The V8 Owners Forum -

Hi
I'm looking for some experienced recommendations.

I've got a 3.9 hot wire Range Rover Engine in my Morgan +8, about 8 years ago (25k miles) I fitted 2 heads along with a (Crane) high lift cam & double valve springs, over the last year or so I have been burning oil which has been getting progressively worse,

I decided to pull the heads as all the checks & symptoms were pointing to the valve stem seals, which proved to be the case. When the heads were stripped i found over half of the seals had became dislodged! The only anomaly I have discovered is the ordinary stem seals had a blue rubber insert's the ones removed from the stage 2 heads was green. So the questions I have are
1. Is this a common occurrence for this engine?
2. Is there a significance aligned to the rubber colour
3. Is it possible the (Crane) double springs could be dislodging the stem seals from the valve guide .
4. Anything else?
Thanks for any help anyone can give
Cheers
Smudge

Smudge!
Dislodged stem seals wont help.
I've never seen Green ones though?
If the double valve springs have pulled the seals off it means they are touching the seals which is unlikely.

If the seals have pulled off the valve guides they must have been loose to start with or not fully pushed home when fitted?

Lets look at why the engine could be burning oil?
Do you see oil smoke from the exhaust when decellerating?

I have built many an early RV8 which only has rubber washers for valve stem seals. These break up and end up in the sump after not many miles.

When the oil from the rocker shafts seeps out to lube the bits it needs to it is unlikely that the oil will get right onto the valve stems.

But there is a way that the oil can reach the valve stems. This is when the rocker shafts / rocker gear are worn to excess and too much oil runs out and fills the heads to the point where the oil level in the heads builds up to a point where it meets the vlave stems. This is often accompanied by nuisance oil leaks from the rear corners of the rocker covers ?

To observe the amount of oil that is being discharged from the rocker gear you need to run the enigne with the rocker covers removed.
This will make a mess with oil being flicked all over the place. But its the simple way to see just how much oil is being dumped from the rocker assemblies on each head.

When the engine is hot and at idle you should only see the odd drop of oil from the rocker gear. Just enough to make sure that the moving parts get lubed. If you see that oil is building up in the head before it can drain away then your rocker gear is worn out?

Are you sure the valve spring retainers are not smacking the stem seals on full lift due to your performance cams increased lift ? never known the later seals to just break up or become dislodged 1st time for everything I guess

At least three of the engines that I've built have had to have the valve guides machined down in order to stop the valve spring retainer knocking the crap out of the oil seal!

sidecar wrote:At least three of the engines that I've built have had to have the valve guides machined down in order to stop the valve spring retainer knocking the crap out of the oil seal!

I mounted my guides so with my chosen cam lift I have 2mm approx before the steel valve caps kiss the comp cams seals, stock Rover heads are not never accommodating lift wise with stock guide heights its why TVR pressed the guides into the already restricted throat further because they installed punchier cams

I've never seen the stem seals come adrift. In fact, they can be a right tw*t to get off!

Chris.

ChrisJC wrote:I've never seen the stem seals come adrift. In fact, they can be a right tw*t to get off!

Chris.

Agreed they was introduced around the emission clamp down/Cat era for that very reason

Thanks for all the posts, after I fitted the new oil seals ( using a drill press) Ive came to the conclusion the seals were not fully home as the remaining ones came off easily with a screwdriver , yet i have had to remove old ones in the past with mole grips
cheers