“SUN” SERVICE STATION

Sun (Auckland), Volume IV, Issue 1066, 2 September 1930, Page 6

“SUN” SERVICE STATION

npHli) “Motordom" section of The Sun Includes in Its service to readers a Queries and Answers Department, the object of which is to give accurate information regarding mechanical and touring subjects. Whatever the particular puzzle may be In either diagnosing irritating troubles or Motoring information of any kind, “Headlight,” will endeavour to help respective^hne^ 1 *° men w * lo are re °ognised automobile experts in their , com ™ u^ ation s m ust be accompanied by the inquirer's name and address (not tor publication;, and sent to THE SUN “Service Station column 0 ” 1 ’” ™ E SUN Auckland - Answers will appear weekly in this

“Nox.” —(a) In a Whippet six-cylin-der what would make the starter stick? That is, I press down the starter, run it for, say, three seconds, but the engine does not start. When I try the starter again I find the cogs are stuck, and it will not work. I frequently have to put the gear into top, and rock the car backward and forward, then the starter will act again, (b) My engine has a tappy sort of knock at most speeds, mostly when cold. If I retard the spark the tapping is not so strong. Is this piston slap or ignition knock. The engine was overhauled a month ago. (a) It is probable that the bendix drive spring is broken. You will have to have it replaced. (b) I’m afraid you haven’t given me enough information to judge accurately. If the engine was overhauled recently, then it is hardly likely to be a piston slap. Have you had the timing overhauled? “Mac.” —Would you kindly answer the following questions: (1) How does a cut-oift work? (2) What is the exhaust system on the Austin sports car? (3) Would I be within the law if I were to remove the silencer on my car and only have a fishtail on the exhaust pipe? (4) If the tappets have too much clearance, will that cause a slight tapping noise when the engine is cold, and yet not noticeable when it is well warmed up? (1) A silencer cut out is usually an opening in the exhaust pipe before it reaches the silencer and a shutter fitted so that it can be opened and shut from within Hie. car. The whole fitting, however, is illegal, and 1 don’t recommend trying it. (2) The exhaust system on a standard sports is through an exhaust pipe to a silencer, then from the silencer through a flexible pipe and fish tail. (3) The law relating to silencers, etc., states that an efficient silencer must be fitted, and all exhaust gases must pass through it. t believe that some cars run with a straight pipe and fish-tail, but this is not within the law, and the drivers

are liable lor a penalty. (4) If the tappets have too much clearance, they will tap when cold, and yet not be noticeable when hot. This is only when the clearance is slightly too much, i.e., .008 or .010. Then there is a possibility of end play in the cam shaft, or piston clearance being too great. There are many ways of testing these to ascertain the trouble—to«» numerous to explain here. A.8.C. — 1 have a Chev. car with artillery wheels, the spokes of which have become shabby; the paint or varnish is all off some of them. They look to me to be made of oak or some similar wood, and appear to have only bad varnish on them when new. Could you tell me bow to renovate these spokes, and if varnish only is used, what varnish to get, and how many coats are necessary; also if two coats are necessary if it is required to sandpaper first coat before applying second coat? The bodywork (duco) is quite as good as new; the wheels only require renovating. _ Varnish is used on these wheels. You can remove the existing coat with sandpaper and apply now coats with ease. Remove the wheels from the car, of course. Apply two or more coats, for a durable finish. There are a number of suitable hard carriage varnishes on the market. Be sure to keep the wheels out of the sun until the last coat is quite bard, and spray them often with water after vou begin to use the car. N.H.R. — I was reading your notes in The Sun tonight and notice*! an unsuccessful inquiry regarding the “Inverted Rocket” airplane stunt. I have the information. This stunt can be performed only by one class of plane, viz., the Bristol Bulldog single-seat fighter—the most manoeuvrable fighting machine ever built; capable of I*o m.p.h. The stunt is as follows: From a fair height the plane rushes to the ground and when about 50 feet away it does a. half-barrel roll and shoots into the sky again.