roller rockers, Adjustable pushrods etc.
Discussion
So as per previous post I've pulled the top end part to investigate the ticking noise and check cam, rockers, lifters etc. All looks pretty good with very little wear. I checked the preload before pulling the rockers and it was all over the place.
I've now stripped and cleaned all the lifters and rechecked the preload and its pretty much the same, as per table below:
The engine is already fitted with 30 thou' shims and working by the normal tolerances of between 20 & 60 thou' it doesn't look like I can add thicker shims, to reduce the preload on the of the higher ones, with out putting cyl 6 exhaust below spec.
I was planning to install adjustable pushrods, but looking at the clearances, it looks a bit tight especially on cylinder and I don’t really fancy removing the heads to drill out the slots.
The other option seems to be the Yella Terra roller rockers, Probably the best option, but expensive, difficult to get hold of and potentially need taller rocker covers or spacers.
I had thought about swapping over some of the push rods between the high and low valves, but was told that the rods should be kept paired with the lifters / rocker arms and shouldn’t be swapped over. Not sure about this as they don’t seem to be worn and surely new rods would have the same issue?
Any other options I’m missing? Really want to get the car back on the road while we have the good weather.
I've now stripped and cleaned all the lifters and rechecked the preload and its pretty much the same, as per table below:
The engine is already fitted with 30 thou' shims and working by the normal tolerances of between 20 & 60 thou' it doesn't look like I can add thicker shims, to reduce the preload on the of the higher ones, with out putting cyl 6 exhaust below spec.
I was planning to install adjustable pushrods, but looking at the clearances, it looks a bit tight especially on cylinder and I don’t really fancy removing the heads to drill out the slots.
The other option seems to be the Yella Terra roller rockers, Probably the best option, but expensive, difficult to get hold of and potentially need taller rocker covers or spacers.
I had thought about swapping over some of the push rods between the high and low valves, but was told that the rods should be kept paired with the lifters / rocker arms and shouldn’t be swapped over. Not sure about this as they don’t seem to be worn and surely new rods would have the same issue?
Any other options I’m missing? Really want to get the car back on the road while we have the good weather.
The differences you are seeing are not the rods it is the amount the valves have worn back into their seats. As mentioned you can see this if you put a straight edge across the valve tips.Using shims will not deal with this so adjusters are needed.
When I fit adjustable pushrods with the heads in place I pack all the gaps with paper towel then cut to size some rag to cover the whole valley then drill out all the holes. Wash with brake cleaner spray from top down. Carefully remove the rag which will take away ost of the swarf. Then vacuum out before finally removing the towels. Time consuming but not as much as removing the heads.
Drill as slow as you can to reduce how far the swarf gets thrown.
Steve
When I fit adjustable pushrods with the heads in place I pack all the gaps with paper towel then cut to size some rag to cover the whole valley then drill out all the holes. Wash with brake cleaner spray from top down. Carefully remove the rag which will take away ost of the swarf. Then vacuum out before finally removing the towels. Time consuming but not as much as removing the heads.
Drill as slow as you can to reduce how far the swarf gets thrown.
Steve
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