All I know is that valve seals are getting crushed

[stopintime]

Last year a spring, supposedly from a valve seal, appeared in my oil.

Now my mechanic reports damaged/crushed seals. Not sure, but I think he said all of them...
He says the rockers hit the seals.

Recently modified S2R 800, port & polish, 900 cams, larger intake valves and Pistal guides(unknown specs).
Chocolate/grey spark plugs, runs great, ~ a quart oil each ~3k miles.

WTF??

Is there a way to modify valve guides? (if they are too large/long)

Thoughts?

[ducpainter]

It would be easier to modify them before they were installed.

Who installed your guides?

[stopintime]

It would be easier to modify them before they were installed.

Who installed your guides?

Kämna. Also inspected the heads after the surprise seal spring discovery...

[Speeddog]

900 cams have ~1mm more lift than the 800 cams, so that ate up a bit of room.
And perhaps the guides are a bit long.

Indeed, tough to modify guides once they're installed.

By the time you've got the heads stripped down far enough to modify the guides, it'd actually be easier to just push in some new/correct ones.
Requires a re-cut of the valve seats, and then re-shimming the valves.

[ducpainter]

Nick is right.

Far easier to just bite the bullet and replace them...

or run them like they are with new seals occasionally until they wear out.

[Speeddog]

BTW, which 900 cams?

ie, ST2?

Or Kaemna or?

My previous comment on lift is only for the OEM 900ie and ST2 cams... I've no idea what Kaemna's cams are like.

[stopintime]

BTW, which 900 cams?

ie, ST2?

Or Kaemna or?

My previous comment on lift is only for the OEM 900ie and ST2 cams... I've no idea what Kaemna's cams are like.

900ie

[stopintime]

Talked to Kämna.

What they normally do on heavily tuned engines is to ditch the seals and let the engines use a little oil - good for cooling.
It doesn't do any harm in the combustion chamber if it's high compression and pushed hard enough (revs a.s.o.)
The quality of the guides is good enough to not let too much oil through (I guess that means they must be replaced more often to ensure they are fresh though)

I'm not 100% sure this is the end of this story - but if nothing else, it's interesting

[brad black]

guzzis don't run any stem seals.  well, didn't later stuff probably does.

you could grind the underneath of the rockers.

[stopintime]

guzzis don't run any stem seals.  well, didn't later stuff probably does.

you could grind the underneath of the rockers.

I'll stop by Kämna later. They'll inspect and repair/modify if needed.

Thanks for the tip

[gatorgrizz27]

I haven't had to replace the guides on a Ducati head yet, but have run into an issue on other motors that would be hard to spot if you weren't looking for it.  If the guides aren't tight enough in the heads, the friction from the valves due to scoring or carbon buildup can actually pull the guides up through the heads a bit, causing the rockers to whack them eventually.  Ducati guides may have a flange at the bottom to prevent this but I'm not sure.  If it is all 4 seals though, it is likely from the larger cams.

[stopintime]

............
If it is all 4 seals though, it is likely from the larger cams.

It is all four, so I'd think the cams are responsible, yes.

It's SBK/4valve seals - don't know if that matters - if they are longer/higher it could, but I don't know if they are.

[stopintime]

.........

you could grind the underneath of the rockers.

Done. No more heavy oil consumption.

New exhaust valve guides. Lots of wear on those.

[suzyj]

Awesome. I still haven't gotten around to installing valve guides in mine. I've actually been toying with having the heads reamed out for 8mm guides, as then I have a much wider range of valves than with 7mm guides. I think the 8mm guides are shorter, too.

In the meantime I've bought a spare pair of stock heads (one with 7mm guides, and one with 8mm, but that's just what was available) to get the bike back on the road.

[stopintime]

Machining from 7 to 8 mm is advanced tech, so if you want 8 mm and have an 8 mm head - use that   That would be from a non-'07 803cc bike??