[jpiper]

Installation of GT Valve springs halted!

Hey Opelers;
I started this morning putting the head back together for my 71 GT and halfway through installing the valve springs I noticed that the "O"ring on the exhaust valves are being pushed out of thier groove. It appears that the valve cap is pushing it out when I compress the spring enough to insert the keepers. After a closer look and comparing the valve caps from the exhaust and intake valves, I found that the "necks" are longer on the exhaust valves.
Is this correct? Is the "O" ring supposed to go inside the cap?
I tried sliding the cap over the "O"ring, but it appears to big. I received new "O"rings from OGTS so they should be correct, so I don't think that is the problem.
Oh yes, when I took the valves apart, one at a time, all pieces were "bagged and tagged" before moving on to another to ensure things wouldn't get mixed up.
I can't proceed any farther until I get this figured out. Can someone help me on this one?

STUMPED and at a STAND STILL

 

[GTJIM (R.I.P.)]

Yes, John

The exhaust valve spring retainers are longer and the "o" ring fits up inside them - but not easily. Try putting a bit of oil on the inside of the retainer nearest the head to make it less hard for the rubber ring to slide inside the retainer. Here is a pic of what they end up like on the exhaust side:

 

[jeff denton]

It's a bitch to put 'em together. I haven't found a spring compressor yet that really fits nicely and makes it as easy as they should be.
One of these days I will build one that works.
Meanwhile, take your time and be patient, as Jim says get it slippery, that is rule number one with any O-ring!

 

[kwilford]

John,

Opel varied the valve stem seal designs along the way, so different years use different seal configurations, and most gasket kits supply a variety of stem seals to cover the choices.
The early models (until sometime in 1970 I believe, so you could have either version) used square O-rings on both intake and exhaust stems (although it has been reported that there were no, none, nil, zilch seals on their early intake valve stems).
Then, they changed to "positive" seals that slip over the intake guides (these are the little rubber umbrella seals that have the wire ring around them, which should have come in your gasket kit) and proper O-rings on the exhaust valves.
I believe that change coincided with the change to the "later" valve keeper design (the old one used a rounded groove in the stem that matched the keeper, while the newer design has a squared groove for the keeper).
Later again (sometime post 1976) Opel went to positive seals on all valves.
I was told this was a worthwhile improvement, so I had the exhaust guides on my '71 head machined to accept the positive seals, which was quite cheap at something like $5 per guide. Just make sure that they machine them down to the correct size to match the 9 mm Opel valve seals. Or, if you are using Chevy/Pontiac valves, to the GM 11/32" stem size, which use a different guide outside diameter.

HTH

Former Moderator's Note: Revised post to reflect blond moment when I said that the positive seals were on the exhaust valves, when I had earlier, and correctly, stated that they were on the later model intake valves. Read the thread at http://www.opelgt.com/forums/showthread.php?t=4813 Sorry!

 

[jpiper]

Keith,GTJim and Jeff

Thanks for the response guys;
Keith, you now have me second guessing myself to determine if I have identified the valves correctly?
The "smaller" valve is the exhaust and the "larger" valve is the intake? Another way to look at it is if you numbered them from the firewall to the front 1,4,5,8 are exhaust (two grooves on stem) and 2,3,6,7 are intake (one groove on stem)? Is this correct?
With this in mind the "postive" seal will only fit over valve guides 2,3,6 and 7. It also brings the guide up to the same height as the 1,4,5,8 guides.

GTJim I will add more oil to see what happens. I am trying to get this engine together so I can crate it for my move back "east" this summer.

Back to the garage!!!
Thanks again guys.

 

[jeff denton]

Oh, oh, I just figured out your problem, I missed the clue in your first post. I think you are putting the o-ring in the groove, then putting the retainer on and compressing to insert the keepers.
Is this what you are doing?
You have to do it this way: leave the o-ring off, put the spring on, then the retainer, then compress it way down (the hard part) so you can then put the o-ring in its groove, then put the keepers in their groove, and carefully release the retainer.
It's hard. A little sticky grease on the keepers will glue them to the valve stem. It's still hard though. I used all my best cuss words last time I did it.
When I was a kid I put my 327 heads together wrong, compressed the spring/retainer over the o-rings like I suspect you did. Boy, that engine smoked! My whiz friend suspected bad valve stem seals (o-rings). We borrowed the tools to remove the spring with the head installed, started checking 'em. My mistake was consistent. I had cut every single o-ring by doing it wrong. It worked fine after new ones were installed properly.
I learn the most important things the hard way. Still.

 

[jpiper]

Jeff, yes you are correct, I am putting the o-ring in the groove, then putting the retainer on and compressing to insert the keepers. After looking at the picture provided by GTJIM (thanks Jim) I ran out to the garage, picked up an exhaust valve, installed an "O" ring and and tried to fit the cap over the top. There was no way that it was going to go on easy and I didn't want to force it all the way in fear of messing up the seal. If the O-ring has to be "forced" into the cap won't it become deformed thus defeating the purpose of o-ring? If the seal must go inside of the cap then Jeff your method sounds like a plan. But wait....
I was on the phone with Dennis at OpelGTS, about an hour ago ordering a head gasket set and spoke to him about my dilema. I explained to him what was occurring and he said that this was normal. He stated that when he installs the seal, he pushes it to the bottom of the valve stem (helps hold the valve in place) and then installs the spring, cap and keepers. Once the engine starts, the seal will be pushed up to the cap and the seal is made. Whether the o-ring actually positions itself in the cap, he wasn't sure.
New dilema, which method do I select?

 

[GTJIM (R.I.P.)]

In the Groove!

With due deference to Dennis - Opel (well GM ...) designed the "o"-ring to fit into the groove on the stem that is up inside the retainer when installed correctly. Let's look at the reason that the "o"-ring is there: It seals the stem to the retainer so that oil which collects on top of the retainer does not run down past the collets then down the valve stem and onto the top of the valve guide. The sheet metal "Umbrella" or "Hat" between the retainer and the top of the spring is also an important part of this oil control system.

Now, if the "o"-ring is put on first and then just pushed up by the top of the valve guide during operation, it will not get seated up inside the retainer and located into the groove. The best that will happen is that it will seal against the bottom of the retainer - and may even be chewed up by the continual contact with the top of the valve guide.

I have always put it on after the retainer with the spring compressed down far enough ( with my trusty Sykes-Pickavant spring compressor! ) to fit the "o"-ring down into the groove. I slide the ring on with a dab of EP90 diff oil to lubricate its travel down the valve stem over the collet groove and to lube its travel down into the retainer as the spring compressor is released after the collets are fitted. The "o"-ring groove is positioned so that the collets actually touch the top of the ring and are held in place by being caught between the ring and the top of the collet groove before the retainer is released back into position - I have found. But the EP90 does help hold everything in place till the spring compressor is removed.

WoW! Such a tiny part and soooo much explanation.

 

[jeff denton]

I'm certain I did mine the way I described, always have since the goof the first time taught me a lesson. Dennis' way doesn't sound right.
Where are all the experts when you need them?
Help!!!

 

[nobody]

I've always done it the way Dennis described. One note on it is that I rarely do a stock lift so there is little else it can do but go to where it is supposed to.

 

[GTJIM (R.I.P.)]

Heh! Heh!

Starting to look like the GT engine removal discussion!

JPiper, I suggest you flip a coin ......

 

[Hiro]

this is the right way

You have to do it this way: leave the o-ring off, put the spring on, then the retainer, then compress it way down (the hard part) so you can then put the o-ring in its groove, then put the keepers in their groove, and carefully release the retainer.

yes this is the right method with the stock Opel valves.
no need to compress the spring too much:
lube the stem, put the O-ring and push the keepers in place,
then the O-ring will automatically seat in its groove.
HTH,
Hiro.

 

[jpiper]

Hey guys;
Thanks for your input. So far its 3 for installing the o-ring after the spring is installed and 2 for before the spring is installed. I have to wait for the weekend anyway to start back at the head so lets see how many more people will weigh in on the subject.

 

[kwilford]

That certainly seems to be the way the FSM photo shows (GTJim's photo). And I revised my earlier comments about which valve used the positive seal (see my post above)
Tell us how you make out. And I will have to look at the heads from the machine shop to see how they assembled the valves. BEFORE I put them on the finished engines!

 

[GTJIM (R.I.P.)]

Fsm

This Note is beside the picture I uploaded

Valve Stem Oil Seal Replacement

NOTE: To avoid damage to the oil seal ring, first compress spring together with oil deflector and valve seat (?? must mean spring retainer ??) then place the oil seal ring in the valve stem groove.

[UnQuote]

 

[jpiper]

Jim;
Can I ask you which manual you have? In my manual the info isn't as detailed as yours. I have a Chilton and two GM Shop manuals. Looks like you have a better book.

 

[baz]

jim there is a copy of the 1973 factory service manual here
http://opelgt.com/sdownload/index.php?cid=2
you can read or download it from there or if you pm me i can send the full file to you on win messenger

 

[GTJIM (R.I.P.)]

Best Yet!

Baz, I have a 1969 and a 1972 Opel FSM thanks and know about the downloadable 1973 one on this site. Thanks for the info.

Jpiper, The picture and quote I uploaded was off my hard disc. When I went looking for the original it is not in either of my OPel FSMs - It came from my Holden Torana 1900cc Engine Service Manual Supplement!
Holden used the Opel CIH motor from 1975-79 as a four cylinder "economy" engine. The supplement is so detailed because very few people had ever seen an Opel Cam-In-Head motor before in the neck of the woods.
It is a pictorial and text step-by-step everything for the Opel motor that was obviously printed to inform us locals of everything about this motor - to the finest detail!

Sigh!: I supose I am going to have to scan it all and upload it - Eh? Baz!

Pic of cover attached:

 

[jpiper]

Jim;
Maybe all that is required is to scan those items that are not covered in the Opel Shop manuals? Have never seen that book before.
I am going to utilize your method this weekend. Thanks.

 

[GTJIM (R.I.P.)]

Here is a Couple of Interest

Jim;
Maybe all that is required is to scan those items that are not covered in the Opel Shop manuals?

Three pages from the Holden 1900 Opel Motor FSM:
The one about fitting valve stem seals and two others about the tool and method used to check the chain tensioner.