RocketyMan

So I'm getting really tired of my z28 smoking blue every-time I start the thing up. It really makes it look like a POS. In addition, I'm also getting sick of my valve covers leaking oil on the manifolds. This makes it look like somethings burning under the hood. Both of these problems which are annoying and give my car an overall POOR look upon presentation.

I'm wanting to replace the valve guide seals and also the valve cover gaskets while I'm at it. I bought all the nice fel-pro valve guide umbrella with o-rings and fel-pro valve cover gasket. I've been doing research on how to come up with a plan to do this in the vehicle--since most youtube videos I see are done on an engine stand. -_-

I tried searching TGO and came up with VERY little info for clear and concise directions. My Haynes manual also isn't of much help either. But I did come up with other enthusiast websites for adjusting the rockers and turning the crank the minimum amount of times.

I will be doing this project with minimum tools of course and IN CAR as the title states. Hopefully this post will be helpful to others since these engine's valve guide seals tend to go out.

My Plan:
I'm wanting to remove the valve covers (driver's side already done), and change out the valve seals WITHOUT AIR TOOLS. E.G. compressed air inside pistons. I think this is utterly STUPID and more unnecessary steps. Plus I do not have the tools to do so, and I don't think it's ever been suggested or done before. So my plan is moving the piston for each cylinder to TDC and have the valve just coast there while I change out the seals.

1. Moving crank every 45* from TDC to change out valve guide seals starting at piston #1. - This eliminates use of compressed air in combustion chamber to hold valve open. Thus, valve only drops a little and won't fall completely down hole. I should be able to verify this by removing dizzy and where the armature is roughly.

2. Once seals are all changed, move crank to TDC and adjust rocker lash as described here: http://berlinetta.info/Lash.htm

I'm most worried about the first step since I was told the valves will only drop a little bit in combustion chamber. I couldn't find any help online or TGO since this procedure seems uncommon. This was the best I've came up with: https://www.thirdgen.org/forums/tech...placement.html

Please let me know if anyone sees any flaws in my plans or has any ideas or input to add. I will be posting pictures later. Right now I'm trying to move wire harness and other things on top of valve covers...

RBob

iTrader: (1)

Feed a clean piece of rope or spark plug wire into the chamber, then bring the piston to TDC. Be sure to leave a bit hanging out the spark plug hole for removal.

RBob.

Apeiron

If you just let it drop you're going to have fun trying to pull it back up to put the keepers back on when you reassemble. Use compressed air or a rope. There's a reason for them to be stupid.

86T/A_Ram_Air

Yeah if you don't use something to keep it up I don't understand how you will reinstall the valve springs. In all honesty compressed air works best as long as you don't have ring issues

mjdavis68

iTrader: (1)

Compressed air

RocketyMan

Now there's an idea. So what you're saying is put something in the combust chamber so that when I bring it to tdc, it will kinda squish it against the valves, ya? That's a good idea.

I was told that the valves will only drop about 1/4 to 3/8 an inch. And this should still allow me enough room to compress the springs and reinstall the keepers.


UPDATE:

I got both valve covers off and was impressed that the inside of them were fairly clean with no huge gunk build up (see pic below). Of course it had the thick, crappy, cork gasket on there that apparently dried up allowing oil to seep through.

The passenger side is a pain because I have the wire harness that gets in the way. > Getting both valve covers back on is going to be challenging, and I'm going to want to get studs/nuts instead of the crappy little bolt that came stock. Kind of like this: I think the thread pitch is... 1/4" x 20 ???

Also, the EGR solenoid mounting bracket wore a huge gash in the heater core hoses down to the nylon lining. This was a leak waiting to happen. So I'm very glad I found that. Another part I'll need to run to the auto store store and get.

Lurbie

iTrader: (3)

I'm sure the rope trick will work for you, but just because you don't have the tools to do the job with compressed air does not make it stupid! Professional mechanics worldwide do it this way. No reason to insult the best way to do something, or the people that do it this way.

sofakingdom

iTrader: (1)

Rope works better than air. You'll see.

Won't work... the cylinders reach TDC every 90°, not 45°. THIMK... it's a 4-stroke engine; it has 8 cyls; each cyl fires once for every 2 crank rotations; that's 4 per rotation; that's one every 90°.

The shortcoming of the factory hardware isn't that it's a bolt; it's that there's no load spreaders. Studs won't do a damn bit of good. What WILL work however, is to make sure the valve cover flanges aren't dented in from over-tightening the bolts, as they VIRTUALLY ALWAYS are (which GUARANTEES that they'll leak), by tapping them back the other way such that the bolt holes are a dome about 1/8" tall or so, and the whole flange bends UP instead of DOWN for a coupla inches each way from the bolt holes, especially on the exhaust side; using load spreaders such as these http://www.summitracing.com/parts/fel-es72676, again especially on the exhaust side, and slightly longer bolts (I like 1" stainless Phillips head screws, because that way, it's ALOT harder to over-tighten them); and use a good quality NOT CORK gasket such as these http://www.summitracing.com/parts/fe...make/chevrolet, glued into the valve covers with gorilla snot, and with grease on the side facing the heads. And of course, DON'T over-tighten them!!!

Gary Simonds

I just had a friend replace my valve seals(compressed air method). NO SMOKE ANYMORE! i also installed a new headliner (classic industries) now i can install the TPI dist.cover and map light for my over head console .. The car is complete!

RocketyMan

Right...every 90* duh. Good observation. Yeah my driver side valve cover, I noticed it domed down from over tightening especially. Good point on trying to push the dome out on the other side.

This is the gasket set I got from AZ: http://www.autozone.com/autozone/par...33253_35483_0_

It comes with the load spreaders and is the rubber gasket. I figured this was a good deal since it came with them. The metal reinforced rubber gasket looks nice, but I'm not wanting to spend $50.

The fel-pro instructions are saying to leave the gasket DRY on installation. Otherwise they state it WILL leak.

RocketyMan

So I took out all the spark plugs to see what they looked like. On cylinders: 4,8, 3, 7 looked especially bad. The shiny part was just oil that was glazed. None of the plugs were wet. I'm thinking that means my rings are at least somewhat good and that its definitely the valve guide oil seals.

RocketyMan

Okay guys, I'm in bit of a bind. I did the intake valve successfully on #1. The oil o-ring pretty much disintegrated in my hand leaving me with just the rubber stem seal (see pictures below). Installed the intake valve stem seal with rubber o-ring just fine.

Here's my question: The exhaust valve stem seal DIFFERS than the intake (see pics below), does this REALLY matter? Opinions?

I tried researching and asking the auto parts guys (not much help). But instead just sold me both the intake sets instead of the umbrella type sets for the exhaust. I'm not sure if this will have an adverse effect on the exhaust valve or not by altering with the lubricating properties of the seal. Or if it really matters for that part since the exhaust valve opening wont have vacuum on it opening. It seems to me the intake valve stem seals are more stout and seal better.

RocketyMan

I did more research, and it seems using the positive intake seal on the exhaust might have some benefits.

http://www.speedtalk.com/forum/viewt...hp?f=1&t=28056

eseibel67

Exhaust seals are not as critical. Old umbrella style seals ride up and down on the valve and just keep the splash off the stem.

In the first pic, you already have the "O" ring on the valve. If you install the retainer noew, the "O" ring will get mangled. It needs to be installed after the retainer is compressed beyond the groove in the valve, just before you put the keepers in. Use the little clear plastic tube that came with your new valve seals to push the "O" rings on. Make sure the rings are seated nice and square.

RocketyMan

Good eye!
Yeah I jumped the gun a little bit and put the O-ring on preemptively before the spring retainer. But I made sure to correct and put it on AFTER the retainer and WITH the valve keepers.

This kind of made me think of the oil o-ring taking up some valve spring throw since it is seated in BETWEEN the keepers on top and the retainer on bottom. But I'm guessing its being squished regardless.

On the note of the different style of valve stem seals, I made sure to PUSH down the stem seal ALL the way so that it's seated on the upper most part of the valve guide. Then I made sure the clamp was scooted down on the valve stem seal so it had good bite.

I think the positive intake stem seals are superior to the umbrella style for the exhaust. The only real literature I could find was on Summit about valve guides needing proper lubrication from the valve stem seals (see below)...


http://www.summitracing.com/parts/sl...rview/make/gmc
Look towards bottom of the page, under notes.

I never knew the valve guides really needed all that much lubrication because that would then translate to carbon build-up on the valves.

eseibel67

No, the "O" rings do not take up any space in the movement of the valve/retainer. The "O" ring sits INSIDE the retainer. The reason you have to install the ring after the retainer is down is because it would be difficult or impossible to guide the retainer over and past the ring in a perfectly concentric manner in order to install the locks.

The function of the "O" ring is minimal anyway, so I wouldn't sweat it too much. But it's still nice to install parts as they were designed. They are just another means to keep excessive oil off the valve stem. After an engine gets old, the "O" rings usually aren't even there any more because they get so hard and brittle.

RocketyMan

I completed all the valve guide seals replacement of intake and exhaust. I replace both the intake AND exhaust with the positive type seal. This should really minimize my oil usage in addition to replacing the valve cover gaskets with good rubber type.

My only hang up was on #6 cylinder, exhaust valve lifter. For every rocker arm I counted the number of turns and in part threads that each lock nut took before it COMPLETELY spun off the mounting stud. I did this so that I would not have to worry about setting the correct lash of either too tight or too loose. This was simple as I just marked the point of two adjacent flats on the hex and marked it to a position on the rocker (see picture below). Then I counted how many times the socket went around in FULL revolutions with my ratchet.

Once I got to about 10-11 turns (full revolutions), I would be somewhere in the ballpark of zero lash. Once I did 12+ turns, the push rod would then be very tight. I knew this was correct because after about 10-20 minutes, the lifter would then ease up (or bleed out) and I could turn the push rod with my fingers.

Out of all 16 rocker/lifters, I only had ONE concern for the exhaust lifter on cylinder #6. Once I returned it back to the ORIGINAL thread on the stud, it STILL seemed VERY loose. In fact, I could push DOWN on the push rod and it of course sprang back up.

My question is: I'm not sure if this is just a lazy lifter signalling something could be wrong (like cam lobe cavitation) OR if it's just simply bled out all the oil in the lifter causing it just feel very mushy on the lash. I ended up adding 1/2 a turn since this did not deviate too much out of the norm. Even after the 1/2 turn it still seemed loose.

Below you will see a PDF of all the number of turns I recorded for each rocker arm.

eseibel67

This is not the proper way to set lifter preload. The right way to do it is easier than what you are doing here. There have been many posts regarding this, you should have no trouble finding a good one.