The Vega was to be a “corporate car” that all divisions bought into. They reluctantly agreed and paid lip service to what type of product was needed and the quality level to compete with the VW Beetle which set the standard at that time. The car was a joke; the aluminum engine block was expected to be part o the cooling system; of course when it got caked with oil and dirt its radiating qualities vanished, then de the overheating of the sleeveless block cast in Messina New York next to the Alcoa plant warped and oil consumption stated…
A true corporate disaster! Someone once told me that a camel was a horse designed by a committee. The Vega was a lesson in what NOT TO DO and HOW NOT TO DO IT.
he car was a joke; the aluminum engine block was expected to be part o the cooling system; of course when it got caked with oil and dirt its radiating qualities vanished, then de the overheating of the sleeveless block cast in Messina New York next to the Alcoa plant warped and oil consumption stated..
That may have been what happened to your engine…but that was NOT the major problem with that engine. The silicon which lined the piston wear surface would break off and destroy the rings. Engine never warped. If the engine warped then you’d never be able to repair it by putting in steel sleeves. That’s what I did with my 72 Vega…and many others did with theirs. The steel sleeves actually turned the engine into a nice little reliable engine…But as MB mentioned…there were a lot of other problem with that vehicle. The sheet metal was so thin…that when they were testing the station wagon version it broke in half…thus forcing them to install steel rods for support.
The car had potential to be a great car if GM cost engineers didn’t mess with it.
I agree, Mike. I actually liked the car. If it hadn’t been such a bumper-to-bumper POS, if it had offered decent quality, if it hadn’t been downright unsafe, I probably would have bought another GM. Hell, I’d probably still have the Vega!
GM probably made a few extra profit dollars off of me in '72, but they’ve lost a whole lot of sales from me in the succeeding 40+ years. Their history would suggest that they didn’t use those few extra profit dollars very judiciously either.
It’s too bad. Up until the very early '70s GM made some of the best cars in the world for the working class.
The silicon which lined the piston wear surface would break off and destroy the rings.
From Wikipedia:
With its small 6 US quarts (5.7 l) capacity and tiny two-tube 1 sq ft (0.1 m2) radiator, the Vega cooling system was adequate when topped off,[53] but owners tended not to check the coolant level often enough, and in combination with leaking valve-stem seals the engine often ran low on oil and coolant simultaneously. Consequent overheating distorted the open deck block, allowing antifreeze to seep past the head gasket, which caused piston scuffing inside the cylinders.[7]
My understanding is that the block was cast with an Al-Si alloy and that the cylinder walls were not lined with anything. I’d be happy to read a reference that states otherwise. (The plot thickens; see below).
Too much Friction Would Result From An Aluminum Block With Aluminum Pistons.
It’s My Understanding That Instead Of A More Traditional Engine Designed With Cast Iron Block And Aluminum Pistons, Or Aluminum Block With Iron Liners And Aluminum Pistons, The Vega Utilized An Aluminum Block And Iron-Coated Pistons To Allow The Use Of Unlined Cylinders.
The casting process provided a uniform distribution of fine primary silicon particles approximately 0.001 inches (25 µm) in size. Pure silicon provides a hard scuff and wear resistant surface, having a rating of 7 on the mohs scale of hardness, the same as quartz, as compared to diamond which is 10. The blocks were aged 8 hours at 450 °F (232 °C) to achieve dimensional stability. The technical breakthroughs of the block lay in the precision die-casting method used to produce it, and in the silicon alloying which provided a compatible bore surface without liners. ... The cylinder bores were rough and finish-honed conventionally to a 7-microinch (180 nm) finish then etched by a new (then) electro-chemical process. The etching removed approximately 0.00015-inch (3.8 µm) of aluminum leaving the pure silicon particles prominent to form the bore surface.
The material used for the Cayenne blocks is alusil, which has a hypereutectic silicon content of 16 to 18%. During a specially developed multi-stage honing process, the silicon is uncovered in the bores in small-particle sizes. These particles provide the wear resistance required.
My understanding is that the block was cast with an Al-Si alloy and that the cylinder walls were not lined with anything. I'd be happy to read a reference that states otherwise..
I take it you don’t know what a bore surface is.
Taken directly from your article…
“The etching removed approximately 0.00015-inch (3.8 µm) of aluminum leaving the pure silicon particles prominent to form the bore surface.” Thus the final process the silicon was left lining the cylinder walls.
When you consider that the Vega used a timing belt to reduce manufacturing costs yet chose to not incorporate a cross flow head it becomes obvious the primary goal in design was CHEAP.
Thus the final process the silicon was left lining the cylinder walls.
Obviously, and you’re welcome for the education.
Are you saying that even if the blocks hadn’t warped and compromised the head gaskets, the cylinder wall failures would have occurred anyway? Porsche, BMW, and Audi might argue against this.
And yet it was still a good looking and fun car to drive. I’ve come to believe that the original designers “nailed” it, and the value engineers “un-nailed” it. Damned shame. I really enjoyed mine, except when the pieces were falling to pieces.
Are you saying that even if the blocks hadn't warped and compromised the head gaskets, the cylinder wall failures would have occurred anyway? Porsche, BMW, and Audi might argue against this.
YES…And it did happen. While overheating was a problem…especially with the cast iron head…GM was learning how to manufacture the engine…Porsche and BMW spent the time to learn the proper way to design and manufacture the engine.
I rebuilt 3 Vega engines…Not one was warped…all had cylinder scars and small pieces of the cylinder walls broken away. Sent block to machine shop that bored out the cylinders and added steel sleeves (which GM should have done in the first place).
The plating idea was good, but the actual execution, typical GM style was imperfect. Not enough testing was done to make sure the process was as good as it was intended to be. Another half-baked car from GM.
Ah, but if only the cylinders were the only problem…
Need I repeat my list? Need I repeat the reason I dumped mine?
Nay, the cylinders were but one of a long list of problems…
It’s sad, too, 'cause I liked the car.
