Office of Steam Forum for Model & Toy Steam Gas & Hot Air Engines

Here is the other Marklin that Gen got.  They were a pair, see the 4150 post, and this Marklin 4160 / D9.  It is on a 15” x 19” base, 21” to the top of the stack, boiler is 3 1/2” x 10”.  Other than leaks around the fittings (gaskets dried out) the dual engines self-start on air. 

According to one source the Marklin 4160 / D9 was only produced in 1919.  I found several with some searches that looked the same, some with a dynamo.  There were clearly smaller ones made ie D7. 

I do have a question about the exhaust arrangement.  At the exit on the steam chest there is a tube coming off the exhaust with a funnel shape at the top.  Following the exhaust line as it goes past the rear of chimney housing it goes up about an inch and into another vertical tube, which has a sort of covered funnel at the top, open in the center.  That tube runs off the deck like a normal exhaust line.  Why all the other stuff?

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The boiler has a gauge on it but it looks like for some reason another whistle was placed on it.  It is clearly not designed that way.  Neither the whistle or the gauge can be turned, they bump into each other.  I think a cap was supposed to be on the top or the “T”.  In a small bag there was a cap with threads, which I guess at one time fit the “T” before someone re tapped the hole for the whistle. 

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Not sure what I will do here.  I could make a threaded bushing to fit, ie outside thread to match whistle threads and inside thread to match the cap I have.  Or, just make a cap with the whistle threads.  Since I do not have any idea what the cap looks like on a “real one” ie the hole and the cap I am only guessing.  If someone who has the real setup could remove the cap and photo it and the hole in the top of the “T” I could at least get an idea of what the original looked like. 


Bob


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Did you get these from a guy in MN? I believe I went and looked at them back in April.

Great engine - the exhaust "funnel" is a condenser - very nice item.
On the t-part there should be a cap - but that should also have the
same Marklin thread - I remember the size is close to 8x1 mm. Very
strange that you can not remove the whistle/gauge - how was it fixed
to the t-part once?
A very nice and rare engine - just fantastic.
Congrats,
Arnold

Arnold

The gauge / whistle combination only looks like it is together.  The whistle is screwed all the way down but the gauge is only 1/4 of a turn in.  If you look at the pictures you will see that the whistle cannot rotate out without hitting the gauge, and same for the gauge it cannot rotate out without hitting the whistle.  To take it apart I have to turn the gauge 1/4 turn CCW and take it off, then the whistle can be removed.  I am sure that is not what Marklin designed.

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I got a surprise when I decided to check out your recollection of an 8 x 1 mm thread.  I have a lathe that I can single point a metric thread, so making a cap would be relatively easy.  Just to check everything I got my metric thread gauge and a digital caliper.  I measured the diameter of the whistle thread and the filler plug thread from the 4150, the readings were 7.78 and 7.81.  Close to 8mm and threaded sections are usually smaller.  Next I took the thread gauge and clearly 1 mm did was too course. I tried .75 it was too fine.  Next .8, which was too fine, and .9, which was, too course. 

I thought that maybe it was an imperial thread.  I used my TPI gauge and it registered 32 TPI exactly.  Next I switched the readout to inch’s on the caliper and the diameters measured .309 and .310 for the whistle and filler cap.  That dimension is close to .312 or 5/16 inch.   I have been making models since the mid 1970’s and have many taps and die.  There is a series of taps and dies called Model Engineer which uses 40 tpi for 1/8” – 1/4” and 32 tpi for 1/4” – 1/2”.  I have a 5/16 – 32 tap.  I drilled a tap hole in some 1/4” brass and tapped it.

Both the whistle and filler cap screwed in perfectly no wobble, no tightness, no slop.  You can see from the pictures the fit.  The last photo shows the bottom of the filler in the thread, nice and firm.

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I had a 8 x 1 mm bolt and tried screwing it in both the filler hole and the whistle hole on the gauge “T”.  It went in about 1 turn then got tight.  If I wanted to force it I am sure it would have gone through the filler hole being brass or copper, it would have reformed the threads.  The 8mm diameter or the bolt was actually 7.85 mm or .309 inches virtually identical to diameter of the whistle and filler plug.  The real difference is the thread 1 mm vs 32 tpi.   1mm is .0390 inch and 32 tpi is .0313 inchs ie the measurement of the thread pitch.  They are only about .008 inches difference.  That is why screwing the 8 x 1mm bolt in seems to go for a bit ie 1 turn and then gets tight. It almost fits. 

Why Marklin used that thread pitch is a mystery to me.  I believe that thread came into existence in the late teens to early 1920’s.  I have model engineering books from the 20’s that reference the thread as being used for model steam engine fittings.

I hope this information is useful to everyone.

Bob

The secret's out! I've been making parts for Marklin and other engines for years, and you will find, more often than not, that it's an oddball American thread that will best match what was used on pre-1930s engines from Germany. Metric is more common later. Best to have a large selection of taps and dies for both, not to mention good thread gauges.

I agree on lots of them, my collection also includes many from the UK, the ME taps I mention, BA set, and BSP set.

I need to make that cap.  Originally it was likely nickel plated. That would be way too new looking to match the patina.  I am thinking of using SS 304 or nickel rod as a start then try and age it to match with chemicals and heat.  Any tricks in your bag for this, maybe a different material or ??


Bob

Hi

If someone has the cap for the gauge "T" top could they take a picture of it for me, on and off if possible. I know it was used on the 4150 also. One of the pictures that Arnold had showed it but could not see details.  I looked at some pictures on line but most are not clear when blown up.  I cannot tell if there was a hex on it or knurled edge (straight or round).

Thank You and Happy New Year

Bob

Fortunately the (non-metric) taps and dies to match this and most other Marklin threads are relatively easy to get here in the US (as Bob described above).

Yes - exactly both treads are very similar - the good is that 5/16"x32 tpi is comercialy available
the 7,8x0,8 mm is not. The hexagon of the original cap is 11.4 mm or 7/16" - I make these usually from
11 mm - that's okay too.
Arnold