Sunday, January 6, 2013

Sagging With Age

After getting the car, an early sign of the crazy behavior Shelly would come to know too well was my obsession with obtaining an engine crank. Before the 1912 Cadillac introduced the electric starter, all cars were started by hand with a crank to spin the engine manually. Apparently, this older method of starting hung around as a backup option for decades. The MGA was the last in the line of MGs with a hand start capability. Unfortunately, the metal bar needed to try this out was missing from my car when I bought it. It also helps a lot when setting engine timing and other tasks, so I decided I needed this as a matter of urgency.

No battery? No problem. Start your car with this.

They sell replacements but they are expensive, and I heard that they weren't quite perfect. So, I scoured the internet and found one for sale about an hour away for a good price. I bought it, drove up to pick it up, and went out to the garage to try it out.  Unfortunately, it came up short - literally. Turns out the junk yard that sold it to me thought it was for an MGA, but it was really for some other car and was about 5 inches too short to reach the engine through the bumper. I returned it and managed to get a correct replacement after researching and confirming the proper measurements. Armed with this new one I marched back out to the garage only to find that while long enough, the crank was being blocked by the steering rack tube on its way back to the engine. Curses, foiled again. Because the oil drain pan was also too close to the frame under the car, I concluded that the engine mounts were sagging with age.

The engine needs to mount firmly to the frame of the car for obvious reasons, but it also needs to be able to shake a little without rattling your teeth. As a result, engines are mounted not directly, but with a thick rubber spacer that dampens this shaking when necessary but still makes a solid connection. Replacing the mounts involves lifting the 360 pound engine an inch or two if not out of the car completely. Not only that, but in order to access the parts to replace, you need to pull out the carburetors on the driver side and the generator on the other.

As this was an intimidating project for me, the crank sat, mocking me in the garage for months until I gathered the courage. I ordered the mounts from Moss and steeled myself for the task. They arrived, and I began. The generator is not bad to get out. There are three bolts to remove, and a few electrical connections to undo. After sliding the fan belt off, it lifts right out. The ignition coil is mounted to the generator and even makes a nice handle to pull them both out together. They are a little heavy, but not bad.

The generator (big) and ignition coil (piggy backing)
removed and on the bench.
The carbs weren't horrible either, but you have to learn how to contort yourself around to get to the bolts. The gas line coming in is pretty easy to disconnect as I learned when I replaced it. The accelerator and choke cables use a mix of small nuts and cotter pins to connect and aren't bad though it's a little scary wondering if you'll be able to get it all back together correctly later.  I took the air cleaners off (four bolts hidden under the body cowl), and that gave pretty good access to the four bolts holding the carbs to the intake manifold. There is a vacuum line that is hard to reach under the carb closest to the windshield, but I found a previous owner had just cut the line so no need to disconnect that this time. Bugger - future project, though obviously the car runs without it.  With head scratching and re-reading the workshop manual carefully included, probably an hour or two get get all that out.

The carbs out of the car on the bench (with the air cleaners back on).
Now on to the primary job. With the car up on jack stands, I put a spare block of wood (a nice piece of 2" thick Cherry left over from a furniture project, possibly the classiest scrap wood used in car repair) on top of my little hydraulic floor jack and brought it up to rest on the bottom of the oil drain pan (called the sump). It's pretty thick steel and on advice from others is up to the job of supporting the weight of the engine without denting. I removed two nuts on top of each engine mount to allow the engine to come up and started jacking. Slowly but surely the behemoth lifted. Unfortunately, it listed to one side as it went up. I got the mount on one side out no problem, but the other side wasn't lifting enough because of the tilt. At first I suspected the radiator hose was the culprit but after draining the radiator and disconnecting the bottom hose there was no improvement. Gradually I realized that the problem was a creative workaround for a missing part applied by a previous owner that left a bolt stuck in the rubber of the mount. I disconnected the rest of the radiator hoses and pulled the radiator out to give better access to try to wrestle this apart.

The engine mount is out (center) but the offending bolt is stuck
on the bottom plate, making it hard to remove.
Eventually I got the mount loose by loosening the mounting bracket and rocking the engine slightly side to side by hand (well, it is a full body action) and prying with a screwdriver in the other. This is probably less dangerous than it sounds except that as it came free the engine suddenly shifted back toward me and got stuck on the offending bolt. That would have been a broken finger if my hand had been in there. Instead of a bolt, this should have been a countersunk machine screw on the inside with just a nut on the outside, leaving no obstruction to the rubber. As it turns out, these exact countersunk screws are not normally available at your local hardware store, so I wound up ordering a complete set of new mounting hardware from Todd Clarke of Clarke Spares & Restorations. He specializes in supplying the hard to find bits for MGA restorations and his prices always seem fair - in this case $9 for an entire back of high quality and some hard to find machine screws and nuts & bolts.

While I waited for these parts, I worked on a few other little projects that I'll write about later. Once they arrived, the new mounts went in without a hitch and the engine was secure again. I thought of a great little trick to keep the nuts from falling off the bottom while fiddling to get them started. I stuck a strong magnet to the top of the bolt and that holds the nut on even before it gets threaded in. The carbs went back in well, then the generator. With the radiator back in I filled it up with fresh fluid and started it back up. Unfortunately, at this point I found the generator had stopped working while on the bench (or more likely in the process of getting it in and out). More on that later.

1 comment:

  1. Very important to get your vacuum advance working properly. You will be amazed at the difference in the way your car sounds and behaves as you ramp up from idle to feeway speeds. If you haven't yet, also consider calling British Vacuum Unit and replacing the old, hardened vacuum advance unit on the dizzy. When this is working, you won't believe that you thought the engine was fine without it.