Re: Packard Six with dual carbs?

Posted by Owen_Dyneto On 2013/3/27 9:22:57

I think you might get some useful insight into possible performance improvements of dual carburetion on a flathead 6 by chatting with some owners of early to mid 50s Hudson Hornets and Wasps. The standard carburetion on the 308 Hornet was a a single Carter 2-bbl for I think 145 hp. The Twin H option was two single barrels, Carter WA-1s IIRC, with 160(?) hp. Not that you can put a lot of faith in factory hp figures but without doubt the Twin-H was a significantly better performer. How much of the improvement was simple carburetion and how much was enhanced distribution is a good question. Many of those Hudson guys are very performance-oriented and certainly would be a good source of info on dual-carbureted sixes. And I seem to recall that the Twin-H was also offered on the 262, 232 and 202 cubic inch flathead sixes.

The intake manifold is blocked internally between #3 and #4 cylinders so each set of 3 cylinders is isolated from the others except for the vacuum ballast tube that you can see on the far outside of the manifold. In the 7D and 7H versions for 1954 there was also a hotter cam, #311040 if I recall correctly, which gave an alleged hp of about 200. Jack Clifford was the maven of these hot Hornets and offered the cam, higher CR cylinder heads, and a split exhaust manifold which I think was also available on the 7H version. If any of his disciples are around, I'd think they'd be a great source of advice on getting more performance from a flathead Six.

I had some happy times drag racing in stock class years back in a 1954 Hornet Special with Twin H, we had the stock 4-speed Hydramatic reworked by B&M, and also used a DynaPlate dual point ignition system - otherwise stock. On a really good day our best terminal speed in the 1/4 was about 84 mph IIRC.

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