Hydraulic tappets after new valves

[VTS123]

I'm just about to replace the valves that got bent when the timing belt idler bolt failed on my VTS.

My querie is this: presumably I can't just put the old hydraulic tappets back in as they will be holding the adjustment for the old valves - not a problem if there is clearance as, presumably, they will close up after a short period of running - however, if the tappets are too enlarged for the new valves then they will not close and presumably not bleed down? Is this a correct assumption or will they sort themselves? Can I bleed them down or something?

The Haynes book says they should be put back in the same positions that they can from, if you take everything appart but not replace valves, suggesting they don't sort themselves.

I know they are self-adjusting but surely only in one direction, that being to take up clearance over time as things wear. Is this correct?

Any help would be gratefully received

[VTS123]

Any ideas on this anyone?

[VTS123]

Now I've got the new valves in and put back the camshafts I can see that the tappets have bled themselves down, so much so that nearly all the valves are staying shut with the camshafts set to TDC.

When I've got it back together I think I will have to turn it over without the spark plugs in to get the tappets to pump back up before trying to start it, otherwise I think the engine will have trouble turning over due to excess compression. Does all this sound normal?

[raunchz]

Sorry but I don't understand your problem? Are you worried about valve clearances?

The hydraulic followers need to fill with oil and then they'll quieten down - they sort themselves out adjustment wise.

You put the followers back in their old position due to the surface of them wearing in with the camshaft, so you want to put them back with the camshaft lobe they have worn into.

I just put the followers in oil before fitting them (so they have oil in them for the first startup), then fit everything back together (no need to adjust and valve clearances due to hydraulic followers) and start the engine. Not had any problems, have done a fair few now.

Nothing to worry about on the compression side of things, you won't have excessive compression!

If fitting new cams and followers then you'll need to run the cams in (or do as the camshaft manufacture says). Normally around 2.5krpm for 20 minutes (the neighbours will love you)

[VTS123]

Thanks for the advice. I will just start it up as normal in that case.

Cheers

[raunchz]

I've re-read it and i think I understand where you're coming from now.

If you're worried then you can turn it over on the starter motor for a bit to let the followers fill up if you haven't submerged them in oil before fitting.

Don't worry about the compression side of things.

I'd pour some oil over the top of the tappets and camshaft lobes before starting up, and then fill with oil, coolant etc.

[stuartm]

Turn it over with the sparkplugs out, it will fill the tappets with oil & turn over easier

[shannon6460]

your ment to purge(squash) the lifters in a vice to get the oil out of them then put them back in the head. once you started it it will probable run like a bag of shit until the lifters fill with oil once they fill with oil they adjust them self and run fine.