Where do I start.......
My V8 had developed a totally random tapping noise, suspected a tappet, so stripped the engine at the weekend and had a look. Now bear in mind this was rebuilt about 7,000 miles ago with all new parts from RPI stage one high torque cam, new oem tappets rods valves etc you get the picture.
Anyway upon investigation when we removed the rocker arm assembly the "chrome" pad that contacts the valvestem top had in some cases disintegrated or pitted very badly on both sides.
so question, would this be "faulty" manufacture of the aluminium rocker arms as RPI no longer supply them (stel only now) or poor addjusment of the pre load tension on the tappets / shimming of rocker arms or even something else??

Also does any one have a link to or information on the torque settings for the rocker arm bolts and the settings and tightening procedure for the cylinder head bolts.

From memory i think the bolts are 38nm be cearfull thogh i snaped one of mine

fix it said:

From memory i think the bolts are 38nm be cearfull thogh i snaped one of mine

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Well remembered - it is 38nm

I think the sequence for the head bolts depends on your engine. On the 3.9 (both types) you work from the centre head bolts outwards to the edge but on one type the outer row was only 60nm while the rest were 90nm. On Suffix B there was a 2 stage tightening procedure, Stage 1 torque down to 20nm, stage 2 turn 90 degrees, stage 3 a further 90 degrees.

I think that is right but I might be remembering the 3.9. It could be different on the 4.6

MattMatt said:

Well remembered - it is 38nm

thanks how i remembered i dont know.

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MattMatt said:

2 stage tightening procedure, Stage 1 torque down to 20nm, stage 2 turn 90 degrees, stage 3 a further 90 degrees.

I think that is right but I might be remembering the 3.9. It could be different on the 4.6

Click to expand...

i think the 4.6 headbolts are 28nm them a 180 degrees all a once if i can rember again.