Carbon Build-up causing leaky valve seats on local evos?

[scheides]

So, I now know of four local evo owners that had problems with valve seats/seals. First was chukee, but we're pretty sure that was an ever-so-slightly bent valve. Next was Shawn (DoughtCom), then MattD, and now Trevor. Anyone else want to come forward that's down on power and found a cylinder or three to fail a leakdown test?

When we pulled MattD's head off, I was shocked to find about 1-2mm of carbon build-up on top of his pistons, and a nice good thick frosting of it on all of his valves. His motor had 100k miles on it, but look at this:

http://www.scheides.com/albums/MattD-MAPhead-MAPmanis/IMG_2199.sized.jpg

So my question is this: is it possible that carbon build-up is causing these leaky valve seats/seals to occur? Imagine a chunk of carbon built up and not letting the valve seat all the way. The only thing that's weird about that, is that you'd think it would get mashed/swept away over time.

Next question: is it worth (or even possible) to use some sort of cleaning product to get rid of all of this build-up?

Options include:
-seafoam
-Mopar CCC
-AMSOil QuickShot SE (Fuel injector cleaner)
-Wynn's Injector Cleaner

People have been swearing by this stuff on evoM:
http://forums.evolutionm.net/vendor-announcements/384360-wynns-fuel-induction-services.html
but, since its the exhaust valves in trevor's case, is it even going to hit them?

[Kracka]

MCCC is the shit.

[Andrew7dg]

Wow!

I did the sea foam trick on my DSM a ways back. I don't know if it did any good but it left a huge smoke screen and I don't recommend it if you are still running your cat.

E85?... O wait that causes gummy injectors...

[goodhart]

E85 has been known to give engines a good cleaning though.

[scheides]

Trevor has been running E85 for several thousand miles...10k? Idk, i'll let him chime in.

Where would you put the seafoam in this case? In the gas?

What about MCCC, spray it down the spark plug hole, possibly while compressing the valve so it is open, to get the cleaner on the back side of it?

[Matt D.]

The carbon on my pistons came right off with the use of brake cleaner and my fingers. Worked the brake cleaner in with my fingers and then scraped it off with my fingernails. I have no reason to believe that this stuff wouldn't just fall off when the time was right and get stuck on a valve seat. In a couple of the valve recesses on the pistons they were filled in pretty well with carbon, and in that picture you can actually see that the valve hit that carbon.

[Kracka]

The only way I've used MCCC is to spray it in the spark plug hole to let it soak on the piston (could do the same with SeaFoam, always change the oil right after this method) or to spray the MCCC into a vacuum line while the engine is running (you'll need to hold the idle around 3k RPM to keep it from dying).

[t-revzr]

Got about 13,000 miles with E85.. I think Shane looked at the top of the pistons really quick not sure what he told me about them tho...

[Halon]

If they look like that, and you're running E85, I wonder if you don't have some kind of oil leak or something else getting in your combustion chamber. I run E85, my cylinders aren't shiney new clean, but pretty clean overall. Nothing like that!

[turbotalon1g]

They used to make these one cars, I think collectively they were called DSMs there is even a site with VFAQs on them I am sure one included how to use seafoam and MCCC to clean your engine.

Strange.