Re: Straight 8 Head Modifications

Posted by fred battle on 2009/4/10 12:44:17
My 1949 Packard is the 4 dr touring sedan model w/Super 8 (327). The amount that I can mill the head on this engine to realize the power/economy on the octane now available (89-92) that was originally engineered by Packard is my goal. On flathead 6 cyl Studebaker Lark you can remove as much as 0.60" from the head for max. performance. Seems like 0.40" would be a reasonable number on the 8 cyl. flathead Packards. I would need to check valve head clearance before starting it up on the off chance that there is a clearance issue. I do not think an aluminum head was ever manufactured to fit this post war engine.

Un shrouding the valves, i.e. like on Ford flatheads, is an optiion but you will loose some compression ratio numbers(increased head combustion volume)but the air flow number increase should more than make up for that. Did Packard or a privateer ever run a straight 8 engine at Bonneville or on a track in modified form to set any speed records? If so, those modifications would have been captured in old SAE papers of the time. Phred

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