The Birmingham age-herald., 1923-12-02
ny BARNEY 'oLDFIELD

By BARNEY oLDFIELD
 Copyright, 1923, by King Features
 Syndicate, 1nc.)
 Every driver likes to hear the en- zine idle as slowly as it can, with no suggestion of misfiring or uneven running There are many little things which go to make a smooth running engine at low speeds and while sorne of these things affect the engines running at high speed and when under load, some of them have no affect on operation other than at idling speeds.
 An air leak between the carbure- tor and the combustion chamber may destroy good slow speed opera tion of the engine. Usually these leaks re- suit from defective gaskets or poorly frightened nuts between the carbure tor and intake manifold or between the intake manifold and the cylinder block. Paint the outside of the joint with shellac as insurance against possible air leaks.
 Spark plug joints are a source of compression leaks and may affect the opera tion by allowing air to be drawn in to dilute the low speed mixture. Often the spark blug gas kets are not there and the fit of the thread is depended upon to make the
 
 not always exist between the plug and the engine; often the lock nut on plugs is not frightened down.
 Leaky joints at the plugs may af- feet the slow speed operation in number of ways. As in the case of leaky joint in the induction sys- tenn, the mixture may be lost then through the leak when the mixture is under compression or small part of the force by the explosion may be lost through the leak. Seating of the valves, tension of the valve springs, the wear on the valve guides and the adjustment of the tappets will have something to do with the operation of the engine al low speeds Any leak through the intake valve will allow part of the charge to be forced back into the intake manifold and the compression will be lowered. The exploding charge will not have the maximum force.
 Faulty exhaust valves are more common. A poor seat for the eX- haust valve contributes to power loss and irregular operation. Part of the compressed charge may be lost and part of the explosive force may act through the poor seat instead of being effectively used on the pis- ton.
 Weak valve springs affect the en- zine in a very similar manner. Valve stems and valve stem guides even- tually become worn. Aside from the fact that these conditions may cause poor seating of the valves, there IS always the possibility of weakened mixture caused by loosely fitted stems. Particularly is this true of the intake valve. Badly worn parts here affect the engine in the same manner as does a leak in the intake manifold Loosely adjusted tappets or tappets that are adjusted un- evenly have other and more serious affects No engine is at its best Tn smoothress if tappet adjustment IS Incorrect.
 If all of the valve clearances were the same, even though excessive, jerking and misfiring may not be so noticeable. The charges admitted to the cylinder cannot be equal and equal power impulses cannot De given. It Is easy to see that jerky engine will result from such uneven adjustment.
 If compression is leaking past the piston, maximum power cannot be op- tained Neither will smooth operation be possible if part of the exploding gas shoots down past the rings. NOT will a maximum charge Of fuel De drawn into the cyclinder on the lntake stroke of the piston II part Of the auction is allowed to act on an open ing between the cylinder wall and the piston An engine will not throttle down satisfactorily if the explosions are being weakened by all of these power leaks. More than often, one cylinder is a greater offender than the others. Uneven compression means uneven power and jerky engine IS the result.
 Too narrow gap at the spark plug points or uneven setting in gaps causes irregular operation. A defec- tive plug insulator may allow an elec- trical leak that cuts down the lnten- sity of the spark that leaps the gap. X dirty distributor cap or badly worn distributor brush may cut down the current flow. Badly burnt or pitted breaker points will not allow a maximum current to be built up in the ignition coil. Any one of these troubles may cause weakened spark at the plugs.
 The effect of carbon deposits are SC well known to most car owners that it is hardly necessary to mention their effect on slow speed operation. The engine will not do it's best at either high or low speed if much carbon has been allowed to accumulate.
 O O O
 Questions And Answers. Dear Barney Oldfied: Is it possible to procure a new car that was little damaged in the factory for a cheaper i price?
 Can you tell me how much mile- age H. C. s. 4 gets on one gallon of gas and the speed as l expect to get one in the spring? r. G. V.
 Factories do not deal in used cars and such a thing as a damaged" car is unheard of at q factory. The dealer would sell a demonstrator at a price below list The H. c. $. four will average around 13 miles per gall lon, speed 60 miles per hour.
 Dear Barney Oldfield: Where can l get specifications on a "Continen- tai Red Seal' type SIR motor. that is used in Westcott motor car? J. w. S.
 Continental SIR specifications as | follows: L-Head Engine Max brake H. P. 55-5, R. P. M. at max B. H. Px 2300 cylinder Bore and stroke 33s by41a. Engine oil capacity, six quarts Carburetor size 1A.
 Dear Barney Oldfield: After driv- ing my car about 2.000 miles, l noticed slight pounding in the engine when running at about 30 miles per hour This noise is more pronounced wher I accelerate quickly.
 My car has now been driven almost 5000 miles and the pounding is be- coming n1bre noticeable. Could this knock mean that the bearings need tightening I never drive the car al