In the last issue of Engine Masters, we set out to start a series of articles that gets right to the core of engine building by showing the tricks, techniques and tools required to successfully build an engine. The aim is to arm the reader who dreams about putting together a high performance powerplant with the information needed to get it done. How? The goal is to answer the question of "How to do it" as much as "What to do." We covered what goes into building a short-block, and how it is done, in the last issue. This time around, we turn our attention to the cam, valvetrain, and top-end.
Really, this is a pretty broad subject, and the details vary depending upon the caliber of the build, and the equipment being used. The idea is to focus on the ideas that are universal to any engine buildup. Some of the detail may be more than you need to know for a very basic assembly, but knowing more is never a bad thing. We encourage feedback from our readers, so if you have an area of engine building you'd like explored in detail, contact me at firstname.lastname@example.org.
Install and Degree the Cam
At the most basic level, only a few things need to be ensured while installing a camshaft. The camshaft must be clean and properly lubed, and once in, it must spin freely in the block. The lube used will depend on the type of cam. Flat-tappet camshafts require a special high-load break-in lube on the lobes, which is usually packaged with the camshaft. The bearing journals should be lubed with an assembly oil or regular motor oil. Roller camshafts, either mechanical or hydraulic, normally do not need special cam lube on the lobes, and can be installed with oil on the lobes and journals.
Installing the camshaft can be as simple as sliding the stick into the bore, and making sure the timing dots are in alignment at TDC when the timing set is bolted in place. Most mild to stock rebuilds, and a surprising number of high performance engines, are put together this way. Taking such an approach is like flying blind, since the camshaft's installed centerline will not be known unless it is actually checked by the process commonly referred to as "degreeing-in." Unfortunately, inaccurately degreeing-in the camshaft is one of the most common engine assembly blunders, often making matters worse than just lining up the dots. If the cam is going to be degreed-in, it has to be done with the utmost in accuracy. Tools for degreeing a cam are relatively inexpensive; degree wheels can be purchased from most cam manufacturers, while some such as COMP Cams offer kits with everything you'll need.
Degreeing-in begins with accurately finding TDC, which serves as the key reference point f
Proper lube upon installation is vital to a cam's survival, especially with a flat tappet.
Now that the degree wheel and pointer are set up to read exactly TDCNow that the degree wh
Lifters basically come in four types: flat-tappet and roller, available in solid or hydraulic versions depending on the camshaft type and design. Always use the appropriate lifters for the type of camshaft being used. Flat-tappet lifters must rotate in the bores, while rollers must maintain their alignment to keep the roller wheel in line with the lobe and avoid destruction. Typically, solid rollers and retrofit hydraulic rollers use a link bar arrangement to pair up the lifters and hold them in alignment. OEM hydraulic rollers will typically use alignment yokes and a spring-steel spider for alignment. The essentials for lifter installation are cleanliness, proper lubrication and free movement.
Solid roller lifters are often shipped with protective grease in the bearings, and require
When installing the link bars for a roller set-up, makes sure that the link bar is orienta
In contrast to a roller, a flat tappet must rotate in the lifter bore for survival. Lube a
With hydraulics, either flat-tappet or roller, the lifters should never be pre-filled or p