Side loading of the piston is the biggest issue with the 4.5” stroke, along with the short cylinder of a Pontiac block pulling the piston down out of the bottom of the bore. Short piston life and quickly diminishing ring seal I’m thinking.
To end up with the same 1.57:1 rod to stroke ratio as a stock 455 which ain’t that great to begin with (6.625” rod - 4:21” stroke) you would need a rod close 7.1” long with that 4.5” crank.
Is it possible to put a rod that long into a stock deck block or would you need to go to a tall deck block? I’m thinking there’s no way to move the pin that far up into the ring pack on a stock block.
Makes me wonder exactly how GTO Jones is getting away with that 4.75” stroke in his 571. Which block standard or tall and what rod length?
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1964 Tempest Coupe LS3/4L70E/3.42
1964 Le Mans Convertible 421 HO/TH350/3.08
2002 WS6 Convertible LS1/4L60E/3.23
1966 VW Type 2 Single Cab Pickup 140hp 2276
1956 VW Type 2 Panel Van 36hp 1200
1957 VW Type 1 Beetle 180hp 2276
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