Also early 40-hp cases did not have cam bearings. The cam rode directly in the case much like a cam in a motorcycle. Late-1965 40-hp cases started to get cam bearings, but there is no guarantee what cases got the bearings because the factory was already changing over to the new 1,300 engine.
The single-port engines are almost impossible to tell apart without looking at the beginning of the serial number. They came in three different displacements: 1,300, 1,500, and 1,600 cc. The 1,300-cc engines were the oddest of them all because they only came in the 1966 Beetle in the United States. A mixture of old and new parts, they really aren’t the most desirable engine to have unless you are restoring a 1966 Beetle to absolute 100-percent stock condition. Then you might be able to justify the more expensive parts it will take to rebuild it due to the rarity of the parts on a one-year-only build.
If you have a single-port-engine vehicle (1966–1970) and want to keep it looking period correct but have a little more horsepower, building a 1,600-cc single-port is the way to go. Starting with a 1,300-cc will not be cost effective due to the amount of machine work that will be needed to the engine case and cylinder heads for the installation of the larger pistons and cylinders. But the 1,500 cc available from 1967 through 1969 can easily be converted to 1,600 cc by simply changing out the pistons and cylinders. No machine work is necessary due to the outer dimensions of the cylinders being the same. You will get the benefit of more displacement and horsepower with minimal work and expense.
Serial Number
The only way to be sure of what you are looking at is to read the serial number stamped into the engine case. On all Type 1–based engine cases, the serial number is located just beneath the generator stand and just above the dipstick. In the United States, the serial numbers on early 40-hp engines didn’t begin with a letter; instead, the numbers started with a 5, 6, 7, 8, or 9. Worldwide the letter D designated the 40-hp engine cases, so the case may or may not have a letter D stamped near the serial number.
In 1966, Volkswagen started designating engine models by adding a prefix of letter or letters to the serial number. All of the single-port engines have just one letter, starting with the letter E for the first 1,300-cc single-port engines.
Here is an example of the serial number of a factory manufactured engine case. The previous serial number was machined off with the exception of the A that designated it as a dual oil pressure relief case. The VW re-manufacturing symbol was stamped in and then the letters AK. The area next to that might have the serial number that was being replaced stamped in, but it rarely does.
With the introduction of the 1,600-cc dual-port engine in 1971 came a new numbering system. All of the 1,600 Type 1–based engines had two letters to start the serial stamped on the case. The first letter is always an A. It’s super easy to remember: no letters means a 40 hp, one letter is single-port, two letters that start with A is a 1,600-cc dual-port.
Other Indicators
There are additional pointers that are helpful when trying to determine what vintage engine is in your car. The fuel-injected versions introduced in 1975 are easily identified by the lack of any mechanical fuel pump machining done to the case just left of the alternator stand.
Say the engine is not installed in a vehicle and you can’t find the serial number in the usual spot under the generator stand area. It could be out of a Type 3 (fastback or squareback). The absence of a dipstick will be your first clue.
Type 3 engines will have the serial number on top of the case right behind the fuel pump. Right along where the two engine case halves come together. No numbers there either? More than likely it’s a factory replacement case or even an aftermarket replacement case.
Years ago, a replacement case could be purchased directly from a VW dealer. Today, aftermarket manufacturers have stepped up and now produce OEM-quality replacement engine cases. To keep costs down, these cases are universal, meaning they are made to fit almost every configuration of Type 1, Type 2, and Type 3 engine. The only downside is they are only available in the 1,600-cc bore size: 85.5 mm.
Is This Engine Worth Rebuilding?
Many factors will determine if it is cost effective to rebuild a certain engine. Every engine could be restored but not every engine should be restored unless it holds special sentimental value or is super rare. Your engine may be beyond repair and may only be good for a few usable parts.
Let’s start with a visual inspection. Does it have a giant hole in the top of the case? If so, more than likely, it threw a rod and the entire lower end is beyond repair.
Has it been left outside in the elements uncovered? Is it lying directly on the dirt floor? Mother Nature is the number one killer of stored vehicles and their components.
Read the dipstick. Does it have any oil? What does it look like? Black is actually okay. What you absolutely do not want to see is water. If the oil is milky like coffee with a lot of cream or even chocolate milk or has any presence of water at all, it might not be a good candidate for a rebuild. What happens is the water, being thinner than oil, settles down at the bottom of the sump. Water and magnesium do not play well together. Corrosion happens very quickly and will destroy the engine case from the inside out. Corroded magnesium is impossible to weld cleanly, and corrosion around the sump plate can render an engine case unusable.
If the engine is installed in a car and it runs, more than likely it will be rebuildable. Even if it runs poorly; is missing, chugging, or knocking; is running on three (or fewer) cylinders; is leaking oil from every corner; etc., it more than likely will be just fine once rebuilt.
If it doesn’t run, the first step is to determine if the engine is locked up. Grab the fan belt with both hands and try to rotate the engine one way or the other. No fan belt? Try turning the pulley or even the flywheel. If it rotates easily, it’s good. If it’s difficult to move but it does move some, it’s likely still rebuildable.
If the movement stops abruptly in either direction, more than likely the lower rotating assembly is unserviceable and the engine would not be a good candidate for a rebuild. If it rotates slightly but binds up at any point and doesn’t spin completely around, then it’s usually just the piston rings dragging on rust in the cylinder bores. If this is the case, the engine is more than likely serviceable but it may take some work to get apart.
The worst-case scenario is that the engine is locked up tight and doesn’t move in either direction. Try pushing and pulling on the lower pulley. Do you have a little movement? That’s the glimmer of hope you are looking for. It’s going to be a bear to get apart, but it may be savable. The value of this condition engine is very low, like almost free. Take this into account. You may want to look into another prospect.
Planning
Starting any project always requires three things: knowledge, money, and time. With this book will come knowledge. Rebuilding the engine yourself will save money. The last thing is time. How long is this going to take? A big factor with time is your mechanical ability, but some factors will be out of your control. For example, the machine shop might have a backlog or your parts might not arrive in a timely manner. Preplanning will speed things up and keep you on track.
Plan for engine teardown to take 8 to 10 hours. An entire weekend should be enough time to get the engine completely apart with the parts sorted. Organize the parts into three piles: parts to clean up, parts to throw away, and parts to take to the machine shop. While parts are at the machine shop, the rest can be cleaned, inspected, prepped, and painted.
The machine shop will determine what bearings you need and if anything is beyond servicing. Once you get that information, you can place an order for the parts you need. Don’t be surprised if you find things later that should be replaced as well. This process may take a few weeks, depending on