Thread: V8 Valve Guides

Originally Posted by Pedro_The_Swift

a bottomless rabbit hole even...

but hey,, if the valve seats are bad--

My thoughts exactly, if the valves need replacing then the seats are going to need to be machined anyway... so if the seats need machining

Originally Posted by TheTree

My thoughts exactly, if the valves need replacing then the seats are going to need to be machined anyway... so if the seats need machining

Just fitting new valve guides requires the Valve Seats be recut and lapped in, Regards Frank.

Turns out that bigger valves only really give you extra power in the top end which is not what I am after.

The heads are off and all cylinders bar one look pretty oily.

I took an exhaust valve out and the valve itself looks fine, but it had more play in the guide than the ones on my old heads which had done over 200K !

So they are off to Headworx tomorrow

Steve

Originally Posted by TheTree

Turns out that bigger valves only really give you extra power in the top end which is not what I am after.

The heads are off and all cylinders bar one look pretty oily.

I took an exhaust valve out and the valve itself looks fine, but it had more play in the guide than the ones on my old heads which had done over 200K !

So they are off to Headworx tomorrow

Steve

Was the exhaust valve you removed , from #1 or #7 ?

From the pic i`d be looking at both .

What is the piston top on # 3 looking like not nice and clean i would hope but that`s what the pic suggests .

How much work has it done since last apart and does the carbon just wipe off or is it hard baked ?

Originally Posted by PLR

Was the exhaust valve you removed , from #1 or #7 ?

From the pic i`d be looking at both .

What is the piston top on # 3 looking like not nice and clean i would hope but that`s what the pic suggests .

How much work has it done since last apart and does the carbon just wipe off or is it hard baked ?

The valve was from #1

I only looked at the one so far and assumed they were probably all knackered

The #3 Piston is cleaner than the others, do you think that means coolant getting in?

It's done about 7,000 KMS since it was last apart and the carbon seems hard baked

I'll look a bit more closely tomorrow

Thanks
Steve

Originally Posted by TheTree

The valve was from #1

I only looked at the one so far and assumed they were probably all knackered

The #3 Piston is cleaner than the others, do you think that means coolant getting in?

It's done about 7,000 KMS since it was last apart and the carbon seems hard baked

I'll look a bit more closely tomorrow

Thanks
Steve

It`s probably just the way the picture shows but it look like #1 exhaust head sits lower on the seat and appears to have an odd carbon build up around the edges but as i say could be the pic .

The inlet in # 3 is an unusual colour you`ll notice it is unlike any of the others .
Heat is generally what give the exhaust valves the whitish colour , the inlet in #3 is similar to the exhaust but i doubt the same type of heat has done it .

Don`t know what`s going on can just see you need to look at it closely .

Someone else may have more ideas on it ?

For # 3 what does the exhaust port in behind the valve appear as , is it also clean in comparison to the other exhausts . If it is moisture it won`t be the gasket .

top left chamber is covered in ???
looks like oil glunk,

Much oil gunk in the combustion chambers and oily intake ports

The shiny bits are where no carbon has been deposited since last time it was off, so it doesn't seem there are any issues with coolant.

I took it to headwerks and we pulled a couple of other valves, one was OK but the others were stuffed. The valve themselves seemed fine no stem wear was evident.

He is going to resleeve all the Valve guides and machine the seats then fit commodore stem seals which are a perfect fit.

Thanks to everyone for their help with this issue

Steve