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Plastic debris under valve covers - spring retainers?
I pulled the valve covers on my 65 olds 330 that was running when parked 8 years ago, found quite a bit of plastic debris. I'm guessing it's the valve spring retainers as they're the only plastic parts I can ID in the valvetrain. Here's what I fished out of one bank:
Debris
Pretty much every piece bigger than a sliver is curved, so I'm guessing it's the part that seats inside the springs that's broken, likely on several.
From what I can tell the retainer is about a dime thickness, so maybe .07", so I'm guessing if the retainer is completely broken I'd effectively be reducing my valve length by that much.
here's a couple pics of the springs themselves where you can see the broken retainers.
I'm guessing I need to remove the springs and replace all the retainers to prevent power loss, right? I don't imagine the springs are going anywhere but I don't think I want them opening 10% less, either...
The keepers are steel and should be fine. I would be concerned about the camshaft gear needing replacement, not because of what you found but out of good practice.
The keepers are steel and should be fine. I would be concerned about the camshaft gear needing replacement, not because of what you found but out of good practice.
Good luck!!!
Thanks!
I saw some talk about the cam gear going in another thread. I've got the intake off right now so I guess now is the time to pull the front cover and replace it if necessary.
I think that and the valve seals are the only plastic in the engine...
The chain and gears may have been replaced. You could remove the fuel pump and look in with a borescope. Cell phone borescopes are not too expensive.
Good luck!!!
Good call. I'm planning to put a Sniper EFI on the 7111 I've got ready for match porting then installation so I'll be pulling the fuel pump anyways, may as well save myself the work of pulling the cover if it doesn't need it! Just got the first of two gasket kits I need to port the intake, I figured I'd use the glue method.
Thanks for posting what you found. I just pulled my valve covers and found the same thing. I also started the engine with the valve covers off and found that one valve was not working at all and another was really weak. I will be starting my own thread very soon.
Thanks for posting what you found. I just pulled my valve covers and found the same thing. I also started the engine with the valve covers off and found that one valve was not working at all and another was really weak. I will be starting my own thread very soon.
Thanks
Hoat
Sounds like you've been running on 7 cylinders!
I've gotten through replacing the seals and 4 out of 16 of the Springs so far - all 4 umbrella seals were destroyed, most of the pieces were inside of the springs so expect to find about 2-3X as much plastic material as you remove and replace the seals. I'm guessing by the time I'm done I'll have confirmed that all 16 were broken.
The compressed air approach to replacing them in the car works and is pretty quick if you're just replacing the seals. Just make sure you compress the springs enough to make removing and reinstalling the locks easy.
My springs had signs of chipping and corrosion and were likely at the end of their life cycle, so I'm replacing them too. If you're replacing the springs too it'd honestly probably be easier to pull the motor, put it on a stand, then remove the heads and do the work on a bench. Mostly it's a pain to reinsert the locks in the spring retainers near the firewall. I wish I'd had some extra retainers lying around. Then I could compress a new spring and have it ready to insert right after I remove the old one, which would save my compressor running for 15 minutes straight for each cylinder I have to do.
I would think you'll probably want to make sure the hydraulic lifters and pushrods are OK for the two valves that aren't working - could be a problem there. I had one slightly bent pushrod that was preventing one intake valve from opening fully. If you've got the intake off you can use a magnet to pull the hydraulic lifters partially out of the bore and use some channel locks to pull them out from there. There's also a little tool you can get that inserts into the lifter then expands to clamp it from the inside.
Last edited by InfinityOlds; December 29th, 2020 at 07:42 AM.
Pull it apart, chances are, time for a rebuild. Post a pic of the oil pickup screen when you get to that point. Good luck, I will be following along with the rest.
Do a compression test or better yet a leakdown test so you know what you are working with unless you're going for a full rebuild.
If you pull the heads to do valve seals the compression ratio will decrease due to thicker replacement head gaskets. Replacing the valve seals with the head in place avoids this.
When changing the cam if the nylon gear is missing chunks it would be good to remove the oil pan to clean the sump. The chunks go up inside the covered section of the oil pump pick-up, they're easy to overlook if unaware.
If you pull the heads to do valve seals the compression ratio will decrease due to thicker replacement head gaskets. Replacing the valve seals with the head in place avoids this.
Good point! This was one of the reasons I forgot to mention that I decided to do it with the heads on. My understanding was that you can get thin head gasket replacements but it's... "cost-prohibitive". I see the Copper head gaskets are available in a .021 thickness, which is pretty close to factory spec if you're willing to deal with the difficulties with sealing the water passages. They'd be re-useable at least, if you're going to have the motor apart more than once.
November 24th, 2020, 04:15 PM
Good luck, I will be following along with the rest. 
