I've just been trying to clean down my long unused engine and found it very difficult finding useful information on checking cam and crank gear markings. Woodrow always difficult to interpret. Old forum posts had good snippets on some wrong timing marks on aftermarket gears, and this from Austin in the Shed:
Looking from the front of the engine
With the crank at Top dead centre,keyway is vertical. (i.e12 o'clock)
Camshaft gear key way should be at 45 degrees left of vertical. (i.e.10.30 on clock)
Austins timing marks were usually "0".
Double check on timing when crank on TDC inlet valve should start to open at this point.
To clarify for the newb (please correct if wrong), I add:
1. make sure you are moving the flywheel anticlockwise from the back of the engine to get its proper rotation
2. 1/4 TDC is going to give you two cylinder TDC positions - you need 1 TDC so check BOTH positions, and the imminent opening of no1 inlet, which is NO.2 VALVE. (this confusing when reading "no.1" while trying to look) So, more correctly, you are looking for the 1/4 TDC flywheel mark to indicate a vertical crank keyway* or commencement of opening no.2 valve.
3. crank is little one; cam is big one.
All that said, I finally found my marks! And I APPEAR to be one out. BUT the no.2 valve is opening and all my piston tops are correct. So what does one do now? I cannot see the crank keyway(*) but don't want to disassemble any more than necessary. Can I infer that because there are woodruff locators on both pinions/gears, the cam gear MUST be correct, and thus taking the crank gear/pinion off will enable me to check the key position and then move the cam round? Or do I need to remove the cam gear too because I can't 100% trust its markings?
Looking from the front of the engine
With the crank at Top dead centre,keyway is vertical. (i.e12 o'clock)
Camshaft gear key way should be at 45 degrees left of vertical. (i.e.10.30 on clock)
Austins timing marks were usually "0".
Double check on timing when crank on TDC inlet valve should start to open at this point.
To clarify for the newb (please correct if wrong), I add:
1. make sure you are moving the flywheel anticlockwise from the back of the engine to get its proper rotation
2. 1/4 TDC is going to give you two cylinder TDC positions - you need 1 TDC so check BOTH positions, and the imminent opening of no1 inlet, which is NO.2 VALVE. (this confusing when reading "no.1" while trying to look) So, more correctly, you are looking for the 1/4 TDC flywheel mark to indicate a vertical crank keyway* or commencement of opening no.2 valve.
3. crank is little one; cam is big one.
All that said, I finally found my marks! And I APPEAR to be one out. BUT the no.2 valve is opening and all my piston tops are correct. So what does one do now? I cannot see the crank keyway(*) but don't want to disassemble any more than necessary. Can I infer that because there are woodruff locators on both pinions/gears, the cam gear MUST be correct, and thus taking the crank gear/pinion off will enable me to check the key position and then move the cam round? Or do I need to remove the cam gear too because I can't 100% trust its markings?