lost the plot??

[bengalcharlie]

HI all,

I used to be able to do a search on a particular topic in the different forums and most of the time I would find what I was looking for.
Has this been changed because I can not do a search at all anymore and so it has become very frustrating.
I am looking for a site called stromberg needles and i think that stevew was the author.
PS I am also interested anyone who can tell me where to find some adjustable needles for the stromberg carb.

cheers

Robin

[ElliottN]

Have to agree that something's amiss. Searches I have just tried do not find any results in the Forum - only things in the \publish\ thread (or whatever you call it!).

Jeff - can you help?

[ppnelan]

Robin,

Was this what you were looking for ?
http://www.lotuselan.net/uploads/stromberg_needle.xls

Matthew

[jcocking]

Have to agree that something's amiss. Searches I have just tried do not find any results in the Forum - only things in the \publish\ thread (or whatever you call it!).

Jeff - can you help?

The search engine reindexes the website every other day. Something went "bump in the night" and it did not index the forums. I am running the index manually to fix the problem.

The \publish\ is the normal webpages of the website.

The reindex will take a little while to run. It has to index all 13,000 pages of the website.

jeff

[jcocking]

All fixed. Searches include forums.

jeff

[steveww]

I am not sure the XLS file on the uploads is big up to date? IIRC there are some profiles missing? I have a complete version if you need it.

For Stromberg parts contact www.burlen.co.uk they still make all the bits. If you need to know anything just ask

[bengalcharlie]

Many thanks to you all for the quick responses.
Thank you jeff, the problem has been fixed and I am happy that it was not my fault, I would have felt so stupid!
I have been looking through all forums related to stromberg carbs and it is still pretty confusing.
My car is an ex US emission car converted to UK spec. I got rid of the vacium retard capsule, fitted low balancing pipes between the carbs instead of the cross over stuff and changed the carbs for non emission carbs.
ignition is ignitor, head is a S head ( big valve, normal compression).
I still have a problem and that is that the car runs on after shutting off the engine.
Have advanced the ignition and it has helped but not cured the problem.
Cabs have the fixed needles but running and even idling are pretty OK although there is probably a slight drop in revs at idle before it climbs again to the recommend 950 RPM.
I have noticed play in the throttle spindle so first I will replace the bushes to rectifie this. Does anyone have experience doing this?
thanks mathew, I looked at the needle list and that makes it even more confusing.
Thanks also Steve for the burlen info.
I did have a look and printed all the info for all different elan specs.
How do you know which carburator you have? Are all the bodies the same and the difference only being the jetting? Is there a number on the carb telling you which spec?
if so should I replace the needle?
Carbs have been overhauled by a service kit CD029 bought from Paul matty many years ago. the packet has W.C.L. sunbury of Thames written on it.
so all gaskets, needle valves are new.
Do you think it is necessary to buy a O2 sensor machine in order to fine tune the carbs?
because this engine has been altered to UK spec as much as possible, are there any other areas I could improve on and which advance curve should I follow?
compression is OK, all about 12 and even.
cheers

Robin

[ppnelan]

Robin,

My Stromberg S4 has a Big Valve high compression head and sometimes runs on, especially in summer or when used 'hard' i.e. when particularly hot. I've put up with it, assuming it is a result of the skimmed head & block increasing the compression ratio, lower octane modern fuels, and the lean running of the Strombergs (as explained in The Lotus Twin Cam Engine book by Miles Wilkins).
Sometimes it even seems to run on backwards !?!

It goes OK otherwise, so I am reluctant to fiddle about....
I tend to stop it in gear and let the clutch in immediately after turning off the ignition if I think there's a chance it might run on !

Matthew

[steveww]

Originally the carbs would have had a tag on them to identify the model type. However after 30+ years I am sure that has long gone. As you have changed over from the original cross over inlet to the european spec the needle you require will be different. Have you changed the needle? When the carbs were serviced did you change the jet? The needle and jet will wear out with time and should be replaced. You may be luck and find that it is just the throttle spindle that has worn and not the bushes, you should replace the spindle any way. IIRC the correct distributor is the 40953 (I can not look this up at the moment. The Miles Wilkins book has these details). The running on may be due to dieseling i.e. oil getting in to the cylinder. How are the piston rings and valve guides? It may also be a coke issue. If the cylinders have a big build up of coke in them it will heat up when the engine is running and provide an ignition source carrying on running the engine once the ignition has been switched off. To ensure that the carbs are set up as good as possible it is best to use a wide band lambda sensor to see that the mixture is good across the rev range and different loads. The engine should be set up to run slightly rich; AFR 12.6

On my S4 SE with flowed head, high flow air filter, big valves and high compression I found that the B2Y profile works best. My web site www.stig.uklinux.net will have a section on Stromberg engine tuning in the near future.

[bengalcharlie]

Thanks for your info Steve,

the distributor is a 40953 but converted so without the vacium retard capsule.
I will check the ignition advance again and change the spindle/ bushes of the carb.
engine does not use any oil and the compression is perfect so it could be coke, I will check that.
needle valve seat has been replaced, but not the needle itself, so I should try a new needle as well.
I will keep an eye open for your website and keep you posted of my progress.
I will also look into buying a heand held O2 sensor device so I can experimente myself.

cheers

Robin

[elansprint71]

Jeff,
Once again I have to say thanks for everything that you do for us here.

Best regards,
Pete.

[Otto]

Sometimes it even seems to run on backwards !?!

I know it is non Lotus related...but my 21 year old vw Passat allways "afterburn" and allways backwards....fun to se that i am not the only one...
O2

[1964 S1]

Coking up and fuel quality would be my first considerations, or timing could be the culprit. What do the piston tops look like when you peek down the spark plug holes? I've had run after problems with some MG's and Riley's but never Lotus. What's the fuel supply like for you locally? I'm in the USA and run premium unleaded, with occasional splashes of leaded racing fuel.

[bengalcharlie]

Just an update what is happening ( or better what is not happening)
checked float levels, changed to adjustable needles, checked compression, changed to NGk BP5ES plugs and still no improvement.
I suspect the advance curve of my distibutor to be the culprit so I will have that checked out.
Mi dizzy is not a 40953 but a modified 41225A (retard capsule removed) but I think that the advance curve is wrong.
I will have my dizzy adavnce curve checked by a specialist.
Does anyone know of a replacement for the 40953 dizzy because I read that they are not available any more ?
car still runs well even with a lot more advance than the 7-9 degrees stated in the manual but I expect that I get to much advance with higher revs.
cheers
Robin

[david.g.chapman]

I have a very similar engine - stromberg emission carbs converted back to UK spec, but with fixed jets.

I agree with steve's comments on what to look out for, especially making sure the mixture is not too lean. I have CPL2 cams with a low compression ported head - also not skimmed at all.

I did have problems with burning exhaust valves, and one of my fixes was to go to B2Y needles from B1G. I also have access to leaded petrol, which I put in evry now and then.

Dave Chapman