Ok. So I've been thinking... maybe I've got a lot of carbon buildup in the motor. It seems to run hot, and I know there's crap in the cooling system because last time I cleaned it out with vinegar.. a lot of crap came out and I KNOW there's got to be some more left. The head could use some porting. :D and it will receive some porting.

So what did I do? Well I got bored and I pulled the head off. haha. Took me about 25 minutes to pull it just because getting everything else out of the way and making sure I kept the push rods and everything in order was important.

And boy is it a good thing that I pulled the head. It was CAKED with carbon. The valves are perfectly seated (I already did a leak down test) but they are COVERED in carbon. Not only that, but the water ports on the head were all almost completely closed. So... the work begins.

Here's what I'm starting with. Picture overload, but I wanted to document it all. I've put it next to the big valve Metro head I have for my 1360 build. The large intake valves on my 998 head are at least 2mm smaller than the little exhaust valves on my metro head. haha.

Pictures

Here's the car sitting in the garage



And the block.. ick


Check out those water ports... plenty of flow, right? ugh...


And... the head. Man oh man.


Ports on the head are just as bad





Caked on in the chamber



Here's the Metro head so you can see the valve size difference, and how it SHOULD look.





Comparison of the two heads. Nasty 998 head on the right


And the ports on the 998... notice the size of the gasket, and the size of the ports? the gasket is matched to the aftermarket headers I have... looks like some porting is in store. :D



Anyway... Stay tuned because the girlfriend is busy all day tomorrow which means I'll be playing with my mini.... lol

 

A couple of things.......since you are cleaning the cylinder head completely, I would pop out the freeze plugs on the block as well and run some long brushes thru it. As for porting the head, be sure to do the intake as well so they match. If you haven't already invest in a colortune. This is a tool where you can see the color of your combustion while the engine is running. This will help with keeping the carbon build up down along with running at least a mid-grade fuel.

 

Sorry to disappoint you, but your head is NOT caked in carbon - at least in the valve area - those look very good actually.....it does look like you're burning some oil tho....

Your cooling system OTOH is fully crapped up and needs a thorough cleaning!

What are you gonna do here, just clean it up and reinstall for now, or are you ready to drop in the new motor?

If it were mine, I'd make sure the cooling system is completely cleaned out, and since you're gonna replace the motor soon anyway, just clean up the head and reinstall it.

 

Well I wish I could have taken a better picture to show how bad it really was. It was almost 1mm thick in some places and it was beginning to make its own shelf. I should have taken a picture of it half way through cleaning so you could see the thickness. The buildup on the wall was starting to encroach on the valve clearance.

Anyway. The cooling system will be completely gone through before the head goes on. Greatest news is that the decks are almost perfectly flat apart from a few burrs around the outer edge of the deck which are easily fixed.

I'll give more pictures when it's all finished before re-installed.