Replacing piston rings, top end service

[sacwac]

Piston ring and cylinder head service. Good results, not for the inexperienced! Pics at the end.

Disassembly:
The air cleaner, carburetor, and vacuum hoses need to be removed. The timing belt cover was removed, and the tension pulley was adjusted to give maximum slack on the belt. The belt was then slipped off of the cam pulley. The distributor, and fuel pump were removed, as well as the alternator bracket. The accessory belt was also removed. The manifold bolts were removed from the head, and the down pipe disconnected at the catalytic converter. The manifold and down pipe assembly were then removed.

Head removal:
The valve cover was removed, exposing the oily mess inside. Next, the rocker arm shaft was removed, via the five bolts. Loosen each bolt a little at a time. The camshaft was then removed, by removing the holding brackets. The front oil seal and bearing stuck to the head, so minor persuasion was needed to remove camshaft. The ten cylinder head bolts were then loosened a tiny bit, one by one. Follow the loosening order in the factory service manual. The cylinder head did not want to lift off of the block with out lots of help from a large pry bar. Care was taken not to scratch any surfaces with the pry bar. When the head finally lifted off, half of the head gasket stuck to the block, and the other half to the head. Most of the coolant ports in the gasket were nearly plugged with what looked like flaky rust. Some oil from the cylinder head leaked out onto the pistons. Solvent was used to remove the carbon at the top of the cylinder walls. A ridge reamer was not needed.

Oil pan removal:
The oil pan gasket was leaking badly, this was a great time to fix that. There are about thirteen bolts on the oil pan, with the ones in the rear, over the front differential being the most difficult to reach. Finding and removing all these little bolts takes a long time. It only took one tap with a mallet to break the seal on the oil pan. The sway bar needs to be out of the way in order to slide the oil pan out. The two brackets on the sway bar were removed, thus dropping the bar low enough for the pan to slide out. Care was taken to not ding the oil sump while removing the pan. The oil sump was then removed.

Piston removal:
The connecting rod nuts were then loosened, a little bit at a time. Pistons were removed one at a time, using a long socket, while the piston was even with the top of the block. With the connecting rod bracket removed, the piston was then removed by pushing on the connecting rod bolts. Since the pistons were at the top, they did not have to be pushed very far. Once the compression rings are exposed, the piston can be removed by hand. The engine was then hand cranked to place the other two pistons at the top. All the parts were kept in order, to ensure proper reassembly.

Piston cleaning and ring replacement.
The carbon buildup on the pistons was extremely tough, and was removed using a dremel with a wire wheel. Snap ring pliers were used to expand the old compression rings. Once expanded, the compression rings lifted off the piston. The oil ring is actually three rings, one wavy ring, and two thin retaining rings. These are made from very thin metal, and are easy to remove by hand. One of the old compression rings was then broken, and used to clean the ring grooves. The snap ring pliers were also used to expand the new rings. The new oil ring was installed, and then the next compression ring, and finally, the top ring.

Deglazing the cylinder walls:
Since all the previous parts were removed, the engine was much lighter, and was lifted out by hand. (Follow the steps for engine removal). The crankshaft was removed as well. The block was taken to a local mechanic to have the cylinders de-glazed. I had no desire to use my engine block as a guinea pig for learning how to service the cylinders. The mechanic had all the proper tools, as well as the experience of doing this before. For not much more than the cost of renting or buying a hone, the mechanic was able to measure the clearances, and service the cylinders. They needed no re-boring, only de-glazing. The connecting rod and crankshaft bushings were all found to be in excellent condition, so they were reused. The engine block was then washed, so that none of the metal bits made it back into the engine. Re-install the engine block. You might not care to remove the block if the cylinders are not being de-glazed.

Cylinder head service:
The valves had some serious oil buildup on them, from leaking oil seals and guides. Each valve assembly needs to be removed. A valve spring compressor was rented for this task. The "C" shaped compressor was used, the kind that prevents the valve from opening while compressing the spring. This tool is self explanatory, once you see it. There are several small parts that need to be kept track of, such as the tiny spring retainers, and the shims at the bottom of the springs. The head and valves had heavy carbon buildup. Some of the valves were slightly warped; all had damage to the surfaces, such as deep pits and bits of carbon on the seats. New valves, springs, guides, and oil seals were purchased. The completely disassembled head was then taken to a mechanic for service. Once again, I did not want to learn how to do my first top end job on my own cylinder head. The head was bead blasted, resurfaced for the 0.004" warp, the valve guides were replaced, and the valve seats were resurfaced. Well worth the fees. The cylinder head looked brand new. After receiving the cleaned head from the mechanic, the valves were then installed. Re-assembly of each valve goes fairly quickly, and painlessly.

Cylinder head installation:
The head was then installed onto the block. Care was taken to gradually tighten the bolts. Then, the camshaft was installed, next the rocker arms. The rocker arm shaft was easy to install after loosening the screws for the valve clearances. Those clearances needed adjusting anyway. The camshaft pulley was installed, and the timing belt slipped back onto the teeth. The crankshaft and camshaft need to be aligned properly before installing the timing belt.

Piston install: (do this before head install, duh!)
A piston ring compressor was used, if re-using parts make sure to use them exactly how they came off the engine. The pistons went back in up to the middle ring. The oil rings went in easily. Use plenty of new oil when tapping the new pistons in.

Install the rest:
After the head installation, the process is the opposite of removal.


The factory service manual documents the piston ring replacement, and head servicing really well, there were no surprises during this entire ordeal. I would recommend having a local mechanic do the drilling, blasting, resurfacing, and valve guide replacement. It helps to be good friends with a mechanic who has a full service shop. You could perform these tasks yourself, but taking the bare parts to a shop is very cost effective. The rest of the bolt turning can be done yourself.

After all the parts were installed, I performed a carburetor tune up. This tercel runs like it's brand new, the idle is perfectly smooth and you can barely tell it's running. The engine is much quieter, burns no more oil, and seems to perform much better.

No more typing... I'm done. There are probably some steps I left out. I know this whole thing might seem over simplified, but it would take forever to document each step in great detail, and only the experienced should be performing these tasks anyway. I took pictures; they should be attached, or linked to geocities. These pics had to be resized just to fit all of them on the geocities server. That's why they are tiny.

http://www.geocities.com/sacwac123/terc ... head/1.jpg
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[takza]

Wondering how many miles this engine had on it and what was the oil use?

Good to hear the job went OK. Good writeup.

Maybe you can judge the condition of the cylinders by the height of the ridge at the top?

[sacwac]

takza, this engine has 203,000 miles (326.000KM) on it. The oil use is hard to pinpoint, because it was both leaking at the pan gakset, and burning.

No driving, would result in about 1qt per month. Nice puddle on the ground.
Long trip, 500mi, I would put 3qts of oil in.

Most of the valves had oil sludge on them, at least a couple of cubic centimeters worth, each.

The oil consumption was not that big of deal before, as this car is my backup transportation, and it sees about 3,000mi per year. Just had the free time to fix it.

[GTSSportCoupe]

Thanks for the writeup and pics sacwac; that is awesome! This site has some pretty serious documentation on it now. Thanks for adding more to a great resource.

[T-Bone]

nice writeup and good pics.

[xirdneh]

No more typing... I'm done. There are probably some steps I left out. I know this whole thing might seem over simplified, but it would take forever to document each step in great detail, and only the experienced should be performing these tasks anyway.

what kind of break-in driving did you do to ensure seating of piston rings?

[shogun]

really nice writeup

im doing some work on my engine soon it will help

[Typrus]

About how much did this cost? I know services are different place-to-place, but I need to do the same thing soon, so I need to know what I have to save.

[MootsMan]

sacwac, you ROCK !! That's a great write-up, and it's something I need to do to my Terc. This will give me something to read over and over again to be sure I know what I'm doing if I decide to attempt it ! Thanks !!

[Typrus]

http://www.importperformanceparts.net/

Shows performance bearings available, a HV Oil pump available, and the basic re-build kit available.