Valves will not close all the way

[eclipse_420]

Ok I bought a 91 Laser turbo that had a burned valve in it(car still ran
when I got it). So I figured if I was going to pull the head off and fix the valve I would just redo the whole thing. So I purchased 1mm oversized valves, dual springs,titainium retainers, bronze valve guides, valve seals,Web street grind cams, large orfus lifters and adjustable cam gears...I then took it to a local machine shop and they hot tanked it, milled it, done a 3angle valve job and installed the valve seals, valves,springs & retainers..at that point the valves all seated fine. When I took it home and put the lifters and cams in none of the valves will seal all the way. So I searched the forums and I found one that told me to bleed the lifters with a paperclip so I did they all compressed down all the way and you could see and hear oil come out (you can squeez them in with your fingers now). After I done all of them I cleaned all the oil out of the holes they sit in. I then reassembled everything and the valves still will not seat..any and all information would be very helpful. Thanks for taking the time to help me.

 

[toybreaker]

There's several possibilities for this...It's likely that the assembled height of the valvetrain is incorrect.

When the oversize valves are installed, the seats must be re-machined to have the correct geometry/installed height. I would think this would result in a low installed height, but the machine shop could have gotten carried away, and sunk the seat, and then not recut the valve stem to compensate.

In addition, the titanium retainers may be too thick, (or the stem may have been cut too much) and the rocker may be touching the retainer instead of the valve stem tip. Please check the clearance between the rocker and retainer. ( A local shop lost two evo motors to this exact problem, the retainers would move, and it let the keepers out....twice )

Another possibility is the base circle of your (reground?) cam may be incorrect. I have seen several regrinds be off enough to cause problems. Usually, this is a cheap knock off from e-bay/overseas, and the problem is insufficient base circle. (This gives the opposite problem to what you're having, but with knock offs/off brands the possibilities are endless) Web cam is a pretty good company, but errors do occur. If you have your original cams, just do a mock assembly with them and see if it's all good.

Lastly, it may just be tolerance stack up. Every part is made to a +/- specification. If you stack up a bunch of + parts, you can end up overspec enough to create issues. Add in machine work, and you can end up with a problem.

I would suggest you return to the machine shop with some beer, and calmly approach them for a solution.

Good luck, and please let us know what the solution is, I'm curious

 

[eclipse_420]

1st off thanks the the help it is appreciated. The rocker arm is not touching the retainer there is clearance like there should be. Unfortuneatly I do not have the stock cams to rule out the lobes. However I took the back end of a rubber handeled screwdriver and tapped the valves' with the cams installed and the valves' closed all the way. I then rotated the cams to open the valves back to see if they would close again and they did not. I did notice that when I tapped the valve closed the rocker pushed up and forward. It is almost like the springs aren't strong enough to pull the valve closed. Do you think it could be the lifters?

 

[gurmanator]

did the lifters get bled down?it sounds dumb but you know how things happen.had the same problem last week,put all new valves in,put everything together and no compression,valves to long,take it all back apart,fix it put it together again.