If the engine shows any tendency to knock on the hill it would be well to have the carbon removed before starting. It is very disagreeable to have to take a hill on second speed that could be taken on high if the throttle could be kept open without causing knocking. Trips may be practically spoiled by the fact that the engine is full of carbon and does not have sufficient power to negotiate the hills.
Of course the car should be gone over systematically to see that all nuts are tight and properly supplied with cotter pins or lock washers. All parts should be scrutinized carefully to see that there are no cracked or badly worn parts likely to give out under the severe strain of touring.
The compression of the engine should be tested and if found weak in any cylinder the valves should be ground in. Spark plugs should be made perfectly clean, magneto interrupter points cleaned and adjusted to gauge and high-tension distributor cleaned out, and the battery should be tested to make sure it is in normal condition. If almost discharged, a charge should be given it from some external source. The commutators of the generator and starting motor should be examined and if badly scored they will need to be trued up. If the storage battery is depended upon entirely for ignition, a set of dry cells should be carried so that in case of entire failure of the storage battery, ignition and lights may be had for a short time, even though the engine has to be cranked by hand.
Some annoyance may be saved by examining the springs to see if there is a cracked leaf to be replaced. Spring repair attachments are sold, but it depends upon the ingenuity of the individual whether repairs of this sort can be made upon the road.
In addition to tools and the other things previously recommended to be carried, the tourist should take at least one set of electric bulbs for the car. Spark plugs may be cleaned with very little trouble, but it is handier to carry two or three extra ones for quick exchange, cleaning the ones removed at the end of the day, or at the noon stop. One or two extra tires carried inflated and on the rims are usual, and it is wise to have two or three extra inner tubes. If one does have tire trouble it seems to come in bunches and it is just as well to be prepared for the worst. The tourist who is traveling very far from garages should carry also patches and cement.
Of course each car will carry a real fire extinguisher and a tow rope. If you do not need to be towed out of a mud hole yourself someone else will. Be prepared. Most drivers like to have along a spool of annealed wire, a pair of side-cutting pliers, and a roll of tire tape. It is really wonderful what an ingenious man can do with these things. The tools to be carried should be sufficient to do ordinary road repairs and the outfit suggested in a previous chapter is recommended.
As previously stated, it is not the man who rushes around and plans maximum distances for each day’s run who gets the most out of the tour; he makes work out of pleasure keeping up with a schedule. It is better to allow more time for the runs, and then if one gets ahead of schedule to lay off a half day and see the sights and keep the car in condition.
CHAPTER XXXVIII
LITTLE KNOCKS ARE HARDLY BOOSTS
One of the worst things with which the autoist has to contend mechanically is the accumulation of carbon in the cylinders, clogging the piston rings, filling and short-circuiting the spark plugs and causing a knock which is not only annoying, but productive of trouble sooner or later. There are various reasons for the accumulation of carbon, such as poor gas, defective ignition, insufficient pressure, but few have assigned as a cause of carbon trouble and knocking a too high cylinder compression.
Too high compression occasions much of the knock ordinarily assigned to other causes. Engines are designed with a certain size combustion chamber, and with a chamber of that size to get a certain compression in pounds per square inch. The nearer we get to the point of pre-ignition without actually reaching pre-ignition, the more efficiently will the engine operate. Pre-ignition, of course, would make a knock.