1953/54 7X Engine

[Owen_Dyneto]

I've been looking at a 1953 Hornet advertised for sale with the claim that it has a 7X engine.  It does have a "7X" logo trim on the right lower corner of the trunk lid.

 

My questions are (1) what were the enhanced performance features that distinguished a 7X from a 7C or 7D engine;  (2) how can I verify just by physical observation that the engine in question is truly a 7X; and (3) did the 7X option include any running gear changes or was it solely related to the 308 engine? 

Edited September 1, 2016 by Owen_Dyneto (see edit history)

[StillOutThere]

I'm not the expert on this but I can tell you there have been hundreds of standard Hornet engines built up at home and at machine shops "to become" 7X motors and most claim authenticity but are NOT.    No "7X" badges on trunk lid or anywhere else.    The engine was a stand-alone option.   There were other "Severe Usage"  (SU) parts available in the parts books that could be ordered like shocks and springs and spindles with larger bearings, and brake drums to suit those.   These were sometimes part of export packaged cars.for rougher world roads.   Half inch head studs (std. '55-56 anyhow) and greater block relief for breathing with oversize valves are part of the 7x.    Suggest you presume what you are looking at is NOT real or let seller document it to you.

[Xander Wildeisen]

You should also have the split exhaust, but this could be bolted on to any engine as well. Out side of bigger head stud bolts as said above, all the goodies are inside the motor. I used to pick up the mail for Mac (owned McDonald Motors in Seattle) He was one of two old Hudson dealers left, Miller Motors being the other one. Mac said he bought out the Hudson Plant in Portland And had truck loads of 308 twin-H engines in the crate. Sold them for $250 dollars to people on exchange. Said he had so many used 308 engines that they just started scrapping them.

[StillOutThere]

I remember Mac.  Great guy!   Opened in 1934 and never closed until his end.  Which made him the last CONTINUOUS operating Hudson dealership.  The Ypsilanti one was closed out of business for many years until the son decided to reopen to liquidate the parts counter inventory.   Bought many items from Mac and learned a great deal walking through his parts bins.  Thanks Xander for the memories.

 

The split exhaust 7X NASCAR real deal manifold is nearly a hen's tooth.   There is a modern "splitter" for the standard manifold that gives the look but is not equal to the original.    In the original, the main manifold was a unique casting split in the middle with no heat riser.  Then a elbow continued the split.  Sounded FABULOUS on my Hudson.

 

[Xander Wildeisen]

Mac was a great guy, always had a new Cadillac. A wealth of knowledge was lost with him. He had some great NOS parts in that building. He still had the original Hudson neon sign in the window that he would turn on every morning.