Tappet pre load advice needed

[steve 500]

I'm in the process of finishing an engine rebuild on a Griff 500. As the heads needed a light skim, I want to check the tappet pre load before going any further. I have read the advice on other threads and specialist websites, but I have one ( probably obvious! ) question. I have installed the lifters without priming them with oil. Is that correct?
If thats ok, is it then safe to start the engine and let the lifters prime themselves, or is it better to prime them beforehand? Any other advice in connection with this part of the rebuild would be great.

[paul gotts]

I'm certainly no expert, but I believe you must soak em in oil for a while before installation.

[andy43]

Think the theory is to soak them in oil, then check preload before starting the engine - preload can only be checked correctly with the lifters 'un-pumped-up' - just soaking in oil won't pump them up (oil pump needs to be spinning for that) and affect the readings, but will help on initial firing up.
There's a really good bit on V8 Developments or RPI website - can't remember which - showing you exactly how to check preload, with pix and instructions

[Boosted LS1]

When the lifters are subjected to oil pressure they become uncompressable so take up slack in the valve train.

Even so, there is still a stiff spring inside them. I usually soak them in oil for 24 hours just to get some oil into them. When I set the pre-loads they can be oiled or dry. I use 2 bits of wire (paperclips can be good). One piece is squashed down to .020" and the other piece is nearer the .060". Get the valves on the compression stroke and then try to slip the wire in between the plunger and the underside of the retaining circlip. You will need to bend the wire slightly and you will find it helpful to have a pencil torch as it's quite fiddly. They will probably rattle quite a lot until they get oil pressure and then should go quiet.

Boosted.

[steve 500]

Thanks Boosted. My main concern was whether I should check the pre load dry or oiled. From what you have said I can check them dry and then pop them out and oil them before final installation.

[stesrg]

Yes put them in dry i made a tool for setting /checking pre load using a welding rod grinding the end flat to the corrcct thickness using a mike, i then bent it to an angle to get it in the follower, fantastic though i used adjustabel push rods which i set everyone OH my back