Performance Tip—
Indicates a procedure or modification that can improve performance. Step most often applies to high-performance or racing engines.
Critical Inspection—
Indicates that a component must be inspected to ensure proper operation of the engine.
Precision Measurement—
Illustrates a precision measurement or adjustment that is required at this point in the rebuild.
Professional Mechanic Tip—
Illustrates a step in the rebuild that non-professionals may not know. It may illustrate a shortcut, or a trick to improve reliability, prevent component damage, etc.
Documentation Required—
Illustrates a point in the rebuild where the reader should write down a particular measurement, size, part number, etc. for later reference or photograph a part, area or system of the vehicle for future reference.
Tech Tip—
Tech Tips provide brief coverage of important subject matter that doesn’t naturally fall into the text or step-by-step procedures of a chapter. Tech Tips contain valuable hints, important info, or outstanding products that professionals have discovered after years of work. These will add to your understanding of the process, and help you get the most power, economy, and reliability from your engine.
INTRODUCTION
To describe me as a lifelong car guy would not be much of a stretch, as I can trace my interest in things automotive back to the tender age of 10. And while my ever-growing passion was not particularly understood or encouraged at home, it wasn’t stifled either. I credit my copious reading habit with the formation of a basic understanding of how the internal combustion engine functions and my strong interest in performance modifications. I devoured every car magazine I could get my hands on. And somehow during this formative time in my life I decided that I was a “Ford man,” despite an overwhelming percentage of my contemporaries preferring Chevrolet.
My early interest led to some hands-on mechanical experience when I began handing wrenches to a teenaged neighbor when I was 12. He had a real hot rod of the time—an Oldsmobile Rocket V-8-powered 1933 Ford coupe. I was hooked. This led to my rescuing an early Holley 2-barrel carburetor from the trash behind my local Ford dealership. After repeatedly dissecting this simple method of fuel delivery, I formed a basic understanding of its function and eventually got to where I could tear it down and reassemble it in my sleep.
As time went on, older guys in the neighborhood enlisted my assistance with their cars, which led to my participation in numerous street races and my decision to pursue a career in the automotive trades. The vocational technical training I received in high school allowed me to learn the trade that would provide a living, while a part-time job in a speed shop further fueled my passion for performance. After working in the service and parts departments at a local dealership, I eventually chose a different career path, but I exercised my passion for cars as a parttime drag racer and shade-tree mechanic for the next four decades.
Along the way, I gained valuable experience by rebuilding engines myself and watching professional engine builders. This book will cover a stock engine rebuild with simple performance- and reliability-enhancing modifications noted. Keep in mind that there are very distinct differences between a stock rebuild and a race-prepared engine, and while this book will help you enter the slightly modified engine arena, I leave the full-race engines to the pros.
CHAPTER 1
DETERMINING THE NEED TO REBUILD YOUR ENGINE
There are a number of factors involved in deciding if your engine needs a rebuild. This chapter covers the symptoms associated with a worn-out engine and the simple diagnostics involved in making an informed decision as to whether your engine needs to be rebuilt.
High Mileage
While engines with 100,000 or more miles will certainly benefit from a rebuild, many high-mileage engines that have had regular oil changes while being kept in good tune may be less in need of rebuilding than a low-mileage engine that hasn’t been properly maintained. Mileage alone isn’t a determining factor in the need for a rebuild; maintenance history is just as important.
Excessive Oil Consumption
As a general rule, if your engine uses a quart of oil for every 1,000 miles or less, it is consuming an excessive amount. Take note that I’m referring to an engine that “uses” oil, as opposed to “burning” it. You should devote the time to determine the cause for excessive oil consumption before assuming that your engine is burning it. Check carefully for external oil leaks, as a leaking rear main seal, intake manifold gasket, or valve cover gasket that leaves a few drops of oil on your driveway can contribute greatly to overall oil consumption since the leak will be constant when the engine is running.
Internal oil loss may be the result of worn or cracked valvestem seals or guides, problems that are correctible without completely rebuilding the engine. All engines have clearance between the stems of the valves and their guides for lubrication, and over time, the clearance increases, allowing oil to pass down the valve stem into the combustion chamber. Likewise, the rubber seals on the valve stems may become brittle and crack, allowing an excessive amount of oil to flow past the valve guides. Valve stem seals are replaceable without removing the cylinder heads from the engine and may greatly reduce internal oil consumption. A common indicator that an engine is suffering from a problem with valve seals is a puff of blue smoke from the exhaust upon engine startup that dissipates within a short time.
Some years back, I encountered a 351W Ford engine that was using oil at a prodigious rate and smoking heavily from its exhaust, giving the appearance of a terminal engine problem yet not making any unusual noises. The culprit in this case turned out to be a cracked fuel pump diaphragm that was allowing motor oil into the fuel.
Drop in Oil Pressure
Sadly, at some point, someone in the automotive industry got the foolish idea that real oil pressure gauges were unnecessary, thus beginning the era of the “idiot light.” I have heard more than once: “How can I be three quarts low on oil—the light never came on?” As it turns out, the average person went blissfully through life secure in the thought that if there were any problem relating to engine lubrication, the magic light would come to the rescue, while the rest of us installed aftermarket gauges in our cars at a furious pace. And since I am covering vehicles equipped with Ford’s Lima series engine, I can’t think of one that rolled off the assembly line sporting an oil pressure gauge as standard equipment. This tells me that in most cases a drop in engine oil pressure will go unnoticed until something catastrophic occurs and the oil light glows brightly from the dash.
Lima Series History
Ford’s 385-series engines, also known as Lima engines because they originated from the Lima, Ohio, engine plant, were first introduced in 1968. They were developed to replace the aging MEL (Mercury, Edsel, Lincoln) series, which consisted of the 383, 410 (E475), 430, and 462. The newly designed, thin-wall