The V8 Owners Forum -

Hi peeps, would someone be able to do me a favour and tell me on newer style valve guides (with step for stem seals) the diameter of the part where the seal slips over and how long it is???

I have to take my heads off soon and want to see if we have a tool the right size to do them with.

Nobody have a head sitting somewhere with the newer guides fitted? I found out the diameter of the machined part for the neoprene seals should be 0.485" but just need to know the depth from the top of the guide, to the mm would be ok.

The TVR heads are 0.5", I believe they are std LR as most use common a garden LR stem seals.

I have a cutter for them, I use chevy? viton seals that are a little taller (need deeper cut), but that may be down to the shortened guides? sorry I've not really even looked at any LR heads.

If you need a cutter something like this:
.http://cgi.ebay.com/ebaymotors/ws/eBayI ... MEWNX%3AIT
will cut the shoulder for the seal and reduce the guide height if you wish.

Thats the sort of thing, what is the depth- cant be .5" surely?! I was thinking about 8mm or so?

I've got a scrap 4.6 head in the poop pile somewhere. I'll look in about 20 mins Tom.

I have a Real Steel shortened Bullet exhasuts guide here which has the step top for the neoprene seal and the step is 12.45mm diam x 6.05mm

Andrew

Cool, cheers guys, 12.45 makes 0.490" so about right!

Yep!
I measured 12.47 and 6mm high

Pel

Depth may vary a fair bit, cam lift / how much the guides are shortened... I'm sure I've seen a few where the seals seem to sit proud of the guide instead of fully engaging. I just know there is plenty to work with on the heads I tend to play with and prefer the seal that is longer with internal rings to grip better to the guide, so the ones I use are nearly 0.5" high as well, I set the cutter to 12mm depth from the guide tip.

Just measured an old std LR seal and thats only @ .25" high as a comparison.