Pontiac Straight Eight Crankshaft and Block

[RShepherd]

On another forum, I read someone's opinion of the Pontiac straight eight and he said that one of them rarely made 80,000 miles without the crankshaft breaking or the engine requiring a complete overhaul. He said the propensity for the engine to have the crankshaft break was made worse by the block's tendency to sag over time and that Pontiac dealers in the '40's and '50's sold a brace to support the block and eliminate or at least lessen the sag. Is any of this true? The only problem I had ever heard of on this engine was that they tended to burn valves even if they were kept in adjustment and, of course, that was not unique to Pontiac among L-head engines.

[Guest rshoestock]

There is much ignorance out there about the S8 L-Head. Mine just turned over 80k and still going strong. I have two spares in the backyard in case I ever need them. I've had mine at 75 mph recently and it's smooth. Who wants another booring V8 when you can keep it original, plus these engines were well engineered and balanced when built. I live on the side of a mountain at almost 3,000 feet here in Western, NC and the S8 L-Head has never failed to get me back home, yet. One ETC member drove his from Utah to Ohio a few years ago to the flathead reunion. Yes, the valves need adjustment, good luck finding anyone who knows how to adjust them anymore. Long live the S8 L-head!

-Rick Shoestock