All right guys pray for me I got the intake manifold off I got all the push rods removed with the push rod removal tool I've got an air fitting to pressurize the cylinder I'm debating on whether or not to actually use the pressurized method or to use rope any thoughts on that???? I got a tour all the way down to where I'm ready to change the valve seals that kind of ran out of daylight and I was getting overwhelmed and frustrated any tips or insight on this will be highly appreciated thank you
When you get overwhelmed it's time to step back and look at it tomorrow. Air method is fine, just be sure you have a reliable 90 PSI or more air source. You won't have to go savage at it, a few taps here and there, you'll be fine. Take your time and make sure everything is in place.
Rope can be tricky in the sense that it can get lodged between the quench zone of the head and the piston:
When the rope gets stuck there, the piston can't move up any further, but the valves are not held up. I had this issue with a 1/4" cotton rope. With a 3/8" nylon rope, I was able to make the rope method work. This was with a dished piston though; probably this is less of an issue with the stock flat-top piston.
Do you have a good spring compressor?
I used this kind:
Once the spring is compressed, it holds itself hands-free.
[This message has been edited by pmbrunelle (edited 11-13-2022).]
⚠️ Even when you use an "Air Holder" in a plug hole you need to top out the piston because break valve seal for any reason let the valve to drop. Compressor can fail or someone/something hit a stem w/o warning the valve drops.
⚠️ When using rope... only turn engine backward just enough to free the rope to remove it. Some engine parts don't like turning backward including the cam in Dukes.
When using a wrench on crank bolt... Take wheel and dirt trim off. carefully jack the control arm to clear the wheel. Use 1/2" drive w/ long extension(s) so clear the car body. Support handle end w/ a jack stand. (If need to have wheel off w/o you watching use small jackstand on the car too even tho too low to get under in this case.)
That way the wrench stays on the bolt between rotations. Can use a pipe on handle so less effort and rotate tiny fractions of a turn if needed.
------------------ Dr. Ian Malcolm: Yeah, but your scientists were so preoccupied with whether or not they could, they didn't stop to think if they should. (Jurassic Park)
So far so good using the rope method I've got the easy side done I got to wait for some more valve seals tomorrow because I decided to do away with the o-ring and put seals on both sides the hard part for me is going to be climbing my fat ass up in there to do the back and then set setting the valve lash I'll get her done though.
I can't be the only person to have ever done away with the o-ring and put seals in both sides and a brand new engine it might not be the hot setup but considering this thing has got almost 200,000 miles on it the guides have enough clearance to suck plenty of oil past that o-ring that's for sure
I can't be the only person to have ever done away with the o-ring and put seals in both sides and a brand new engine it might not be the hot setup but considering this thing has got almost 200,000 miles on it the guides have enough clearance to suck plenty of oil past that o-ring that's for sure.
It's been a l-o-n-g time since I've installed valve guide seals... but from what I recall, it's just O-rings used on the exhaust valves. Unlike the intake valves, there's not a lot of suction occurring in the vicinity of the exhaust valves, which is why seals aren't normally installed on their guides.
Originally posted by Patrick: It's been a l-o-n-g time since I've installed valve guide seals... but from what I recall, it's just O-rings used on the exhaust valves. Unlike the intake valves, there's not a lot of suction occurring in the vicinity of the exhaust valves, which is why seals aren't normally installed on their guides.
True + exhaust stem and guide get hotter and may "cook" a seal made for the intake valve causing more headaches.
Exhaust will leak a tiny bit there even for new engines and part of fumes the PCV suck out. PCV doesn't just get "blow by" from the piston rings. A intake seal to fight vacuum pull oil may do little or nothing for exhaust side even if doesn't cook. May fail and cause other problems.
If you ignore that... Guides need some oil or guides and stems wear fast. When Exhaust side uses o-rings, the rings keep most oil away from hole but let enough to lube them. Wrong seal may not cook but seals too tight and guide starves of oil. Even "hat type" for intake let a little oil in the guides for same reason but stops intake sucking major oil.
Most times, if guide(s) have oil leaking problems... Replacing seals often won't help for long if they help at all.
I understand the concern in me using the seals on both the exhaust and the intake guides if it was a brand new engine I can see it possibly causing an issue but all the guides are already worn anything is better than what this thing had there wasn't a single person left in it they were all completely deteriorated which leads me to believe that one time somebody possibly let this thing overheat pretty well the intake gasket was also leaking you could see that it was leaking from the ports that are closed , I consulted one of the elders that I work for sometimes he builds engines and has his own machine shop they told me that the wait I did the seals will be fine and that was a lot of work, in the morning I'll be set in the lash and putting her back together
Got her off of back together she runs like a charm no more smoke is still trying to get it time just right
Congratulations on your experiment! The 'proof is in the pudding!' as they say. Still, you'd think that the exhaust valve stem would be hotter than the intake and might, as Ogre mentioned, lead to cooking the seal over time. I wonder if anyone has measured the temperature difference? Is it significant?
Originally posted by Notorio: Congratulations on your experiment! The 'proof is in the pudding!' as they say. Still, you'd think that the exhaust valve stem would be hotter than the intake and might, as Ogre mentioned, lead to cooking the seal over time. I wonder if anyone has measured the temperature difference? Is it significant?
Because Thermal couples come in many types and fit in a lot off places even w/o mod'ing whatever to clear them But Doubt anyone would try that... More so w/ V6 because so hard to access the valves w/ valve cover and intake setup. Might be "easier" w/ dukes and Felpro xxxT valve cover gasket (silicone w/ new hardware.) because that gasket is a bit reusable if installed carefully.
I'm "worried" more about E-side and oil. Even w/ worm guides, "better" seals may starve the Exhaust stems and guides making worse problems and sooner. May never see smoke w/ "better" seals but added wear makes something breaks and dies on the highway often at the worse times.
Bad guide/stem wear can cause these Examples: Valve burning because face can't close right. If found early maybe can rebuild the head and replacing some or all valves... Stem breaking and drop the face in the cyl. Most times happens w/o warning and destroys the engine.
Oil leak for this is often blue smoke at cold start at first then can be most starts as parts wear more. later smoke as hit the gas but that can be other things doing it or adding to smoke at that point.
When I did these on my 2.8, Felpro gave me two sets of seals, they looked similar but were different colors, the exhaust seals were supposed to be able to handle the heat as compared to the intake seals.
Felpro gave me two sets of seals... the exhaust seals were supposed to be able to handle the heat as compared to the intake seals.
Interesting. I'm curious about a valid point that the Ogre brought up. With oil seals installed on the exhaust valve guides (where there is no vacuum being exerted), just how do the exhaust valve stems/guides get lubricated?
Well at least on all the engines from different manufacturers that I have worked on, there are always seals on both intake and exhaust valves, and they are always different from one another. My 2.8 also had seals on both sides even before I rebuilt it.
Looking into it it looks like the valve seals are designed for "controlled leaks", and the seals on intake and exhaust may have different rates of "controlled leak". Having no seal on the exhaust would probably allow too much oil to enter the guide and therefore the exhaust runner.
On my first 2.8 motor it used to puff smoke on startup and it smelled oily when engine braking. I replaced the seals and while it helped, the real issue was valve guide wear in my case. The point being though that even with new seals, the seals do let oil past in an amount calibrated for a non-worn valve guide. Otherwise my issues should have been solved. Getting the heads rebuilt did solve the issue.
Originally posted by Patrick: Interesting. I'm curious about a valid point that the Ogre brought up. With oil seals installed on the exhaust valve guides (where there is no vacuum being exerted), just how do the exhaust valve stems/guides get lubricated?
Likely several ways the E-side gets enough oil to work. "Simple" tolerance of a seal to whatever can make a big dif. Some seals or parts they work with can have intentional "defects" to make sure a little oil will get thru. For Parts... Sim to Rear Axle knuckle "seals" w/ a drain hole at bottom. Those seals are mainly a dirt shield to protect the rest of axle and bearing assembly that has own seals to keep out water and grease in. (and is another reason to never drive most vehicles in water deeper then a few inches...) For Seals... Things like Moog BJ w/ grease release at the stud so prevent boot blowout when greasing after install. From Moog DYK11_102_ENG-R.pdf to install BJ boots.
(in the rear knuckle... most never see the drain hole at bottom of inboard seal even when they replace the seal. Is fairly small and hidden when you have the axle in the knuckle. I have spares w/ axle installed and the drain is nearly hidden by axle's shield/guard ring and tip of stud of the BJ when in the car. is nothing to take pictures w/ axle installed and don't have just a knuckle.)
Looking into it it looks like the valve seals are designed for "controlled leaks", and the seals on intake and exhaust may have different rates of "controlled leak".
quote
Originally posted by theogre:
Some seals or parts they work with can have intentional "defects" to make sure a little oil will get thru.
Makes sense, I was thinking along the same lines. A "perfect" seal would definitely yield negative results!
putting her back together
From Moog 
