The Last GM Big-Block V-8 Rolls Off the Line

DesScorp writes "It's the end of an era in auto technology, as the very last big block V-8 engine from GM has rolled off the production line. The L18 engine was the last variant of an engine that had been in continuous production for over 50 years. The big blocks powered everything from the classic muscle cars of the '60s and '70s to heavy-duty trucks today. From the Buffalo News: 'When GM said last June the L18 would be eliminated by year's end, the announcement triggered another show of devotion to the product. Some customers ordered two years' worth of L18s, to put on the shelf for future use.' More than 5 million big blocks have been produced over the engine's history. The final big block engine to come off the line in Tonawanda, NY is headed for the GM Heritage Center in Sterling Heights, MI."

Comments

Re:I suppose it was inevitable

[afidel]

Uh, this was the 8.1L (496 cu) engine that's being retired, it was a true big block. It was also a big hunk of cast iron with iron headers and hence heavy as all get out (734 lbs shipping weight vs 564 for the 6200).

Re:Innovation!

[w0mprat]

No not really, V-engines have a little added complexity, which may drag down reliability, but for all practical purposes there is no dramatic difference that makes a inline superior in peformance and reliability.

A V allows you package more displacement in to smaller overall volume or to have less car to package around given in engine. Weight savings from a V engine boosts handling performance and economy. Yet an inline engine will be cheaper than a V, due to one, block, single manifolds, two camshafts instead of four.

Difference in power may come from firing order, and the path intake charge and exhaust gas take and a small reduction in friction in a Inline 4 or 6. Inline 6s can have a good cross flow set up for top end power when mounted longitudnally in a front engined car (short straight intake runners and 6 into 1 headers, make a good turbo platform. BMW, Nissan and Toyota have exploited this to great effect in racing and in road cars. Aftermarket Nissan Skyline motors with 6-1 turbo manifolds make whopping power.

In the end, V8s rose to greatnews because it was probably the best balance between a number of cylinders, dimensions, displacement etc. A four cylinder block is about as long as you want to go. Big displacement engines need a greater number of pistons to stop the piston speeds getting out of hand along with smoothness reasons. Eight cylinders is just right, for big power or a big engine.

A inline 6, and a 90 degree V12 and a boxer six are probably the three ideal engines, having perfect balance. The greatest engine of them all on the balance of all considerations, including, cost, complexity and packaging is the inline four. That's why V8s are made out of two of them:

American V8s most often really are just two inline four engines stuck together. Right down to the split-plane (cross-plane) crankshaft. Yes there are hack mechanics who have lopped off one bank of cylinders to make a inline four, it works. Unfortunatley cross-plane crankshafts have a lot of drawbacks including difficult to control vibration, unbalanced piston movement, poorer exhaust scavanging in certain exhaust configuartions and need for counterweights that add rotational inertia. Yes every American V8 you drove had a dirty kludge under the hood.

IMHO, a real V8 has a flat plane crankshaft. Truly the correct format for a V8, better firing order, more power, more balance and even better sound :)