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. This is part III of a 3 part series dedicated to the different AirCooled Aftermarket Axis of Evil modifications. So, if the other 2 were Iraq and Iran, then this one must be my North Korea.
Evil Aftermarket Modification #3: removing the thermostat or more of the temperature regulation system
I've never really understood why people do this, but it happens so often, it has become a practice. Kind of like selling nuclear equipment or materials to non-proliferation countries, this will only come back to haunt you. Eventually. We call these engines "air cooled" which sounds like they're always hot and need cold air blowing on them all the time or they'll melt in front of your eyes. While this is true when you're running through the desert in mid-afternoon in August, most of us aren't doing that. Ever. So why should you care? Your heads can warp if you blow cold air on them when they are not in need of cooling, for one thing. For another, your fuel won't burn properly, driving down your power and your mpg. A thermostat and the air vanes help the engine get to its most efficient temperature, and then helps keep both the oil and the engine at that temperature. "The oil?" you ask. Yeah, the oil. Although we call these "air cooled" John Muir pointed out that we should probably call them "oil cooled" as well because its the oil that transfers a lot of the combustion temperature out. If you don't have the air vanes, you aren't getting air to your oil cooler, and you're heading for an overheating.
How do I recognize this evil?
This evil comes in 2 forms-
First: no thermostat. Get on the ground behind your bus with a flashlight and shine the beam through the exhaust above the lower right-side engine tin so you're looking between the right heat exchanger (manifold) and the block. Is there a cable running from the front end back to a pulley and then up to the top of the engine? No? Someone took your thermostat off and didn't replace it.
Second: no vanes. Open the rear engine door and reach over the top of the fan housing (the big silver thing on the very back of the engine). Is there a bar there that runs the length of the back of the housing? No? They got your vanes too! It is very rare that you'll have lost your vanes but kept your thermostat. This is because the thermostat has a cable running from it to control those vanes, and removing the vanes is much more time consuming than pulling the thermostat plus cable. As much as the removal of the thermostat irritates me, the removal of the vanes is just hazardous to your engine. This needs to be remedied. While you're at it, put a thermostat on there.
How do I eradicate the evil-doer(s)?
If all you're missing is the thermostat, you can no longer get the original styled part. Maybe this is why the old one didn't get replaced. Nah... You can get a newer version type1 thermostat and have it altered to suit a type4 (pancake) engine. I had the fine folks at aircooled.net do this for me and it bolts right in. Tie a small fishing weight to a length of string. Tie the other end to the vane rod and drop the weight through the tin-hole in the top of the engine just to the left of the right-side of the fan housing. If you use a flashlight and a mirror (or stick your head in there) its pretty easy to see that there's only the one hole. Tape the cable end to the string and pull the cable up through the hole. Push the rod all the way forward and thumbscrew the cable to the rod. Wait, you don't have a rod?! Then we need to fix that first.
Replacing the vanes and actuating rod takes a little more time and requires some used parts (theBusCo.com is my personal playground for stuff like this). Its actually easier to do this by dropping the engine, but if you don't want to do that (like I didn't), follow these instructions. You need to remove the exhaust (from the heat exchangers back), and the rear engine tin. Do you have a heat reflector between the muffler and the lower engine tin? No? Yeah, that's not surprising. As long as you're there, you should find and install one of these. It will drop your engine temperatures a few degrees when the engine is running it’s warmest - when you want the temp drop. Anyway, remove the alternator tin (leave the alternator there, though), and remove the fan grill, timing scale and fan. Remove the little tins (covers) between the heat exchangers and the fan housing. There's one on each side and they're about 3 inches by 1 inch and held in by 2 flathead bolts each. If you have the little flappers in there, grab them. If you don't, add them to the list for the used bus parts place. Now, for the heavy part: support the fan housing with something and remove the bolts (in the hole where the fan was) that hold the fan housing to the engine block. You'll probably discover a few flathead screws that you didn't take out holding you up. Pull them and wiggle the fan housing back. There is just enough space to fit the new-to-you vanes into the fan housing. Make sure the bottom of the vanes click into the little hinge pins or they won't operate correctly. Hold the rod steady and fit the housing back into place. Test the action of the rod. No scraping noise? They move freely and make a clatter-clunk noise at each end of travel? You're good! Put those big bolts back in and take a breath. The install is genuinely the reverse of the install. Don't forget to put the little flaps in where the heat exchangers meet the fan housing, and cut a gasket for the little covers when you put them on. Put the fan on squarely and torque it down in steps, don't forget your timing scale. Make sure you place the gasket between the alternator and its tin properly. When you're ready to put your rear engine tin back on, get your heat reflector ready - it is held on by the same flathead bolts. Its recommended to use new fasteners and gaskets when you put your exhaust together. I use stainless steel bolts, washers and nuts whenever I can so I can reuse them. And they don't rust.
I think somewhere along the line someone in Southern California or in the desert states came up with a few hot-rodder ideas that worked in their area. Everywhere else we have dew points, stop signs and morning chill that we have to think about when tooling on these buses. Once you've removed these 3 demons from your bus you will notice that it runs better in all kinds of weather, has better power and gets better mileage.
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