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From: gvcormack@watmum.UUCP (Gordon V. Cormack)
Newsgroups: net.auto.tech
Subject: Re: Oil burning and piston rings
Message-ID: <317@watmum.UUCP>
Date: Mon, 4-Nov-85 10:33:27 EST
Article-I.D.: watmum.317
Posted: Mon Nov  4 10:33:27 1985
Date-Received: Tue, 5-Nov-85 22:31:33 EST
References: <314@g.cs.cmu.edu.ARPA> <187@cdstar.UUCP> <289@watmum.UUCP> <518@ttidcb.UUCP>
Organization: U of Waterloo, Ontario
Lines: 43

It is not hard to replace the piston rings at home.  You need a
socket set, a torque wrench, a ring compressor, and drive-on ramps
(or a jack and axle stands).

To change the rings you must remove the oil pan and cylinder head.
The oil pan can usually be removed with the engine in the car.
If this is the case, you can do the whole job with engine-in-car.
In order to remove the head you must either disconnect the manifolds
from the head, or disconnect the exhaust pipe and hoses and remove
the head/manifolds/carb as a unit. 

Disconnect the bolts that hold the piston rods to the crankshaft.
Then remove the lower half of the bearing and push the piston and rod
out the top of the engine.  Remember which side of the piston faces
the front of the car, and replace the bearing half on the same piston
rod.

Remove the rings from the piston and scrape all traces of carbon from
the grooves.  I use a broken ring as a scraper.  Install new rings on
the pistons, oil them, and put them back in the cylinders using a
ring compressor.  Replace the piston-rod bearings on the crankshaft,
replace the oil pan, replace the head (using a torque wrench and a
new gasket).  Fill the crankcase with oil and you are done.

How long does it take?  The last 2 cars I did at home (a 76
Mazda 808 and a 76 Honda Civic) took about 8 hours each.
(these are estimates only; your time may vary due to ... ...).
In each case the oil consumption went from  >> 1 qt/200 mi to
<< 1 qt/2000 mi.  Each cost << $100 in parts.


What else might you do while you have the engine apart?  You might
take the head to an auto store or machinist to have the valves ground.
I would do this only if there is evidence of faulty valves.  You
might want to replace the connecting rod bearings.  These cost $20
to $50.  Before disconnecting them, try to wiggle them up and down.
If there is a ticking noise caused by movement, replace them.
Many people say you must hone the cylinders before replacing the
pistons.  I think honing is not necessary in most cases, and is not
a good idea in the home environment.  Honing creates metal particles
that can easily permeate (and destroy) your engine.  Also, if
you aren't careful, you can easily make your cylinders too big, requiring
oversized pistons and rings.