Hi Guys

I was reffering my B310 Repair manual, i want ot adjust of it's valve because they are too noisy now.

Manual Says like this

"With the valves of number three cylinder in the rock
position adjust the valves of number two cylinder."

what do they mean by rocking ?

thanks
regards
sumith

rock means, the rocker arm push the valve.

Hi Bakat

But there are 2 rockers for each cylinder ,which rocker ?

thanks
regards
sumith

number three means third valve from front of engine. you count from the front. so in this case, three means intake of second cylinder

just put the engine on tdc and adjust the rocker arms that move up and down others that are tight you move the engine around another full turn back to tdc so the other rockers will loosen up and you then adjust them.

Yes, that wording is confusing. It is much easier than that. As a12datto120y says you only need to put the engine at TDC and adjust four of the valves, and then rotate one full turn and adjust the other four.


For another description of the procedure, see our article Adjusting Valves

Distributor Rotor pointing to #1 plug wire
* adjust valves 1,2,3,5 (counting from front of engine)

Distributor Rotor pointing to #4 plugs wire
* adjust valves 4,6,7,8

Thats all too complicated too.
Just use the "rule of 9".
Wind your crankshaft around with a ratchet with a big socket on the king bolt. (Take out the spark plugs if your engine has high compression, or you have thin girly wrists)
With the rocker cover off, watch the valves open. When a Valve is fully open, subtract whichever number valve it is, (One to eight) from 9. The remainder is the valve which needs adjusting.

Quote:
The good ol' rule of 9, I completely forgot about that! I find the method dd explains is quicker and easier though, as you only have to turn the motor once.

In answer to your question Sumith, "on the rock" is the point when the exhaust valve is fully closed and the inlet valve is about to open. At TDC, you'll see either #1 or #4 cylinder finish it's exhaust stroke and begin it's intake stroke by seeing the corresponding tappets (1 & 2 for #1 cyl, 7 & 8 for #4) "rock" between closing and opening. When #4 is on the rock, #1 cylinder is about to start it's power stroke. At that point, the tappets for valves 1,2,3,5 will be loose (i.e. valves are closed) and can be adjusted. When #1 is on the rock, tappets 4,6,7,8 can be adjusted.
Remember to tighten them just enough so that the feeler gauge has a slight amount of drag or resistance when you pull it.

even better: open the dizzy cap, adjust the valves on the cylinder the dizzy rotor points. when the dizzy rotor points at that cylinder (the plug cables, not literally pointing at the cylinder), it means the cylinder just started the spark, so both valves are closed. this method is true for any cylinder counts

Hi DD

I actually initially tried standard 1200 manual method, actually it doesn't work on this A12A engine,
So decided to go for Datsun b310 repair manual,and it was damn confusing

Please refer this detail document extracted from it

thanks
regards
sumith

(2) Rotate the engine clockwise as viewed from the front until the number one piston is on tdcon the compression
stroke. In this position the mark on the crankshaft pulley will be aligned with the tdc .

scale on the timing cover and the two valves of number four cylinder will be on the rock. (That is, one just closing
as the other is opening).

The clearances of number one cylinder inlet and
exhaust valves may now be checked and adjusted.
NOTE: Never turn the engine against the normal
direction of rotation or anti-clockwise as
viewed from the front.
(3) To check the valve clearance insert a feeler gauge of the specified thickness between the end of the
valve stem and the adjusting screw. A light drag should be felt if the clearance is correct.
(4) To adjust the clearance, loosen the adjusting screw locknut and using a screwdriver turn the adjusting
screw in the desired direction until a light drag is felt on the feeler gauge. Tighten the locknut.

(5) Check with the feeler gauge to ensure that the clearance has not altered while the locknut was being tightened.
(6) With the valves of number one cylinder correctly adjusted, rotate the engine in the normal direction
of rotation until the valves of number two cylinder are rocking.
With the valves of number two cylinder in the rocking
position adjust both valves of number three cylinder.

NOTE: With the valves of number two cylinderrocking number three cylinder piston is on tdc on the compression stroke.
(7) With the valves of number three cylinder correctly adjusted, rotate the engine in the normal direction
of rotation until the valves of number one cylinder are rocking. With the valves of number one cylinder rocking
adjust both valves of number four cylinder.
Adjusting No.
NOTE: With the valves of number one cylinder rocking number four cylinderpiston is on tdc on the compression stroke.
(8) With the valves of number four cylinder correctly adjusted, rotate the engine in the normal direction
of rotation until the valves on number three cylinder are in the rock position. With the valves of number three cylinder in the rock position adjust the valves of number two cylinder.

(9) With all the valves correctly adjusted instal the rocker cover on the engine using a new gasket. Tighten
the rocker cover securely.