Tuning/balancing the 2 Stromberg Carbs on 72 Europa

[marks]

Is there a recommended method of balancing the Stromberg carbs on a 72 Europa.  I had a broken cable strand in my accelerator cable sheath, that I fixed, and now need to balance the carbs.  Thanks!  Mark

[Kendo]

I don't know if this will help, an old scan of a Stromberg tuning guide. "Tuning Stromberg CD Carbs" Unfortunately it is over the 1Mb file size limit. So if you want it, send me your email address.

The very best balance I got on my Strombergs was when I used a motorcycle mercury balance gauge. (Then I got it smogged and they destroyed the tune to get it to pass the emissions test.)

[BDA]

I don't have any experience with balancing strombergs on a TC but there are a few ways to test the balance or synchronization. The cheap way is to get a length of hose (between 3/8" and 1/2" would be good) holding one end to the carb opening and at idle listening to the sound it makes and adjust the carbs so that the sound is as close as you can get. A Uni-syn is another inexpensive way to test the balance but the best method I've used is one of these (https://www.ebay.com/itm/202876557316?hash=item2f3c629804:g:YJMAAOSwb55eHBrb). Very easy to use and much more accurate than the methods noted above.  If you look around, you might be able to find it a little cheaper.

As far as how to do it, here is the manual page for it (http://lotus-europa.com/manuals/tcwork/l/index.htm#fig12).

[jbcollier]

There are all sorts of work around methods to check carb balance: using a length of hose, short each cylinder and check rpm drop, etc.  However, the quickest and fastest method is to use a proper air flow gauge like the one BDA recommended.  I like to use a right angle adapter on mine as access can be tight in the Europa engine bay.  Uni-Syns are cheap and plentiful but they strangle the air flow, instantly altering the engine idle which makes them difficult to use accurately.

Was your engine running fine before?  It just needs a trim?

Yes?  Then re-syncing the carbs is a fine thing to do.  Get the air flow tool, uncouple the two throttle shafts, adjust the idle speed screws until both carbs are drawing the same and the idle speed is correct, and then tighten throttle shaft coupler.

Was your engine running poorly?  Idle lumpy?  That's a bit more involved and we can get into it, if that is the issue.

[EuropaTC]

I've nothing else to add other than I'm also a fan of the kit that BDA posted. I've tried most of the usual methods from a bit of tubing to manometers but that's the simplest and most accurate piece of kit I've had. Makes balancing Weber/Dellorto very straightforward.  Well worth the money, even at twice the price.

Brian 

[marks]

I appreciate all the help on the balancing of the carbs.  To answer the question of was the engine running good before:  I received this Europa as a true basket case, and the engine had been rebuilt.  I have the car all together now; and the engine seems to run okay; but I thought that the carbs might need to be synced.  The only other area that concerns me is the brakes.  Everything has been rebuilt; however, I seem to lose pressure after a while.  Could it be possible that I might be losing vacuum through the servo system.  I am new to this; so I appreciate the feedback.  Mark   

[jbcollier]

Were the carbs overhauled?  New jets and needles?

If the pedal is slowly going down, but the fluid level stays up, then either the master cylinder or the servo slave cylinders are "bypassing" internally.  While you can get kits for both the master and the servos, they also wear internally which means the new seals can't seat properly.  The fix is to have the cylinders sleeved.  It isn't cheap, and it doesn't always work properly afterward.

Myself, I only fit new master cylinders and servos.  I do not overhaul them due to the 50 years of wear and tear.  You can also delete the servos and run an 0.70 master and the brakes are great.  Thankfully, one of the later Triumph Spitfire masters can be moderately easily adapted to fit.

[marks]

The carbs and servos were rebuilt.  The pedal is hard for a while and then it slowly goes down.  You may be correct on the rebuilt servos not working well because of wear.  Thanks again!  Mark

[jbcollier]

If the carbs were properly rebuilt then they will have new throttle shafts, needle and needle jet.  Once you get the carb air flow tester, set up the idle and then reach in gently lift the dashpot up 3 to 5 mm.  If the idle speed rises and stay up, it's too rich.  If the idle speed instantly falters, then it's too lean.  If the idle speed rises a little bit then falters, it's spot on.

[marks]

Thank you very much for the additional information!