From: Noddy on

"Yvan" <me(a)privacy.net> wrote in message
news:5qqp9fF113ft1U1(a)mid.individual.net...

> Because I could not tune it to function properly. I had very poor
> running on both petrol and lpg when engine is cold / warming up.

Was it the standard carburettor for the car in good, working condition?

The fact that it wouldn't run properly on gas *or* petrol suggests to me
that there was a problem there somewhere.

> I have separate adjuster for each barrel on the Y piece.

Right.

Then, in that case I'd look for an adjuster that could be opened & closed in
time with the secondary.

> It performed OK when warm, but I could start easily on lpg, and engine
> would not die if I was quick with my foot on the accelerator. Now I can
> not start on lpg, and engine will die if I switch to lpg before it
> warms up more than 1/4 of a normal operating temperature, and will
> stall at idle before temp needle passes 1/2.
>
> And I did not change anything else, just the carburetor.

From the looks of things in your photo's the spuds are quite small, maybe
quarter inch in diameter or so, and they seem to extend a long way into the
carburettor body. My experience with spud pipes is limited as they generally
are a huge compromise that don't work terribly well at all, but from the
size & position of yours I would expect them to get a very poor vacuum
signal. I would also expect that being positioned right under the middle of
the booster venturi as they are they're likely to affect petrol performance
as well.

I don't know what part of the world you're in, but down here in Oz we have
similar carbs running dual fuel installations with the gas delivered to the
engine through a simple low profile mixer that sat on top of the carburettor
within the confines of the standard air cleaner.

Here's a pic of one from one of my gas powered cars that I've just removed
to replace with a different system:

http://i31.photobucket.com/albums/c389/dasgib/100_3190.jpg

This is commonly referred to as an "Amos Ring, or Hat" in Australia. They're
used principally in applications such as yours were clearance prevents a
better system being employed, and while they're not the best thing in the
world as far as gas delivery devices go they can perform adequately if
effectively sealed so they create a good vacuum signal.

This particular ring was fitted to a Weber 34 ADM (which is a similar carb
to yours) that was standard fitment on a 4 litre Ford 6 cylinder engine down
here, and it worked okay. Far from brilliant, but adequate with the
advantage of it not making any external physical changes to the air filter
housing causing clearance issues. It ran a single gas line and adjuster
between the mixer & converter, and was "tuned" for best performance at the
expense of economy.

I don't know if such equipment exists were you are, but if it does it's sure
to work a hell of a lot better than the system you have now.

--
Regards,
Noddy.


From: Yvan on
Nedavno Noddy piše:

>> Because I could not tune it to function properly. I had very poor
>> running on both petrol and lpg when engine is cold / warming up.
>
> Was it the standard carburettor for the car in good, working
> condition?

Something was not right. When the engine was at normal operating
temperature all was OK. Pierburg 1B2 has electrically heated device
that opens choke flap, electrically heated device that controlls amount
of petrol admitted at idle, and some device that is heated by coolant
and moves piston that controls amount of air that bypasses throttle
butterfly at idle (so throttle butterfly is at fixed position at idle
at all temperatures). I guess that something is wrong there. I replaced
device that is heated by coolant, but that did not help.

> The fact that it wouldn't run properly on gas *or* petrol suggests to
> me that there was a problem there somewhere.

I also come to that conclusion, but me, some local garages, and BMW
dealer could not find the fault (dealer suggested changing carb at more
than thousand US$ :-)

>> I have separate adjuster for each barrel on the Y piece.
>
> Right.
>
> Then, in that case I'd look for an adjuster that could be opened &
> closed in time with the secondary.

Does something like that exist? It had to be some mechanical device
complicating things even more, and one more device that can fail.

>> It performed OK when warm, but I could start easily on lpg, and
>> engine would not die if I was quick with my foot on the accelerator.
>> Now I can not start on lpg, and engine will die if I switch to lpg
>> before it warms up more than 1/4 of a normal operating temperature,
>> and will stall at idle before temp needle passes 1/2.
>>
>> And I did not change anything else, just the carburetor.
>
> From the looks of things in your photo's the spuds are quite small,
> maybe quarter inch in diameter or so, and they seem to extend a long
> way into the carburettor body. My experience with spud pipes is
> limited as they generally are a huge compromise that don't work
> terribly well at all, but from the size & position of yours I would
> expect them to get a very poor vacuum signal. I would also expect that
> being positioned right under the middle of the booster venturi as they
> are they're likely to affect petrol performance as well.

Spud pipe is 8 mm outside diameter, that's about quarter inch inside
diameter. Someone told me to cut it at 45 deg. and to insert it half
way inside venturi. Like this (hope ASCI dwg is OK):

| |
| |
\ /
/ \
____________ |
___________/ |
| |
| |


I did not notice anything when on petrol.


> I don't know what part of the world you're in, but down here in Oz we
> have similar carbs running dual fuel installations with the gas
> delivered to the engine through a simple low profile mixer that sat on
> top of the carburettor within the confines of the standard air
> cleaner.
>
> Here's a pic of one from one of my gas powered cars that I've just
> removed to replace with a different system:
>
> http://i31.photobucket.com/albums/c389/dasgib/100_3190.jpg
>
> I don't know if such equipment exists were you are, but if it does
> it's sure to work a hell of a lot better than the system you have now.


I can not find anything like that over here (Serbia). Probably because
production of this carburetor stopped more than 25 years ago :-)



--
___ ____
/__/ / \ ** Registrovani korisnik Linuksa #291606 **
/ / \/ /\ \ ** Registered Linux user #291606 **
/__/\____/--\__\ ** http://counter.li.org/ **
From: Yvan on
Nedavno Yvan piše:

> I will now (when the engine cools down) do the "one barell" lpg test,
> and report the result.

I tried. I disconnected second barrel, plugged all openings - nothing
changed. Cold engine would run only with throttle nailed to the floor
at ~2500 rpm.

When warm it runs OK. Fault in vaporizer?



--
___ ____
/__/ / \ ** Registrovani korisnik Linuksa #291606 **
/ / \/ /\ \ ** Registered Linux user #291606 **
/__/\____/--\__\ ** http://counter.li.org/ **
From: John McKenzie on
Yvan wrote:
>
> Nedavno Yvan piše:
>
> > I will now (when the engine cools down) do the "one barell" lpg test,
> > and report the result.
>
> I tried. I disconnected second barrel,

just to be 100% clear - you disconnected the second barrel throttle
linkage, wiring it so it might not be sucked open even a little it, AND
you plugged the lpg/spud hose going to that barrel too?


--
John McKenzie

tosspam(a)aol.com abuse(a)yahoo.com abuse(a)hotmail.com abuse(a)earthlink.com
abuse(a)aol.com vice.president(a)whitehouse.gov president(a)whitehouse.gov
sweep.day(a)accc.gov.au uce(a)ftc.gov admin(a)loopback abuse(a)iprimus.com.au
$LOGIN(a)localhost world's #1 sardine whisperer root(a)mailloop.com
$USER@$HOST $LOGNAME(a)localhost -h1024(a)localhost abuse(a)msn.com
abuse(a)federalpolice.gov.au fraudinfo(a)psinet.com abuse(a)asio.gov.au
$USER(a)localhost abuse(a)sprint.com abuse(a)fbi.gov abuse(a)cia.gov
From: John McKenzie on
Noddy wrote:
>
> "Yvan" <me(a)privacy.net> wrote in message
> news:5qqp9fF113ft1U1(a)mid.individual.net...
>
> > Because I could not tune it to function properly. I had very poor
> > running on both petrol and lpg when engine is cold / warming up.
>
> Was it the standard carburettor for the car in good, working condition?
>
> The fact that it wouldn't run properly on gas *or* petrol suggests to me
> that there was a problem there somewhere.
>
> > I have separate adjuster for each barrel on the Y piece.
>
> Right.
>
> Then, in that case I'd look for an adjuster that could be opened & closed in
> time with the secondary.
>
> > It performed OK when warm, but I could start easily on lpg, and engine
> > would not die if I was quick with my foot on the accelerator. Now I can
> > not start on lpg, and engine will die if I switch to lpg before it
> > warms up more than 1/4 of a normal operating temperature, and will
> > stall at idle before temp needle passes 1/2.
> >
> > And I did not change anything else, just the carburetor.
>
> From the looks of things in your photo's the spuds are quite small, maybe
> quarter inch in diameter or so, and they seem to extend a long way into the
> carburettor body. My experience with spud pipes is limited as they generally
> are a huge compromise that don't work terribly well at all, but from the
> size & position of yours I would expect them to get a very poor vacuum
> signal. I would also expect that being positioned right under the middle of
> the booster venturi as they are they're likely to affect petrol performance
> as well.
>
> I don't know what part of the world you're in, but down here in Oz we have
> similar carbs running dual fuel installations with the gas delivered to the
> engine through a simple low profile mixer that sat on top of the carburettor
> within the confines of the standard air cleaner.
>
> Here's a pic of one from one of my gas powered cars that I've just removed
> to replace with a different system:
>
> http://i31.photobucket.com/albums/c389/dasgib/100_3190.jpg
>
> This is commonly referred to as an "Amos Ring, or Hat" in Australia. They're
> used principally in applications such as yours were clearance prevents a
> better system being employed, and while they're not the best thing in the
> world as far as gas delivery devices go they can perform adequately if
> effectively sealed so they create a good vacuum signal.
>
> This particular ring was fitted to a Weber 34 ADM (which is a similar carb
> to yours) that was standard fitment on a 4 litre Ford 6 cylinder engine down
> here, and it worked okay. Far from brilliant, but adequate with the
> advantage of it not making any external physical changes to the air filter
> housing causing clearance issues.

the thing to be mindful here - as there is normally locally some
criticism of that combo - it's not the amos ring thats the big problem -
it's that the adm weber is too small for a reasonable breathing 4 litre
engine.

It ran a single gas line and adjuster
> between the mixer & converter, and was "tuned" for best performance at the
> expense of economy.

It's what I'd suggest too.

--
John McKenzie

tosspam(a)aol.com abuse(a)yahoo.com abuse(a)hotmail.com abuse(a)earthlink.com
abuse(a)aol.com vice.president(a)whitehouse.gov president(a)whitehouse.gov
sweep.day(a)accc.gov.au uce(a)ftc.gov admin(a)loopback abuse(a)iprimus.com.au
$LOGIN(a)localhost world's #1 sardine whisperer root(a)mailloop.com
$USER@$HOST $LOGNAME(a)localhost -h1024(a)localhost abuse(a)msn.com
abuse(a)federalpolice.gov.au fraudinfo(a)psinet.com abuse(a)asio.gov.au
$USER(a)localhost abuse(a)sprint.com abuse(a)fbi.gov abuse(a)cia.gov