Valve always slightly open when cam fitted

[therealnovaboy]

I'm fitting an ast2 cam to a b+ head. I was trying to find full lift but found that the valve is never fully shut. I fitted the cam to the old head and the valve is open the same. I fitted the previous cam to both heads and found that the valves at always slightly open too.

Ive measured the cam carrier heights and they are all the same. I've measured the valve heights between the std and b+ head and they are the same. Also when the cam carrier is off the head all the valves are shut

so how is the valve open. The only thing I can think of is the hydraulic tappet isn't fully down, but I didn't think this was possible with zero oil pressure

[burgo]

Is it a cam designed for solid lifters maybe?

[Stuart]

The ast2 is not a solid profile cam.

can you get a photo of all 4 cylinders with the cam fitted.

[mowgli]

has someone skimmed the cam carrier down?

[burgo]

Be rare to have two skimmed carriers mowgli

And have you drained your lifters?

[meritlover]

you seem to have meausered everything and tried as many combinations of cam/carrier/head that would rule out any physical dimensional or cam differences, the only thing that remains is that the lifters are pumped up. Perhaps if you drain them or crank the cam over a few times to 'pump out' the excess oil? If you have a high lift cam on big valves would maybe not be a good idea to do this with the head built up on the block, incase you get some clearence issues. The links below show that this does happen, although the guy seems to have other issues.

http://www.honestjohn.co.uk/forum/po...=46739#m522259

http://www.honestjohn.co.uk/forum/po...=46739#m522265

the world can be such a scary place sometimes. O_o

[mowgli]

Be rare to have two skimmed carriers mowgli

And have you drained your lifters?

I was banking on the OP having fitted the camshaft to a carrier, then tried it on 2 heads...

actually, I think the lifters are most likely

[therealnovaboy]

I've tried two carriers with two different cams on two different heads. Both the carriers are the same width. Both heads don't fully shut the valves. This points two being a tappet issue. They must be jacked up somehow, I've never had this problem before. It might be because I've never actually looked at a valve when the carrier is bolted down, and just never noticed. It maybe has always just sorted it's self when I crank it over.

ill have another look later and take a few pics. Pics always help

[therealnovaboy]

[therealnovaboy]

You can hardly make it out bit the valves rant fully shut. I had left the other can to the other head over night and it looked like the valves had gone fully shut. It must just take a a while for the spring to fully compress the tappet. I'll leave it over night and hopefully there isn't a problem.