I read an article today about 8 engines you should avoid. There was one from Chrysler, Ford, GM, Saab, Toyota, Audi and Nissan and Mazda. First of all I would suspect a Honda fan wrote it, and secondly, I wonder why none of the Korean cars made the list? The problems, though unique to each corp, was always about head gaskets blowing, sludge buildup and overheating. It seems that several of them have "hot spots" where oil congeals, and becomes sludge forming a blockage. After more than 100 years of pressurized oiling systems, you would think that a company would know how to make an engine block with holes enough to drain oil, distant enough from the super-heated parts that oil retains its lubrication requirements. Since I have never heard of an Oldsmobile V8 engine seizing due to oil supply, sludge or blown head gaskets, I am more sure that restoring a proven workhorse 60's engine for less than half the price of a crate engine is the correct decision. My Dad and I put hundreds of thousands of miles on the 13 Olds we had without ever having significant wear or an oil related failure. I can remember having the 455 in my 442 so hot that it continued to diesel for 15 minutes after the car was shut off, and the head gasket remained intact for another 7 years before it was sold. It was so hot that the plug ceramics broke, plug wires were melted and I was sick about it...but, it NEVER stopped running as well after as it did before. Was I lucky? Maybe, but more likely it was due to the extra nickel in the block which made it incredibly strong, flexible and durable. Aluminum engines get one shot at overheating and they become boat anchors. Aluminum heads are fine to get HP, and for racers with big budgets, but I will take cast iron, the variety put in the 50s-through mid 70's engines for their ability to withstand the stupid moments, and surprises, and still work great. Yep I am an old fart, but there are some things that cannot be made better and cheaper in the same instance. Cast Iron is only as good as metallurgy. Cheaper casts are not better just because they are lighter. Heat dissipation is important, and any of the metals used today simply cannot stand up to the one time you have an emergency overheat. It fits the thinking of today when it happens, don't fix it, empty your bank account for a crate engine! YIKES!

 

It's my impression that head gasket failure in modern engines can often be blamed on extensive use of aluminum, especially on engines that combine an iron block with aluminum head(s). You just can't afford to drive these vehicles much over their normal operating temperatures.

 

I have never read any actual materials science writing on nickle content of any GM block, only apocryphal.

 

I would have to agree. The two metals cannot be expected to expand and contract the same. Bolts aren't elastic...something has got to give eventually!

 

Oldsmobile and Pontiac blocks are made of high quality cast iron with plenty of nickel to make it strong. Olds and Pontiac engines were cast with extremely high nickel content until mid 1977. Chevy used very little nickel in any of their blocks. You can see where the nickel content is if you look at the valve pockets of an Olds or Pontiac head where they have machined it virtually smooth, like it was "polished" at the factory... hmmmmmm