AirCooled Aftermarket Axis of Evil

Yesterday's posting about the Weber Progressive Carb in the Wintertime reminded me of my AirCooled Aftermarket Axis of Evil. What is this Axis of Evil? Well, its not Korea, Iran and Iraq. It is a collection of modifications performed on aircooled vehicles that are all done together for some reason. It seems like there are 3 different things that all get changed around the same time by folks that mean well, but don't realize they're doing their air-cooled VW a disservice. Maybe they got misled by some flashy advertisement. Maybe they were talked into it by a mechanic that "used to race" so "he knew what he was doing". Regardless, if you find one of these aftermarket modifications, the odds are very good that the other 2 have been made as well. Bear in mind, if the VW engineers could have left off a bolt, they would have saved the company a big ol' pile o' cash after producing millions of these engines.
I'll spend my next 3 posts on each of the different AirCooled Aftermarket Axil of Evil modifications. After yesterday's post about the Weber 32/36 progressive, we'll logically start there. Its not the worst of the Axis of Evil, but its not part of the Coalition of the Willing either.

Evil Aftermarket Modification #1: Weber Progressive 32/36 Carb.
I know fellow bus drivers that swear by these carbs. Usually it comes up in a conversation about why they only drive their bus in the Summertime. "Busses can't be used all year 'round," they say. "They don't like the cold." Ahh yes... good old balmy Germany... that's where my bus wants to drive. That's crazy talk. If you don't like driving your bus in the cold because it doesn't have heat, say so, and I'll happily help you fix it. Your bus likes the cold fine. Your centermount progressive carb doesn't. It really isn't the carb's fault, though, its the fault of the long intake that the carb sits on. After the fuel and air mix together, it travels down 15" or more of pipe to the intake port on your head. That pipe is out there in the elements, not heated by anything, so the fuel mixture gets all dorked up and by the time it hits the combustion chamber it doesn't burn right. This carb was designed to sit right on top of the Pinto engine, getting warmed by the engine block. No such luck on theVW, especially the pancake motor in 1972-1983 bus/vans.

How do I recognize this evil?
When you pop the rear engine door and look inside, there will be a silver squarish thing sitting right in the middle of everything. If it is exactly as it comes out of the box, it will have a chrome aircleaner on it. It is sitting on long silver tubes that look like electical conduit. "Aw.. but it looks so pretty," you say. Yeah, pretty, but grossly inefficient when the air temperature drops below 70F or gets near the dew point. Here in the Pacific NorthWest, its a rare day when its not near the dew point except in the Summer..... which, oddly enough, is when the local Weber drivers think is the only time to drive a bus. Coincidence? No, they've been confused by the evil-doers.

How do I eradicate the evil-doer?
There are a few options for reducing the negatives of the Weber (containment of the evil-doer), or you could toss it completely for the correct induction system for your make/model/year.
Option 1: you could add insult to injury by trying the GM Cavalier trick. The Cavalier had a similar problem with its induction system, so GM added a heated gasket to warm the system. Whaddaya know, it fits between a Weber and that ridiculous electrical conduit intake. I have not personally done this, but I have heard that this does actually work, but you need some kind of thermal sensor to tell it to turn itself off. Sounded dangerous and little like like nonscience, so I tried...
Option 2: find a source of warm air and route it into the aircleaner. This helps the carb work better down to the mid 40F's, and drivable into the mid 30F's. I went into more detail in yesterday's post about this. The best solution is replacing the whole thing with what was removed in the first place - either dual carbs or fuel injection. These are more expensive options, but doing it right isn't usually the less expensive way in the short term. It is usually the less expensive way in the long term, though.

Dual carbs and fuel injection are not harder to dial-in than the Weber, nor are they harder to routinely maintain. What's hard is finding what's wrong with the used parts you have. Run a Weber for 30 years, and see if you don't have a similar "what's wrong with it" head-scratching session. The Dual carbs and fuel injection that came with the bus have 30 years of millions of owners experience to draw on. Removing the evil-doer in this case is easy; its the establishment of a stable system after the fact that's the challenge. That's usually because you're doing the work with the parts you have, not the parts you wish you could have. Hmm.. that sounded eerily familiar.....

Next time... Evil Aftermarket Modification #2