D.I.Y. Rolling Road on-the-real-road ; how would you go about it? serious Dellorto subject creep in this thread

[anthony1956]

1 hour ago, 7 wonders of the world said:

Sort the idle jets first and the pump jets last.

https://www.caterhamlotus7.club/blogs/entry/1073-bdr-dellorto-dhla-45c-jets-venturis-etc-figuring-out-what-i-have/

All my jets are in the above.       My idle jets are Dellorto 58 

in fact: but the above link shows actual pictures of each jet with its number displayed

38mm Choke 1 -checks similar to an example
180 Main Jet 3 -checks similar to an example
150 Air Jet 9 ("Air Correction jet") (or is it 7.50?) -checks similar to an example
7772.5 Emulsion Tube 7 -checks similar to an example
42 Pump Jet 6 possibilities appear to be: .33, .35, .40, .45, .50, .55, .60, .65, .70, .75, or .80 CODE is 7211 and my 42 is not on the list, great.
58 Slow run jet  4 (Idle Jet) -checks similar to an example
xxx Needle valve and seat 11
8010.1 Auxiliary Venturi 2 

 

Edited September 10 by anthonym

[anthony1956]

28 minutes ago, anthonym said:

2 hours ago, 7 wonders of the world said:

Sort the idle jets first and the pump jets last.

 

actuallyyyy - this isn't about choice of jets, it's about having the existing jets work as documented  - which embarrasingly I may have discovered the problem, the upside down ball bearing.

[Miker7]

Do we know how similar a Weber DCOE is to a Dellorto? I've got the Haynes weber manual which covers DCOEs. I'll happily lend to you if it will help.

[7 wonders of the world]

Similar in looks, different in operation

[OldAndrewE]

11 hours ago, anthonym said:

I found an online pic, but frustratingly neither end is shown - never mind if you find you cannot extract it without turning the car upside down. 

Not a problem, engine is not in the car and the carbs are not on it!  The brass rod is flat both ends on mine

[anthony1956]

1 hour ago, OldAndrewE said:

The brass rod is flat both ends on mine

ohhhhhhh... right then. I'll switch mine around, put the worn part at the top.

 

1 hour ago, OldAndrewE said:

engine is not in the car and the carbs are not on it! 

made me laugh! 

one of my carbs (the offending one) is here on the coffee table..

Edited September 11 by anthonym

[anthony1956]

10 hours ago, Miker7 said:

Do we know how similar a Weber DCOE is to a Dellorto? I've got the Haynes weber manual which covers DCOEs. I'll happily lend to you if it will help.

Good man, thanks. However, I have the book by Des Hammill 

My bible to date - I think I have now followed every chapter (7wow: not the jet choosing!)

Edited September 11 by anthonym

[Gridgway]

Those are very short trumpets!

[anthony1956]

Hi Graham, oh yes so they are; never thought about it. I have wondered about tuning to trumpet lengths which was discussed on here many moons ago; but always more important things to fix so far.

[anthony1956]

Right then, front inlet manifold now added liquid gasket and sealed the huge air leaks. All put back together, dizzy cap included (it's far too easy to forget that, I need some sort of visual reminder. Maybe just to disconnect the coil's HT lead at the coil end; or perhaps better the coil ignition wire so nothing can spin.

Well, Gordon Bennet, it was like going back in time a week or two; impossible to start, lots of backfires and so on. Gave up and tweaked the timing with the dizzy a bit, got it started (this is long frustrating story very short), strobe light, reset the dizzy timing (per revilla) and running nicely, reduced tick-over, balanced Carbs using Manometer, no need to tweak mixtures or air compensations because both pairs of barrels practically identical, to my pleasant surprise.

Anyway, the massive air leak problem has clearly gone. Forgot to check the accelerator jets, but that can wait; I have turned over all the pump jet "weights" all of which have ball bearing impressions worn in to them. TRICK: blow compressed air down the weight's hole and the weight jumps out - and hard to catch. 

Raining again so further tuning has to wait, but bit of a celebration at this balanced point.

Edited September 11 by anthonym

[anthony1956]

I've moved to a new thread since this really isn't rolling road stuff 🙂

https://www.caterhamlotus7.club/forums/topic/276471-bdr-dellorto-dhla-45-emissions-ok-but-want-better/

[anthony1956]

Dribble solved: it was the ball bearings wrongly placed and MAYBE the weights all having wear marks in the end resting on the ball bearings, so all reinserted the other way around.

I mean not just solved - d r i z a b o n e !

Edited September 11 by anthonym