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Hudson 232-262-308 engine tech

Discussion in 'The Hokey Ass Message Board' started by PacaRacer50, Dec 11, 2010.

  1. PacaRacer50
    Joined: Oct 3, 2010
    Posts: 115

    PacaRacer50
    Member

    Guys I thought I would start a Hudson Big Six engine tech thread due to questions I have been receiving from quite a number of people. I'll start with the basics of the history and go into where to get the engine parts then to some of the best modifications to make these old monsters scream.
    History:
    NARROW BLOCK
    Hudson introduced the Big six engine line in 1948 as a 262 cubic inch only. Bore is 3.5625" and stroke is 4.375". This is the Narrow Block engine and was produced as 262 cubic inch in 1948, 1949 and 1950. In 1950 a 232 cubic inch version was introduced for the Pacemaker line of Hudsons. The 232 version has the same bore as the 262 but used a 3.875" stroke crankshaft. Narrow block engines have different cylinder head water passages and the lower oil pan rail is straight from the front engine plate to the rear engine plate.
    Engines made in 1948 and some 1949 used aluminum 2bbl intake manifolds.
    All 232 versions used a 1bbl intake manifold. Cylinder heads were either aluminum or cast iron and were unmarked in 1948 and 1949. In 1950 the cylinder heads were marked next to the thermostat housing location "500" for the 232 version and "501" for the 262 version.
    Valve sizes are 1.8125" for the intake and 1.5625" for the exhaust. These sizes remained as the standard valve size through the entire production run from 1948 until 1956.
    All engines received hand fitted pistons and bearings during production. The information for the pistons was hand stamped into the block behind the lifter and valve covers on the right hand side of the block. All of these engines were assembled with the utmost care at the time of manufacturing.
    Crankshaft flywheel flange uses 7/16" bolts pressed into the crank with nuts and a special lock plate. These have been an issue since day 1 of this engine. The flywheels for both stick shifts and Hydra-matics must be sealed to the crankshaft to prevent leaks with good high quality Permatex #1 sealer.
    These engines are suitable for stock and mild performance rebuilds but not recommended for high performance usage. Cylinder heads and oil pans do not interchange with the 1951 and later big six engines.

    WIDE BLOCK
    1951 saw the release of the Wide Block Hudson big six. With this came the release of the 308 cubic inch Hornet engine. Cylinder head water passages were improved and the block has a kick out for the longer stroke crankshafts of the 308 cubic inch version.
    Bore of the 308 is 3.8125" and the stroke is 4.500". The 232 and the 262 retained the same bore and stroke as previous years. The 308 version also has stiffening ribs added to the lower area of the block about 2" above the oil pan rail. Minor refinement was incorporated each year until 1955. Valve relieve area was improved each year to increase air flow over the cylinder.
    All Hudson big six engines used 7/16" head bolts except for the 7X racing engine built by the Hudson Race Shop. These 7X engines used 1/2" head bolts for added head gasket retention. Details on the 7X engine will be covered down later in the information.
    Twin-H was made available in the 1952 Model year. It consisted of a special cast iron intake, twin Carter 1bbl carburetors, two air cleaners, special linkage and an exhaust manifold with two choke stove pipes in the center two exhaust ports. Twin-H added 10 horsepower to the standard 262 and 308 engines. It was not available for the 232 version. The Twin-H was an assembly line option as well as being available as a dealer add on item.
    Aluminum cylinder heads were optional on all three engine displacements during this time. Usually the aluminum head bumped the compression by .5 and gave a slight increase in horsepower. Head gasket retention with the aluminum cylinder head has always been an issue so beware if buying a used aluminum cylinder head.
    Camshaft selection changed several times over these years. Two of the performance camshafts Hudson used in most engines were the "742" and the "040". Both of these camshafts started out as 7X racing camshafts and are suitable for a daily driven Hudson. The "742" camshaft had the ramp opening and closing rates altered in 1955-56 for use with hydraulic lifters and work very well with mechanical lifter for street performance.
    The actual specifications for these two camshafts have never been accurately listed except for the lift. The "742" has .354" valve lift and the "040" has .390" valve lift. Both lift specs are at Zero lash. New reground camshafts are still available that offer more performance than these two so keep that in mind.

    7X
    The 7X engine was released sometime during the 1952-53 for racing and severe usage. These were not assembly line installed but available for installation at the dealerships or as a crate engine. These engines were hand built and modified by the Hudson Race Shop on a very limited basis.
    It was only available as a 308 cubic inch version.
    These 7X engines started out as hand selected block cores for modifications. Each block was selected for the least core shift and the thickest cylinder walls for durability.
    Each engine received larger 2.00" intake and 1.6875" exhaust valves. The valve ports and bowls were hand ported and opened to match the larger valve sizes. The relief area was hand machined to remove any flow restrictions over this area of the block into the cylinder.
    The head bolt threads were enlarged to 1/2" diameter for better head gasket retention. All 7X engines used a 232 cylinder head for higher compression, 8.7 to 1 with the cast iron head and 9.2 to 1 for the aluminum version.
    Camshafts started out as the "742" camshaft and then progressed to the "040" camshaft sometime during the fall of 1953.
    Each 7X engine received a Twin-H intake, carburetors and a special exhaust manifold with a bolt on twin outlet elbow in place of the standard single outlet elbow. The exhaust manifold itself is different internally in the intake manifold heat chamber. The 7X version is totally sealed off from the intake so no direct exhaust gas flows into the intake. This offers a improvement in flow for the center two exhaust ports.
    Pistons, bearings and crankshafts were hand selected and fitted to these 7X engines for the best clearances and lowest amount of rotational drag.
    Horsepower ratings were never given as exact numbers due to the hand fitting and modifications but were listed as 210-220hp.

    AMC years 1955 & 1956
    Major modification were added in 1955. Hudson had already prepared to make these changes for better durability. The only big still in production was the 308. Both the 232 and 262 were dropped for the 1955 year.
    Cylinder head bolt holes were enlarged to 1/2 for better gasket retention. Cylinder heads were either the 308 cast iron and aluminum for 1955 and 308 cast iron but used the 262 cast iron in place of the 308 aluminum for higher compression in 1956.
    The valve relieve area of the block was enlarged again for better air flow. These blocks have the best out of the factory unmodified air flow of all Hudson big six engines short of the 7X engine.
    As stated above the lifters were changed at the end of the 1955 year to hydraulic along with the reprofiled "742" camshaft due to problems with adjusting the valves in the Nash chassis. A special slip-on fuel pump eccentric was added to the arm that is 1/2 moon shaped to reduce camshaft fuel pump wear.
    Twin-H was still available for these two years. The intake changed to incorporate the balance chamber so it was possible to adjust the mechanical lifters in the Nash chassis. These intakes do not flow as well as the 1954 and earlier versions. The exhaust manifold flange on the intake was also changed so earlier intakes will not fit the 1955 & 1956 exhaust manifold.
    The exhaust manifold takes a different elbow flange so the twin outlet elbow will not fit these manifolds.
    The crankshaft flywheel flange is 1/2" shorter than the 1954 and earlier engines and had 1/2" threaded holes for bolts now. This crankshaft is a much stronger crankshaft and flywheel retention is no longer a problem as with the earlier style. A modern neoprene seal is used at the rear main location in place of the older rope seals.
    Oil pans were changed to a center sump to clear the Nash chassis.
    Thermostats housings take the modern style thermostats now as the bypass is blocked off with the mounting flange.

    The next installment will cover modification to wake up these engines for performance and street use.
     
    Last edited: Dec 12, 2010
  2. Shaggy
    Joined: Mar 6, 2003
    Posts: 5,208

    Shaggy
    Member
    from Sultan, WA

    Good stuff, thanks!
     
  3. 38FLATTIE
    Joined: Oct 26, 2008
    Posts: 4,349

    38FLATTIE
    Member
    from Colorado

    My next build is going to be a 308, so I'm all over this one! Great post!
     
  4. PacaRacer50
    Joined: Oct 3, 2010
    Posts: 115

    PacaRacer50
    Member

    Thanks Guys,
    tomorrow when I go into the shop I plan on getting pictures to show several of the modifications to make to make these live... unless the snow gets deeper over night.
    PaceRacer50
     
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  5. Don't forget - hydraulic lifters were in the '56 308 engines, since the solid lifters were extremely difficult to get to and adjust in the '55 cars.
     
  6. PacaRacer50
    Joined: Oct 3, 2010
    Posts: 115

    PacaRacer50
    Member

    thanks Patrick66, I did have a little note in there but went back and added it to the 55-56 section along with the special slip-on fuel pump arm eccentric that was added.
    PaceRacer50
     
  7. Some pics of a Twin-H and real factory 7X exhaust manifold and elbow and 2-into-1 exhaust pipe that I owned back around 1970. These are digital scans of print photos. Yep, back then I painted them gold. Today a real 7X exhaust manifold and elbow is truly GOLD.
     

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  8. hoggyrubber
    Joined: Aug 30, 2008
    Posts: 568

    hoggyrubber
    Member

    great info, can't wait for more!
     
  9. PacaRacer50
    Joined: Oct 3, 2010
    Posts: 115

    PacaRacer50
    Member

    Due to being snowed in today I am going to post some information about transmissions used behind the Hudson Big Six. Tomorrow I will be taking pictures at the shop and get back to the modifications.

    When Hudson released the big six in 1948 there was several transmission choices, 3-speed manual, 3- speed manual with overdrive, 3-speed Drive-Master and 3-speed Drive-Master with overdrive.

    Drive-Master was offered only in 1948 and 1949 on all Hudson models and renamed in 1950-1951 to SuperMatic-Drive. Basically they are the same units that function the same. SuperMatic-Drive was offered only on limited vehicles in 1951 and not available with the Hornet 308 engine. (My 1950 PaceMaker actually had the SuperMatic-Drive with the 232 cubic inch six however it had been removed by a previous owner.)
    Drive-Master was an added on electrical & Vacuum controlled shifting mechanism used to shift the standard 3-speed and 3-speed with overdrive.
    The Drive-Master equipped Hudson's also used a special 2nd gear ratio that was lower than the vehicles without Drive-Master. This was because Drive-Master would start the car out in 2nd gear and self shift to third or 2nd overdrive then into 3rd gear or Direct Overdrive. It is a very complex system that also included a vacuum operated clutch.
    If working properly a Drive-Master equipped Hudson is a very smooth operating vehicle that simulates an automatic transmission. The clutch would only be used during the initial starting of the engine or shifting into reverse. Its so complex that I will not get into the details here about it and in my opinion it should be avoided unless you really want something totally different from everybody else.

    The standard 3-speed and 3-speed with overdrive transmissions are a Hudson designed and build transmission. From 1948 until the end of 1951 Hudson used a single lever transmission. These had one shift lever from the column to the transmission along with a cable that attached to the shift tube to the transmission used to select either R-1st gears or 2nd-3rd gears.
    These transmissions suffer one common problem: the input shaft is a soft material and not hardened. They will twist even with stock horsepower ratings even when run even a little hard just due to the torque of the big six engines. For a daily driven vehicle they will survive but will not handle abuse at all.
    The overdrive unit was made by Warner Gear and is the R-10 unit. Parts for both the transmission and overdrive such as gaskets, bearings and seals are easy to find. Hard parts like gears are only available as used or some NOS parts pop up from time to time.

    1951 saw the release of the GM built single range Hydra-matic on Hudson vehicles. It was a limited option and not available on the PaceMaker model at first but added later. The Hydra-Matic was a very popular option on Hudson vehicles on all years it was offered. The durability, flexibility and performance of the Hydra-Matic makes it one of the best choices for a performance and driveability standpoint.

    In 1952 Hudson came out with a dual-lever 3-speed transmission as a heavy duty replacement. It no longer used a cable for gear range selection as the single lever, this new transmission is like the Ford toploader 3-speed and others offered by other companies. Problems with the soft input shaft were not corrected however so in a high performance application its still possible to twist the input shaft and have the clutch disc drag when engaging or disengaging.
    The same Warner Gear R-10 overdrive was offered behind the dual-lever 3-speed transmission. Service parts are just as easy to find for this newer transmission as the early single lever transmission.
    Mid year 1952 also saw the adoption of the GM dual range Hydra-matic that allows 4th gear lockout for better in town and low speed (under 35mph) performance and engine response.

    1953 transmission options remained the same across the Hudson line with no changes.

    In 1954 the GM Hydra-Matic transmission plant burned to the ground in only a few minutes. This lead Hudson to explore other transmission options for an automatic transmission. Warner Gear was chosen (no other real choice existed at this time) to provide the DG-250 transmission to Hudson. These are different from the transmissions provided to Ford as the Cruise-O-Matic line with all its various names and the FMX. The DG-250 was used by Studebaker and a very complex transmission as well as very expensive to build. These are a true 3-speed transmission with a torque converter in place of the fluid coupling of the Hydra-Matic. There is no aftermarket support except for rebuild and service parts for the DG-250.
    Due to the short production usage in Hudson vehicles I do not recommend using a DG-250 transmission behind a Hudson big six, even for a concourse restoration. Towards the end of 1954 Production the GM Hydra-matic was once again available in the Hudson line of vehicles.

    1955 saw major changes in transmissions across the board. This was a direct result of the merger with Nash to form American Motors. The Nash chassis was set up to use a torque tube drive rear end which meant the transmissions needed to be changed to accommodate this. Hudson adapted the Nash 3-speed and 3-speed with overdrive transmissions to their engines with a change of bell housings and switching to a dry clutch. (More on clutches later in this section). The Hydra-matic that Nash used was also used behind the Hudson 308 big six at this time as well as making the switch to the slant-pan version of the dual range Hydra-matic.

    The 1956 model year continued the same transmission choices behind the Hudson 308 big six. The Hydra-matic remained the slant-pan version of the dual range instead of offering the Controlled Coupling version.

    Out of all of the transmissions used behind the Hudson big six engines the dual range Hydra-Matic offers the best performance and reliability for any type of hard driving. Problems with the input shafts of the 3-speed manuals and the use of a torque tube drive of the 55-56 units render those a possible issue to adapt as well as service problems down the road.

    Several companies offer modern transmission adapters for the Hudson big six. 21st Century Hudson offers adapters for GM 350-400 automatics and maybe the 200-700 overdrive automatics. Wilcap offers both stick shift and GM automatic adapters too. This provides a good cross section of options for modern transmissions.

    Clutches: The Hudson fluid Clutch
    Hudson offered two sizes of cork clutches behind the Big six engines: 9" and 10". The 10" version was used in all vehicles equipped with overdrive transmissions and as a heavy duty clutch used with all 308 Hornet engines. The 9" was reserved for the 232 and 262 with non-overdrive 3-speed transmissions.
    The cork clutch is one of the smoothest operation clutches made. They are quite durable and will handle all the power a Hudson engine can make. Fluid leaks and fluid contamination are the two biggest problems this type of clutch system can face. Pressure plates are used to seal the complete system along with a special throw out bearing. NOS clutches, pressure plates and throw out bearings are about non-existent.
    Right now there is only one choice for having these clutches, pressure plates and throw out bearings rebuilt and that is Wildrick Restoration in Indiana. Dr Doug is the clutch expert and can help you get the fluid clutch set up to handle what ever you need.

    Four types of flywheels were used with the fluid clutch.

    The first type is the 9" flywheel. This will only work with a 9" clutch. The 9" version has three driving lugs built into the flywheel for the pressure plate.

    The second if the 10" flywheel. This will only work with a 10" clutch. The 10" version has the driving lugs build into the pressure plate. These two flywheels can be interchanged on any 1948-1954 Hudson engine, regardless of displacement. You can update a 9" clutch to a 10" clutch but you have to use the 10" flywheel, clutch and pressure plate. All throwout bearings are the same.

    The third type is the 1955 and 1956 dry clutch flywheel. Hudson's used a dry clutch and a special flywheel for these clutches. The crankshaft flange is 1/2" shorter on the 1955 and 1956 engines to allow a thicker flywheel to be used with the dry clutch. Standard Hudson fluid clutch flywheels are very thin compared to a dry clutch flywheel. These are only suitable for a stock restoration of a 1955 or 1956 Hudson and not easily adaptable to the earlier pre-1955 Hudson engines due to the depth without some extensive engineering.

    The forth type is a hybrid that Hudson offered on replacement crate engines and over the parts counter. This type is a 10" stepped flywheel used to adapt the 1955-1956 short crankshaft to a 1948-1954 Hudson fluid clutch transmission. It is a fluid clutch flywheel and damn near impossible to find. Its designed with the needed 1/2" offset and larger 1955-1956 flywheel bolt pattern to make this swap a direct bolt in. If you are putting a 1955-1956 engine with the short crankshaft into a 1954 or earlier Hudson with a fluid clutch you HAVE to use this flywheel to do it.

    Since the crankshaft was shortened in 1955-1956 on the 308 engines 1/2" several people have made 1/2" spacers to put the Hudson open drive shaft Hydra-Matics behind these engines. It allows you to use the 1955-1956 Hudson Hydra-Matic torus bowl flywheel with the larger crankshaft bolt pattern and bolt to the older 1954 and earlier torus bowl. These 1/2" spacers should NEVER be used with the fluid clutch flywheels period! Several people have tried this and failed with horrible results and great damage to the back of the Hudson engine blocks when they came apart in spectacular fashion.

    Once I get to the shop I will start taking pictures and adding them in a little gallery to show some of the differences. Also in the modification section I will go into some details for suggestions on transmissions as well.
    later,
    PaceRacer50
     
  10. Wow PaceRacer...great thread.

    On a side note. If any of you have a Hudson engine for sale...I may be interested.
     
  11. woodienut
    Joined: Feb 17, 2009
    Posts: 349

    woodienut
    Member
    from So.Cal.

    Thanks this really brings back memories. My friend and I built one of these engines in the late 60's with a 5/8" Hank the Crank stroker and 4" (I think) bore = 365 ci. we built a 1"x1" bar stock girdle (surfaced ground to make in flat) that the 1/2" headbolts went through to cure the head gaskets from blowing. A real stump puller!
    Good Stuff
     
  12. hoggyrubber
    Joined: Aug 30, 2008
    Posts: 568

    hoggyrubber
    Member

    so far this may be my favorite thread, and it doesn't even have any pictures yet!
     
  13. PacaRacer50
    Joined: Oct 3, 2010
    Posts: 115

    PacaRacer50
    Member

    guys, thanks for your patients about the pictures. I did get some today of a mild 308 Hornet rebuild we are doing right now along with some of the flywheels & clutches. I will be getting more for modifications when we start the next 308 or 262 but it may be a few weeks. Sorry about the delay on these.
    first two pictures show the left and right side of the 308 block. the rib located 2" above the oil pan rail is only used on 308 blocks. the 232 & 262 do not used this. if your Hudson engine has this reinforcement rib on both sides its a 308 block.
    the third pictures shows the crankshaft bolts used in all 1948 through 1954 Hudson big six engines. if you are building a performance engine using one of these early crankshafts remove the bolts, have a machine shop drill and tap these six holes to the next size bigger and use ARP flexplate bolts here instead of the stock bolts. Hudson's with this bolt and nut arrangement on the crankshaft have the habit of snapping the bolts & throwing the flywheel off and it takes most of the rear of the engine & trans with it in big sharp pieces.
    the forth picture shows a 1954 308 block with a mild polish on the relief area. usually you would place a old head gasket on top of the block, scribe the outline for the valve chamber and relief area in the block and grind the entire area out at an angled depth of 3/16" at the cylinder then tapering up to .090" at the deck area behind the valves near the port side of the block. I will get good pictures of the 328 relief area in my engine once I get it appart and detail it out better. This mild polishing does help out but its no where as good as a full relief grind.
    the fifth pictures shows a 9" flywheel with the drive lugs made in it on the left and a 10" flywheel on the right.
    the sixth picture shows a 9" pressure plate with the three empty slots for the drive lugs in the flywheel to fit.
    the seventh picture shows a 10" pressure plate with the drive lugs incorporated into the outer cover fitting into the slots in the clutch pressure plate.
    the eight pictures shows 9" clutches with the heavy duty without springs on the left and the standard duty with springs on the right.
    the ninth picture shows 10" clutches with the heavy duty without springs on the left and the standard duty with springs on the right.
    the tenth picture is the chamber side of a 308 cast iron head showing the valve pocket, transfer slot and cylinder wedge. the 308 head offers the least flow resistance on a 308 engine but a lower compression ratio than using a 262 or 232 cylinder head. the major difference between all of them is the depth of the transfer slot (area above the relief in the block) and how far the cylinder wedge penetrates towards the center of the cylinder.
    Compression makes power on a flathead just like on a OHV engine BUT there is a major trade off in loss of air flow to support high RPM. In a Hudson flathead its kind of a mute point because the 308 is all done by 4800 RPM due to the 4.5" stroke. My point is that a 308 head works the best for air flow and does not impeed airflow at its max RPM of 4800 but you can make a little more power with a deeper relief cut in the block and a 262 cylinder head. using a 232 head on a 308 creates a detonation machine, not worth the compression gain and loss of airflow.
    More will be coming soon with information on oil system modifications first.
    PaceRacer50

    308_left.JPG

    308_right.JPG

    308_crank_bolts.JPG

    308 relief.JPG

    flywheels.JPG

    9 inch pressure plate.JPG

    10 inch pressure plate.JPG

    9 inch clutches.JPG

    10 inch clutches.JPG

    308_head_chamber.JPG
     
  14. hoggyrubber
    Joined: Aug 30, 2008
    Posts: 568

    hoggyrubber
    Member

    thanks for the info and pictures. i am going to see if i can get my 262 running this winter. can't wait for more.
     
  15. PacaRacer50
    Joined: Oct 3, 2010
    Posts: 115

    PacaRacer50
    Member

    Hudson Big Six oil system modifications:
    Below are more pictures showing which galley passages are which and if they are modified.
    Picture 1
    Main feed from oil pan pick-up to oil pump inlet. No modifications needed.

    Picture 2
    Main feed from oil pump to main oil feed galley above camshaft in block.
    No modifications needed. You can intersect this short galley by plugging it about 1.5" above the pump, drill & tap two holes with one before the plug and one after the plug to plum in an external full pressure oil filter.

    Picture 3
    front main oil galley plug. Modification is to tap this hole for a screw in plug. I found the oil galley plugs for the 429-460 Fords is a perfect match. You cannot install the plug too deep into the galley or it will block oil to the front main bearing. (If a plug is not installed its possible for the factory plug to leak bad when the oil pressure is above 50psi.) NOTE: make sure the plug is installed flush or below flush with the front of the block for flush engine plate fitment.

    Picture 4
    rear main oil galley plug. Modification is the same as the front plug shown in picture 3. Note: make sure the plug is installed flush or below flush with the rear of the block for flush engine plate fitment.

    Picture 5
    Main oil pressure relief valve. Modification is to carefully remove the special bolt, spring and regulator valve. Install one thin flat washer between the spring and special bolt. The washer I used was .047" thick. This will raise the oil pressure and in my case increased it by 15lbs.

    Picture 6 & 7
    right side cam galley oil plugs. Modification is to fill the passage between the cam bearing and these plugs from the inside of the block before the cam bearings are installed. This is to prevent any oil being blown out these plugs, especially if the engine has a supercharger or turbocharger.

    Picture 8
    front main cap timing cover area oil drain into crankcase. Note the hole is actually above the lowest point in this oil drain area. See photo 7 for modification.

    Picture 9
    Area of front main cap to drill extra oil drain hole. Find the thinnest area in this recess and the recess on the back side, mark the area and drill a matching sized hole as shown in photo 7.

    Picture 10
    Timing gear oil guide bolt. Note: this bolt intersects the main oil passage that runs between the main front to rear oil galley, actually right into the main bearing oil passage. If you forget this bolt like I did, you will not have any oil pressure until the engine has been rev'd some. It is not present in all Hudson big six engines and this oil guide is not used with the aftermarket timing chain set.

    Hopefully this gives you guys some idea of how good the oiling system is in the old Hudson big six. It used a gear-rotor style pump that has plenty of volume for the job it needs to do.
    In all my experience I have never seen or heard of a Hudson engine failing from an oiling problem so there is no need to re-invent the present oiling system, just fix some little issues.
    PaceRacer50
     

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  16. hoggyrubber
    Joined: Aug 30, 2008
    Posts: 568

    hoggyrubber
    Member

    very good info. i am have tapped several oil gallery plugs on 3rd generation chevy sixes are these chrome moly blocks a lot tougher to do? i used pipe plugs, even found a allen head brass plug that i machined off a little of on my last one. what did you "fill" the holes in 6 and 7 with?
     
  17. pdq67
    Joined: Feb 12, 2007
    Posts: 787

    pdq67
    Member

    Everybody does know that the big Hornet engine can be B&S'd out to something like 350 cube's, don't you?

    I think I have the spec's at work??

    All this said, I would start with the big Parkard straight-8 at 356" to 384" depending on years.

    And I will just about bet anybody that I can balance a nickel straight up on a headbolt while idling, the big old SOB's run THAT smooth stock!!

    pdq67
     
  18. Pete66
    Joined: Jan 4, 2011
    Posts: 1

    Pete66
    Member
    from Finland

    Hello!
    On my 1951 4d Hornet's cylinder head says: "H145" and "Super Power Dome".
    It has one 2bbl carburetor.
    Is this just a regular Hornet engine?
     
  19. PacaRacer50
    Joined: Oct 3, 2010
    Posts: 115

    PacaRacer50
    Member


    Yes this could be the stock Hornet engine. In 1951 the Hornet only has the head that says "H145" and "Super Power Dome". The "H145" stood for Hornet 145 Horsepower. The one 2bbl carburetor was standard. The head and intake will fit all 51-56 308 Hudson engines so the short block could have been replaced at some time. Also in 1951 all Hornets came with the same 308 2bbl engine. Twin H was only available over the counter very late in the 1951 year.
     
  20. PacaRacer50
    Joined: Oct 3, 2010
    Posts: 115

    PacaRacer50
    Member


    Yes the High Nickel Hudson blocks all the way through 1956 was one tough old block to do any machining on. New tools can take it without much problem but die grinder tools have a severely limited life span.
    On the four holes shown in photos 6 & 7 these are not subjected to oil pressure as the cam bearings do block these holes. I filled mine up with the black Mopar ATF-RTV then installed the cam bearings. Just trying to keep the outside of the block clean as they were weeping a little oil after a hi-boost run.

    pdq67... I am taking a Hudson 308 out to 386 cubic inches and plan on going to 421 on my next one. I really like those old Packards but I'm sticking with the King of the Flatheads... Hudson!

    thanks and more will be coming soon. Business at the shop restoring a 1950 Hudson PaceMaker convert with a 54 Hornet 308 2bbl engine is taking presidence.
    PaceRacer50
     
  21. hoggyrubber
    Joined: Aug 30, 2008
    Posts: 568

    hoggyrubber
    Member

    take your time, it's worth the wait! 421 cid- WOW!
     
  22. 4284555sd
    Joined: Jun 29, 2009
    Posts: 62

    4284555sd
    Member

    Could anyone tell me what a Twin H Power junk yard engine might be worth. It's all there Thanks
     
  23. 51hornetdude
    Joined: Jun 25, 2008
    Posts: 80

    51hornetdude
    Member
    from denver

    As long as it is a hornet and not a Jet, and it is complete with air cleaners, I would think $400 would be a pretty good price. You probably won't lose anything at that price and if it is nice, you could make a few bucks.
     
  24. 38FLATTIE
    Joined: Oct 26, 2008
    Posts: 4,349

    38FLATTIE
    Member
    from Colorado

    Do you have any flow numbers from a stock, or hi-po 308?
    Any idea on how those numbers change with the relief, and heavy port work?

    Have you, or are you aware of, anyone modifying the chambers, to keep compression up, while improving flow?

    What are stock cam specs? What options are there for cams? Dp you know what kind of lift the block' will allow, before it has to be modified?

    This is a great thread- Thanks for doing it! I'm not trying to 'beat you up' with these questions- you seem very knowledgeable about these engines, and I'd like to build a full out race Hudson!

    Thanks again.
     
  25. Gigantor
    Joined: Jul 12, 2006
    Posts: 3,805

    Gigantor
    Member

  26. demodriver
    Joined: Oct 1, 2006
    Posts: 49

    demodriver
    Member

    Some great info here. I will be staying tuned for updates.
     
  27. demodriver
    Joined: Oct 1, 2006
    Posts: 49

    demodriver
    Member

    I have read all the info that I can find on these engines but the one thing that I can not find is the torque specs for the bolts to put it back together. Im gettign ready to tear mine down and do the mods that are posted here and a few more. If all goes well mine will end up with dual grand national turbos.
     
  28. hoggyrubber
    Joined: Aug 30, 2008
    Posts: 568

    hoggyrubber
    Member

    i think the shop manuals for the specific year would have all the torque specs. also the hudson club at classiccar.com has online manuals that should have what you need. might take a little hunting and clicking. i prefer the paper copys myself, i want 24/7 access.
     
  29. ol Racer
    Joined: Dec 29, 2010
    Posts: 26

    ol Racer
    Member
    from McKean, Pa

    PacerRacer,

    I just stumbled onto your Tech Site and must compliment you for taking time to share your experiences of building Hornet Motors quite thoroughly and avoid some minor pitfalls and potentially motivate more builders of Hudson Powered Cars:). I couldnt add anything....Good Work & Great Info,
    Thanks,
    Ol Racer
     
  30. hoggyrubber
    Joined: Aug 30, 2008
    Posts: 568

    hoggyrubber
    Member

    had to dig up this thread just to read the oiling system mods. i want to try the washer. i switched out the oil pump gear with a new one from Randy Maas. was pretty easy and it sure fixed my dist "slop". glad it wasn't the timing chain.
     

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