Page 1 of 2

Manometers was: timing problem

PostPosted: Tue Apr 19, 2005 4:12 pm
by grat
On Mon, Apr 18, 2005 at 01:16:59PM -0500, Tim Engel wrote:

Unless you have to tune for emissions in your area, use a 4-tube
manometer and tune for peak vacuum (strongest vacuum) at idle.

which brings up the question: What method is used to connect a
manometer to a weber carb? Do you use a venturi plate, or clip inside
the stack, or some other method?

fj..
--
The one thing that unites all human beings, regardless of age, gender,
religion, economic status, or ethnic background, is that, deep down
inside, we all believe that we are above-average drivers.
-- Dave Barry

Manometers was: timing problem

PostPosted: Mon Apr 25, 2005 1:02 am
by bill308
I drilled and tapped the underside of each intake manifold runner and
added a fitting at each location. When not in use, the fittings are
sealed. My friend Tim drilled and tapped the topside which make
connection of the manometer much easier but the fittings are visible.
Either location works very well with a 4-tube mercury manometer like
the motorcycle guys use. In all cases, you are measuring manifold
vacuum. This method is by far the best way to synchronize multiple
carbs. It is exquisitely sensitive and when all colums are equalized,
there is no question they are flowing equally.

Bill



--- In ***@***.***, "Franklin R. Jones" <[email protected]> wrote:
On Mon, Apr 18, 2005 at 01:16:59PM -0500, Tim Engel wrote:

> Unless you have to tune for emissions in your area, use a 4-tube
> manometer and tune for peak vacuum (strongest vacuum) at idle.

which brings up the question: What method is used to connect a
manometer to a weber carb? Do you use a venturi plate, or clip inside
the stack, or some other method?

fj..
--
The one thing that unites all human beings, regardless of age, gender,
religion, economic status, or ethnic background, is that, deep down
inside, we all believe that we are above-average drivers.
-- Dave Barry

Manometers was: timing problem

PostPosted: Mon Apr 25, 2005 2:04 pm
by hantsjo
Hi Bill,
how high is the coulomb of mercury? and is there another way of taking a
tapping, without drilling. Also does anyone know of a good web site
concerning tuning dellortos.
The car's running now!! thanks to every one on the list for the help, and
Jeff for providing this forum.

TIA.
Jo
66 S2 broom broom ;-)

----- Original Message -----

I drilled and tapped the underside of each intake manifold runner and
added a fitting at each location.......................

Manometers was: timing problem

PostPosted: Mon Apr 25, 2005 11:59 pm
by bill308
Jo,

I apologize in that I'm not exactly sure what the column height of
mercury is for the Elan at idle. The last time I synchronized the
carbs I used manometer fluid, for my Elan, with a specific gravity of
2.95. The column for this fluid was about 10-feet tall if I recall
correctly. Last summer I did my friend Tim's S3 Elan with a mercury
manometer but don't recall the column height of mercury. I did
however check photos I made synchronizing 40DCNF's on my 308 GTS and
they were at the 25-inch height with mercury. So, 25-inches of
mercury, with a specific gravity of about 13.54 yields a manometer
fluid column of (13.54/2.95) x(25 inches)=114.7 inches = 9.56 feet.
This agrees well with my recallection of about 10 feet. Further, you
can think of a 308 engine as 2 TC's in a V-configuration. The bottom
line is that you can expect about a 25-inch column of mercury at
idle. Remember, a near perfect vacuum will support about a 30-inch
column of mercury at atmospheric pressure.

Bill

--- In ***@***.***, "J. Lewthwaite" <[email protected]>
wrote:
Hi Bill,
how high is the coulomb of mercury? and is there another way of
taking a

tapping, without drilling. Also does anyone know of a good web site
concerning tuning dellortos.
The car's running now!! thanks to every one on the list for the
help, and

Jeff for providing this forum.

TIA.
Jo
66 S2 broom broom ;-)

----- Original Message -----

I drilled and tapped the underside of each intake manifold runner
and

added a fitting at each location.......................

Manometers was: timing problem

PostPosted: Tue Apr 26, 2005 1:05 am
by gwnorth68
More manometer tales. I can't believe anyone would actually do this!
Tom

Manometers was: timing problem

PostPosted: Tue Apr 26, 2005 6:30 am
by triumphelan
I think that as long as all the manifold are reading the same ,then the carbs are in balance.
Regards John S41969 DHC
----- Original Message -----
From: William Sebestyen
To: ***@***.***
Sent: Tuesday, April 26, 2005 12:59 AM
Subject: Re: Manometers was: [LotusElan.net] timing problem



Jo,

I apologize in that I'm not exactly sure what the column height of
mercury is for the Elan at idle. The last time I synchronized the
carbs I used manometer fluid, for my Elan, with a specific gravity of
2.95. The column for this fluid was about 10-feet tall if I recall
correctly. Last summer I did my friend Tim's S3 Elan with a mercury
manometer but don't recall the column height of mercury. I did
however check photos I made synchronizing 40DCNF's on my 308 GTS and
they were at the 25-inch height with mercury. So, 25-inches of
mercury, with a specific gravity of about 13.54 yields a manometer
fluid column of (13.54/2.95) x(25 inches)=114.7 inches = 9.56 feet.
This agrees well with my recallection of about 10 feet. Further, you
can think of a 308 engine as 2 TC's in a V-configuration. The bottom
line is that you can expect about a 25-inch column of mercury at
idle. Remember, a near perfect vacuum will support about a 30-inch
column of mercury at atmospheric pressure.

Bill

--- In ***@***.***, "J. Lewthwaite" <[email protected]>
wrote:
Hi Bill,
how high is the coulomb of mercury? and is there another way of
taking a

tapping, without drilling. Also does anyone know of a good web site
concerning tuning dellortos.
The car's running now!! thanks to every one on the list for the
help, and

Jeff for providing this forum.

TIA.
Jo
66 S2 broom broom ;-)

----- Original Message -----

I drilled and tapped the underside of each intake manifold runner
and

added a fitting at each location.......................








To search the mailing list archives:
http://www.escribe.com/automotive/europ ... index.html






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Manometers was: timing problem

PostPosted: Tue Apr 26, 2005 7:19 am
by steveww
Rather than use columns of liquid why not just use some vacuum gauges,
just like the bike boys.

e.g.
http://www.vehicle-wiring-products.co.u ... 2/vga4.jpg

William Sebestyen wrote:

Jo,

I apologize in that I'm not exactly sure what the column height of
mercury is for the Elan at idle. The last time I synchronized the
carbs I used manometer fluid, for my Elan, with a specific gravity of
2.95. The column for this fluid was about 10-feet tall if I recall
correctly. Last summer I did my friend Tim's S3 Elan with a mercury
manometer but don't recall the column height of mercury. I did
however check photos I made synchronizing 40DCNF's on my 308 GTS and
they were at the 25-inch height with mercury. So, 25-inches of
mercury, with a specific gravity of about 13.54 yields a manometer
fluid column of (13.54/2.95) x(25 inches)=114.7 inches = 9.56 feet.
This agrees well with my recallection of about 10 feet. Further, you
can think of a 308 engine as 2 TC's in a V-configuration. The bottom
line is that you can expect about a 25-inch column of mercury at
idle. Remember, a near perfect vacuum will support about a 30-inch
column of mercury at atmospheric pressure.

Bill

--- In ***@***.***, "J. Lewthwaite" <[email protected]>
wrote:

>Hi Bill,
>how high is the coulomb of mercury? and is there another way of

taking a

>tapping, without drilling. Also does anyone know of a good web site
>concerning tuning dellortos.
>The car's running now!! thanks to every one on the list for the

help, and

>Jeff for providing this forum.
>
>TIA.
>Jo
>66 S2 broom broom ;-)
>
>----- Original Message -----
>
>I drilled and tapped the underside of each intake manifold runner

and

>added a fitting at each location.......................










To search the mailing list archives:
http://www.escribe.com/automotive/europ ... index.html



Yahoo! Groups Links










--

Regards,

Steve Waterworth
***@***.***

Einstein: "The faster you drive, the slower you age..."

Manometers was: timing problem

PostPosted: Tue Apr 26, 2005 3:21 pm
by "Tim Engel"
--- In ***@***.***, "J. Lewthwaite" <[email protected]>
wrote:
Hi Bill,
how high is the coulomb of mercury? and is there
another way of taking a tapping, without drilling.
Also does anyone know of a good web site concerning
tuning dellortos. The car's running now!! thanks to
every one on the list for the help, and Jeff for providing
this forum.



Jo,

I have written a Word.doc on the subject and would be happy to
forward it to you as a file attachment if you wish. Just ask and
forward the e-mail address where you wish to receive it I tried
uploading it to the Files section, but it's full. Are you also a
member of [email protected] ? The file is also posted there? as
well as S1S2S3Owners (naturally aspirated Esprits) and Turboesprit.

The Word.doc is written with DHLA 40's and 45's in mind (Lotus 907/
910/ 911/ 912 engines), but most of it will apply to Elans. The
only caveat is that some older Dellortos don't have all the ports the
newer ones have. For instance, the 9XX carbs have manometer vacuum
ports built in (no drilling required) as well as Air Bleed Screws for
balancing barrel to barrel on one carb. If you run into differences
we would have to talk through them.

If you drill vacuum ports, they need to be as close to the throttle
butterfly as possible. Some really funky flow dynamics take place
in an engine manifold and pressures are not uniform throughout. Get
very far from the butterfly and you could be measuring the pressure
of some reversion wave that really has nothing to do with what's
going on at the butterfly.

Tune the idle mixture screw to produce the strongest vacuum (highest
column) per cylinder. Then use the carbs' air bleed screws (in
their absence, twist the butterfly shaft) to balance the two bores on
one carb (weaken the stronger bore to match the weaker bore).
Finally, use the linkage coupler balance screw to balance one carb to
the other. The details are in the document.

I strongly recommend the Carbtune II mechanical manometer for
balancing carbs and have included source info for it. It uses steel
rods sliding in glass tubes instead of liquids. Most importantly,
it's mercury-free. There's also a link to the website of a guy who
built his own carb balancing manometer. An open manometer using a
light liquid (ie, not mercury) will be very tall. To avoid that,
he connects one end to one carb bore and the other end to the other
carb bore. That way the manometer only registers the difference in
pressure and can be quite short.

Pick up a copy of Des Hammill's book, "How to Build and Power Tune
Weber & Dellorto Carburetors".

Regards,
Tim Engel
Lotus Owners Oftha North

Manometers was: timing problem

PostPosted: Tue Apr 26, 2005 8:45 pm
by LotusRod
Bonjour Tim,
I sure would like to read your instructions on carb tuning.
If you have the time please send me a copy:
***@***.***
Cheers
Rod
On 26Apr 2005, at 11:21 AM, Tim Engel wrote:


--- In ***@***.***, "J. Lewthwaite" <[email protected]>
wrote:
> Hi Bill,
> how high is the coulomb of mercury? and is there
> another way of taking a tapping, without drilling.
> Also does anyone know of a good web site concerning
> tuning dellortos. The car's running now!! thanks to
> every one on the list for the help, and Jeff for providing
> this forum.



Jo,

I have written a Word.doc on the subject and would be happy to
forward it to you as a file attachment if you wish. Just ask and
forward the e-mail address where you wish to receive it I tried
uploading it to the Files section, but it's full. Are you also a
member of [email protected] ? The file is also posted there? as
well as S1S2S3Owners (naturally aspirated Esprits) and Turboesprit.

The Word.doc is written with DHLA 40's and 45's in mind (Lotus 907/
910/ 911/ 912 engines), but most of it will apply to Elans. The
only caveat is that some older Dellortos don't have all the ports the
newer ones have. For instance, the 9XX carbs have manometer vacuum
ports built in (no drilling required) as well as Air Bleed Screws for
balancing barrel to barrel on one carb. If you run into differences
we would have to talk through them.

If you drill vacuum ports, they need to be as close to the throttle
butterfly as possible. Some really funky flow dynamics take place
in an engine manifold and pressures are not uniform throughout. Get
very far from the butterfly and you could be measuring the pressure
of some reversion wave that really has nothing to do with what's
going on at the butterfly.

Tune the idle mixture screw to produce the strongest vacuum (highest
column) per cylinder. Then use the carbs' air bleed screws (in
their absence, twist the butterfly shaft) to balance the two bores on
one carb (weaken the stronger bore to match the weaker bore).
Finally, use the linkage coupler balance screw to balance one carb to
the other. The details are in the document.

I strongly recommend the Carbtune II mechanical manometer for
balancing carbs and have included source info for it. It uses steel
rods sliding in glass tubes instead of liquids. Most importantly,
it's mercury-free. There's also a link to the website of a guy who
built his own carb balancing manometer. An open manometer using a
light liquid (ie, not mercury) will be very tall. To avoid that,
he connects one end to one carb bore and the other end to the other
carb bore. That way the manometer only registers the difference in
pressure and can be quite short.

Pick up a copy of Des Hammill's book, "How to Build and Power Tune
Weber & Dellorto Carburetors".

Regards,
Tim Engel
Lotus Owners Oftha North










To search the mailing list archives:
http://www.escribe.com/automotive/europ ... index.html


http://www.lotuselan.net/publish/legal_stuff.shtml
Yahoo! Groups Links









Cheers,

Rod McIntyre

Manometers was: timing problem

PostPosted: Tue Apr 26, 2005 11:11 pm
by "Paul Thompson"
Pls send me carb tuning instructions ***@***.***

-----Original Message-----
From: ***@***.***lto:***@***.***
Behalf Of Rod McIntyre
Sent: 26 April 2005 21:45
To: ***@***.***
Subject: Re: Manometers was: [LotusElan.net] timing problem


Bonjour Tim,
I sure would like to read your instructions on carb tuning.
If you have the time please send me a copy:
***@***.***
Cheers
Rod
On 26Apr 2005, at 11:21 AM, Tim Engel wrote:


--- In ***@***.***, "J. Lewthwaite" <[email protected]>
wrote:
> Hi Bill,
> how high is the coulomb of mercury? and is there
> another way of taking a tapping, without drilling.
> Also does anyone know of a good web site concerning
> tuning dellortos. The car's running now!! thanks to
> every one on the list for the help, and Jeff for providing
> this forum.



Jo,

I have written a Word.doc on the subject and would be happy to
forward it to you as a file attachment if you wish. Just ask and
forward the e-mail address where you wish to receive it I tried
uploading it to the Files section, but it's full. Are you also a
member of [email protected] ? The file is also posted there. as
well as S1S2S3Owners (naturally aspirated Esprits) and Turboesprit.

The Word.doc is written with DHLA 40's and 45's in mind (Lotus 907/
910/ 911/ 912 engines), but most of it will apply to Elans. The
only caveat is that some older Dellortos don't have all the ports the
newer ones have. For instance, the 9XX carbs have manometer vacuum
ports built in (no drilling required) as well as Air Bleed Screws for
balancing barrel to barrel on one carb. If you run into differences
we would have to talk through them.

If you drill vacuum ports, they need to be as close to the throttle
butterfly as possible. Some really funky flow dynamics take place
in an engine manifold and pressures are not uniform throughout. Get
very far from the butterfly and you could be measuring the pressure
of some reversion wave that really has nothing to do with what's
going on at the butterfly.

Tune the idle mixture screw to produce the strongest vacuum (highest
column) per cylinder. Then use the carbs' air bleed screws (in
their absence, twist the butterfly shaft) to balance the two bores on
one carb (weaken the stronger bore to match the weaker bore).
Finally, use the linkage coupler balance screw to balance one carb to
the other. The details are in the document.

I strongly recommend the Carbtune II mechanical manometer for
balancing carbs and have included source info for it. It uses steel
rods sliding in glass tubes instead of liquids. Most importantly,
it's mercury-free. There's also a link to the website of a guy who
built his own carb balancing manometer. An open manometer using a
light liquid (ie, not mercury) will be very tall. To avoid that,
he connects one end to one carb bore and the other end to the other
carb bore. That way the manometer only registers the difference in
pressure and can be quite short.

Pick up a copy of Des Hammill's book, "How to Build and Power Tune
Weber & Dellorto Carburetors".

Regards,
Tim Engel
Lotus Owners Oftha North










To search the mailing list archives:
http://www.escribe.com/automotive/europ ... index.html

CopyrightC LotusElan.net and the author:
http://www.lotuselan.net/publish/legal_stuff.shtml
Yahoo! Groups Links









Cheers,

Rod McIntyre







To search the mailing list archives:
http://www.escribe.com/automotive/europ ... index.html

CopyrightC LotusElan.net and the author:

Yahoo! Groups Links

Manometers was: timing problem

PostPosted: Tue Apr 26, 2005 11:27 pm
by bill308
Hi Tom. I saw your response below and was a bit surprised.

I think I've tried most methods at carb synchronizing over the years
so my preference of methods, in decending order, from least effective
to most effective, is as follows:

1. listening to the air hiss using a tube to the ear - not easily
repeatable and very subjective

2. a Unisynch - affects engine running at idle and is sensitive to
orientation. Can only look at one carb throat at a time

3. a BK synchrometer - gives a measure of flow rate but only does
one throat at a time. By the time you cycle through several carb
throats, the engine rpm has changed or you forgot the previous
reading. The best way to use a Synchrometer is to fix one in a carb
throat and use a second one to match the remaining throats to the
control meter. This method requires matched Synchrometers.

4. a 4-tube manometer system, one per throat, measuring the manifold
vacuum of all carbs simultaneously - all throats are monitored
constantly. An adjustment to one will affect all others and this will
be immediately visible and measureable. Actual readings are not
important, only that all columns are the same height.

Prior to purchasing a pair of 4-tube manometers for my F-car, I
considered the carbtune-II, which uses metal rods floating in a
tapered bore of glass. Environmentally, this is a good way to go but
I wasn't convinced the performance/accuracy was there.
Irregularities in the tapered bore, bore verticality, or a
contaminant causing intermittant sticking of the steel slug, was a
potential problem. In the end, I thought it difficult to beat
mercury, with all its toxicity issues. There is no sticking of the
fluid or dependance on bore taper or verticality.
Sensitivity/pulsations can be be controlled by line restrictionsl
It's the the verticle height of the column that counts. When the
columns are equal, the manifold vacuums are equal, the flows are
equal, and the engine will tick over nicely if the mixtures are
correct.

Balancing carbs is really an issue at idle and off idle. A good
balance allows one to accelerate smoothly from a stand still with
smoothness and little effort. Low speed gear changes are much
cleaner. Fuel economy is improved. I'm a happy driver.

The down side is that one has to install vacuum taps in the intake
runners. At idle, air flow is very low. Position of the tap is not
real important IMHO but, I would/did position the drilling/tap
fitting a reasonable distance from the butterfly valve of the carb.
In the case of the Weber TC head of my S2 Elan, I hid them on the
underside of the runners. For my F-Car, I modified the air injection
(emissions) plumbing from steel tubes to flexible (silicone) tubing
and achieved the same result. Balancing 8-throats is more difficult
than balancing 4-throats, but manometers make it predictable and
sure. Once you've tried it, you'll kick yourself for not always doing
it this way. The results are quite obvious to the tuner.

Bill

--- In ***@***.***, "tom moore" <[email protected]>
wrote:
More manometer tales. I can't believe anyone would actually do this!
Tom

Manometers was: timing problem

PostPosted: Wed Apr 27, 2005 1:23 am
by "Tim Engel"
----- Original Message -----
From: "Paul Thompson" <***@***.***>
To: <***@***.***>
Sent: Tuesday, April 26, 2005 6:11 PM
Subject: RE: Manometers was: [LotusElan.net] timing problem
Pls send me carb tuning instructions
***@***.***



Paul,

See the attached Word documents. One is the instructions for tuning
Dellortos and the other is a photo with the various screws identified (it
usually opens at the start of the text... scroll up for the photo).

Feel free to get back to me if something doesn't make sense.

Regards,
Tim

Manometers was: timing problem

PostPosted: Wed Apr 27, 2005 1:32 am
by "Tim Engel"
Oops, I forgot to cut-n-paste addresses.

To the list, sorry.
To Paul, patience, it's coming.

Later,
Tim


----- Original Message -----
From: "Tim Engel" <***@***.***>
To: <***@***.***>
Sent: Tuesday, April 26, 2005 8:24 PM
Subject: Re: Manometers was: [LotusElan.net] timing problem
Paul,

See the attached Word documents. One is the
instructions for tuning Dellortos and the other is a
photo with the various screws identified (it usually
opens at the start of the text... scroll up for the photo).

Feel free to get back to me if something doesn't
make sense.

Regards,
Tim

Manometers was: timing problem

PostPosted: Wed Apr 27, 2005 9:36 am
by hantsjo
Hi Tim,
That would be much appreciated, Please send the attachment to
***@***.***

Thanks,
Jo
65 S2
----- Original Message -----
I have written a Word.doc on the subject and would be happy to forward it to
you as a file attachment if you wish.
The Word.doc is written with DHLA 40's and 45's in mind.... but most of it
will apply to Elans.....

Manometers was: timing problem

PostPosted: Wed Apr 27, 2005 9:40 am
by "Simpson, Karl"
Ditto me Tim.

Thanks,

Karl

S4 FHC SE

Mailto:***@***.***

-----Original Message-----
From: J. Lewthwaite [mailto:***@***.***
Sent: 27 April 2005 10:37
To: ***@***.***
Subject: Re: Manometers was: [LotusElan.net] timing problem



Hi Tim,
That would be much appreciated, Please send the attachment to
***@***.***

Thanks,
Jo
65 S2
----- Original Message -----
I have written a Word.doc on the subject and would be happy to forward
it to
you as a file attachment if you wish.
The Word.doc is written with DHLA 40's and 45's in mind.... but most of
it
will apply to Elans.....







To search the mailing list archives:
http://www.escribe.com/automotive/europ ... index.html

Copyright(c) LotusElan.net and the author:

Yahoo! Groups Links









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