Degrees of rotation required to adjust valve clearances sequentially

[jedwards]

Gentlemen, this will probably be a seriously dumb question for those who have already worked it out, but I'm trying to determine how many degrees of rotation I need the crank the engine through to allow me to sequentially adjust the valve clearances on our Inlet over exhaust engines, as the Rule of 9 is far harder to apply on our engines.

What I would like to do is to be able to the set all the inlets valve clearances first and then all the exhausts.
I'd like to set the Inlet valve #1, then know how many degrees I need to rotate the engine through (using the crank handle) to bring up the next inlet valve, which will be #3, then rotate the same degrees again to bring up #4 and then finally #2.

Can someone help me with the maths on this?
regards
Jeff

[JDNSW]

I can't answer the actual question, but if I remember correctly, on these engines you can actually see the camshaft and the cam followers, since you have the side cover off. If you turn the engine until one inlet valve has the cam follower directly opposite the peak of the cam, that valve is in the correct position to adjust. From there, the rest of the same type of valve (inlet or exhaust) will be half a turn on the crank to the next one in the firing order (1-3-4-2) since there are four cylinders and the engine is a four stroke. Repeat for the other type of valve.

[LR1953]

Jeff, I use another approach: lift off the distributor cap and observe the cam lobes. Hand-crank the engine until No. 1 lobe has just opened the points. (Rotor button pointing to No. 1 HT lead terminal) At this point No. 1 Cylinder will have both valves fully closed and the tappets can be correctly adjusted. Then advance to the next dizzy cam lobe and adjust tappets on no. 3 cylinder, and so on.
Cheers, Rob S

[Blknight.aus]

720 degrees to adjust all valves on all 4 stroke engines, most however can be done with just 360.

to do the valves in sequence... front to rear one valve at a time takes (depending on the layout of the engine) 8-12 turns of an engine depending on the port layout and cylinder count. (sometimes adjacent valves move at the same time so can be adjusted without additional turning)

lr1953's answer of doing it with a timing light and then adjusting is the simplest way to keep track of it.