My sister used to own a '71 Skylark back in the day. It was a pretty good car. Now and then a carb choke hiccup or something like that but no major issues. She sold it and bought a slick '64 GTO.
The only problem the GTO ever had was the dreaded starter motor gear gnash but that was fixed with a 2 dollar set of shims.
On another note, an old man here who passed away about 5 years ago was still driving the '71 Skylark he had up until his death. He bought the car new in April of '71. The interior still looked like new with a few rust flecks on the rear bumper.
You could probably get through the engine on this without spending a huge sum unless the cylinders needed to be bored. A check of AutoZone showed a crank kit at 185, full gasket set 50, and a set of rings for 60 or so bucks. Freshen up the cylinder heads for a few hundred, etc.
The last Mitsubishi 4 banger I overhauled set me back a 110 bucks just for a set of rings.
I agree the rings are rusted to the cylinder wall. I also think if the piston is near Top Dead Center or BDC, you are at a mechanical disadvantage when trying to turn the crankshaft. Do not pound on the piston.
I experienced this in the 1960ās and put a rag in the cylinder and filled the cylinder with diesel fuel. Did this for a week then removed the crankshaft vibration damper/pulley and put a big pipe wrench with a long pipe (4 ft.) to break the crank free. Had to file the pipe wrench grooves off the crank afterwards. Today I would take a long rectangular piece of steel and figure out how to attach it to the damper.
The engine ran ok afterwards.
Have you tried to use the starter to break it free (a long shot but maybe.) after soaking, you might try it.
Yeah,We did try the starter before breaking it all down.
Update. Bad weather and work has delayed things but. The engine is out, mounted on motor stand. Turns out I had two stuck pistons, side by side. Freed
the one I had known was stuck no damage, the other piston took some damage, cylinder walls looked fair. Plan is to Hone them with cylinder honer, skip boring it out. Ended up banging the last one out, which was how the rid got damaged
The engine turns with the one piston out, tightly. Marked all pistons prepped to remove them and continue breakdown today.
The piston bump looks like a machining center. Notice the taper machined into the casting. It would allow support from the piston top while machining the skirt.
Congratulations on getting it apart. Another old timer approach (with head on), is to first shoot ample penetrating oil or thinned ATF through the plug holes for a long soak followed by identifying a piston with both valves closed (if at TDC, disconnect the rod), filling it completely with oil or grease, followed by gradual pressurization with a loaded grease gun. This can achieve thousands of pounds of force, but gently, provided the valves and head gasket arenāt too leaky (if a little leaky substitute all grease for oil). If the head is off, and after soaking the pistons, one could try filling the space above a stuck piston with oil, inserting an inverted āsacrificialā piston, and banging on that indirectly through a block of wood, or using a machine press. Remove the ridges prior to this or you wonāt get the ātoolā piston back out if its rings were on.
Donāt leave any ridges, obviously, those will break rings. Even ripple or āswalesā may cause early ring failure and cylinder scoring, and be sure to remove the ridges at the top of the stroke with a ridge reamer. Measure cylinder walls for both taper and out of round with an inside micrometer, there are go-no go specs for determining when to rebore (you only need to do the bad ones). Rust left in pitted cylinder walls is likely to cause premature wear (rouge being iron oxide). Much depends on how much you intend to drive the car. If itās just a hobby car you probably can cut more corners than if you want a reliable daily driver.
The ānippleā in the center is purposely designed in as a means to control detonation to the center of the piston if it occurs. I had almost forgotten about that design until seeing it here. It sure seems to go against everything known about piston design since thenā¦
EDIT- funny, I just went looking to see if I could find more info and found one guy saying that old thoery about detonation was just that and that the center was for machining the piston and bean counters decided not to remove it to save some money. That seems like a stretch to me, to leave that there with potential hot spot etc rather than a designed in feature but there you have it- yet another decades long debateā¦
Weird. Youād think if this was a good way to control detonation others would have used it. Iām more believing the bean counter idea. But who knows?
I guess not control as in stop it but direct it to the center axis so the piston isnāt rocked to one side or the other. So much more science in piston/combustion chamber design since then, plus emissions concerns. I guess either theory has some meritā¦
Main crank bolt is super stuck too, oiled, tried, oiled, heated, oiled, hammered, tried, still stuck. oiled again and sitting longer. I plan to order my overhaul kit soon.
Was hoping to get a single connecting rod of rock auto, the price looked good. But i didnt notice you have to buy the set of 8ā¦ I have found a couple decent replacements on ebay, looking for input on these 2, which should fit better, will either work?
The ones i removed were 12 point. It looks very close to the one pictured on the 68. the top is like the 68. Surely not square, marking those rounded ends with letter punch was kinda tough. seems like the 68 is better.
The ridge at the top of the cylinders must be removed before the pistons are removed, pounding the pistons out can damage the ring lands in the pistons.
Engines from that era had soft cast iron blocks the wore, I always had a machine shop rebore the cylinders and I replaced the pistons.
A set of pistons cost me about $125, hot tank, bore and hone and new cam bearings cost me about $150. That was 20 years ago so adjust for inflation.
Yeah, that carbon ring on the top was probably our biggest problem. We took time with the others to clean as much of the ring off as possibleā¦ Pistons, rings, bearings, lifters, oil pump, cam shaft, seals&gaskets all included in my overhaul kit, but im holding off in buying the kit till i find a connecting rod that im pretty sure will will work. The plan is just to hone the cylinders rather than rebore them, they dont look horrible.
friend had a balance shaft assy wear out on his buick due to crud in the pushrods restricting oil flow. or that was his theory. you sure your cyl bore is stock dia?
