By Glenn Goodspeed (December, 1996)
I say "The" because it's my first engine rebuild. Just finished it today after working on it for more than a year.
It was about seven years ago that I bought the engine core for $20. The owner had pulled it out of a Volvo 120 station wagon and left it in his garage for years. I didn't want to buy an engine -- I went to look at a '71 P1800 that he was parting out. I purchased the seats and the hood prop, had a philosophical discussion with him, and started to leave. He asked me if I wanted to make an offer on the engine. I said "Nah," and left. A couple days later, I called and offered him $20. "Come and get it," he said.
Then it sat in my garage for several years. It didn't have many parts, like the generator or starter, but I used it for spare parts a couple of times, like when one of the valve spring retainers broke on my '63 P1800, and when I needed a valve clearance adjuster screw to replace one I had broken. But mostly, it just sat in a corner of the garage, the butt of wifely party jokes and the bane of movers.
My P1800 started to burn a lot of oil a year ago, and the broken valve spring retainer and constant oil and coolant leaks from every imaginable part of the engine made me think that it was not long for this world, so I formed a plan for its replacement. I would rebuild the old engine in the garage and swap it with the one in the car.
Let me explain here that I use the P1800 to get to work every day, and the only other practical means of transportation is the city bus. The bus is practical, but it is not a P1800, and so I wanted the "downtime" for the car to be as short as possible.
I began by taking the old engine apart to see what it would need. The block and head were sound, but the pistons would have to be replaced. The crankshaft and connecting rods looked good, but I wasn't so sure about the valves. And there was no flywheel, which meant not only the expense of buying another one, but also the expense of balancing the complete engine.
Next, I checked the catalog from IPD, an aftermarket supplier of Volvo parts based in Oregon. Some of the people on their staff have been down this road before, and they have a great selection of high-quality parts. I am very particular about parts. I spend much of my spare time doing high-quality work on my car, and I feel the work is wasted if the parts fail.
I took a deep breath when I saw the prices. As usual, I called Boston Volvo to find out whether they could offer comparable prices (Volvo's genuine parts quality is generally comparable to IPD's). Also, I wanted to see if the original size pistons were available. The larger pistons in IPD's rebuild kit would require that the cylinders be bored out. Boston Volvo's price on the pistons was high enough to justify the extra work using IPD parts, and it would be convenient to have all the parts in IPD's kit.
I thought I would get the block bored out before I bought any parts. That way, if the machine shop messed it up, I wouldn't have to return a bunch of parts to IPD. I took the block to the local auto supply, but they said they would have to have the pistons before they sent it to their machine shop, so I took the block back home.
The more I thought about it, the more I wanted to deal with the machine shop myself, rather than trust the auto supply people to relay my wishes to their machinists. I asked around to find a good shop. I decided on Dick Smith's machine shop here in Fort Worth, Texas, because no one had any horror stories about it, and it's been in business since 1947.
I bought the rebuild kit and a cam kit from IPD and took the pistons and block to Dick Smith's. The people were courteous and helpful, and the place was well-liked, judging from the constant stream of customers on foot and telephone. The block was bored in the time specified, and when I measured the bores with a micrometer, I found them accurately sized.
I have to admit that as a novice, I did not know how to measure the pistons, which resulted in a little confusion. It looked like the pistons were too small for the bores. I called Scott Hart at IPD, and he told me how to measure them. Come to find out, pistons are not exactly round -- they are oval at the bottom and tapered toward the top. To measure the largest diameter of a piston, you must measure near the bottom and perpendicular to the piston pin.
Measured that way, my new pistons were a perfect fit. For the next several months, I made many trips to Dick Smith's. They resurfaced my new used flywheel, installed connecting rod bushings and balanced the crankshaft. I balanced the rods and pistons myself using a triple-beam scale.
I took the cylinder head to have it reworked, fearing they might want to replace some of the valves, but they said it only needed machining and new exhaust valve guides. It looked great when I got it back, but I took it apart anyway to inspect the work. I noticed some resistance when sliding valves in and out of their guides. It felt like dirt had entered the guides. After a careful cleaning, the resistance was still there, so I used 1500 grit sandpaper to polish the stems, and that corrected the problem.
I spent most of the summer painting my house, so the engine had to wait until fall to be completed. As soon as the weather turned cool, I began the assembly.
I used three books constantly for reference: the Haynes manual for the Volvo 120 series and P1800, a copy of Volvo's parts manual for the early-to-mid production P1800, and Engine Service* by Gary Lewis. I have my own copies of the first two. I checked Engine Service out of the Fort Worth Public Library and liked it so well that I decided to buy a copy for myself. Unfortunately, the book was out of print. Fortunately, the library had two copies of it, and I managed to keep one or the other copy checked out for three or four months running.
I was surprised at how well the work proceeded. Using the proper tools, parts and techniques, it was a pleasure to put everything together and know that it was done right. When the big day arrived, I got my father-in-law to help me rent an engine hoist from Gateway Auto Supply and swap out the engine. Even though I spent two days preparing the car for the swap, it was still an all-day job.
Then the work began in earnest. I took off two weeks from my job and spent almost all of it working on the car. Reconnected all the wires and hoses, cleaned and reinstalled the manifolds, starter, generator, radiator, fan, clutch, transmission and the entire exhaust system. Finally I was ready to start the new engine.
After several false starts related to my cockiness in setting the ignition timing, I carefully studied the situation and the Haynes manual until I discovered the problem -- the distributor drive gear was out of synch. After reinstalling it a couple of times, I finally got it right and the engine started up immediately. It ran for five minutes before I shut it down due to overheating.
I removed the thermostat, which solved the overheating problem, but may soon cause an underheating problem if the weather gets very cold. I'm hoping the engine will stop overheating once it is broken in. And of course I will try a new thermostat.
Other than that, everything is working perfectly. Here's to my first engine rebuild.
The photo on the left was taken after installing the new engine, but, obviously, before installing the manifolds and carburetors. On the right, attached to the old engine, is an article not seen on many P1800s: a crankcase breather pipe. This was standard on early engines and was replaced on later models by the crankcase ventilation system. My new engine had a tab near the rear of the block that interfered with the placement of the pipe. Rather than struggle with it underneath the car, I used the old engine as a model to prepare the pipe to fit the new engine (i.e., bending and shimming).
*Engine Service is in print again. In fact, it is in its tenth printing, the latest batch having hit the shelves in June, 2006. The new edition has larger pages with more and larger photos, and contains additional chapters not found in the edition I used to rebuild my engine ten years ago. It is a credit to the books I used that the engine is still running strong with about 35,000 miles on it. See this site for purchase info: http://www.engine-books.com