16V carb

[SteffenJ3316V]

Right I'm in the process of building a 16v engine on carbs for my Sprint. Does anyone have experience with what size jets etc I should use. The carbs are Dell'orto 40 mm.

[PETROLHEAD]

Hi mate (thanks for joining buddy, good to see you over here!)

those manifold adapters look interesting, nicely machined from billet clearly, but did you manage to blend the different spacings ok?



as for jetting, if the 40's came from a 1712cc 8v initially, and were jetted accordingly, that will suffice as a starting point, but if it were me i'd be doing the majority of the jetting/fuel adjustments as part of a very final set up, on a rolling road and mixture analyser.

i can give you the set up i have on my carbs earmarked for my next converted car, but every motor is different of course, and they are dellorto 45's!

but if you think they will help, i will dig them out for you?

cheers,
thanks again

shrew

[SteffenJ3316V]

Hi. I have not fitted them yet but they should be a direct fit. A danish guy made a few set of them on a CNC machine because he wanted to run carbs on a 16v in his Beach Buggy. They should fit with the original gaskets I'm thinking 58 idle jets and 145 main jets for start up Maybe 45 mm carbs needs bigger jets?
And thanks for the welcome

[kammatic]

those manifolds look great! better than the junk i bought from "motorman" on ebay,,...

[Fluffyduff]

I'm using the standard s2 1.7 jetting in mine with the larger (9164.4) emulsion tubes. It has worked out well and the old 146 engine I was using was putting out 141bhp at the flywheel on a good cold day. It dropped to 139 the second time I had it tested but it was a lot hotter the second day.

I had a small dip in the power/torque graph at 3000 but apart from that, it was linear power throughout the rev range up to 7250. I've since switched to a 33 engine with the same carb setup and the pickup seems sharper but I haven't had it on a rolling road to confirm.

Jetting lists if it's any use to you:
http://www.alfa-pages.co.uk/carbjet.php

[PETROLHEAD]

yeah those motorman versions have been complained about plenty haven't they!

however, once you stop them leaking everywhere, they do actually work well enough.

a few of us did a group buy of some about a year or so ago, and we decided it would be between the Gazoli's or the German versions, which looked pretty similar, so the german dealer won us over on price. The important things is that those of use that are already using them, reported them hassle free and working well, so good choice!


as for the carbs i currently have, they are currently set like this

Chokes - 38
Mains - 180
Idles - 60
Air correctors - 200
Emulsion tube - 9164.2


i will very likely be coming down a bit on mains firstly, as they were off a motor that could rev a good deal higher than my 16v, so not quite the same need to pail it in like 180's will!

as i recall my 1712 8v sprint idled much better and picked up well off the bottom at 55 idle jet, so i'll see how these 60's go for starters.


shrew

[SteffenJ3316V]

I think I will start with 55 idles and 145 mains and take it from there on a rolling road

[SteffenJ3316V]

I ended up with 57 idles, 147 mains and emulsion tube 9164.4. My PiperX filter are toast so I also ordered 4 Ram Air socks