Posted by Gordon Biggar on March 07, 1998 at 21:51:11
In Reply to: Re: Timing the A
posted by DJ.Voyce on March 07, 1998 at 01:25:09
: G'Day Tim, : Locating TDC is a fairly simple exercise, so here's how. Remove all spark plugs & turn the engine slowly with your thumb or heel of your hand over #1 plug hole until you can feel compression pressure (the paper trick would work here). You can then either look into the cylinder with a torch, which is probably the easiest way & watch for the piston reaching the top of its stroke, or slide a long thin screwdriver down the plug hole across towards the cylinder & feel for the piston coming up remembering to pull the screwdriver back as the piston comes up or you'll jam it in there & have to turn the engine back a bit to free it. As a check that you're definately on #1 compression stroke, look into #4 plug hole & both valves should be slightly open. If you turn the engine back & forth a little with the fan, the valves should rock, or in other words the exhaust will just be closing & the inlet just opening when the engine is turned in direction of rotation. Once you're happy that you've definately located TDC, take the drill bit to be used & smear grease in the flutes to stop any shavings falling into the engine, then using either a hand drill, or with the drill bit in the chuck of an electric drill, turn the bit slowly by hand to make the dimple in the gear. This way you can check on your progress bit by bit as the fibre material of the gear drills pretty easily. Hopefully you can now continue with setting your ignition timing. : Regardz : DJ. : OutOfAfrica A's
: : Open to Any Ideas,
I prefer Doctor Voyce's method for locating TDC.If you set your timing correctly, you shoudn't have to be doing it again any time soon, and the procedure he describes is speedy. Try having your friend crank the engine slowly, while you hold the timing pin in.Because of the roundness of the pin head, you must press it firmly against the timing pulley.As a sort of "purist," I'm not in favor of drilling holes into the timing gear.I've just installed one (with some helpful comments from Herr Voyce), and there isn't a lot of meat (i.e., fiber) on those pulleys near the timing teeth.If you feel you must get a better feel, try machining the end of the timing pin to make it less round.But, if you press hard enough and crank slowly, using DJ Voyce's method for locating TDC, I'll bet you find the recess! Peace! Gordon Biggar |