Thread: Rebuilt V8 - Very Rattly ValveTrain!

Originally Posted by PLR

Are the 3.9 heads 10 or 14 bolt ?

10 bolt. Even with 14 bolt heads in teh past we have only ever used 10 bolts. The other 4 were torqued only slightly and threadlocker used on them.

Sure you`ll work it out nothing sounds unusual just a matter of locating , i presumed the noise wasn`t too severe when driving to a mechanic was mentioned .


There was a batch of later rocker arms that the metal insert came loose and rattled .

Originally Posted by PLR

Sure you`ll work it out nothing sounds unusual just a matter of locating , i presumed the noise wasn`t too severe when driving to a mechanic was mentioned .


There was a batch of later rocker arms that the metal insert came loose and rattled .

Thanks PLR. The feeler gauge idea is a good one. We'll do that first thing tomorrow. I'll double check the metal inserts too. I'll report back once the problem is located.

Apart from the terrible noise, the motor runs pretty nicely. Nice and smooth, and the vacuum is rock steady.

Hi with the rocker covers off can you visually see oil dripping onto the tops of the valves from the rockers?
Also the rockers shafts were handed with the oil holes pointing in the right direction.
From memory they had marks on the ends of the shafts of left and right...
If they are on the wrong way you will get oil flow but not as it should be..
keep us posted!
Brad

Ditto Bradtot, my experience with a rebuilt 3.9 was that the new replacement rocker shafts were not notched at the ends to mark correct orientation as per original shafts and on initial assembly I had the feed holes directed outwards instead of inwards towards the inlet manifold = much reduced oil supply to pushrods and in turn to lifters.

How confident are you in the lifter preload measurements? I found it quite difficult, utilising the projecting depth gauge of an electronic vernier caliper, v hard to keep it dead square to the top of the lifter for the harder to reach rearmost lifters, deducting from your measured depth the distance form the top lip of the lifter to the lower edge of the recessed groove where the retaining spring sits (? 0.011" from memory). Ensuring you're on the back of the cam lobe for each measurement. Also I had a hell of a time getting the lifter preloads within the .020" to .060" specification despite trying various shims under the rocker pedestals. In the end it took a set of new rockers to achieve specification as even though the old rockers had only done about 40000km a couple had just enough wear to throw some lifter preloads out so couldn't get a uniform set of measures when altering the pedestal heights with shims. All this was with new cam, new lifters, new pushrods, new rocker shafts, heads machined with valves seated to a uniform height.

Final thought... you say there is plenty of oil supply so assume the oil pump was properly primed before the motor started.

Originally Posted by Bradtot

Hi with the rocker covers off can you visually see oil dripping onto the tops of the valves from the rockers?
Also the rockers shafts were handed with the oil holes pointing in the right direction.
From memory they had marks on the ends of the shafts of left and right...
If they are on the wrong way you will get oil flow but not as it should be..
keep us posted!
Brad

Thanks Brad. I cannot see oil dripping onto the valve stem. Is there an oil hole on the valve end of the rocker? There is plenty of oil seeping out between the rockers, BUT i cannot see any oil running down the pushrods. I assume there should be?

The driver side rocker shaft has the two etch marks facing the front of the motor. The passenger side has the etch marks facing the rear of the motor.

Originally Posted by aRRon

How confident are you in the lifter preload measurements? I found it quite difficult, utilising the projecting depth gauge of an electronic vernier caliper, v hard to keep it dead square to the top of the lifter for the harder to reach rearmost lifters, deducting from your measured depth the distance form the top lip of the lifter to the lower edge of the recessed groove where the retaining spring sits (? 0.011" from memory).

Thanks RRon. I measured the preload using wire feeler gauges, with the end bent into an L shape. It is interesting that you mention to minus 11 thou to take into account the width of the groove of the circlip - i didn't do this. Although with the 25 thou shims removed i'd say this may now be accounted for - but i'll definitely have a look at my measurements again! I didn't think at the time, but there was a fair bit of play in the circlips. Probably a lot more than 11 thou in fact. Hmmm, you may be onto something...

Yes i primed the oil pump with vaseline, then spun the top of the pump with an electric drill.

Is there any chance that the pistons are hitting valves? I am using new high comp pistons (9.35:1).

Edward

Originally Posted by I Love My Landy!

Yes i primed the oil pump with vaseline, then spun the top of the pump with an electric drill.

Did that once, many years ago, never again. Way too much trouble getting the vaseline to dissolve. An electric drill and lightly oiled pump gears is all you need. Maybe if you go for a long enough drive it'll all go away when the oil gets sufficiently hot.