Hey guys, First off il start by saying i dont know a whole lot about heads, I've never overhauled heads, nor have i done anything with them until I got myself into an ls.

I had a set of prc 227 cc heads installed (with cam, headers, intake, exhaust etc..) and ran it for 2 seasons (approx 10,000kms total) and then last season I installed a single 78mm turbo to the setup. The car ran awesome all season long, and decided to rip the car down this winter due to some blowby issues. Upon inspection of the heads i noticed that in between the intake and exhaust valve seems to be burnt away, not on just one cyl, but all cyl's. heres some pics.. Wondering if the heads are pretty well scrap or what?

Any info would be good.

 

Is there any material missing between the valves? I had a set of AFR heads that had material missing, but the machine shop said they pressure tested fine. What you are seeing could just be carbon buildup.

 

to me it looks like the material is gone. if so they are easily fixed by a machine shop or if they check out ok you can probably run them

 

AFR heads are notorious for that. Pretty much every used set in the classified section have that material missing.

 

Only negative to this is that the sharp edges will become a hot spot which WILL initiate detonation. Very bad for a turbo application.
Bigger valves mandate bigger valveseats equals little or no material in between.
I would trade you some new GM 799s CNC'd with hollow LS6 valves just to help ya out........Kidding
Those heads sure are nice....bet it makes loads of power.

 

I wonder why AFR and PRC do that and not use interlocking seats, like TFS does...

 

Good question. Maybe Ton Mamo's new company will use rhem on their heads.