831-359-0863

A Ferrari, as with most automobiles, can be divided into three basic sections. The body, the chassis and the engine. Of these three, the Commendatory felt strongly enough about two of these three elements that he keep them in house and completely under his considerable control. He relinquished some control and outsourced one element, the body. So what can we accrue from this? When it comes to Ferrari’s, to paraphrase a former president, it’s the power and the handling stupid!

The heart and soul of a Ferrari has always been, regardless of what most books focus on, is the engine power and European inspired road handling. But as is the case with far too many vintage vehicles, the engine and chassis are generally the most neglected. My personal feeling on this matter is that the “don’t put too much time or effort into it as the owner will not drive it much” is simply an excuse for mediocre and garage level work a far too prevalent an attitude in this sector of the automotive industry. One should always strive to do their best, period. The quality of ones work should never be dependant upon assumptions and speculation.

So this article will focus on what is the most mysterious and the most neglected of our three basic vehicle elements, the engine.

The term “engine builder” has become a seriously misused one and accepted erroneously as synonymous with engine assembly. While a competent mechanic with reasonable skills and patience can “assemble” a collection of engine parts. There is a Grand Canyon chasm difference between “assembling” an engine and actually “building” one. Actual engine building entails the complete measuring and testing of all original engine parts and components to evaluate and determine the condition, damage and problem areas of the engine so that you can plan a competent course of action. A real engine builder should know enough about machining work to oversee the work and know that what is being done is done by a competent shop in a professional manner. Measuring that completed machine work to check its accuracy and quality and to make sure that all parts and components are set to proper oil and operating clearances. Measuring and machining are two of the most demanding, time consuming and most over looked aspects of engine building. Once everything is properly machined and measured, assembling the engine is the easy part of all of this. Most people and shops that call themselves engine builders do not even have the proper instruments and tools to measure anything. If you can not measure the components how do you know what you have or where you are? As for machining, most “assemblers” would not know a Sunnen CK-10 or 616 from a can opener. This is a very brief explanation of the differences between these two terms. Education is priceless so learn before you leap. When you take your engine to a shop, ask the right questions and make sure that the people that you are dealing with actually can work up to the level that they say they can. Remember, you get what you pay for. The unhappiness of a bargain job gone wrong greatly outlasts the temporary glow of a low price.

Aluminum is a wonderful though mercurial and often inconsistent material and that is holds true for new aluminum. When the aluminum is forty year old, things can become even more problematic.

The engine that we are writing about is a typical example of 1960’s Ferrari V-12 technology. After decades of abuse the engine smoked like a group of back room political hacks. The cylinders were worn, ring sealing was minimal and the cylinder sleeves were leaking water into the oil. The block was bowed and had a twist in it and the crankshaft bore was no longer parallel to the cylinder deck surfaces. The crankshaft bore was closer to the deck surface in the back of the block that it was in the front of the block. What this means that the compression ratio was un-even and different from the front of the engine to the back of the engine.

Pistons house and hold the piston rings and together they seal the floor of the combustion chamber. Pistons transmit the pressure of the expanding gasses into mechanical motion. Proper machining of the cylinder sleeves is paramount to proper ring and combustion chamber sealing. The sleeves must remain round under thermal and combustion stress and loading. This demands not only good base material but also top machine work and the machines and jigs necessary to properly accomplish this task.

Occlusions in the connecting rods seem to be a standard occurrence. This occurred because the stamping dies that formed the original con rod matrix were not routinely cleaned. So errant metal from previous rods would remain in the dies and contaminate the following rod stampings. This occurred over and over and over again. This extra metal ended up in the surface the following rod. This scrap can fall off, break up and end up floating around in the oil supply. This steel refuse ends up at best in bearing babbitt gets absorbed and stays put. Or at worse it stands proud and scratches the hell out of the crankshaft mains and con rod journals. It could also end up plugging an oil supply passageway or between a piston and cylinder wall scouring the wall and damaging ring sealing integrity. I could go on, but I am sure that you get the idea. Freely circulating errant metal, albeit steel, iron or aluminum is not a good thing inside any internal combustion engine.

Connecting rods are one of the hardest working components in and internal combustion engine. They are subject to physical forces of acceleration, compression, torsional loading and heat. A thin film of pressurized oil keeps the con rod big end from welding itself to the crankshaft and little more than a splash of oil finds its way to the small end bushing to keep the wrist pin from doing the same up there. Though oil is the primary bearing in an engine, its success in preventing metal to metal contact in an engine depends upon proper and consistent housing dimensionality.

The connecting rods big end depends upon the clamping forces of the con rod bolts to keep the two rod halves together and dimensionally sound. Proper finish machining, a honing process, prepares the surface for the bearing shells and makes sure that the big end hole is round. An area that is consistently ignored on con rods is the proper clearance and fitment between the con rod bolts and their housings. An overly tight bolt in its housing can induce a false reading when you torque it. A loose bolt can fall out twist or cock and again cause problems. The faces of the big ends bolt holes are another neglected area. Few people or shops spot face the bolt head and nut surface on the connecting rods.

If the face is not machined perpendicular to the housing then the bolt and nut will not exert equal force upon the cap and rod uniformly around the holes. If the bolts do not exert equal force upon the caps then the housing bore will not remain concentric and the bearing to journal oil clearance will change.

The small end bearing must support the piston via the wrist pin. It must keep the wrist pin stable and no allow it to rock or twist. If the bearing clearance is too small it will gall and or seize. Should the clearance become too large the wrist pin and the piston will rock off axis and prematurely wear the cylinder and loose ring sealing integrity. This will loose compression and power in the engine.