With reference to members comments about a 40 year old crankshaft pulley not necessarily being correctly marked for timing purposes. After all, the pulley might not be the original fitted to the engine. I followed Zed's excellent advice about finding the TRUE Top Dead Centre with an adapted sparkplug. Basically drilling out the insides, inserting a rod then carefully rotating the engine by hand until the top of number 1 piston touches the end of the tool. Mark where the pulley lines up with the crankcase centre. Then rotating the pulley the other way until the same happens. The TRUE Top Dead Centre is then the centre point between the 2 marks. Doing this showed the TRUE Top Dead Centre to be some way off the mark. Measuring the pulley's circumference to be 55.3cm means the TRUE Top Dead Centre is some 10mm ie about 6-7 degrees away from the pulley mark. Here's a piccy of the pulley showing 1. the one and only original mark on the pulley (nearest the engine) 2. the new TRUE Top Dead Centre using Zed's tip. ( On the white line under it, I'll write TDC - as soon as the paint's dry ) 3. - the red mark is 28 degrees advanced from the newly found TRUE Top Dead Centre The reconditioned engine's number is AB 262589. It has an aftermarket vacuum advance distributor. Can anyone please tell me the correct timing for this engine. Thanks Here's Zed's excellent gadget to find an engine's TRUE Top Dead Centre. dear Zed. Why is your garage in Cambs? Kindly re-locate to South Glos immediately
There's another nut "concealed" where the ceramic part used to be. The 2 nuts tightened against each other keep the threaded stud secure, and enable varying the length of the exposed thread. With the amount of thread exposed as in the photo, the 2 marks on the pulley were 55 mm apart.
