Comparing potential ink intake of a Pelikan 400 & 800

[fountainbel]

Hallo Pelikan friends,
Sorry for writing in English, but unfortunately my German is not so good.
Being a fan of the excellent Pelikan pens, I collected a nice bunch of vintage & new Pelikan pens.
I have a Pelikan 800 as a user pen, excellent nib, great writer , but unfortunately I'm somewhat disappointed in the ink intake of this pen.
In my experience a "vintage"Pelikan 400 can hold more ink as the 800.
And it looks looks I'm not the only one, on the FPN board there is actually a discussion on this problem.
Being a mechanical engineer I was intrigued by this phenomenon , so I decided to disassemble a compare the filling system of the pens.

I've first measured the piston bores, and surprisingly the piston bore of the modern 400 & 800 is smaller !
"Vintage" Pelikan 400 : 9mm piston bore
"Modern" Pelikan 400 & 800 : 8.2mm piston bore
I then measured the effective piston stroke : removed the nib unit, turned the piston fully to the section stop, installed a steel pin through the nib bore contacting the piston top & measured the length of the pin sticking out the section.
Same measurement was done with the piston fully retracted, difference between both measurements being the effective stroke.
"Vintage" Pelikan 400 : 31 mm stroke
"Modern" Pelikan 400 : 24,5 mm stroke
"Modern" Pelikan 800 : 26 mm stroke
I was rather surprised with the short stroke of the 800, so I thought the piston lead screw was not engaged properly. I dis assembled the piston mechanism and engaged the lead screw obtaining a maximum stroke backwards.
In fact the lead screw was engaged so it axially contacts the bore end in the filling knob.
Repeating the stroke measurement with this setting confirmed however the disappointing 26 mm stroke.
These measurements result in the following "potential" ink intake figures :
"Vintage" Pelikan 400 : 1,97 ml
"Modern" Pelikan 400 : 1,29 ml
"Modern" Pelikan 800 : 1.37 ml
Conclusion : Contrary to what one should expect, the Pelikan 800 features a 30% less "potential" ink intake capacity compared to a (vintage) Pelikan 400.
This sounds not logical to me, so I hope one of you ,or better one of the Pelikan engineers can clarify this matter.

Thanks & regards, Francis

Edited for adding also spec's for "modern"Pelikan 400

[diogenes]

You might be interested in

http://www.nibs.com/pen_measures/

The capacities for Pelikan M400 and M800 are listed on page 5:

M400: 1.8 ml
M600: 2.0 ml
M800: 2.0 ml
M1000: 2.2 ml

[fountainbel]

Hi diogenes,
Thanks, I'm aware of these comparative figures, but my findings are quite different!
Francis

You might be interested in

http://www.nibs.com/pen_measures/

The capacities for Pelikan M400 and M800 are listed on page 5:

M400: 1.8 ml
M600: 2.0 ml
M800: 2.0 ml
M1000: 2.2 ml

[diogenes]

Thanks, I'm aware of these comparative figures, but my findings are quite different!

That's right, of course, but your values seem to be too small to me, at least this is my subjective impression (which may be wrong, of course). The next time I clean my M800 I will measure the amount of water it can hold.

[fountainbel]

Hello,
Allow me to write that I'm somewhat disappointed the Pelikan engineers did not chime in on my comparative filling rate figures.
Does this mean I'm spot on ?
Francis