How to Rebuild VW Air-Cooled Engines: 1961-2003. Prescott Phillips
A box of lint-free shop towels is a good alternative paper towel for wiping off critical components, such as bearing journals, prior to assembly.
• Brake cleaner
• Paper towels
• Various containers
Our Engine
The focus in this book will be on the most popular and most desirable air-cooled flat 4-cylinder engine that Volkswagen ever produced. It is no coincidence that the most popular engine is also the most powerful stock 1,600-cc air-cooled engine that Volkswagen ever produced for the American public. With its 60-hp engine and upgraded cooling and oiling systems, the engine installed in 1971–1972 Beetles, Super Beetles, and Ghias will be the engine we will use for the detailed disassembly and reconstruction.
Simple and inexpensive items work great for organizing parts. Muffin tins are great for sorting hardware, and cake and bread tins help with larger items. All of these items can be found at your local thrift store, at a rummage sale, or possibly in your own kitchen. Maybe your wife would like new stuff and your anniversary is coming up. Problem solved.
Volkswagen produced more than 700,000 units with this powerplant during those two model years. The serial number designation is AE. It has a 1,600-cc engine with dual-port heads, a doghouse-style oil cooler, a dual oil pressure relief case, a wider engine cooling fan, and a generator charging system.
Our particular engine was previously installed in a 1970 Beetle that was converted to a Baja Bug. As in most cases where the engine isn’t original to the car, the mileage is unknown. We didn’t even try to start it because we knew it was hard to turn over by putting a wrench on the crank pulley bolt. Even with the spark plugs removed and oil squirted into the cylinders, it was difficult to turn over. Since there weren’t any obvious signs of complete destruction, we decided this would be a good candidate for a rebuild. Fingers crossed.
This engine was plucked from a 1970 Beetle that was converted into a Baja Bug. Much of the engine tin was already missing due to the fact that it was installed in an open air–type vehicle. The distributor had been changed out for the more popular Bosch “009” mechanical advance distributor.
Here you can see the improved cooling system that was introduced in 1971. Commonly known as the doghouse cooling system, it was a huge improvement. The oil cooler moved from inside the fan shroud to its own housing behind the fan shroud. The oil cooler increased in size and was now made of aluminum.
This is the serial number for our engine. Notice the location is right under the generator stand and above the dipstick. The number AE699256 designates it as a 1971 1,600-cc dual-port engine.
CHAPTER 2
ENGINE DISASSEMBLY
It is human nature to be curious and wonder about the past a certain object has had. The old adage “if these walls could talk” is very fitting to the life of an engine and what it has endured over the years. With all the millions of Volkswagen engines still in service, the possibility of your engine having as many lives as a cat is not out of the question. Telltale signs of engines being rebuilt three, four, five, or more times may appear during the disassembly process.
Spotting a Rebuilt Engine
Most rebuilt engines are very obvious. The most obvious sign is a paint job. Volkswagen never painted its engines from the factory. Sure, the valve covers and other sheet metal was painted a semigloss black, but the engine case and cylinders were never painted. They had a coating that preserved them and prevented them from oxidizing for a period. The coating had a slight maple syrup color to it and didn’t last very long. Though a paint job doesn’t always constitute a rebuilt engine, a very good paint job is hard to achieve without cleaning all the grease and grime out of every nook and cranny and getting the paint to look nice.
Another sign that the engine has been rebuilt is random hand-stamped letters or numbers other than the factory serial number. These are usually stamped near the generator stand area. Don’t be discouraged if your engine has been rebuilt by a less-than-reputable rebuilder. As long as the majority of the components are intact, everything should be fine.
Be Patient
Don’t get frustrated during the disassembly process when fasteners may seem to be welded together. Remember, this piece of equipment might not have had a wrench put to it in more than half a century. Be patient and use the right tools.
Solvent-based rust penetrants, such as Liquid Wrench, WD-40, PB Blaster, etc., can help loosen things up. Apply them days in advance if you can, and don’t be stingy.
Apply heat if necessary to help loosen stuck fasteners. MAPP gas is a great, inexpensive source of intense heat. It works when a standard propane torch falls flat.
Tearing down an engine “just for fun” is a good learning experience. Perhaps you came across a two-for-one deal while shopping for an engine to rebuild or someone is willing to give you a free engine to get it out of their way. Older 6-volt engines and partially disassembled engines are great candidates for an afternoon of fun and education. Whatever the case, it’s a great way to see what you are getting into before actually tearing down the engine you are going to rebuild. ■
If you are putting enough force on a fastener that you think it’s going to snap off, more than likely it will. There is nothing worse than a snapped off stud. Broken exhaust studs are super common and there is no reason for it to happen. An easy way to remove the nut is to sacrifice it. By that I mean to use the sharpest chisel you own and chisel the nut in half. Nuts are cheap, but broken studs are not.
The small 6-mm screws that hold on the sheet metal are commonly frozen as well. Hitting the top of the head of the screw to “shock” it loose works great. It’s worth a shot before pulling out the big guns (i.e., the torch). If hitting it doesn’t work, use an acetylene torch to heat the area around the screw. It will expand and break the fastener loose.
A Word About Safety
While you are swinging hammers and lighting things on fire, please use your head and be safe. Take your time and think about the what-ifs. Safety is not only the smart thing to do but also the most economical. A trip to the emergency room to get stitches or to get something removed from your eye can be very expensive and really throw a wrench in the budget and the timeline.
After you have an accident you always have the feeling of remorse. You instantly regret not being more careful or not taking the necessary precautions. So wear those safety glasses and put on those gloves. Get help if you need it and take a break if you need one. Nothing is more important than your well-being, and nothing slams the brakes on a project faster than a needless injury. ■
Get Organized
You’ve gathered all the tools and equipment necessary to start tearing down the engine. Before you begin, you will also want to gather items to keep your disassembly organized. The last thing you need is to start misplacing items from the very start.
Plastic bins are great for staying organized and hold up much better than cardboard boxes that just soak up oil and fall apart. The bins are available at most warehouse and home-improvement stores. Get enough bins to separate parts into three categories: parts to clean up, parts to take to the machine shop, and parts to replace. The parts you need to