Buckaroo Banzi

Is the below statment true?
"The ceramics are not all smooth in the exhaust ports at the exit junction...you can't sand it because it is cast that way....that is the way some (not all) of them are...if it is rough, it is not from the exhaust heat, because it does not get hot enough to melt ceramics...it is from the manufacturing process."

My understanding is the exhaust ports are to be as smooth as a baby's behind.
No rough spots and no dimples.

rebuilt head has rough spots and dimples in exhaust ports.


thanks,

Marks951

ceramic material melts at a REALLY high tempature.....try 1125 degrees CELSIUS, but pieces can break off.

theedge

The ceramic should be smooth. That head is probably junk now.

RolexNJ

Bump, the liners need to be smooth and totally intact too. When we pulled the engine out of my car, we inspected the existing head. I couldn't believe it, but with only 30K original miles on it, the ceramic liners had 2 cracks, yikes!

Anyway the 951 heads are a dime a dozen, you can find them in junk yards cheap.

Brian: It must be cold as hell where you are now, right? Its damn cold here. I hate this crap! Sorry for the OT.

theedge

Sunny and clear and apparently cold Im a cold weather person in a big way

RolexNJ

You can keep it, yuk! I want warm weather... is it spring already, eh?

theedge

There isnt much winter in Vancouver itself, its all on the hills

a4944

You think that's bad, check out this ...



Want to trade?

Mark

RolexNJ

That's a prime example Mark. Can you say junk?

Bill

The ceramics should not be sanded, ported, filed, touched. Once the ceramic coating cracks and starts chipping as we see in this picture, replacement of the head is required. If you go to the Lindsey Racing web site, they note that prior to headwork the ceramics will be inspected. Should any cracking or chipping be found, the head can not be rebuilt.

RolexNJ

Bump, I went thru this with them exactly, so I know. Hence why I said 951 are cheap to get.

Buckaroo Banzi

Your comments please??

lart951

The one in top looks fine to me but the lower picture is that a crack?

Buckaroo Banzi

I think it the start of a crack or flaking? It feels rough to the touch but not jagged as you might expect from a crack..

lart951

I had a head that I pulled out of a car with 146k miles and the ceramic had a big chunck missing, the weird thing is that the turbo had no damage watsoever and neither the cylinder walls were damaged, has anybody ever documented the fact that little pieces of ceramic could damage the turbo or the cylinder walls? .