1G Valves are shot, need advice

[trapdad]

So bought my car with a rebuilt head around 2000 miles ago, and for probably the last 1500 miles I've been experiencing pretty much no power exactly like a boost leak. It's been running stupid rich ever since I bought it. Only mods are walbro 255, aftermarket fpr, evo iii 16g, and egr delete. I finally get around to compression testing it and its consistently ~100psi +-2. Checked
the timing to make sure it didn't skip, and it didn't. So I start pulling everything apart. All the intercooler piping seems solid and I couldn't find any leaks with a simple hand over one side, mouth on the other test. N
ot really a valid test but I trust all the piping. I end up pulling the head for a visual inspection of everything because I'm too cheap for a leak down tester. I rotated one of the cam gears while it was off once or twice I'm not sure if that screwed anything up but it seems as if there's a huge gap when my valves should be seated. My question is what's the next step? Does an automotive machine shop fix this or should i just find a different head for sale? Mine is in very good condition other than this.

 

[ohlegend]

Just buy a set of new valves and take it to a machine shop and have them install them. Also have your head resurfaced too.

 

[trapdad]

Just buy a set of new valves and take it to a machine shop and have them install them. Also have your head resurfaced too.

Any other supporting parts or just new valves?

 

[Marchev]

Get new valve stem seals as well. Maybe even look into new guides since it'll be all apart

 

[95REGF150]

Are you sure your on the base circle of the cam for those pictures? Only time ive ever seen valves stick up that far is when they are bent from contact and there doesnt seem to be any evidence of that here.

 

[Chumpaumpalumpa]

Any other supporting parts or just new valves?

Valve guides especially if you plan on running E85 or Meth injection. Keep in mind that with the cams still in, Some valves are always going to be open. You can loan a compression or even leak down tester from autozone for a deposit you get back in full when you bring the tool back.

 

[donniekak]

With the cams in the head, all the valves are never closed at the same time on a dohc 4g63 head. I bet if you remove the cams, or just the rockers that they are all closed.

 

[Tiki2777]

Depending on where your lifters are at (IE fully pumped up or empty), the valves can hang open even on the base circle of the cam.

 

[95REGF150]

Depending on where your lifters are at (IE fully pumped up or empty), the valves can hang open even on the base circle of the cam.

Really? But without oil pressure to the lash adjusters shouldn't the valve spring pressure collapse them down?

 

[trapdad]

Really? But without oil pressure to the lash adjusters shouldn't the valve spring pressure collapse them down?

Right? Why would there be pressure when the head is completely disconnected.

 

[Tiki2777]

You need to do some research on lash adjusters if you aren't getting this. The only way to release the pressure is applying a lot of pressure (only real method for first gen lifters) or probing the release valve through the pin hole in the top of the lifter (best method that works with 2nd and 3rd gen lifters) and squeezing them. Just because you pull them out of the head doesn't mean they all release the oil and pressure they were holding wherever they were at when the engine stopped. The valve spring pushes your valve back up after the cam and rocker shoves it down. Its actually the cam if anything that applies the pressure to the rocker that decompresses the lifter. Our lifters are self adjusting. Once again, read up on the subject rather than assuming things.
Link for cleaning:
http://vfaq.com/mods/lifters.html
Heres a video:

You must be logged in to view this image or video.

And another:

You must be logged in to view this image or video.