what could cause the head to melt?

[joe sobo]

well, i'm just doing a stock rebuild on my 2g awd, and have the engine at the machine shop getting the crank turned and the block line honed.
so i figured that i would pull the head apart to put new seals and to clean it up when i noticed that one of the intake dividers in the head is completely melted down to nothing.
will i still be able to use the head even on a t-25, or should i find another?
also what i noticed is that this happen only on cyl. number 3, and the rest are great.
the same cyl. also has two different looking intake valves, which tells me that it was a rebuilt head at one time. any knowledgeable advice is welcome
the first pic. is what the other three look like

am i able to just sharpen it some and leave it alone?

 

[TSIfreek]

I would say that head is junk. Never seen that before. I dont have an answer why that happened WTF

 

[joe sobo]

I would say that head is junk. Never seen that before. I dont have an answer why that happened WTF

well, the car ran fine with it on there, and the only reason i noticed it was because i was going to get my porting pro to clean it up some.

 

[No_Skillz]

Doesn't really look like it's melted. More like someone messed with it while rebuilding. If you are sticking to a t25 and don't really care about flow, you can still use it provided damage does not extend down to where the valves mate. Don't bother sharpening it cause it doesn't look like there is much material left.

 

[joe sobo]

i dont think it was done by anyone cause on the cylinder, the two exaust vavles are different from the rest. but it is too thin to sharpen, but the car seemed to run fine with it

 

[turboglenn]

The head looks like some one was going to join the 2 ports together or something.. I ahve never seen anything like that happen from an "accident" before *shrugs*

Well, I know a streetbike guy (has a webpage with all kinds of M/C tech) that uses a technique called "shrink porting" and his theory is similar to that of comparing the 1g head to a 2g head (2g = smaller ports shaped differently, but can supposedly flow better in many areas)

Anyway before i get off track here.... He uses JB weld to fil in ports on engines that are raced all season and it holds up... You could rebuild that area that's missing and then have the head taken care of. taken care of by the mahcinist... I mean it would probably be hard to sell, butif you believe the head is in god working order and trust in Motoman's methods you could have your head back to at least the stock dimensions with his techiques

EDIT: Getting a link for you

Here ya go - If this link doesn't worrk you just have to go to his home page and put in your email addy to sign his guestbook/register with the site. TONS of great info here though, I suggest everyone give it a read
Homework

 

[HIGHPSI4]

If all you are running is a t25, I would just radius that divider a little and let it go. I really doubt you will see any problems flowing low air numbers.

 

[keltalon]

Casting flaw during production. Metal contamination! That head is going to do nothing but cause you problem therefore you need to replace it!

 

[joe sobo]

it is def. not from production, cause when you look in the cyl., you can see where the aluminum is actually melted and stuck to the inside walls of the head port

 

[No_Skillz]

I'm still doubtful that it's accidental melting. Heat damage would radiate and melt evently. Those borders are very well defined, like someone ground it down.