anti run on valves

[Z320]

2 hours ago, Andy Moltu said:

It seems a lot of effort. 

I have fun with it 

Making a second set is boring already.....

[John Morrison]

Ah so that won’t work then, 

Understood

John

[John Morrison]

I love Marco’s engineering abilities I really do, and wish I could do half the things he can, but in you car with this issue, why wouldn’t you just put a switch to earth the coil?

John

[Z320]

1 hour ago, John Morrison said:

Ah so that won’t work then, 

Understood

John

FIRST - it has to work!

[Ian Vincent]

8 hours ago, John Morrison said:

I love Marco’s engineering abilities I really do, and wish I could do half the things he can, but in you car with this issue, why wouldn’t you just put a switch to earth the coil?

John

Another name for running on is ‘dieseling’. In other words the spark isn’t needed, the fuel air mixture ignites spontaneously under compression. 

Rgds Ian

[Z320]

About heat, pressure, coak and explosion without ignition spark

I like that guy and his experiments

Edited July 29, 2025 by Z320

[Ian Vincent]

15 hours ago, Z320 said:

About heat, pressure, coak and explosion without ignition spark

I like that guy and his experiments

👍

[Z320]

Hi,

ready to ship, this is the hole story:

This Pierburg valves for VW I made suitable to fit 175 CD Stromberg carbs with the "brass plug" from below on the float camber lid.

Indeed the "brass plug" is only a covered plastic plug, easy to get out.

The plastic plug holds the o-ring, sealing the lid in the bore. I had to solve this different because of limited space / diameter.

With the lid back on the carb a "snokel" is visible, via this the petrol gets up to the jet, inside there is the jet needle.

The "snorkel" is needed because the jet is on a higher level than the max fuel level in the float chamber.

The issue is to  connect the Pierburg valve with a o-ring this "snorkel", a 10 mm and a 4 mm brass bush helps.

Two tight loops of wire (Michael: don't unroll it) are pushed on the "snorkel" (yes, a bit fiddly)

Next a bush shaped like a "sewing thread bobin" is needed to connect "snokel" with the valve (inside) AND and to get the fuel down to the valve (outside).

Like this, later the "bobin" is no longer visible and no issue of any attention.

Because it is inside the valve holder

This way the unit is fitted on the "snorkel" / on the carbs.

I mentioned there is no space to seal to the lid like original,

I did it with a o-ring in a groove / on a flange, as I know it from my BMW R90S with Dellortos (fibre there)

Assembly the whole issue: the valve holder first and SLACK through the lid.

Next the 6 screws SLACK though the lit, next the valve holder slightly tight (the original plug is not even tight!)

Next the 6 screws tight. One edge has e drilling for a 1 mm wire to secure it anywhere on the carb.

I made a clip o fit under the next screw clockwise, if nothing usable is possible on the carb.

This Pierburg valves are switched open, this is why they can simple be connected to an igintion switched terminal.

Iginition on -> valve opend, ignition off -> valve closed. I would connect it to the + terminal of the ignition coil.

If they fail, they stay closed. For this unlikely issue I recomment to carry the original plugs and o-rings in the cloves box or boot!

Ready to go out to Dortmund tomorrow to be installed and tested.

The construction is very close to the Mercedes Benz construction, this is why I hope it works.

Perhaps the carbs need a slightly new adjustment, but I guess this is not needed.

Looking forward to hear from Michael.

Ciao, Marco

Edited August 4, 2025 by Z320
empty lines out at the end of the post, wrong writing

[Z320]

Report from my mate Michael:

the valves are installed and the engine does no longer run on.

He is very pleased and is looking forward for the summer without this problems.

Ciao, Marco

[Chilliman]

Well done Marco, nicely engineered. 👍