Author Topic: Valve work (Read 8903 times)

Adam · « **on:** April 10, 2003, 09:35:32 AM »

Hi,
My valve guides leak more than my window seals so I'm thinking of changing them myself- for finantial reasons and for fun. So im wondering about the logistics of such an excersie in general. Can it be done in a home garage? How long could it take? Is it easy or difficult?

While the heads are off maybe I would give them a quick port, are there other things I should change while the heads are off (within reason). Also how likely am I going to get my exaghst off without leaving half the bolt in my heads?

The only major mechanical thing I've done is totally rebuild a manual gearbox so I'm also wondering if I can even do it.

Adam

Brutus · « **Reply #1 on:** April 10, 2003, 07:01:43 PM »

You can do the valve seals without taking the heads off. It requires a special adaptor that fits into the spark plug hole that when connected to compressed air holds the valve up while you replace the seals. I have heard of another way that doesn't necessitate an air compressor. All it involves is a length of soft rope that's fed into the same spark plug hole with the piston at the bottom of its stroke and when there is sufficient rope fed into the hole you then turn the motor over (by hand of course) until the rope is compressed by the piston which then also suspends the valve.
Btw, which seals are you going to use to replce them with. I believe that umbrella seals are the preferred option compared to the standard valve seal.

Adam · « **Reply #2 on:** April 11, 2003, 12:38:27 PM »

Good idea, and thats what I'll do these school holidays.

I don't know what seals I'll use, but they'll prolly be the ones that fit!

Adam

Adam · « **Reply #3 on:** April 27, 2003, 11:27:17 PM »

Well it's finished, and so far has had the desired effect! No start up smoke puff, which would also mean no foul plugs (i hope). I had to make my own valve spring compressor tool as the one I had fell apart after 2 valves. Note- a lever style tool is a lot quicker to use than a corkskrew type- unless its well made. I used the rope method but I found putting a small amount of rope at the TDC of the stroke alowed less valve play than stuffing a lot of rope at the bottom stroke and then cranking it up. As I said I found some nice umbrella seals too, they fit onto the guide boss in addition to the standard flat ring seal which fits onto the valve. The umbrella should only be used on intake valves because of the vacuum effect, it would leave the exaghst valves too dry.
It's a bit of a bastard of a job if u havent got a method and tools sussed out, but its not brain sugery. Only time will tell if I did a good job...

Brutus · « **Reply #4 on:** April 28, 2003, 07:42:57 AM »

Sounds like a good job out of the way. How about posting the part number of the umbrella seals for anyone else considering the same job. Every little bit helps.

Adam · « **Reply #5 on:** April 28, 2003, 07:07:19 PM »

Yea, well it says #460483 on the packet. It's a genuine GM part for '81-'92 V8, but it fit just fine on my '80. There pretty high quality seals, they have 2 metal rings to keep em in place. I got them from Chevparts in Yennora- $25 for 8. If your looking for umbrella seals, take a valve spring with you, the standard ones they sell everwhere were too big for mine.

So far so good, after 24h of standing the vette started clean, and eaiser too.

Adam