Opportunity to bring back the Chuck and Rudy Performance Head

50C8DAN50C8DAN Posts: 2,607Senior Contributor
I have been discussing with Kerry Dancy about making more of the heads designed by Chuck and Rudy a number of years ago.  Some of you may remember these heads were optimized for the Hudson engine for flow and combustion.  They had what is state-of-the-art features designed and tested.  Unfortunately, Empire Casting in TX basically stole the design and tooling and produced the heads, selling them in the WTN for a short period of time.  Only a small number were ever made, but Kerry had one of the heads scanned and turned into a solid model such that another set of tooling could be produced.  I have discussed this project with one of the guys I am working with on the new 2x2 manifold and he has priced it out from start to finish.

 With no profit involved it will cost $1,850 ea for a run of 20, $1,650 for a run of 30 and under $1,500 for 40.  These heads would be ready to put on your engine - all machining would be finished unless you wanted the combustion chambers unmachined for your own design.  I am testing the waters to see if there is enough interest to even move forward.  I know this isn't cheap, but considering the market and the cost of materials etc. it is a reasonable amount.  I will to take 2 of them myself, so that would take it down to needing 28 for the 30 off.  

Let me know what you think.  If we move ahead it will be renamed POWER DOME II between the fins.

BTW the manifold project is a bit stalled due to my CAD guy getting Covid and his full time CAD job soaking up all of his time.  My plan is to have a printed plastic manifold some time next spring, March/April for fit testing and then by late summer actually have real heads.


  • superwaspsuperwasp Posts: 326Member
    Just for the rest of us who weren't around then, what's the performance results from these? Is it similar to throwing on a smaller head like the ol' 262 on a 308 trick?
  • atcatc Posts: 31Member
    I would buy at least two of these. What size are the head bolt holes? Is there a 7/16" and 1/2" option?
  • 50C8DAN50C8DAN Posts: 2,607Senior Contributor
    edited September 2021
    I will get more details on the combustion chamber size and compression ratio, but it will be a definite boost from stock.  The holes will be 1/2" standard with possibly a 7/16" option.  The spark plug location and combustion chamber design/flow characteristics are superior to a stock Hudson head and also the old Clifford head which has been out of production for some time.

    Please note these heads will be cast from 6061 Al and heat treated.  
  • ski4life65ski4life65 Posts: 1,152Expert Adviser
    I will take 2. Don
  • 50C8DAN50C8DAN Posts: 2,607Senior Contributor
    Here is the original information about the heads when they were first designed and cast.  Note sorry the heads will be 356 T-6 not 6061 :

    Hudson Vortex Head

    We are now manufacturing and making available for sale a new designed aluminum cylinder .head for the 232-262-308 Hudson engines. This head will fit all of the wide block engines offered by Hudson during the 1951-1956 production years. The wide block head is being manufactured using 356-T6 (aircraft aluminum) which produces a product with a tensile strength of 36,000 pounds. The finished heads will have a textured finish including rows of 0.190-inch thick cooling fins to aid in heat dissipation and for added strength .(see the attached photos)
    Featured updates 
    · The head manufacturing included using the latest casting techniques to assure improved coolant flow throughout the cylinder head is achieved.
    · The gasket surface of the head is .100 inches over the stock Hudson head so the head can be safely milled to increase the CR above the stock 8.4 to1ratio this head achieves in standard form. 
    · The thermostat housing selected is a GM type which is located in the same position as stock heads. The flange was selected to assure better service without the cracking problems found in the Hudson OEM Thermostat housings. 
    · The head was designed to allow the use of ¾ inch reach, 14 mm type thread spark plugs. (Less chance of stripping them) and allows the use of a wide Heat-Range spark plug. The sparkplug location was engineered to be close to the piston as opposed to the OEM Hudson head location over the exhaust valve. This design assures the sparkplugs will be cooled by the Air-Fuel charge from the Intake valve. 
    · The head bolt holes are 7/16 and can easily be drilled out to ½ size if needed
    The head has completed several testing actions 
    · The Twin Vortex feature of this new aluminum head was flow tested. The modified combustion chamber was compared to the combustion chamber of a stock head. What we learned was the new head created a vortex that flowed around the valves towards the piston and out the intake valve. The stock chamber flow patterns indicated kickback of the flow to both valves.

    Rudy Bennett credits Chuck Fellows, also an avid Hudson fan, with the combustion chamber design and testing. The product shown is the result of months of research into the successes and failures of past flat head engine head designs. Coupling this with practical flow testing a final design was produced which is incorporated into the TWIN VORTEX head

  • 50C8DAN50C8DAN Posts: 2,607Senior Contributor
    Head ad from Empire - NOTE do not contact Empire about these heads.  They stole the design and tooling from Rudy and Chuck and never paid for the use of the designs.  

  • 50C8DAN50C8DAN Posts: 2,607Senior Contributor
    Well so far up to 7 heads!  Almost 25% for a 30 off run!  
  • 54coupe54coupe Posts: 955Member
    Damn, I wish I had the budget for this.
  • TwinSuperchargedTwinSupercharged Posts: 49Expert Adviser
    Count me in for one. BUT, I will need 7/16 holes. I am not going to pull engine to tap 1/2 threads. Thanks, Fred
  • 50C8DAN50C8DAN Posts: 2,607Senior Contributor
    I am running a stock '56 Al head on my Hornet with 7/16" bolts and not having any issues, for several years now.  We could make all heads with 7/16" holes and you can drill them out to 1/2" perhaps. Will need to give it some thought.
  • 50C8DAN50C8DAN Posts: 2,607Senior Contributor
    There have been some discussions and questions about how this compares performance-wise to the Clifford Al head and the real answer is no one knows.  What is known apparently is that Jack Clifford never actually raced his own head in competition, but stuck it out with a 232 or 262 cast iron head.  I have a NOS Clifford head in my garage and it is truly a beast but that does not mean it performs well.  As for cost, if I remember correctly the last heads offered before Clifford discontinued them was on the order of $1,200 or so, and things have gotten a lot more expensive since then and I would guess it would be close to what I am looking at with the new finned head. 
  • 50C8DAN50C8DAN Posts: 2,607Senior Contributor
    OK up to 10 - 1/3 rd the way there.  Notice has gone out to Chapter contacts.
  • 50C8DAN50C8DAN Posts: 2,607Senior Contributor
    For more information on comparison to the Clifford Head here is some info on discussion from Rudy Bennet who has raced stock, Clifford and Twin Vortex;  Thanks Kerry, We were at the plant yesterday and they are still working on the chambers of and on as other projects are on.  That is the hard part of the head as all of the chambers are different   And it will have to fit 232-262-308 engines the area around the valves and the Vor-Tex area is very hard to do and keep the 80 cc in all of them.  We hope it will be ready in about a week to start casting     The Clifford head was cast as chambers only and did Not Flow at all.    I raced with 2 of them and lost power with each one,and the 232 Hudson head put the power back in,it flowed better.

       Have a safe trip Kerry   Pal   Rudy and locals

  • MartinMartin Posts: 56Member
    Need a group buy, like a go fund me, to generate $56K to buy 40...Then waffle them at $100 per Ticket..sell 15 tickets a time for each head. until they are gone. This will generate $4k profit for the group,then we could invest in manifolds or something else.Need investment strategy and proper accounting/ escrow. We probly got some lawyer /banker guys in this group  ? Maybe someone could fund the whole deal.... Ill buy a ticket right now....Good evening.
     P.S.  if you win a head with another ticket after you already have one  ....sell it at 1/2 price u make $600/  There are other strategies that would work as well...
  • blondwookieblondwookie Posts: 261Member
    Will someone explain to me just how the vortex head design works in the flathead engine. I like the head design, yet at this time, i do not have the funds to get in on this offer
  • 50C8DAN50C8DAN Posts: 2,607Senior Contributor
    I have asked if Rudy or Chuck will do this as they designed the chamber.  I can but it is not my design.  However an answer will be posted.
  • 50C8DAN50C8DAN Posts: 2,607Senior Contributor
    I talked to Chuck this morning and got some good info on the Twin Vortex design process.  

    Chuck said he spent hours studying flathead head design and the best ones out there.  The ones he found the most successful were:

    1) Harley Davidson pre-OHV engines
    3) 1954 Packard - last interation of the famed flathead I8 (I am not able to find a photo of this head combustion chamber!)
    4) Navaro - Famous Ford Flathead racer (see below)

    He said he and Rudy took a stock head and first looked at the carbon marks and the vortex "horns" are where they made their cuts.  They then took and did water flow tests to seee how this worked and it just was a natural flow process.  He said if the engine wants to flow one way, don't try to change it.  The twin vortex allows the air - fuel mixture to flow on both sides of the chamber and circle back down to where it is ignited and then out the exhaust.  The air fuel mixing is the key and the swirl from this works the magic.  Chuck said the initial results were a big surprise.

    Here is a photo of the Navaro heads that are still being made and sold to Flathead guys.


  • bob wardbob ward Posts: 1,349Senior Contributor
    How thick are the Twin Vortex heads? 
    Lockyer Valley, Queensland
  • 50C8DAN50C8DAN Posts: 2,607Senior Contributor
    Here are some details:

    1) Head is 2" thick, slightly thicker than stock Hudson cast iron head (~1.85"), but thinner than Clifford style head.  Strength comes from design not thickness.  Ribbing as stiffness to Twin Votex.

    2) Combustion ratio is based upon stock 308, 8.4:1.   Higher ratio can be reached by milling the head.
    3) Run on pump gas 87 octane.
  • bob wardbob ward Posts: 1,349Senior Contributor
    It’s important to realise that aluminium has only 40% of the stiffness of steel, that for similar head designs the aluminium version will be a lot ‘floppier’ than the steel version.
    Jack Clifford recognised this which is why he made his aluminium heads 3” thick which actually makes them a little stiffer than a stock 2” steel head.
    Young’s Modulus and all that.

    Lockyer Valley, Queensland
  • 50C8DAN50C8DAN Posts: 2,607Senior Contributor
    Bob I am aware of the issue with the modulus (floppiness) of aluminum and steel.  My company deals in modulus of aluminum and aluminum alloys a lot with our customers.  The way to work around the lower modulus of aluminum alloys is by the structural design, i,e. ribs and how they are placed.  Below is a flight chassis we made a number of years ago for a DARPA contract where we used cast aluminum composites in place of machined 6061 Al,  The Chasis target was to weigh 1/2 of that of the 6061 version.  Part of the stiffening was done with the composite but the other was the way the webs were placed.  The Clifford head weighs 31lbs.  I know since I have one in my garage, the Twin Vortex head weighs 24lbs., but it uses the cooling fins to greatly enhance the structural stiffness.  Remember Hudson made Al heads (I have one on my HOrnet) that were not reinforced and were 2 in. thick.  

  • Hudson_in_SeattleHudson_in_Seattle Posts: 196Member
    are there any dynamometer tests to compare stock vs improved head hp/torque curves and outputs?
  • 50C8DAN50C8DAN Posts: 2,607Senior Contributor
    Per my post on turbulent flow:

    Dyno testing would be nice and actually, one of the original twin vortex heads was given free of charge to a HET member that sometimes appears on this forum!  Unfortunately, the head was never tested and was put on a car that the member sold!  Dyno testing takes money as you pay for time on the machine, and we would need a setup with a 308 such that we could swap out heads in real time.  Maybe the guys on Hot Rod TV would do that?  Remember this project is being done for no-profit, all at cost and we are probably looking at no more than 30 heads cast.  However, if someone wants to take that on I would be willing to LOAN them a head.

    One of the benefits of the Twin Vortex head BTW is that you can run it at 8.5 or even higher compression ratio and not get pre-ignition like the stock heads, that max out at about 7.5.
  • blondwookieblondwookie Posts: 261Member
    Would you use a stock 308 or a 7X engine
  • blondwookieblondwookie Posts: 261Member
    For these tests
  • 50C8DAN50C8DAN Posts: 2,607Senior Contributor
    Stock, as that is what most Hudson owners have.
  • blondwookieblondwookie Posts: 261Member
    I like to build performance engines
  • blondwookieblondwookie Posts: 261Member
    I'd have to find the funds to get in on that new head
  • 50C8DAN50C8DAN Posts: 2,607Senior Contributor
    OK closing in on the halfway to 30 heads!
  • InlineEricInlineEric Posts: 45Member
    At first glance it seems a bit pricey, but considering what you see old stuff go for, I think it is a very fair price... put me down for 3.
Sign In or Register to comment.