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first start up after head rebuild

Posted: 03 Jan 2014, 14:11
by hedgejumper
Hi all, finally got my head all repaired after cam belt failure, very lucky indeed only two valves required. Changed valve seats and seals on all cylinders.

I should have everything back in place tomorrow ready for a start up. Just a bit unsure of these hydraulic tappets though. I guess they are empty at the moment but I cannot work out how thay will perform on first start up. There is a line in my manual that states the pistons will hit the valves if the tappets are empty. This has left me flummoxed and worried!!

Re: first start up after head rebuild

Posted: 03 Jan 2014, 18:02
by kevtherev
the travel compression of the lifter is 4mm it is highly unlikely that the piston will hit the valve.
the valve timing will be affected if they are empty in that the valve will open late, close early and not open enough.
this is momentary as the lifter will pump up very quickly...

turn the engine over a few times without it firing up.. that should put some pressure in the lifter gallery and pump them up even quicker

Re: first start up after head rebuild

Posted: 03 Jan 2014, 18:13
by BOXY
Does a diesel have hydraulic lifters?

Re: first start up after head rebuild

Posted: 03 Jan 2014, 20:04
by kevtherev
ah ha... I just saw the sig line :oops: