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Technical new in Dodge Flathead 6 - any improvement available?

Discussion in 'The Hokey Ass Message Board' started by GTfastbacker, Aug 21, 2023.

  1. IMG_1309.PNG Thank you Gentlemen for all your input !!!

    First intention was to buy performance stuff soon to throw it in trunk for saving shipping costs.
    The reds headers I will order torday, maybe will do a antrazith ceramic coating for better look.

    These Transmission is a Mysterium to me. The big cylinder on the left is maybe a power clutch?

    Have to wait 12 weeks to get the car in my garage... enough time to philosophy about the engine

    Joe from
    Germany
     
    Last edited: Aug 23, 2023
  2. Looks like that cylinder ia a vacuum assist. The park brake is that drum gizmo on the tailshaft.
     
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  3. 62rebel
    Joined: Sep 1, 2008
    Posts: 3,233

    62rebel
    Member

    It'd be a good idea to join another forum for more information just because; the P15/D24 forum. They love the flathead six and know more ways to wring another pony out of one than ways to skin a cat.
     
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  4. Budget36
    Joined: Nov 29, 2014
    Posts: 14,441

    Budget36
    Member

    If you’re considering milling the head, you should verify valve clearance first with the cam in it, and especially if you may change it. Some use clay, some use loosely wrapped balls of foil. I’ve always read that they snug the head down without a head gasket, then the head gasket, then the gasket provides the clearance.
    I’ve never had the need to do it on a flat motor, so can’t give specifics. I used to read about it on the FordBarn, consensus seemed to be you really never know if the head was milled before.
     
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  5. RodStRace
    Joined: Dec 7, 2007
    Posts: 5,567

    RodStRace
    Member

    These guys have you covered, but I'll mention a couple obvious things.
    The flathead was never a HP engine, and even if you do all the usual hop up things, it still has old breathing and bottom end. A twin cam, cross flow conversion is still going to be limited by the rest of the original design. It was over-engineered for it's original output to last a long time. Asking it to provide 3 times as much power is not happening without a huge amount of effort and still a vastly shortened lifespan.
    You also have the additional issue of residing in Germany. From what little I've heard about car regulations there, you can't go too crazy with mods. I'd say resign yourself to piloting the car like it was a prewar German car that will remain nameless.
     
  6. I know the Low-formance from my 33 Rockne Flat6. Torque isn’t that bad, but it’s not a rocket.
    I will not open the engine or do something big, was only looking for some hp thru contemporary adaptation/ optimizing.
    When i need the speed, i can drive my 427 Ford..
    So at the end my choice will be split headers for the sound, Bigger 2Barrel or double Carburetor (will see what i get) and a 12V conversion with better Distributor.

    That should be enough for the ol Dodge
     
    Last edited: Aug 23, 2023
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  7. tubman
    Joined: May 16, 2007
    Posts: 7,364

    tubman
    ALLIANCE MEMBER

    Do not overlook optimizing the combustion chamber quench and increasing the compression (if you do it right, they both happen at the same time). It is the cheapest (and in my opinion) the most effective way of getting more performance out of these old engines.
     
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  8. Pete1
    Joined: Aug 23, 2004
    Posts: 2,261

    Pete1
    Member
    from Wa.

    That engine is the same basic design as the early Ford and it will respond to the same hot rod techniques as they do.
    Speed equipment is rare these days but it is out there. Cams are easy to find.
    The larger Chrysler industrial model of that engine of that era will bolt into that car easily and require much less work to go fast.
     
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  9. I wait until the car arrives. Then i will drive it a lot, if i think it’s a dog after, this will be a great option. so i can keep the original engine untouched.
    Thank you
     
  10. gene-koning
    Joined: Oct 28, 2016
    Posts: 4,582

    gene-koning
    Member

    Eons ago I picked up a 40 something Dodge 4 door sedan that had the straight 3 speed trans. The car was a pile, but I couldn't resist spending some time getting it running. Didn't really take very long. The car only had the drive shaft brake drum for brakes, but I took it for a short ride up and down the gravel road in front of my house. I did take the car on that same short ride several times in the year the car hung around. Someone wanted it more then I did. Have no idea what he ever did with it.

    All these years later, I still remember how surprised I was by the car's acceleration up through 2nd gear. It was much better then I expected it to be. Not a race car by any means, but would have been OK for normal driving up to 60 mph.

    I also drove a few other 40s Mopars with the fluid drive, most were dogs compared to the straight 3 speed Dodge.
     
  11. George
    Joined: Jan 1, 2005
    Posts: 7,818

    George
    Member

    my understanding is the radiator is moved forward for clearance.
     
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  12. tubman
    Joined: May 16, 2007
    Posts: 7,364

    tubman
    ALLIANCE MEMBER

    Pete, is there an industrial model larger than the 265?
     
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  13. Los_Control
    Joined: Oct 7, 2016
    Posts: 1,182

    Los_Control
    Member
    from TX

  14. tubman
    Joined: May 16, 2007
    Posts: 7,364

    tubman
    ALLIANCE MEMBER

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  15. Los_Control
    Joined: Oct 7, 2016
    Posts: 1,182

    Los_Control
    Member
    from TX

    I really was just intrigued by your question & looked around.
    They truly are physically different while at the same time they are a Dodge flathead 6?


    https://www.curbsideclassic.com/blo...s-engine-could-well-be-bigger-than-the-hemis/

    This is a 1952 or 1953 Dodge truck. As best as I can tell, the hemi V8 was first available in Dodge trucks in 1954 (1954 Dodge truck CC here). Chrysler also built some really big flathead sixes, for the big trucks and other industrial uses. That family started in 1937, and went from 282 cubic inches all the way to a mighty 413 inches, in ’53 – ’54 trucks. These were physically much larger engines than the Chrysler automobile and light-medium duty truck flathead sixes, and they had 12 ports and dual carbs. The 413 was an absolute torque monster (424 lb.ft.), and was rated at 177 hp, almost the same as the 331 hemis in these Chryslers. Here’s a picture of that mighty flathead:
    [​IMG]
    As I said, it had 12 ports, unlike the passenger car sixes, and genuine split manifolds for both the intakes and exhaust. On the 413, bore was 4 1/16′ and stroke a mighty 5 5/16″. It had a rep for a bit of a drinking problem.

    Of course that Dodge truck could be sporting the 111 hp 250 six; there’s no easy way to tell from this picture
     
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  16. I love the design of these Old Coupes.

    Will add a Fulton Visor and Fender Skirts. that's it.

    Bildschirm­foto 2023-08-25 um 10.09.59.png

    Bildschirm­foto 2023-08-25 um 10.10.04.png

    Bildschirm­foto 2023-08-25 um 10.10.10.png

    Bildschirm­foto 2023-08-25 um 10.10.16.png

    Bildschirm­foto 2023-08-25 um 10.10.23.png

    Bildschirm­foto 2023-08-25 um 10.10.52.png
     
    Last edited: Aug 25, 2023
  17. You guys are the definition of squares lol.
    It's even better in a vintage car.
    Cars are meant to be driven not pampered.
    Old cars no matter which way you cross it are essentially a novelty or an adult toy just as they have been so they're meant to have fun with, I don't think any car guy including the guy doing a burnout is deliberately trying to break their car and most people that drive an old vehicle can usually repair them and know the consequences of their actions.
    That being said I am no longer a big burnout guy (I don't like fixing rear axle bearings, U joints, clutches or potentially rod bearings in 70 year old engines) but I have no problem with seeing the bias plys or radials turned into asphalt crayons and on occasion I may still evendo a burnout, endless power brakes where you "cook off" half the tread I am past that age But watching a burnout competition at a car show is still entertaining and it's even better when it's something like a slammed Model A tudor just getting sh*tty either doing donuts or wasting some coker repop tires.
    My point is life is too short to worry about what other people are doing let them haze their tires.
     
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  18. That is a clean little business coupe.
    I have always wanted one of those up and until a few years ago they were pretty cheap and I never manned up and bought one. Now they are worth a little bit of money and I'm too just to cheap to buy one but I still like them a lot and it's definitely a bucket list car. Honestly I'm surprised they are as cheap as they are since they are one of the only true coupes left In the '40s and '50s. Such great looking cars.
    You found a great find.
    By the way I have a 1960 Dodge d100 3-speed on the column flathead 6 long bed pickup (1960 is the last year the Flathead six cylinder was used in a vehicle, it was used in industrial type equipment all the way into the late '70s but don't quote me on that). What I will say It's a wonderful engine I wouldn't say it's a powerhouse especially for modern standards but it's an excellent engine It could easily keep up with the Chevy stove bolt 6 and the Ford overhead valve 6 cylinder of the same era and Not that it means anything but my pickup truck is slightly faster than my old Rambler flathead six So by no means is it a slouch for its era.
    Like everyone else has said compression ratio is going to be one of your biggest helps. Back in the early '40s I want to say the compression ratio was right around 6.0:1 or 6.5:1 and throughout the 1940s and '50s the compression ratio got better My 1960 I believe is right at 8:1 It's a pretty significant difference as my truck makes 120 hp and I believe right around 200 ft lb of torque. I think your coupe made right at 100 maybe 105, 15 to 20 horsepower may not sound like a lot but it's pretty significant when you think about it in percentage terms I believe the later head is a straight bolt on (The engine in my truck is actually a 53 Plymouth and it has the 1960 cylinder head intake and exhaust bolted on to it and It runs fine but please double check don't buy something without doing some research.
    If you want to rod the engine There is or at least was (as some of this may not be made now), four barrel intakes out there, twin two barrel intakes split exhaust manifolds, tube headers, finned aluminum heads, more aggressive camshafts at the normal hop up parts that you see for pretty much every vintage engine. Now that being said this engine died in 1958 in cars and 60 in trucks it's a really old outdated engine at this point A lot of the performance has dried up and on eBay the parts can get pretty pricey pretty quick if you get a couple of guys bidding for the parts unfortunately you being in Germany you can't hit the local car swap meets although that being said I've had my truck for at least 10 to 12 years now and I've only came across a handful of performance parts at the local car swap meets here in Southern California and all of them seemed kind of pricey And it isn't like the truck is a total slug It's not fast by any means but considering what little bit of power those performance parts actually give it's hard to justify the price.
    I think for you I would figure out if the later head will fit on the earlier block because the stock late '50s flatheads are fairly common and you should be able to come across a stock head for pretty cheap I can't imagine too many people are buying them and even with shipping it shouldn't kill you even though it's kind of heavy it's only an inch and a half thick by 27ish long so it's pretty easy to package.

    Anyways as I said great find it'll be a fun car keep us posted on what you do to it.
     
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  19. G-son
    Joined: Dec 19, 2012
    Posts: 1,418

    G-son
    Member
    from Sweden

    Also think about that being the peak power, at one usually rather high rpm. On your usually far lower cruising rpm the available power will be far less, and the power improvement may be far from linear - in other words, the improvement on the rpm you use most may be far bigger or smaller than the change in peak power may suggest.
    Different forms of tuning give different results, some work best for low rpm, some work well for all rpms, others may only give a high rpm improvement, sometimes even reducing low rpm power. Very common for people to bolt on bigger carbs, high rpm cams etc, missing that they in reality wanted more power at cruising rpm - they may get loads of extra peak power, but they would have to go to a lower gear to access any of it - making the car feel even more sluggish going uphill on the highway in high gear!
     
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  20. Yes you are right. I would prefer more torque instead of HP. My Wife's starliner 352 is a heavy car, but its torque propellered it very fast at the traffic light. That's what count. more than 60-70mls I will not drive such an old car.

    So what's the best way to impair the torque?
     
  21. Oh I know these swap meets in US very well. Been in Carlisle PA and Columbus many times and saw a lot other Shows and Meets. The most Problem is to find the needed part just in tis small time slot while I am there...
    Personally I like the originality of these Coupe very much, I don't like to tinker it. Some good improvements yes, but not like a hot rod or a fair carousel.
    Changing the head isn't rocket since, maybe I can find a head for a reasonable price and throw it in trunk for shipping. Shipping by parcel service becomes unbelievable expansive the last years.
    I shipped a 9" Ford rear in 3 separate Boxes for 60 Bucks all together by UPS 20 years ago. Same thing will cost today more than $500...
     
  22. Budget36
    Joined: Nov 29, 2014
    Posts: 14,441

    Budget36
    Member

    As far as the head goes, I’d bet bolting on an aluminum head vs milling your head, you wouldn’t notice the difference except for a smaller bank account.
    I’d focus on intake and exhaust.
     
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  23. vintage6t
    Joined: Jul 30, 2007
    Posts: 398

    vintage6t
    Member
    from CT

    That cylinder is an optional vacuum shift assist. Should be connected to the shift linkage. When working correctly it allows you to shift with a very light push of the shift lever. The other tell-tale sign of this option is the chrome winged knob on the shift lever. Cars without shift assist will have a typical bakelite/plastic knob.
     
  24. chicken
    Joined: Aug 15, 2004
    Posts: 594

    chicken
    Member
    from Kansas

    Compression. It adds power everywhere but very good at lower rpm. Ignition timing curve will help too...experiment to find what the engine prefers with the fuel being used.

    Terry
     
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  25. George
    Joined: Jan 1, 2005
    Posts: 7,818

    George
    Member

    Always thought those look like crap....
     
  26. G-son
    Joined: Dec 19, 2012
    Posts: 1,418

    G-son
    Member
    from Sweden

    I think you want to improve it, not impair it. ;)
    These are not engines I'm used to, but I would agree with Chicken.

    Increased compression (within reason) tends to improve just about everything, meaning more power on all rpm and better fuel economy as a bonus. Just don't go so far so you have to run it rich or back off ignition advance to keep it from detonating, at that point you are robbing Peter to pay Paul.

    Getting the ignition timing right on all rpms AND on all throttle openings is also important to unlock all that potential performance the engine holds. I don't know how advanced your distributor is, but generally you want both centrifugal advance and vacuum advance. The centrifugal advance adjusts according to rpm, and vacuum advance adjusts according to throttle position. Distributors w/o vacuum advance was fairly common once, at full throttle they perform the same, but they keep the engine running with the ignition less advanced than ideal on part throttle - and as you know, street driven cars spend most of their life on part throttle, so that should make a descent difference on how much throttle you need to get enough power to cruise down the road, and in turn the fuel economy.
     
  27. distributorguy
    Joined: Feb 15, 2013
    Posts: 111

    distributorguy
    Member
    from MN

    Most of those distributors had a vacuum unit built into the clamping assembly. If yours doesn't have it, search Ebay for a 50's model distributor and make the upgrade. Most of these you could set timing to 16 BTDC at idle with no ill effects, unless the springs were stretched BUT the spring posts are "adjustable" so you can add a little tension as needed.
     
  28. 27 MoPar T
    Joined: Mar 7, 2023
    Posts: 45

    27 MoPar T
    Member

    I built that engine in 2008. It was a P25 230 out of a 1954 4 door Plymouth Belvedere. The rotating assembly was balanced, had EGGE pistons and what Delta Camshaft in Tacoma Wa called an RV cam in it. Carbs were Holleys on an Offy 2 x 1 manifold and a set for langdons cast dual headers. It was backed up by a 2 speed powerflight. I lost interest in the car and sold the engine to @Dynaflash_8 around 2010. Marty ended up putting it in a 47 Plymouth and taking in on the flathead reliability run to vantage that year. Ended up spinning 5 out of 6 rod bearings racing a fox body mustang up snoqualmie pass. filled the crankcase with all the oil he could find at the summit and splash oiled it all the way to Vantage and back to his house in Auburn before it gave up the ghost. Upon teardown it turned out that one of the rods twisted and it squirted a wrist pin out and scored a cylinder too.

    I suspect with a full flow oil filter mod and a shim job on the oil bypass to raise the bypass pressure that it would have survived. but Marty and I were teens at that time and didn't know what we know now. If I build another HyPo Flatty (I have a spare P24 218 for my T) I'll be modifying the oiling system for better filtering, pressure and volume while also looking at running heavier beam rods so they don't whip and twist.
     
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  29. proartguy
    Joined: Apr 13, 2009
    Posts: 704

    proartguy
    Member
    from Sparks, NV

    Looks like a pretty nice Dodge. I am sure waiting for the long boat ride delivery is frustrating.

    I understood that rod problems can happen if those engines are run at higher rpm and that is why I did mods (compression, carb, exhaust) to increase torque rather than rpm, and use an overdrive. Not to mention a manually operated overdrive gave an effective 5 speeds and to better utilize the narrow (1500-4000) power band. If I was doing one now a 5-speed trans might be a better setup.

    The 251/265 are around, but the speed equipment has always been very rare. My ‘53 Dodge truck required the front crossmember to be notched for the longer (2”) 251 swap.
     
    Last edited: Aug 25, 2023
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  30. Rusty O'Toole
    Joined: Sep 17, 2006
    Posts: 9,711

    Rusty O'Toole
    Member

    First thing, these engines are foolers and will continue to run without protest in an advanced state of wear and decay. They just get slower, hard to start, and burn more gas and oil.
    Therefore the first thing to do is check the oil pressure and do a compression test. If you have 30 PSI at 30 MPH and 100 PSI or better on all cylinders, you have a good engine.
    If not, the first thing to do is an overhaul or rebuild.
    This may be all you need. I know guys who wanted to hop up these cars, started by rebuilding the engine, and were surprised at the new found power and performance. They are never going to win a drag race but have enough power for all practical purposes. High torque is very handy in every day driving.

    Second thing is, yes there are speed parts available but they are expensive, like $600 or more for an aluminum high compression head and $300 for a 2 carb intake and extra carb.
    To me, the best bang for the buck is supercharging. For various technical reasons flathead engines respond well to supercharging especially a centrifugal supercharger or turbocharger.
    The cheapest would be a turbocharger. I believe they can be bought new off the well known jungle site for around $150 bucks. Then you have to make up your own pipes for intake and exhaust, etc.
    The drawback of the turbo is it can cause excess heat in the exhaust valves, and exhaust valve seat area. This should not be a problem if you keep the pressure down to 5 to 7 pounds and have a free flowing exhaust.
    A Paxton or McCulloch centrifugal blower could also be adapted and sometimes they turn up used off Mustangs and Camaros. And, guys have made their own belt driven centrifugal blowers from truck turbos.

    Then there is the larger Chrysler/DeSoto six, up to 250 or 265 cu in and 132HP. Nearly a bolt in, you have to move the rad and front motor mounts forward about 2 inches to clear the longer motor. They do turn up cheap from time to time in junk yards, or guys take them out to put in a V8.

    So, there are possibilities. I would start by putting the engine in top shape if it is not already. This step can't be skipped, many a worn engine would have gone for years if it was babied, but will blow sky high in a month if you hop it up. So, good bearings, oil pressure, pistons, rings, valves etc are vital. You may even find that a good running stock engine is all you need.
     

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