Valve seal placement without removing the heads (Page 1/2)
Mustang eater NOV 13, 12:17 AM
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

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Louis Shields

jelly2m8 NOV 13, 03:07 AM
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.
pmbrunelle NOV 13, 08:35 AM
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).]

theogre NOV 13, 05:27 PM
⚠️ 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.

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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)

The Ogre's Fiero Cave

Mustang eater NOV 13, 08:00 PM
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

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Louis Shields

Patrick NOV 14, 02:01 AM

quote
Originally posted by Mustang eater:

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.
theogre NOV 14, 04:04 AM

quote
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.
Mustang eater NOV 15, 01:20 AM
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

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Louis Shields

Mustang eater NOV 16, 01:58 AM
Got her off of back together she runs like a charm no more smoke is still trying to get it time just right

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Louis Shields

Notorio NOV 16, 10:59 AM

quote
Originally posted by Mustang eater:

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?