Setting Tdc No: 1 On A K Series Motor

[Banjo]

I was working on a fellow Rollaclub members KE20 with a 4K engine fitted, a couple of weekends ago, chasing a few electrical gremlins, as the result of a dodgy electrician being let loose under the dash. It had been a long day, and we still had to refit the freshly cleaned & oiled distributor, as the timing light had indicated no auto advance, the bob weights having all frozen up. The day light was fading fast, and the engine had been turned over with the spark plugs out, when we measured the cylinder compression pressures.

We still had to “time” the engine & find TDC. This is always a pain, and can involve at worst, removing the rocker cover, and watching the rockers on no 1 cylinder, or sticking your finger in number 1 spark plug hole, with the possibility of a trip to hospital, if your finger gets sucked in.

I’d already put a bit of “whiteout” on the crankshaft pulley nick for lining up TDC, and not wanting to go through all that rigmarole of finding TDC, I took the quick method.

 

There are two points in a cycle (2 revs of the crankshaft), where the nick in the crankshaft pully lines up with the TDC marking on the timing chain cover.

 

One is TDC No1, and the other is TDC No4. So if you arbitrarily choose one of these, there is only a 50% chance of getting it wrong.

So we set the crankshaft pulley nick arbitrarily against the TDC mark & installed the dizzy, with the vacuum advance mechanism parallel to the block, with the rotor button pointing to a point on the head, approx. between 1 & 2 cylinder spark plugs. Popped the leads on, in the usual 1, 3, 4, 2 firing order in a clockwise direction, looking down on the top of the dizzy cap. Hit the starter switch & there was a back fire, which woke the neighbours dog, and scared a few nesting birds in the tree above us.

 

We had got TDC wrong !

 

Rather than line the nick on the crankshaft pulley up again, & then remove the dizzy & reinsert with the rotor button moved 180 deg, we simply pulled all four (4) leads off the dizzy. Connected No 1 spark plug to the opposite side of the dizzy cap (where no4 had been connected), then plugged the remaining leads to nos 3, 4, & 2 spark plugs, clockwise from no: 1 lead. Hit the starter, and away the engine went, and we were both home in time for dinner.

 

From the time of the back-fire, to it running sweetly, took less than 1 minute.

 

So if your ever in the dark, on a country road, & have to swap out a dizzy, this is a sure fire method of getting the timing right, without having to find TDC No:1 precisely.

 

Hope this helps someone who is new to K engines.

 

Cheers Banjo

Edited August 17, 2016 by Banjo