Lotus Elan

Weber Carb Flooding During & After Cornering On Race Track.

PostPost by: Esprit2 » Wed Sep 06, 2017 6:10 pm

IMHO, the old Italian Weber DCOEs are the best DCOEs. But not all DCOEs are the same (like how the air horns fit, or how the aux. venturies & chokes are retained), nor are they created equally. I'm seriously not a fan of the Spanish built -151 and -152 DCOEs. I can't add any fire tales to the list, but I have found them to be more prone to fuel leaks, more difficult to set-up (there are some body-to-linkage interference issues, depending upon the throttle arms used), they're more difficult to tune/ keep in tune, and just generally... more of a pain in the butt.

The modern DCOEs are built in several countries, not just Spain. And IMHO, it's the Spanish models that are the most problematic. I won't buy them. The German DCOEs are good.

*~*~*~*
It's just my humble opinion, but the best cure for all Weber DCOE issues is the installation of a set of Dellorto DHLAs. That was Lotus' solution in 1972... they switched to Dellortos.

I have 3 907s with pairs of Dellorto DHLA45E carbs, plus I work on local club member's Dellortos.

I currently have one, single, 'Italian' Weber 45DCOE-9 on my Europa S2. That one DCOE causes me more ongoing tuning and maintenance work than all the Dellortos I work on put together. Just sayin'...

Bruce,
Keep your Westfield, dump the Webers.

Regards,
Tim Engel
Last edited by Esprit2 on Sat Nov 02, 2019 12:19 pm, edited 2 times in total.
Esprit2
Third Gear
Third Gear
 
Posts: 331
Joined: 02 Apr 2008
Location: Twin Cities, Minnesota, USA

PostPost by: mojoluthier » Fri Sep 08, 2017 1:04 am

Ever impulsive, I have bought a pair of DHLA 40 on eBay that look pretty good with linkage intact. I have no info on the chokes or jetting, but they should be here in a couple of weeks and I will go through them. They were less costly that expected, or course that # can rise considerably if the internals are off.
mojoluthier
New-tral
 
Posts: 9
Joined: 17 Apr 2016
Location: Petaluma, CA

PostPost by: StressCraxx » Sun Sep 10, 2017 4:08 am

mojoluthier wrote:Ever impulsive, I have bought a pair of DHLA 40 on eBay that look pretty good with linkage intact. I have no info on the chokes or jetting, but they should be here in a couple of weeks and I will go through them. They were less costly that expected, or course that # can rise considerably if the internals are off.


Check your private messages.
There is no cure for Lotus, only treatment.
User avatar
StressCraxx
Fourth Gear
Fourth Gear
 
Posts: 932
Joined: 26 Sep 2003
Location: San Francisco Bay Area, California

PostPost by: elancoupe » Sun Sep 10, 2017 9:30 am

As Tim can tell you, there are many, many types of 40 DHLA's. The majority are emission carbs, but the preferable types occasionally come for sale.

I did a LOT of reading and research, and was able to acquire a pair of DHLA E's some years ago, and would never go back to Webers.
Mike
elancoupe
Fourth Gear
Fourth Gear
 
Posts: 923
Joined: 11 Sep 2003
Location: USA

PostPost by: Ita124 » Mon Oct 30, 2017 9:57 am

Anyone know where I can buy these risers and caps from?

Cheers,
Paul
Ita124
New-tral
 
Posts: 1
Joined: 30 Oct 2017
Location: Sydney Australia

PostPost by: prezoom » Tue Oct 31, 2017 3:58 pm

How do you have your auxiliary venturis secured in the carb throats. If you are using the standard "P" clips, they do not provide enough pressure to seal the venturi against the transfer port, which can leak fuel.

There are a couple of quick and dirty fixes you can try. Find some flat rubber stock approximately the thickness of the "P" clip. Take a hole punch and cut out a small piece that will fit inside the P of the clip. This will prevent the clip from collapsing as easily. Then cut a strip of the rubber to slip in the slot cut in the carb throat bore. This will help prevent escaped fuel from running up towards the air horn. Lastly, try to find a very thin O ring that will fit behind the locating boss on the air horn towards the carb body. This is just an additional measure to prevent fuel from escaping the carb body. If the recess for the boss is too small for an O ring, use some non-fuel soluble sealant. All this should make removing the aux venturi a real PITA.

I had the same problem with the DCOE's on my pre-crossflow S7 back in the 60's when I started auto crossing and racing, but no fires. I currently do the same with any 40 that I install on any of my engines. On 45's this problem does not exist, as they have an external grub screws to push the aux venturi up against the transfer port and lock the chokes in place. There are two bosses on the 40 carb body that are unused, that could possibly be used with the grub screws from the 45's for the same purpose.
Rob Walker
26-4889
50-0315N
1964 Sabra GT
1964 Elva Mk4T Coupe (awaiting restoration)
1965 Ford Falcon Ranchero, 302,AOD,9",rack and pinion,disc,etc,etc,etc
1954 Nash Healey LeMans Coupe

Lotus is a life sentence with no parole
prezoom
Coveted Fifth Gear
Coveted Fifth Gear
 
Posts: 1203
Joined: 16 Mar 2009
Location: Escondido, California

PostPost by: patrics » Tue Nov 28, 2017 8:39 pm

Hi,
Looking on TTR site they sell weber's with the following description:

WEBER CARBURETTORS 45 DCOE9 INCLUDING COLD START BYPASS KITS FITTED ( ANTI FIRE )

Is that all you have to do for anti fire is blank of the cold start?

Regards
Steve
patrics
Fourth Gear
Fourth Gear
 
Posts: 526
Joined: 21 Sep 2003

PostPost by: vstibbard » Wed Nov 29, 2017 12:24 pm

I just noted Craven's post on last weber 40's made in Italy. I had a number of Alfa 105 coupe's in the past and the standard DCOE40's fitted had no ram tubes and ventures's just like those in the picture. the reason is they fitted to the runs can air filter that was immediately adjacent to the carburettor mouths. When I initially played with a 1750 used for Group S historic racing in Australia I used the dellorto type ram tubes.

V
vstibbard
Third Gear
Third Gear
 
Posts: 430
Joined: 22 Jul 2008
Location: Sydney, Australia

PostPost by: SJ Lambert » Sat Nov 02, 2019 5:32 am

2292de8c-4341-4ed8-b1bc-136dcf1348eb.jpeg and



I’ve been chasing a “high end” breakdown that I decided was load related after replacing everything on the electrical side, a fuel pressure check afterwards revealed only 2 psi - a new pump and bingo - 4 psi and I’m a happy camper again!
Ford Escort Mk1 Lotus Twin Cam
Elfin Monocoque (Twin Cam)
Elfin Type 300 (Holbay S65 - 120E) mechanic

[email protected]
User avatar
SJ Lambert
Fourth Gear
Fourth Gear
 
Posts: 727
Joined: 19 Nov 2010
Location: Victoria, Australia

PostPost by: Vaughan » Sun Nov 03, 2019 2:49 am

Re the risers, they were commonly fitted to HARTT Twincams and later March type F2 cars running Twin cams and similar engines with larger webers, this was due the lateral cornering forces that they could generate, not dissimilar to auto-crossing, the difference in circuit racing is longer high speed corners caused issues which the risers solved.

Craven's post is showing an Alfa style carburettor, they never had trumpets fitted due to the design of their air filter housing, hence the different venturi design, it is same regardless of Italian or spanish made carburettors.
Vaughan
First Gear
First Gear
 
Posts: 40
Joined: 11 Apr 2009
Location: Sydney, Australia

PostPost by: fatboyoz » Sun Nov 03, 2019 4:57 am

Hi Tim,
Can you please let me know which dellortos would be best for my standard (105 hp) S4 Elan.
There seems to be a lot of different types floating about.
Cheers,
Colin.







quote="Esprit2"]IMHO, the old Italian Weber DCOEs are the best DCOEs. But not all DCOEs are the same (like how the air horns fit, or how the aux. venturies & chokes are retained), nor are they created equally. I'm seriously not a fan of the Spanish built -151 and -152 DCOEs. I can't add any fire tales to the list, but I have found them to be more prone to fuel leaks, more difficult to set-up (there are some body-to-linkage interference issues, depending upon the throttle arms used), they're more difficult to tune/ keep in tune, and just generally... more of a pain in the butt.

The modern DCOEs are built in several countries, not just Spain. And IMHO, it's the Spanish models that are the most problematic. I won't buy them. The German DCOEs are good.

*~*~*~*
It's just my humble opinion, but the best cure for all Weber DCOE issues is the installation of a set of Dellorto DHLAs. That was Lotus' solution in 1972... they switched to Dellortos.

I have 3 907s with pairs of Dellorto DHLA45E carbs, plus I work on local club member's Dellortos.

I currently have one, single, 'Italian' Weber 45DCOE-9 on my Europa S2. That one DCOE causes me more ongoing tuning and maintenance work than all the Dellortos I work on put together. Just sayin'...

Bruce,
Keep your Westfield, dump the Webers.

Regards,
Tim Engel[/quote]
'68 S4 DHC
fatboyoz
Fourth Gear
Fourth Gear
 
Posts: 584
Joined: 04 Oct 2003
Location: Gold Coast QLD Australia
Previous

Total Online:

Users browsing this forum: No registered users and 1 guest