GhostHacker

Hey guys I'm replacing a bunch a stuff while I'm off and thought I'd post pics of my head and pistons and see if anyone has any advice. Other wise its gonna be scraped clean and get new gaskets.

I am also doing new timing belts, rollers, and water pump.

Clint's 944

Make sure you check the head for any corrosion, BTDT. Maybe get a port and polish while it's off?
Not sure if you know but, Seafoam will clean up the piston tops nice.
How many miles on the motor?

GhostHacker

about 100k. A friend told me I should take it to a machine shop but I'm thinking I'll save the money, throw the head back on and save up for a motor swap instead of a front of engine service.

Techno Duck

I would take the cylinder head to a machine shop, have them clean it in an acid bath / steam clean it. Get new valve guides and stem seals and maybe have them do a valve job if you want. Should not cost more than $200 to have that all done, you will get the cylinder head back and it will look brand new.

Just curious, how did you go about taking the cylinder head off..did you take it off with the headers or did you leave them connected to the rest of the exhaust? I was lucky and all of my exhaust studs came out easily by either double nutting or just spinning the nut that was already on there. Getting the head back on with the headers in place took some juggling and an extra set of hands..but was very do-able.

alxdgr8

I took the manifolds off when I pulled mine off last week. I actually just removed the stud nuts, not the studs to take mine off. I did drop the entire exhaust system to do it though. Was a sqeeze, but wasn't bad.

Darwantae951

What are the tiny "X"s on the tops of the pistons?

-Darwin

GhostHacker

Actually I slid the headers off the studs each one a little at time till they came off then I pulled the head out. Seemed pretty easy actually.

apierce918

i think they are just an indicator for the direction they go during assembly

Mongo

second the solvent bath that Jon said. I had my block dipped along with my head. When you have the cylinder head rebuilt, be sure they put silicon bronze valve guides in. If you want to improve flow and combustion a little bit, I suggest having a 3-angle valve grind done. While this did NOTHING to gain HP on my car, the car has better air flow (less turbulence) into the cylinders, therefore running a tad bit smoother. If you're feeling daring. Ask your machine shop to shave your head about 0.0040" (forty-thousandths) to up your compression.

Your engine from the looks of those pictures has normal wear and tear with the use of 87 octane fuel in its life. Poor quality gas usually causes severe carbon buildup on pistons.

inactiveuser92616

I am sorry, but the 87 octane thing is incorrect. The lower the octane, the more completely the fuel will burn, and the less unburned carbon deposits will be left. Running premium in an engine that doesnt require it could, however, eventually leave deposits. Just setting the record straight.

GhostHacker

I run 93 from the Chevron next to my house. I got a quote of 250 for a cleanup and new valve guides from one shop but they have a waiting list till the 12th. ZIMZ wants 500-1000 and they say that it'll probably need 4 to 8 need valves

Techno Duck

Honestly speaking, any machine shop that can do a Chevy cylinder head can do a 944 cylinder head. There is nothing special about them.

I also would not shave the head unless you need to. A head can only get decked so many times before you go past the factory recommended amount. I was lucky that my cylinder head required no milling / decking / shaving (whatever you want to call it).

A 3 or 5 angle valve job is nice to have done for the extra $50-75 it will probably cost you. It probably didnt do anything to increase the performance of my car but i would feel worse if i didnt spend the extra $50 bucks while i had the head off anyhow.

Mongo

Very true Patrat...but so can the quality of the gas.....been to Arco lately? Some gas companies have poor quality gas with minerals in it that are capable of leaving deposits in the cylinders such as above. I find it interesting on my last motor how it had zero deposits in the cylinder but ran 91 octane gas at the same time.

Tearing apart the most recent block I put into my car and a verbal background of that engine provided evidence that this guy used very poor quality regular gas (the person who sold the block to me said so).

Not sure but if I'm using 91 octane from Chevron, perhaps the Techron added in the gas has something to do with my clean combustion chambers...

Zero10

How much oil did that motor use?
If you say none I will be stunned. The edges of the pistons look very clean.

Other than that, clean out those cylinders before you forget. Starting the motor with that grit in there would be bad, mmkay?