Changing oil is probably our least favorite maintenance activity, but is the most important of all for ensuring long engine life. Engine oil serves two major functions: lubrication and cooling. Moving parts rely on a very thin film of oil to prevent frictional wear, and the circulating oil absorbs a good amount of heat from…
Welcome to Under the Bonnet, our quarterly technical column dealing with the basic maintenance and repair of your British car. We’ll be covering topics here that have been the cause of recurrent problems and questions by customers as well as our own staff members. While much of this information may be rudimentary to old-time mechanics,…
Identifying the separate emission control systems within the seemingly hopeless tangle of vacuum lines, hoses, pipes, and mysterious boxes and cans in your engine compartment is the key to understanding how these systems operate. These systems fall into three groups: crankcase emission control, fuel evaporation emission control, and exhaust emission control. This article will give…
Engine exhaust is the sole source of a vehicle’s carbon monoxide (CO) and nitrous oxides (NOx) emissions, and accounts for about 62% of a vehicle’s hydrocarbon (HC) emissions. Ina perfect situation, the only emissions from a gasoline engine would be carbon dioxide and water. However, the combustion process within an engine is never complete. This…
The S.U. carburetor is one of the simplest “full function” carburetors ever put on modern cars. However, since they work so differently from most other carburetors, few people in the U.S.A. really understand them well. Many, if not most, problems attributed to these carbs being “out of tune” are really faults of the ignition system,…
In the last issue, we discussed the basics of ignition timing. Since quite a few readers commented on this article. I would like to address some of their comments here, for all to share. I make no apology for trying to make this Under the Bonnet column as simple and as basic as possible. It…
This is the first of a series of articles on basic tuning techniques to help you maintain your car to original factory specifications. Since the ignition system must be in good order before any other systems, such as the carburetor(s), can be properly adjusted, we will begin with a brief discussion on ignition timing procedures. These instructions…
Fear of the unknown is probably the greatest stumbling block most people seem to have in dealing with Zenith-Stromberg carburetors – they are much maligned largely because they are not understood. The basic Zenith-Stromberg, as used on Triumphs in the mid-’60s. for example, is actually simpler and more reliable than the SU carburetor it replaced….
We all use gasoline, but rarely give it much thought. We have come to accept the lack of lead, seasonal volatility changes, local differences, and the presence of “gasohol”. But most of us still have some concerns about how these affect our cars’ performance and what adverse affects they may have on the components of our cars’…
The D.C. charging system must provide a generator output sufficient to mcci the normal vehicle electrical load plus keep the battery charged. The generator is designed such that it must always be under some form of control, both to protect it against overload, and to protect the battery against overcharge. A control box (commonly called…
