Itinerant Air-Cooled

This may be a fairly esoteric question that highlights my ignorance of several important points regarding fuel delivery, but here goes:

I've had various wonkiness with the Brosol 2 carburetor that Kombi Haus installed on my 1600 DP engine to replace something that a PO had installed in place of the 34 PICT-3 that the bus originally had. I'd asked about getting a genuine Solex 34 PICT-3, but they told me that these were pretty much unobtainable, unless I wanted to pay big bux for a rebuilt without a core exchange.

A friend of mine who dabbled in Porsche restorations was cleaning out his garage prior to moving to South America, and came across a Solex PICT-3. Since he knew I had a bus, he gave it to me. I unwrapped it and found that it wasn't a 34 but a 30 PICT-3. My understanding is that the big difference was that the 34 was designed to accommodate a vacuum retard as well as a vacuum advance distributor.

But here's the thing: I've been running an Aircooled.net SVDA Pertronix distributor, with the vacuum retard port capped off on the Brosol. Since I'm not using the extra port, can I rebuild the 30 PICT-3 and use it on my engine? Or am I missing some profound truth?

And what model of VW was the 30 PICT-3 originally designed for, anyway?

The 30 PICT-3 was used on 1970 Type 1 and 2 single-port 1600 engines. Those engines used a vacuum advance only distributor, so your SVDA is not a good fit. Also, it has a smaller base than the dual-port
manifold has, so you'll need one of these: https://socalautoparts.com/product/carb ... -manifold/

The 30 PICT-3 has some rather oddball jet sizes, so I would suggest you check if anyone has been fiddling with them, the
stock specs are given in your Bentley manual. I once had a '70 bus with one whose main jet a VW "mechanic" kept replacing with one more suitable for the later 34 PICT-3, resulting in a grossly rich fuel mixture.

Well, it looks like I'll be giving away a 30 PICT-3. Anybody want one?

And I'll soldier on with the Brosol. I guess the next step is to take out the float and weigh it, to see if it's leaking.

Re weighing the carb float: I suspect there might be an error in the Bentley specs for that, and it occurs in the manuals for several different vehicle types. They say the floats for the 30 PICT-2 thru 34 PICT-4 (and maybe others with the same type
of float) are supposed to weigh 8.5 grams. I measured 6 or 7 apparently sound floats, and they all weighed in the range
9.3 to 9.7 grams, and carbs I was using some of them in all had normal fuel levels. And of course I did not include the brass
pivot shaft.

When Daniel measured the wonky float, it came out to be about 18 grams (IIRC). A gram or two shouldn't make much difference, but nine grams...

I also found out that leaky floats are so common in Brosols that Kombi Haus keeps replacement floats in stock. So I bought one and will put it in my Box o' Parts that I always carry, in the belief that if you have a spare part in the bus, you probably won't need it.

I am dealing with a 30 Pict 3 on a dualport with the adapter, and you actually can get away with the vacuum signal going to the SVDA. The 30 Pict 3 will over-advance a little so set the timing conservatively at 3,400 rpm to 22-25* with hoses off, then check total advance with the vacuum hose back on, 36-38* max.
Colin

Good to know. It remains to be seen if the 30 is actually going to be an upgrade to the Brosol. I'm not sure I want to be the guinea pig for that, but it is another arrow in my quiver.