Lotus Elan

Webers leaking at O ring mounts

PostPost by: oldchieft » Fri Jan 01, 2016 9:42 pm

From past posts

lotus-carbs-f40/help-with-webers-t31195.html#p218433

Another way to sort levels

Jon the Chief
oldchieft
Third Gear
Third Gear
 
Posts: 402
Joined: 17 Sep 2013
Location: Near Wolverhampton

PostPost by: Hawksfield » Sat Jan 02, 2016 3:08 pm

Hi

The method I use to set float levels on 40DCOE 51 carbs
Attachments
Optical_Fuel_Level_Tool_Instructions.pdf
(637.32 KiB) Downloaded 588 times
Regards

John

+2s130 1971
User avatar
Hawksfield
Third Gear
Third Gear
 
Posts: 387
Joined: 14 Jul 2004
Location: Hartlepool Teesside

PostPost by: elanner » Sun Jan 03, 2016 1:17 pm

Tim,

OK, thanks. So the "+4.5mm" seems to be a typo for "+/- 0.5mm"

I set my fuel level to 25-26mm last year (with the top cover on) so it's probably still a little high. Perhaps that explains my current theory of some occasional leakage from the starter air intake - I park the car in a deep underground garage so the fuel level is definitely unstable while driving up & down. I'll tweak it again next season.

Nick
User avatar
elanner
Fourth Gear
Fourth Gear
 
Posts: 514
Joined: 14 Sep 2010
Location: Boston, MA, USA

PostPost by: simonknee » Thu Jan 07, 2016 9:51 pm

Keith Franck did a lot (like a one man R&D departments worth) of work to show that the Weber spec of 29mm is not optimal at all and results in hesitation on acceleration. The 25mm spec comes from his excellent work. Set it at 29mm and you may alleviate your symptoms (yes your steep incline may be to blame. However you may also ruin your drive!

edit: although perhaps the 29 works from a different datum - all that cover on, cover off stuff. Just go from the top of the internal bit you see when you remove the inspection cover. 25mm down to the top of the fuel.

Weeping from the starter sections is best cured with the blanking plate kit weber will supply. Or the full cold-start elimination kit

http://www.webcon.co.uk/shopdisplayprod ... rchfields=

They take the preverbial on price but it does work
Simon
'67 S3 FHC 36/7002
'69 +2 50/1370 (stolen '00)
User avatar
simonknee
Fourth Gear
Fourth Gear
 
Posts: 916
Joined: 18 Sep 2003
Location: London

PostPost by: elanner » Fri Jan 08, 2016 4:49 pm

Simon,

Ah, that's interesting, thanks.

I must be the only person who actually likes the starter circuit. The sheer simplicity (crudeness?) of the design appeals to me and I use it whenever cold starting. I find it very effective and don't have to bother futzing around with the accelerator pump.

That said, it's an area of the Weber that can go wrong and most people never use it, so I can understand why it gets blanked off. Perhaps I should do it temporarily to prove my leaking theory....

Nick
User avatar
elanner
Fourth Gear
Fourth Gear
 
Posts: 514
Joined: 14 Sep 2010
Location: Boston, MA, USA

PostPost by: simonknee » Fri Jan 08, 2016 5:07 pm

To be fair I think I remember Keith warning that the 25mm level could result in fuel "splashing over" on inclines and perhaps in hard cornering. Maybe this is why Weber went with a conservative value but it is at the expense of driveablility. Though Keith basically thought that Weber (or at least the guy that wrote the manuals at Weber) didn't have a clue what they were doing. Every time I see reference to that old document on this site's technical section I shudder at how bad my Elan drove before I followed the ways of Keith. It should come with a health warning.

Another example of bad Weber documentation is that they do not document how to correctly use the air-bleed-bypass adjustments you get in later 40DCOE. They are very effective at ensuring the airflow is matched through all barrels and preventing stumble when moving off idle. Yet you would not know this if you read the official Weber set up.

Keith also suffered from fuel leaking around the starter cover plates even with carbs set to his exacting tolerances. I did too but since I disconnected the choke cable back in 2003 it was a no brainer to blank it all off.
Simon
'67 S3 FHC 36/7002
'69 +2 50/1370 (stolen '00)
User avatar
simonknee
Fourth Gear
Fourth Gear
 
Posts: 916
Joined: 18 Sep 2003
Location: London

PostPost by: oldchieft » Sat Jan 09, 2016 9:46 pm

elanner wrote:Simon,

Ah, that's interesting, thanks.

I must be the only person who actually likes the starter circuit. The sheer simplicity (crudeness?) of the design appeals to me and I use it whenever cold starting. I find it very effective and don't have to bother futzing around with the accelerator pump.

That said, it's an area of the Weber that can go wrong and most people never use it, so I can understand why it gets blanked off. Perhaps I should do it temporarily to prove my leaking theory....

Nick


+1 for the cold start device.

It is a lot less crude then the two dabs of the throttle.

It saves jetting neat petrol past an open inlet valve and washing the oil off the bores and diluting the lube oil.

Also after the engine is running you have to have the idle mixture set rich to stop a stumble on pickup.

The guys who built these knew what they were doing.

Jon the Chief
oldchieft
Third Gear
Third Gear
 
Posts: 402
Joined: 17 Sep 2013
Location: Near Wolverhampton
Previous

Total Online:

Users browsing this forum: No registered users and 5 guests