Monday, October 18, 2010

Lots of Grease Under My Fingernails

With the harmonic balancer failure giving me the excuse to pull Glinda off the road, Victoria and I decided to do some engine re-sealing with the intention of stopping the oil leaks that are making a mess of the engine compartment and the pavement wherever she’s parked. In preparation for this project, I placed a call to the Corvair Ranch and ordered valve cover gaskets and a rear crank seal. I already have the oil pan, oil filter adapter, and crankcase cover gaskets.

Victoria was busy babysitting all day Saturday, so I was on my own. I pushed the car into the garage and put Glinda’s rear end up on jackstands. Following the service manual’s instructions, I did the minimum to remove the harmonic balancer from the end of the crank. The harmonic balance construction consists of two concentric rings with a bonded ring of rubber connecting the two. This breakage was, like most balancer failures, a failure of the rubber. I’m afraid the excessive oil all over the engine sped up rubber’s demise. As the rubber failed, the outer ring (fan belt pulley) slipped and slid closer to the engine block causing a grinding away of the ring. It was this sharp, broken edge that had me thinking a metal failure during my initial roadside diagnosis. Fortunately, I have a couple GUP balancers on the shelf and will use the better of the two.

Yesterday, after church, Victoria joined me in the garage and we removed the following: carburetors, alternator, spark plug cables, distributor cap, idler pulley, fuel pump with outlet lines attached, vacuum balance tube, oil cooler cover, top fresh air hose, top engine cover, fan and pulley, crankcase cover, and oil filter adapter. We thoroughly cleaned everything we removed, scraped off old gaskets and RTV, and then set about reassembling. The crankcase cover was first. There’s a windage tray that fits against the block first with its own gasket followed by the cover itself with its matching gasket. We carefully applied a very thin layer of gasket sealer to each gasket and tightened the bolts to 120 in-lbs. This was Victoria’s first experience with a torque wrench, so I walked her through the process of tightening each bolt to half the final torque value following a star pattern followed by using the same pattern to tighten each to the final value. Next was the oil filter adapter which I had her install without my looking over her shoulder. We took off the 90 degree oil filter adapter since it wasn’t necessary (smog equipment was removed by PO) and thus removed another joint that could leak oil.

While she was doing that, I was fashioning a sheetmetal blockoff for the large air hole in the top cover. Chevy’s intention was to allow a controlled amount of air to be routed from the pressurized cavity under the cover to the heater box. This “fresh” air is drawn off prior to being heated by the hot cylinders and heads, so it is used to moderate the hot air that’s drawn from the underside of the engine. Control is via the AIR lever under the dash. It is now considered undesirable to use this feature since it removes air that is necessary to keep the #5 cylinder/head cool. So I simply cut out a piece of sheetmetal and sandwiched, with RTV, between the cover and the hose fitting.

With the cover off, I got out my keyhole saw and attacked the flash between fins of the cylinder heads. When I was through there was lots more light shining through than when I’d started. These heads will flow air more easily keeping things cooler. I also took a wire and cleaned out all the air passages of the oil cooler.

The rest of the parts we’d pulled off then went back on in reverse order. By the end of the evening, all that was left to do on the project was remove and reinstall the oil pan and valve covers with new gaskets, and install the harmonic balancer, fan belt, and air cleaner, lift the engine back into place and screw on the nuts of the engine mount, reinstall the rear engine grill, followed by an oil filter and fill of the crankcase.

I thought that I’d replace the rear crank seal, but after close inspection it looks to be in good, flexible, un-cracked shape, so I’ll save the seal for the inevitble future failure.

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