WESCH

Hi
My 68 big block is using a fair amount of oil.
When I pull the ignitor plugs, they have a streak of fresh oil on them.
So, it looks like if the valve shaft seals are leaking.
This are original L71 iron heads with 2.19/1.88 valves.
Whats the procedure to replace the seals ?
I heard that umbrella type seals can be installed without taking the heads off.
Is this true and where do I purchase this seals from.
Sorry for this questions, I'm from Luxembourg in Europe and info on this cars is lousy on this side of the world. ( also to expensive to purchase anything over here ).
Thanks and hapy new year.
Günther :seeya

Paul 75 L82

Any type or brand of valve seals can be installed without pulling the heads. It's really not a hard job. Most hook up an air compressor to the plug hole so the compressed air can hold up the valve after you remove the retainer. I have know some who fish a small rope into the plug hole to fill the clyinlder so the valve won't drop. If in the states you could probally have it done for about $300.

Bill W

I'm going through somehting similar right now. It may be that the valve guides are worn as well as the seals being bad. In that case, replacing only the seals will not help. As stated in the other post, you can replace seals with the heads on the car but not the guides. It would also help to have a leak down test down on the motor to pinpoint where the leak(s) is coming from. Good luck.

Jvette73

I was burning a qt every 3 or 400 miles due to bad valve seals. Fouling plugs too. Fresh oil around the plugs tipped me off to it. Try to get positive seals that lock down around the guide. Some should be avalable that dont require machining to install. Im using positive seals that install over the stock guide diameter. Oil control problem....history. You dont really need the rope method as long as you make sure the piston is at the top when working on that cylinder. The new positive locking seals are tight enough they should hold the valve up while you re-install the spring.

WESCH

Hi, thanks for all answers so far.
So, positive locking seals is the way to go !
Now comes the next problem. Who sells this seals ?
Can I have them from GM , what P/N ?
I don't think that the valve guides are bad. The heads where off about 6000 miles ago for a engine rebuild, but unfortunately, the previous owner only reworked the valve seats, didn't think about the old guide seals.
Is any of the big Vette part sellers ( ZIP ) offering this type seals ?
Thanks again and happy new year. Günther

454Big

Günter,

I think that either PAW in California or Summit sells these seals.
Perhaps you may check their Homepage or shoot them a mail......
The major vendors usually are not specialized enough for these parts.

I order my parts USA direct - works great!

Jvette73

The ones im using are by Crane. pn: 99819. Got em from Jegs.com. Mine is a smallblock though. They should make a similar seal for the bigblock I hope. Also I think there are two different size valve stems on bigblocks.

454Big

Günter,
check out ebay!
I remembered that you were looking for an original 68 Radio - there is one for sale on german Ebay at a reasonable price!

Link is:

http://cgi.ebay.de/aw-cgi/eBayISAPI....tem=1681778103

Good luck!

AlwaysWave

Gunther,

Good luck with your valve seal project :) I have been to Luxemburg a few times :cheers: :cheers:

I just took a radio and speakers out of my 72. It works but not very well. I decided to replace it rather than investigate repair costs. You're welcome to the radio if you want it.

Where did you get the hood? That's the type I want for the 72.

WESCH

Wow, thanks al lot, 454big.
Very nice radio with correct 68 *****.
Will see where this price goes to. Still 5 days on it.
Usually, they raise a lot in price the last day ! :mad
Actually, I got a 70 stereo radio, unfortunately, it has the 70 *****, different from 68. It's also missing the stereo outside amp, but I'm sure, I can hook up a aftermarket amp somehow.
68 aftermarked ***** are around 50 US$ or so.
I also order from the US direct since OPEL/GM asked 1.500 FR LUX ( about 35 US$ for one stamped steel big block valve rocker arm. :mad
I got a complete set ( 16 each ) in the US for that price. :D
Prices for spare American parts are not real over here.
Happy new year. Gunther :seeya

fireball

I called Jegs about ordering seals and they said I needed to know the diameter of my valve stems. Apparently if valves have been replaced, one method is to overbore the guide and install valves with larger stems. Has anyone else encountered this?

WESCH

Yes, that's probably one method, but here are more.
Like installing some kind of a bushing ( normally brass ) or a quick method is to screw in some special tool that wounds some kind of a thread into the guide, this making the hole smaller, than it can be rehoned to the original size. Some people think this is the best method as it allows good lubrication.
I guess your right, measuring the valve stem is the only positive method to assure correct ordering of the seals.
Have a happy new year. Günther :seeya

WESCH

Hi AlwaysWave,
The hood was installed when I got the car.
It does not have the cold air chamber. It's fit is perfect.
I will replace it with a short type L88 hood to be able to reinstall the wiper door assembly, because this is one of the unique features of this early C3.
I might sell this hood, but this will take possibly till next winter.
Sorry for not being of more help of the origine of this hood.
Gunther :seeya

Tom454

To install the "positive" type seals, the tops of the guides need to be machined to match. Check this first before ordering seals. The tool that cuts the "grooves" is called a "knurler". I have been building engines for 36 years (professionally for 30) and I do not use a knurler to repair valve guides... I personally consider this a "Bubba". You end up with half the surface area for valve stem support and a short lived repair. I have $10,000 in valve equipment and I do not own a knurler.... never did. I install bronze valve guide liners when appropriate. Factory Big Block heads and small block heads can vary significantly in design from a valve guide/seat perspectve. BB heads have their own set of problems and unique parts depending on year/application.

WESCH

Hi
I took one valve seal off and very obvious why this car is using oil.
Looking with a mirror through the springs of the other valves shows similar cracked seals.
This are umbrella type seals and the pic shows nicely, where the oil goes through.
So, now I have to order a set of seals and have a job to do.
Thanks for the help.
Günther




[Modified by WESCH, 9:43 AM 1/4/2002]


[Modified by WESCH, 9:44 AM 1/4/2002]

WESCH

Hi 454Big
Thanks a lot for the info on the radio on the German E-bay.
I managed to get it for a very good price for a original 68 stereo with original ***** and stereo amp.
Now I need to get writ of the 70 stereo radio, I purchased previously.
Will offer it at the forum first.
Günther :seeya

WESCH

Hi
Need some help to find positive valve seals that don't require mashining the valve guide boss.
I checked Jeg's online and they don't show anything for big blocks.
I contacetd summitracing and am awaiting a answer.
The valve stem is .370 , should be 3/8 and the guide outside diameter is .635 .
Any idea or P/N.
Thanks, Günther :seeya

Tom454

Have you tried GM # 3998265?
Supposedly, these will snap on to BB pressed in guides without any required machining.... if GM still sells them.

Fit depends on which heads & guides you are working on.

Tom

WESCH

Thanks TOM454
I will check with them here in Luxembourg , but don't have a lot of hope that they can help me.
I did request info by E-mail from a few performance parts sellers, like SUMMIT and am awaiting response in order to order seals.
Thanks for all help. Gunther :seeya