Читать книгу Chevrolet Inline-6 Engine 1929-1962 - Deve Krehbiel - Страница 14

CHAPTER 4

ENGINE AND SHEET METAL PARTS PREPARATION

This engine arrived sitting on a pallet with the oil pan facing upward. I transferred it to one of my wheel dollies so I could move it around. This is a good beginning orientation. Once the head is removed, you have a nice, flat surface to set it down on.

The first order of business is to remove the oil pan. It should be bolted down with exactly 18 number-10 screws and four 1/4-inch hex-head bolts. Once you have that many screws in your hands, use a thick tool, such as a 1½-inch stout scraper, to pry it off the block. I don’t like screwdrivers for this because of making unnecessary pry marks on the pan. Use the same scraper to scrape all the gasket material and crud from the block. Once the oil pan is removed, you can see the condition of the inside of the block.

I haven’t found any better way to roll these engines around the shop. The low center of gravity makes it very stable.

Creating an Engine Cart

These engines are heavy and unwieldy. One good way to move them around is to use an engine cart. Also having an engine stand with hoist brackets allows you to lift and place the engine safely.

Materials

Start with at least 1/8-inch-thickness-wall 1-inch square tubing. Cut the pieces to:

Quantity	Length
4	26¾ inches each
8	6½ inches each
1	9½ inches each
4	18 inches each

You need 20½ total lineal feet of the tubing.

If you want to keep it right at 20 feet, remove 1/8 inch from the four 18 inchers. These are the wheelbases, so the difference isn’t noticeable.

You need two 1/8-inch thick x 2 inch x 11½-inch steel plates to put on the ends.

To finish it off, you need four wheels that are 3 inches in circumference with a 275-pound capacity plus all the necessary hardware (Harbor Freight is a good source). This allows you to cart as much as 1,000 pounds.

Construction Procedure

Place the wheels over two of the 18-inch wheel supports. Make adjustments until you match the steel plate on the wheels with the edge of the tubing, then mark each hole with a Sharpie for drilling. (I used 5/16 x 1½-inch bolts with nuts, flats, and locks.)

Be sure to drop the end plates to 4 inches, so they do not interfere with the oil pan. If this cart is for a 216 engine, drop the intermediate bar from 4 inches to 5 inches. Otherwise the oil pan does not clear.

The finished cart rolls smoothly, and because it’s made out of 1/8-inch thick 1-inch tube, it is very stout. Do not be tempted to use thinner-walled stock. This engine with all of its accoutrements can weigh in excess of 800 pounds.

Prior to making any decisions on what to use for a project, I like to consult these rings of the different sizes I have available.

Once drilled, assemble the two-wheel assembly rails and set them aside. Doing it this way results in a squarer frame.

Place two of the 26¾-inch side rails on a flat table or workbench for welding. Place four of the 6½-inch pieces inside and between the two rails in the following order:

• First one, flush with the edge of the long rail and inside of it.

• Second one, 6¾ inches from the first one (inside between them).

• Third one, 8 inches from the second one (inside between them).

• Fourth one, flush with the end rail and inside of it. (If you did it right, that gap also measures 8 inches.)

Clamp these pieces to the table for welding so you don’t end up with warped side rails. When everything is straight and true, the cart is amazingly stable.

Clean the mill scale and prepare the surfaces for welding. Do a really good job of welding these parts together because engines are heavy and you do not want a safety hazard around your shop. It’s best to clamp the entire frame to a table or workbench to avoid warping. In the end, you want all the wheels to be on the floor.

Once that one side is welded, make an exact duplicate for the other side. The 6¾-inch gap is for the front of the engine.

Orient the two frames so that the 6¾-inch gapped end is across from each other. Set these frames on their sides 9½ inches apart from each other.

At 4 inches down from the top of the side frames, place a 2 x 11½-inch steel plate across the frame. (In other words, you have 4 inches of air space before the plate starts.) Clamp this plate into place, then do the same on the back with another 2 x 11½-inch piece of plate.

Finally, the 9½-inch square tubing goes on the second support (closest to the front of the cart) and 4 inches down. This just barely misses the oil pan and gives the entire cart more structural support. Once you have everything boxed in, you should be able to set a level across the whole thing and verify that each side brace is 4 inches from the top. Weld the braces on and make sure everything stays square.

Turn the new box assembly upside down and lay the wheel assemblies across and to the edge of the frame rails. The wheels being outside of the frame rails offers a wider stance and much smoother range of movement. Weld those into place, and the difficult part is done.

To show quality workmanship, make sure to use a flap disk and clean off all the slag, grind away any welding imperfections, and clean the entire piece for painting.

To finish the job, spray with a rattle-can coat of etching primer followed by some durable engine enamel, then install 1-inch caps on the ends. These caps are available at Amazon, and they are measured by the inside dimension.

The thin end pieces should be placed 4 inches down from the top. They are thin because they need to go between the oil pan and the bellhousing.

If you have your engine sitting on the oil pan, which is never a good idea because it’s made from thin sheet metal, make a small stand for it. Now you can properly drain the oil prior to disassembly.

You also want to purchase a few engine hoist brackets, so you can lift the engine off the stand. I used standard hardware store hooks with 1/2-inch threads on all four corners. ■

The side rails are 9½ inches apart to accommodate the width of the engine. This is standard for all Stovebolts. Only the oil pan depth on older engines is different.

For the oil pan to fit nicely, you need the crossbar to be at 18½ inches.

When you have several of these engines, and shop space is at a premium, this cart can be indispensable.

Bellhousing Disassembly

The only way to separate the bellhousing from the engine is to remove the transmission, clutch assembly, and then the flywheel (if not already removed). You need to remove two bolts on the outside of the bellhousing, then four more on the inside, two of which you can’t access until the flywheel is removed. You can get to all of this via the bellhousing access cover that has four screws directly under the bellhousing. Be sure to save the three tin lock-down plates that hold the flywheel bolts secure. They are necessary and difficult to find if you lose yours. Try not to bend off the tabs.

If needed, you can consult the shop manual for reference. It is easiest to remove the transmission, clutch assembly, and flywheel when the engine is still on the vehicle.

Oil Pan

The oil pan is probably the most neglected piece of tin on the vehicle. Rocks dent it, stress warps it, and often you find an over-torqued drain plug. Water condensation causes major rust pits and even rust-through. I spent an entire day blasting this oil pan and inspecting it.

Once your pan is blasted, use 400-grit sandpaper to sand the entire pan inside and out. This makes it easy to see cracks, bumps, and abnormalities in the surface.

In this example, the previous owner didn’t want to address the small hole made by a sharp rock and used Bondo to cover it. In all, there were three holes. One was from rock damage, another was rusted through, and another was an actual crack, about an inch long. These are not surprising because the pan is more than 60 years old.

Avoid Catastrophic Failure

Being organized takes very little time and could help prevent a catastrophic failure. For example, use resealable bags to keep small items together. Mark one with “oil pan bolts.” Mark the others similarly. You get the idea. Also, take pictures of each assembly prior to the teardown. The images will help with reassembly. ■

It is important to get every crevice completely clean inside the pan so you can assess its condition. This pan has suffered a lot of abuse.

It’s down to the bare metal, so I can add some weld to seal these holes and cracks. First a little body work, smoothing and light hammer and dolly work to make things straight again. Once all the bumps and bruises are smooth, I weld the holes and cracks shut, redress the metal, and then it’s time for another decision: How far I want to go with dressing up this oil pan. There are rust pits and various imperfections. My answer is always; no shortcuts!

If you perform metal working the same as if it were part of the vehicle, it becomes time consuming. I draw the line with putting Bondo on the oil pan because of rocks kicking up and making it look much worse than if you would have used an epoxy primer. Having the least amount of substrate the better.

This pan has lots of dents and damage due to the engine being set on the floor with the pan facing downward. It is difficult to seal these pans even without oil leaks, let alone trying to do it with a deformed pan.

When welding cracks, start about 1/4 inch before the crack on each end. This ensures the unseen start and finish of it is addressed too. Here, the rust-through was minor, and the welding went smoothly.

In this case, I had to address a stripped-out oil drain plug. Someone had already installed an oversize plug, and it stripped out. After redrilling out the oil pan’s drain plug hole to 37/64 inch, I use a 5/8 x 18-inch tap.

As it turns out, this plug is available as a Dorman product (65313). It comes with the nylon gasket as well. This oil pan has a metal reinforcement at the drain plug that is plenty large enough to handle the size of the Dorman plug. Now the pan is like new.

This venerable old engine deserves the very best, and you don’t want to get in the habit of cutting corners. I found many rust pits, dents, dings, deep scratches, cracked metal in the oil pan, side cover, and valve cover. They needed much hammer and dolly work to get them into shape.

Once they are sandblasted, you can use 400-grit sandpaper on a long board to check most of the surfaces of these parts. I recommend using a short Dura-Block to access other areas. You sand by hand if neither of those methods reach the spot.

You are checking for degree of flatness and smoothness. Once the metal is 95 percent there, apply a few thick coats of DPLF epoxy primer to the surface and then finish sand with 400-grit sandpaper. PPG’s DPLF came highly recommended for engine tin because it is safe for up to 500°F. Once it’s dry, you can apply rattle-can engine paint right over it.

Engine sheet metal often requires many hours of work but preserves the tin and makes additional rust virtually impossible. The oil pan, side cover, timing cover, and valve cover receive no paint on the inside. This avoids introducing possible contaminants into the engine internals, which is important. Once the outside is painted and dry, apply engine oil to the inside surfaces, letting the oil soak into the metal.

If needed, retap the pan plug, making sure there is an available plug to go with the size you choose. It’s important to not over-torque the plug. Snug is fine because the plug’s washer does most of the work. Replace the washer if it looks worn or out of shape.

Valve Cover

The valve cover on the 1953–1955 engine has open slits on the top. General Motors wanted the engine to breathe but didn’t take into account the severe damage that underhood dirt and grime getting into the valve cover could initiate. If your valve cover has open slits, a couple of ideas to remedy the situation come to mind. To preserve the look, close the slits from the inside using J-B Weld. It’s even gray. If you clean the area thoroughly before application, it will stay there forever. Or, you can weld the slits closed. It is very important for a new engine rebuild to maintain a clean environment on the inside of the engine where sand and grit cannot ruin it.

If there are no slits, inspect for damage. The bottom of the cover should maintain its indentions that aid in sealing. The holes should be flat and not warped. It’s a good idea to find some reinforcements for the cover screws so the pressure of the screw head is spread out.

Side Cover

Check the corners of the side cover and inspect for any leakage. Improperly installed side covers often cause leaks all over the garage floor! Flatten the screw hole areas, but maintain the natural indentions. A little tin work goes a long way.

Thread damage, holes in the pan; everything takes time but time well spent if it prevents an oil leak.

After blasting and sanding, a crack is revealed that goes all the way through. I could have replaced this pan, but I didn’t want to take another vintage oil pan out of circulation.

Final sanding after metal work, epoxy primer, and high-build primer. This cover is going to look good.