Setting rocker preload
Discussion
Have you inspected a hydraulic lifter?
The parts you can see are the outer body, an inner piston (with a spring behind it that you can't see) and a spring clip holding the piston into the body.
The measurement will be a gap between the top of the piston and the underside of the clip.
I suggest you make three tools from coat hanger wire. Put a piece of the wire in a vice with about 5mm sticking up. Beat that piece over at 90 degrees. Continue beating it until it is .020" thick. File the beaten section until it is the same width as the wire and trim its length to about 4mm sticking out square to the wire. Next form a handle loop on the other end of the wire with the whole tool being about 70mm long. You need the loop on the end so that should you drop the tool it can't disappear into the sump (ask me how I know). Make 2 more at .040" & .060".
It is only possible to set the preload if the lifter is empty of oil. I will assume they are new and empty but come back for instructions if they are full.
When assembled with the rockers and pushrods all in place turn the engine over until the first lifter is on the back of the cam lobe. the pushrod will now be compressing the piston in the lifter. You can then use your tools to check the gap under the clip.
You will need to check all the lifters along one bank and record your findings. Some of these will be guesswork using your tools as a guide. If any gap is less than 20 you will either have to have the rocker pedestals machined or fit adjustable pushrods. If gaps are over 60 you can fit spacers under the pedestals but you have to fit the same spacer thickness under each ped. or the shaft will be bent. In doing this others may then be too small a gap so it is a compromise.
When I do these I keep turning the engine over and just eyeball the gaps. If I spot a large and a small gap I first measure those. If one is below 20 and one above 60 I know straight away I'm going to have to fit adjustable rods.
Steve
The parts you can see are the outer body, an inner piston (with a spring behind it that you can't see) and a spring clip holding the piston into the body.
The measurement will be a gap between the top of the piston and the underside of the clip.
I suggest you make three tools from coat hanger wire. Put a piece of the wire in a vice with about 5mm sticking up. Beat that piece over at 90 degrees. Continue beating it until it is .020" thick. File the beaten section until it is the same width as the wire and trim its length to about 4mm sticking out square to the wire. Next form a handle loop on the other end of the wire with the whole tool being about 70mm long. You need the loop on the end so that should you drop the tool it can't disappear into the sump (ask me how I know). Make 2 more at .040" & .060".
It is only possible to set the preload if the lifter is empty of oil. I will assume they are new and empty but come back for instructions if they are full.
When assembled with the rockers and pushrods all in place turn the engine over until the first lifter is on the back of the cam lobe. the pushrod will now be compressing the piston in the lifter. You can then use your tools to check the gap under the clip.
You will need to check all the lifters along one bank and record your findings. Some of these will be guesswork using your tools as a guide. If any gap is less than 20 you will either have to have the rocker pedestals machined or fit adjustable pushrods. If gaps are over 60 you can fit spacers under the pedestals but you have to fit the same spacer thickness under each ped. or the shaft will be bent. In doing this others may then be too small a gap so it is a compromise.
When I do these I keep turning the engine over and just eyeball the gaps. If I spot a large and a small gap I first measure those. If one is below 20 and one above 60 I know straight away I'm going to have to fit adjustable rods.
Steve
So I followed the great write up above today, and yes, I do need shims! The 60 thou tool/coat hanger giggled about in there like a chipolata in a Kings Cross gash 
I reckon it must be between 70 & 90 thou easily. So will be ordering some shims first thing Monday morning. Might make a 100 thou tool tomorrow and see how close it is.
I reckon it must be between 70 & 90 thou easily. So will be ordering some shims first thing Monday morning. Might make a 100 thou tool tomorrow and see how close it is.
Might just help you when checking. Taken from the V8 forum.
Setting Tappets---Rover V8
Find TDC,
With no1 in firing position,
Set Intakes, 2 & 7, and Exhausts, 4 & 8.
turn the engine 1/2 rotation,
Set Intakes, 1 & 8, and Exhausts, 3 & 6,
turn the engine 1/2 rotation,
Set Intakes, 3 & 4, and Exhausts, 5 & 7,
Turn the engine 1/2 rotation,
Set Intakes, 5 & 6, and Exhausts 1 & 2,
When you are finally happy, fill your followers with oil through the small side hole until oil oozes out of them. Saves a load of clatter on initial start up.
Setting Tappets---Rover V8
Find TDC,
With no1 in firing position,
Set Intakes, 2 & 7, and Exhausts, 4 & 8.
turn the engine 1/2 rotation,
Set Intakes, 1 & 8, and Exhausts, 3 & 6,
turn the engine 1/2 rotation,
Set Intakes, 3 & 4, and Exhausts, 5 & 7,
Turn the engine 1/2 rotation,
Set Intakes, 5 & 6, and Exhausts 1 & 2,
When you are finally happy, fill your followers with oil through the small side hole until oil oozes out of them. Saves a load of clatter on initial start up.
carsy said:
Might just help you when checking. Taken from the V8 forum.
Setting Tappets---Rover V8
Find TDC,
With no1 in firing position,
Set Intakes, 2 & 7, and Exhausts, 4 & 8.
turn the engine 1/2 rotation,
Set Intakes, 1 & 8, and Exhausts, 3 & 6,
turn the engine 1/2 rotation,
Set Intakes, 3 & 4, and Exhausts, 5 & 7,
Turn the engine 1/2 rotation,
Set Intakes, 5 & 6, and Exhausts 1 & 2,
When you are finally happy, fill your followers with oil through the small side hole until oil oozes out of them. Saves a load of clatter on initial start up.
Thanks for that Carsy. In the interest of learning something new, could you explain what the reason/benefit of doing it this way is please? Something to do with the firing order? Or just convenience/efficiency so I don't have to turn it over for each cylinder?Setting Tappets---Rover V8
Find TDC,
With no1 in firing position,
Set Intakes, 2 & 7, and Exhausts, 4 & 8.
turn the engine 1/2 rotation,
Set Intakes, 1 & 8, and Exhausts, 3 & 6,
turn the engine 1/2 rotation,
Set Intakes, 3 & 4, and Exhausts, 5 & 7,
Turn the engine 1/2 rotation,
Set Intakes, 5 & 6, and Exhausts 1 & 2,
When you are finally happy, fill your followers with oil through the small side hole until oil oozes out of them. Saves a load of clatter on initial start up.
caduceus said:
Thanks for that Carsy. In the interest of learning something new, could you explain what the reason/benefit of doing it this way is please? Something to do with the firing order? Or just convenience/efficiency so I don't have to turn it over for each cylinder?
Just minimises turning the engine.Steve
JWzed said:
Have a look at V8 Developments website. There is a useful and easy to follow procedure for setting preloads in their Technical Section under "Valve Train". They also supply shims. Found them really helpful. 
I've had a look at the guide V8 give, and it differs from the method Steve wrote above. Does it matter which method I use? Will it have any adverse effect on the engine? caduceus said:
JWzed said:
Have a look at V8 Developments website. There is a useful and easy to follow procedure for setting preloads in their Technical Section under "Valve Train". They also supply shims. Found them really helpful.
I've had a look at the guide V8 give, and it differs from the method Steve wrote above. Does it matter which method I use? Will it have any adverse effect on the engine? However, as it is worded it will only check the preload of one valve (and alongside a pedestal). I have on several occasions found an engine with some valves less than 20 thou and alongside them valves at 60+ so in that case shims or pedestal machining would not solve the problem. This variation comes from a build-up of wear (valve seat recession, rocker, pushrod, valve tip, lifter, cam etc.)so is quite variable along all the valves on one bank.
I'll stick with my bits of wire.
Steve
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