Restoring your flathead
Some of you may wonder why I am spending so much time in dismantling rather than in the rebuilding. It’s really fairly simple and at the risk of repeating myself, it won’t hurt to stress again this very important method of restoration.
As the engine assembly is taken apart, that is the time to restore, rebuild or replace each individual part, piece or unit. First of all, doing it this way will always let you see progress during this lengthy process. And, by doing it this way, you will find that when it is all apart, it is also restored and only requires reassembly to finish the job.
As I recall, last month we now had the engine on a rotating stand. Hopefully, the starter and generator can be taken to a good auto electric shop for rebuilding. Be sure to have the field coils in the starter replaced with high-output coils. This will make the starter turn over like you had a 12-volt booster battery.
The distributor comes off with just a 1 1/4-inch bolt at the front center after the cap and wires have been removed. Usually the shop that rebuilds the starter and generator can also rebuild your distributor. These are not items to be done by amateurs.
The same is true about your carburetor. Let someone with experience and the right equipment rebuild these units.
The water pump comes off with five bolts and can be restored with a kit complete with detailed instructions, available from many suppliers. It should be noted, however, that a medium- to heavy-duty shop press is needed to install the impeller onto the shaft. Using a hammer usually is not successful and serious damage can occur if tried.
The fuel pump comes off easily with two bolts once the four lines are removed. It is wise to use all-new fittings. Kits for rebuilding fuel pumps are also available from many suppliers. The most important part in rebuilding this unit is a thorough cleaning, including the little horsehair filter. If you can’t salvage this, a small piece of #0 steel wool can be used.
The porcelain exhaust manifolds can now be removed and cleaned up. The decision to clean or refinish them is up to you. If they are to be refinished, send them to a pro—this is not a home shop procedure. This will take at least three weeks and cost about $300.
By the way, powdercoating won’t work. Cleaning can be done with solvent and fine steel wool. It will also be wise to drill out the four bolt holes that hold the crossover pipe and helicoil them at this time. Very seldom will these go back together without stripping out.
With all the removable units off and either restored or in a shop for rebuilding, it is time to start taking apart the engine itself. After taking out the spark plugs, the heads can be removed. This can be tricky because broken head bolts are definitely no fun.
Start by sharply tapping the tops of all the head bolts. It is best to use an impact wrench set on medium power or a small air butterfly wrench. With luck, some of them and hopefully all of them will come right out. For those stubborn ones, leave them be for now and get all of the easy ones out.
For those really stubborn ones, go back and tap them again with a hammer and try the impact wrench with a higher setting. If there are still some of them unwilling, soak them with a good penetrating oil and let them set overnight.
Try tapping them again and maybe apply a little heat from a propane torch. Hopefully a breaker bar or cheater bar won’t be needed, because using them generally ends up with a broken head bolt. If this happens, they usually have to be drilled out and helicoiled by your machine shop. This is not a task for a beginner.
It should be noted that the four bolts that hold on the two upper radiator hose connections are different in head size and length. They are not interchangeable with the other head bolts, and if tried in the wrong holes, fatal damage to your block can occur.
With the heads now off, the block can be inspected for obvious damage and an estimate can be made as to overbore size needed or previous reboring. The tops of the cylinder heads are stamped with any oversize. Clean out the heads real well and take them to your machine shop for milling and truing. When they come back, paint them, put them aside and they will be ready for reassembly when the time comes.
Take off the intake manifold and clean it up real good. Use a die grinder to clean out the interior of the ports. The smoother these ports are, the better the engine can breathe. Paint it and put it up with your other finished parts.
The valve covers and breather can now be taken off, cleaned well, painted with your Cadillac green engine enamel and put aside.
Drain the oil and remove the pan. Clean it good and knock out any dents, making sure the breather pipe is clean. You can lose as much as a quart of motor oil capacity from dents in the pan. It is then ready for its own paint job and to be put aside.
It is time to remove the oil pump and baffles, cleaning them real good. The sump pump screen needs a very good cleaning, as this is where all of the oil goes through for the entire lubricating system. You will need to get either an oil pump rebuild kit or buy an exchange rebuilt oil pump.
Time for a break now and we will continue next month with Part 3. Remember, nobody told you this would be easy, cheap or quick, but it sure is a lot of fun to see the progress and a lot more rewarding to restore as you take it apart.
One last note, your hands and clothes are probably quite dirty, so clean up before you go back in the house. It could keep your home happier and avoid the need for a cot in the garage.
See ya next month.