12:49 pm

Hello.

Im Tom from Poland, And I and my father will use steel,
When I will have from Chrystian his sampel then I will go to
Technology Universyty in My City and I have there some friend who have big expiriens in metal parts, I will let you know how we make them.

Tom

Mon Nov 30, 2009 2:34 pm

kdf-service wrote: Hello.

Im Tom from Poland, And I and my father will use steel,
When I will have from Chrystian his sampel then I will go to
Technology Universyty in My City and I have there some friend who have big expiriens in metal parts, I will let you know how we make them.

Tom

Hello Tom! I think there are a lot of us who are very interested in how the other three arms will be made. Good luck and we look forward to any information you are allowed to give us :wink:

Tue Dec 01, 2009 12:05 am

I'm sure there's no doubt here that the VW38 could not have landed in better hands, who else would go to the trouble of making new control arms from scratch when Kubel arms would bolt right on and only an expert would ever know the difference, if said expert is even the type that would go crawling under the car. That is crazy attention to detail (that's a good thing).

Tue Dec 01, 2009 2:09 am

metalchomper wrote: MODIFIER wrote: Bruce wrote: Crawl under any car you want. You will never find a cast iron suspension part from any factory on earth. Cast iron is very brittle, it has no ability to flex. Suspension parts are highly stressed and flex a lot, just ask the offroad guys. Try to flex a cast iron control arm, it'll just break. It doesn't work. They must be forged from steel.

Cast iron does fine for crankshafts because there isn't any sudden high impact loading on it.

There's a simple way to verify this. Christian can just touch the control arm on a grinding wheel for a microsecond. Orange sparks means cast iron, yellow sparks is steel.
Just curious if they would have used the easier method of production since this is a prototype vehicle.

I'm curious if the metallurgy existed at that time to make this part out of a cast ductile iron.
Even if a suspension part could be made today from cast iron, the VW38 could only rely on the metalurgy of the 1930s. Todays crap alloys are vastly superior to the best they had then.