Took apart a head I purchased and trying to find out whats going on here with 2 of the exhaust valves

 

I was told it was from m1 fuel so I posted here since any1 with experience would be in here

 

Running no filter, is that intake or exh side?

 

Sometimes reading gets tough when ders dem picturizations up.

Looks like possible detonation..... Funky for sure.

 

Just the exhaust side on 2 valves in diff cylinders

 

My guess was detonation from to much exhaust heat and the valves were switched around, these are rev xvt valves if that helps any1

 

The pitting from corrosion?

 

its not all around the valve just where i took the pics

 

They look as if they were "refurbished" it's a few bucks to replace the effected ones and if that's worth your peace of mind it's worth it.

 

i will probably replace them all with something better anyway and go oversized on the intakes. i want to replace the guides, its a alaniz head and has oem guides cut down

 

Turbo motor? Looks like it was from antilag

 

all motor i bought it from pelonbuilt on here, the one in the tbmotorworx 350whp thread

 

Exhaust valve would be CLOSED when combustion is occurring, detonation occurs AFTER spark plug is lit.

My guess would be foreign object...possibly a spark plug losing a portion of its tip or porcelain during normal running.

 

Just a question but what is that? I circled it with RED.

 

is that a crack??

 

That's kind of where I was going with it.

 

just a scratch with the light hitting it at the right angle. anyone know if the new rev valves are the same as the old xvt valves? looking for a price on 2 replacements before i decided to re do the head over.

 

 

Yea brain fart on my part, I would think damaged wouldn't only be on the back of the valve then in one section if it was something foreign. I think it was heat related though, big stroke 17:1 comp is going to need to get a lot of exhaust gas out and fast. Bouncing off the limiter maybe , either way will probably upgrade to some oversized exhaust inconel valves.

 

My guess would be a corrosive fuel like you were told. I don't see how a foreign object would damage only that part of the valve and none of the combustion chamber.

 

foreign objects have a tendency to perform magic at 10,000 rpm.

 

Anybody have any issues at all with rev valves? If I don't need to change the intakes, I will leave them and either ferrea or supertech on the exhaust.

 

Valves are cheap all things considered. Just replace all of them. Another 140 or so likes on my FB page and I'm giving another set away. We have given about 10 sets this year.

 

5 angle was already done on the intake side didn't really want to mess with that side except for the guides, andi already liked u guys lol. Awesome work btw.

 

If you do guides you need another valve job.