Many of the technical stories in this magazine are based on engine-building and testing; it's the bread-and-butter of our hobby. However, very often we forget that not everyone has several successful engine builds under their belt. This leads us to skip over the minute details of engine assembly, assuming that the elemental stuff is common knowledge. Of course, everyone has to start somewhere, and most of us logged hours of experience tinkering and tuning before we'd ever dug in and attempted to actually rebuild one of these beasts. The nature of internal combustion engines and the precision tolerances their mechanical bits operate with makes engine-building somewhat intimidating. The expense of such projects and the damage that can so easily be done if everything isn't just right is enough to scare off plenty of veteran rodders, so it stands to reason that newbies often shy away.
We've been over the basics before, but usually with a small-block Chevy as the basis. So, to mix it up a little, we opted to screw a small Ford together. The bulk of the information in this article will be general, so that anyone wanting to rebuild an engine can benefit, but to provide examples, our 5.0L Ford will serve to illustrate the text.
Prepare to RepairThe entire process of rebuilding your engine could be handled by a competent machine shop, but of course, the idea here is to do it yourself. You won't be able to eliminate the need for the machine shop altogether, but keep in mind that the more the machine shop does, the more you will owe them. At the same time, there are certain services/procedures that you shouldn't cheap out on.
Obviously, if you're planning to rebuild an engine, you need to start with something. If the engine in your car has already expired, that's probably your core. However, if you're still driving your car and want to minimize down time, consider finding a core so that you can get through the rebuilding process before tearing down your transportation. In any case, there are pitfalls to avoid in selecting a core.
First, if your engine has drawn its last breath, you should determine why before you assume that it can be restored to former glory. If it grenaded in spectacular fashion, it might be scrap metal. In some cases, finding an alternate core may be cheaper than having the original repaired.
Step one for all situations should be disassembly of the core. By taking care of this yourself, you're saving charges from the machine shop. Now is the time to clean and bag everything that will be reused during reassembly. Invest in a box of resealable freezer bags, the kind with a white area for labeling, and get a permanent marker. After the bolts and other small parts are clean, bag 'em and tag 'em.
The disassembly process should also be treated as a sort of engine autopsy-you want to determine the condition of the engine, particularly if it failed, prior to sending it to the machinist. The machine shop will still have the final say, but there's no sense in paying them to inspect stuff that's obviously junk. Spun bearings usually do significant damage to bearing journals on the crankshaft and often damage the bearing saddles and caps as well. This can mean that the crank, rods, or block-or all of the above-may require extra work or replacement. Again, the machinist can tell you for sure whether the parts are salvageable or not if there's any question.
If you need to obtain a core, you may want to source a core service, since many offer parts that are already cleaned and inspected, allowing you to avoid more junk. This might not be the cheapest route, but these places often have an exchange warranty in case the parts prove to be damaged when the machine shop checks them out. If you don't have an engine, you may want to start with a whole assembly, so you'll have all the small parts and specialty fasteners to put it back together.