Ive just picked up my Big valve head, but need to fit the lifters & new cam before it goes back on... Does anyone know how to fit the lifters? Do they, or their positions in the head, need oil in before fitting etc?? Its a PB digi head BTW if it makes any difference!! Cheers!
are they hydraulic or mechanical? if they're hydraulic (i'd guess they were) then you just smear some oil on them (not a lot) and drop them in. give them a push with your finger and make sure they're not jammed in any way before moving on the the cam, which just needs a smear of oil too. make sure you put the caps on in the correct order and tighten the nuts in the right pattern. once they're in pour some more oil over the cams and bob's your uncle. never done mechanical ones.
I dump them in oil, and give the inner piston a it of a pump to prime them first. They are hydraulic so self adjusting - also cover the entire spring column. You can't have too much oil on first turn of the cam in my opinion. It takes a couple of turns to set the hydraulic tappets at the right height anyway. Bear in mind that when you first start the car all teh oil is going to have been sitting in the bottom of the sump and with your nice clean cyl head the oil that is usually present in head is no longer there.
My attention span is too short to have remembered what the title was by the time I got to the end of the post.
Might be a good idea to crank the engine over with no plugs in to get some good oil circulation into the head first Hope it goes well mate, i am back in tonight
You should let it sit for 1/2 an hour, crank it by hand a couple of times and then start it. They aren`t interference engines like the valver but it`s better to be on the safe side!
Usually, by the time most people have got the cam on and the cover bolted up, its been 1/2 an hour. But good info if you are a speedy mechanic.
you need to bleed them m8, start the car once the new lifters are fitted, put something on ur accelerator to take the revs to about 3000rpm then leave it sitting at that for about 20 mins and................. hey presto! the tappets are bled and should be nice and quiet!
apparently its not good for it to just drive it because your revs will varie somewhat, i got the info from a vag mechanic who built mk2 golf gtis when he worked for vw motorsport so its definatly the right way to do it
Is'nt that process used for bedding in cams more than "bleeding" tappets? I would want my tappets bled and primed to the right level before I ran my new big valve head at 3000 revs for 20 mins, especially as you have a high lift cam and a skimmed head
Don,t leave it idelling as the oil pressure is Insufficient to bleed the tappets, it will just go on tapping and may cause damage. 3k of revs for a while is the way . Also the tappets are best left soaking in new oil for an hour or two, due to the composite of the metal they absorb it!!
well m8, if vw motorsport done it on their 8v gti rally car, cammed to the moon, big valve head etc as well which produced 197bhp then im sure it is the right way to do it!!!!!
If the cam is new you need to hold the engine above 2 or 3k for at least 15mins, cams work harden and the their two highest load points are at max rpm and on idle.
