Warren and the 3 D's

[warrenz]

For those that have lent me various jets here is were I am at.

 

Started with 145 Mains, 7772.10 emulsion tubes, 55 idles, 35 pumps, 240 air correctors and 0.8 reduced air bleeds.

 

Air bleeds courtesy of Michael in Sydney, thanks for that.

 

This set up was strong from 3000-5000 revs with a big flat spot down low but rich.

 

Sulio's 130 mains improved it down low but still big flat spot under 2800 revs.

 

Purchased 125 mains and was better again but still that flat spot. My Coloutune spark plug was said a slightly lean mixture readings above 3000 revs and as you got higher it leaned out more (due to oversized air correctors). Swapped to Sulio's 7772.6 emulsion tubes and mixture was good.

 

Next was Scootag's 52 idles and again it was better but still flat spot and Colourtune plug said idle was still too rich.

 

Purchased 46 idles and was better but still a flat spot. Idle mixture was now good and plug colour was brownish, so looking good except for flat spot. After pulling all plugs to check colour I found the front 2 were very black. I suspect this is my flatspot with too much fuel into no 1 & 2 cylinders. This was not visible until I got correct mains and idles into the car.

 

So this is the task for this weekend, I have a couple of theories to try.

 

Thanks to Sulio, Scootag and Mick and a great example of pooled components that help me confirm I was on the right track before laying out money for jets.

 

Warren

[warrenz]

Decided to call in the professionals. On Sulio's advice I took it to Mauceri Motors in Clayton. The father is very passionate about these carby's and I well and truly got my money's worth.

 

One problem I had was an air leak, which turned out to be caused by the flexible o-ring gaskets between the carby and the manifold. He does not use them even on the racing Alfa and replaced then with the standard gasket.

Secondly he modified my linkages and added a few more springs to get a consistent return point on release so all carbies started from the same point on the next press of the accelerator

Thirdly he connected up the vacumm advance by drilling a hole in the carby to get vacumm on the intake side of the butterfly and fitted a one way valve and reset the timing.

Then he set about getting the jets correct (replaced my .10 emulsion tubes with .8's), 125 mains and 46 idles were OK and reduced the air correctors to 190. He spent some time synchronising the accelerator pumps as there was still a slight hesitation.

 

Now I think it is great, he thinks about 95%, but more time is more money. Very nice to drive at normal speed around town, in fact best it has ever been in all the time I have had it. Just shows how badly in need of some TLC my SU's were and when you plant the foot it just takes off. The whole exhaust note of the car has changed and best of all that sound of the side draught carbies on full song.

 

Now lets see what the fuel economy is like.

 

Warren

[Scoota G]

That's great news..If you don't mind me asking as i'm sure someone else will, How much were you charged for the whole tune an setup? Also are you running an electronic dizzy? As i know that when i changed to electronic it ironed out a lot of problems.