valves are not closing correctly!!!

[sonicnofadz]

After getting my head back from the machine shop, I began putting my valve-train components back together. After finally getting everything back together, I turned the exhaust camshaft by hand and took a look at the valves. There were a few that never fully closed completely (after a complete revolution) !!!! After trying to figure out what could be wrong, I realize that I might have mixed up a few of the lifters with each other (along with mixing up some rocker arms). So I probably have rocker arms and lifters that are NOT in their original positions. Could this be why some of the valves remain slightly open? Also, I noticed that some of the lifters were slightly clogged with internal sludge, and do not contract to their smallest length. So is it because I've mixed up valvetrain components, or is it because of the lifters being clogged ? I imagine if the lifters are not closing all the way, this would cause the valve to remain open slightly. Anyone have any suggestions??? Maybe I should just get a new set of those revised lifters....

 

[LightningGSX]

Bent valves?

 

[sonicnofadz]

No actually the valves have just been reconditioned by the machine shop. The valves are 100% straight, and are all of the same length. I've just checked the (closed) length of the lifters. Looks like some close to a length of 2.100 inches, while others close to 2.035 inches. I think this is the causing the problem. A new set of lifters is in order. Either that, or I am going to have to figure out a way to clean out all the gunk inside of the lifters. I've let the lifters sit in a bucket full of MCCC but it looks like that didn't totally take care of the problem. I noticed that the little red straw that comes with WD-40 cans can fit perfectly inside the side lifter-hole, is there any type of degreaser that has this same type of straw/nozzle so I could perhaps spray the insides of the lifters?

 

[Suparata]

A set of Revised Lifters would be a good thing to get.
If you choose to clean them follow these instructions to clean and make sure you bleed them down before install. Not bleeding them down can cause the valves to be slightly open but if that's the case you can see that the lifters do not get compressed enough.
On the other hand if the lifters seem to be completely collapsed when installed it means that the valves were sunk too much in the head .
If you decide to get Revised Lifters make sure that you get the right ones for your application since you might need the ones that have a wider range of travel(operation range) .
Mitch.

 

[markgholland]

Just buy new OEM lifters from the dealer... you put all that time and money into a new-rebuilt head, why not do it right?