Wednesday, 12 October 2011

12. Pushrods and Rockers.

We are now going to assemble the Pushrods and the Rockers.
Tilt the engine in the stand until the nos 3 & 4 cylinders are facing up. Use the best rocker stand on this side.

For the Super engines with the aluminium rockers the stands are attached by three 15mm bolts. These bolts use special 10mm washers that have a smaller outside diameter. DO NOT use wider diameter washers as the intake rocker stand will hit the edge of the washer.

The stands only fit one way. Fit the stand using the three bolts and washers and torque to 29 ft lbs. Repeat three times. Repeat this procedure for the other side of the engine.

The normal engines used a cast iron rocker stand that was held by only two 17mm bolts at either end of the stand.

Take 4 pushrod tubes and squirt WD 40 down the tube to make sure they are clean. Roll them on a flat surface to make sure they are not bent. (they will roll in an arc if bent!)

Clean off the tube and fill with engine oil and then pop it into the pushrod hole and down the pushrod tube and onto the cam follower. Make sure it is properly in the cam follower and not resting on the lip by rotating  and wiggling the tube until it drops into place. Repeat for the other three pushrods.


Filling a pushrod tube with oil prior to fitting.

Rocker Stand and Rocker Parts - Note there is a short exhaust rocker and a longer exhaust rocker.

If you have not stripped down your Rockers now would be a good time to do this. Take photos of how they are assembled and clean all the components and blow all the oil holes out with WD 40. Make sure the adjustment screws move easily and the tappets are in good condition.

If you disassemble the intake Rockers the rebuild order (from centre out) is washer, spring, washer, intake rocker, washer and then cap. This is the same for the other side of the intake rocker stand.

Take the intake rocker and place over the three studs and gently ease it into position making sure that the ends of the pushrod tubes fit into the cups of the rockers.

For the middle stud there is just a washer and the nut. For the two outer studs there are saddle washers followed by a washer and then a thin nut. Hand tighten the nuts to hold in place.

Now rebuild the exhaust rockers. Take a shaft and put a cap on one end. The rebuild order is washer, spring, washer, exhaust rocker, washer and cap. (see photo below)


Correct rebuild of an exhaust rocker


Fit the exhaust rockers to their stand. There is a long rocker and a short rocker so get them in the right places. fit the saddle washers, washers and thin nuts. Again make sure the pushrods ends fit in the cups of the rockers.

Tighten the nuts, (note the valve adjustment nuts and the rocker nuts look similar but ARE NOT interchangeable).

Torque carefully to 15ft lbs.

Repeat for the other side and you should end up with something that looks like the photo below.



Stand and Rocker in position - I like to use nylock nuts on the rockers.

We are now going to ADJUST the valves. First we need to set the engine to TDC on the number one cylinder. Look carefully at the photo below which shows how this is done. (double click to enlarge photo)

NB clockwise is turning the pulley to the right when engine is viewed from the pulley end


Engine is set to TDC on number one cylinder. Red arrow points to inlet spring of number one cylinder.


Turn the engine over until the intake spring of number one cylinder compresses.(this is the inlet spring on right side of engine nearest flywheel) continue turning the engine until the spring starts to expand and continue turning until it expands to its maximum and starts to contract again. Look at the pulley and rotate it clockwise until the OT mark on the pulley is at the top in line with the timing mark on the third piece case. This is TDC for number one cylinder.

First adjust the exhaust valve. For a new engine during run in set both exhaust and intake valves at 7-8/1000.

For a normal running car it should be: 

Exhaust 6-7/1000
Intake 4-5/1000

I like to get a feeler gauge and using a screwdriver and ring spanner adjust the valves until they just pinch the blade of the feelers and tighten at this point. Next do the intake valve of number 1 cylinder.

Now Rotate the flywheel 180 degrees COUNTER-CLOCKWISE (anti clockwise) so the OT mark on the pulley is pointing down to the bottom of the engine. This is the correct position to adjust the valves of number 2 cylinder which is the same side as number one but at the pulley end of the engine.

Rotate the engine another 180 degrees counter clockwise to adjust number 3 cylinder (left front) and finally another 180 degrees counter clockwise for number 4 cylinder.
There is a good article on valve adjustment here:

http://www.356registry.org/tech/valve_adjustment.html

Fitting valve covers.


We are now ready to fit the valve or rocker covers. They have a cork gasket which fits inside the cover. In order to stop oil leaks, I find I need to use some sealant on the cover side of the cork gasket. Do not apply it to the side that mates with the cylinder head.


One of the products available.


Applying sealant to the cover inner sealing surface. Cork gasket is seen to left of picture.

The covers are held in place by 2 "bails". Before fitting the covers spray the rocker gear with WD 40.


Bail - painted black - holding Rocker cover in place.

1 comment:

  1. Is there a way that you remove the push rod on the #4 intake without remove the head? If you can, please explain?
    Thanks

    ReplyDelete