New Mixer Ring

[1001leelee]

Vw T25 autogas install.
The mixer ring the p.o fitted is apparently rubbish.
Bought one from tinsley tech for the Pierburg carb fitted to my 1.9dg engine.
The current set up has one pipe from the vaporiser to the mixing ring.
The new one has 2 outlet pipes, one for each carb Venturi.
The y piece to split the main feed pipe from the vaporiser has adjustment screws..
Is the a method to setting this up?
There is a power valve already fitted.
Any help appreciated..!

Cheers

[Gilbertd]

Do both chokes open at the same time or is it a progressive carb where one opens at small throttle openings with the second one opening when you give it some welly? If they both open together you can leave both the adjusters on the Y piece wide open and control the mixture with the single power valve.

[1001leelee]

Do both chokes open at the same time or is it a progressive carb where one opens at small throttle openings with the second one opening when you give it some welly? If they both open together you can leave both the adjusters on the Y piece wide open and control the mixture with the single power valve.

Hi,
The second choke operates by vacuum apparently..
So not at the same time..
Sadly...
It sounds like it needs the majority through the main pipe, then somehow an amount through the second..
Sounds like a pig to set up to be honest...
Was hoping others had already done it..,

[LPGC]

With a vacuum or sequential throttle secondary carb and using a plate mixer it does complicate setting up. When the throttle on the 2nd venturi is closed there's no airflow through the 2nd mixer but the 2nd mixer is still open to slight vacuum signal and may still output a bit of gas. Under these conditions the effect is a bit like having a wider gas feed pipe to a single mixer which will flow more gas than a narrower feed pipe and therefore need less restriction from a manual valve than it would for a wider pipe. As the second throttle opens at first there's a little less airflow through the first throttle / mixer because the second throttle and mixer is doing a part share of airflow. The reducer sees something like the average signal generated over the two mixers but the question is whether this something like average signal is linear according to total airflow through the 2 venturis / mixers during the opening stage of the 2nd and it usually won't be. It can get more complicated if the 2 carb venturis and/or mixer venturis are a different size. Sometimes just at the point of the second throttle opening there can be a flat spot (due to dodgy mixture) that can be a bit complicated to dial out.

You'll get there with this setup but there are various single venturi carb setups available for T25s that would be simpler/easier to setup and get good results on using an LPG mixer system, if you intend on running on gas most of the time you might fit such different carb and a simpler gas mixer setup. The spec of the carb doesn't matter when you're running on gas, you just need the carb's throttle plate to work.

[1001leelee]

With a vacuum or sequential throttle secondary carb and using a plate mixer it does complicate setting up. When the throttle on the 2nd venturi is closed there's no airflow through the 2nd mixer but the 2nd mixer is still open to slight vacuum signal and may still output a bit of gas. Under these conditions the effect is a bit like having a wider gas feed pipe to a single mixer which will flow more gas than a narrower feed pipe and therefore need less restriction from a manual valve than it would for a wider pipe. As the second throttle opens at first there's a little less airflow through the first throttle / mixer because the second throttle and mixer is doing a part share of airflow. The reducer sees something like the average signal generated over the two mixers but the question is whether this something like average signal is linear according to total airflow through the 2 venturis / mixers during the opening stage of the 2nd and it usually won't be. It can get more complicated if the 2 carb venturis and/or mixer venturis are a different size. Sometimes just at the point of the second throttle opening there can be a flat spot (due to dodgy mixture) that can be a bit complicated to dial out.

You'll get there with this setup but there are various single venturi carb setups available for T25s that would be simpler/easier to setup and get good results on using an LPG mixer system, if you intend on running on gas most of the time you might fit such different carb and a simpler gas mixer setup. The spec of the carb doesn't matter when you're running on gas, you just need the carb's throttle plate to work.

Hi,
Thanks for this.
I reckon will be easier to come over to you to sort it..!
Am not that far away..
The van has got currently a single Venturi mixer, essentially looks like a gas hob ring. Van runs well on this, but recently struggled to pass the MOT, and this was given as a possible reason..
So spoke to Tinsley Tech who advised a BLOS system was no longer available and the part I have bought is fitted usually..
But, the issue of set up now comes to light!!
I can’t PM you with some contact details as am a newbie to the forum, but if you want to PM we can set up a service/set up??

Cheers
Lee

[Brian_H]

I can’t PM you with some contact details as am a newbie to the forum, but if you want to PM we can set up a service/set up??

From Simon's signature, you might not be able to see if using mobile browser

Full time LPG installer
Servicing / Diagnostics / Repairs to all systems / DIY conversion kits supplied with thorough tech support
Mid Yorkshire
2 miles A1, 8 miles M62,
http://www.Lpgc.co.uk
Twitter https://twitter.com/AutogasSimon
07816237240

There are certain limits on PM function due to previous issues with spam. it will unlock for you soon though.

[1001leelee]

I can’t PM you with some contact details as am a newbie to the forum, but if you want to PM we can set up a service/set up??

From Simon's signature, you might not be able to see if using mobile browser

Full time LPG installer
Servicing / Diagnostics / Repairs to all systems / DIY conversion kits supplied with thorough tech support
Mid Yorkshire
2 miles A1, 8 miles M62,
http://www.Lpgc.co.uk
Twitter https://twitter.com/AutogasSimon
07816237240

There are certain limits on PM function due to previous issues with spam. it will unlock for you soon though.

Thanks!!