1929 super six

Just purchased a 1929 Essex from a friend, car ran and drove but had a problem with vacuum tank but would run and drive when tank was filled manually. My friend sent the car to a local garage they tried installing a electric fuel pump but couldn’t get it to work right because pressure was too much. They found a working vacuum tank. Now the carb is getting fuel but will only idle but is no longer drivable, what do I need to check because I believe they did something to the engine while they had it for a month. I would like to know how to check the ignition timing also how to check if the timing chain jumped, the carb was checked and is clean and Venturi moves freely and carb body is as good at it was new and was working ok before shop touched it. Any help diagnosing the problem would be appreciated thanks. Tony, Ossipee, NH


  • Jon B
    Jon B Administrator
    edited September 2020
    Welcome to the group, Tony.  I'm sure someone will jump into this conversation with some good advice, since the '29's are especially popular with Hudsonites.  Just be patient, and check back often!

    Meanwhile, I don't know if you are a member of the H-E-T but, if not, you might want to consider joining.   https://www.hetclub.org/

    The New England Chapter is in your area, so -- whether you join the Club or not -- you might want to travel to their annual fall meet is on  Oct. 4 in North Attleboro, Mass.  Here's their webpage:    http://newenglandhetclub.com/ 

    It's always reassuring to have a network of hobbyists nearby, for quick technical help or t help find a much-needed part! 
  • Hans
    Hans Senior Contributor
    You wrote: ( Now the carb is getting fuel but will only idle but is no longer drivable )

    Please describe the operating conditions.

    Ie. is accelerator pump working so engine will speed up? 

    Or just there is no power to maintain any speed above idle?

    ( which sounds like plugged gas passage to the high speed jet, or the jet it self. )

    Also consider the Air Valve, will it move freely from resting at front wall  to a verticle position with no binding?  ( with spring removed )

    The spring in the recess inside the large brass knob is supposed to be 1 1/2 inches long.
    It is a calibrated "damper" in controling the Air Valve and is considered critical in the Marvel Repair Book.  

    Be careful, do not stretch the spring you have if it is only 1  1/16  inch long.  You may have the wrong spring OR  YOU MAY NOT HAVE A 1929 CARB.

    What are the numbers on the side of the carb,,,,,,,,are they 10-140 ?  if not what are they.

  • The engine idles but has no power with choke pulled 1/2 way more choke stalls it out same with no choke. But before garage had it I was cruising in it at 50 mph with vacuum tank filled manually, now the engine just has no power, garage said it didn’t touch the carb, if I can believe them, I disassembled it and inspected it to make sure jets are clear and like I mentioned in 1st post, carb looked as good as the day it was made cork float and all and it’s is a marvel v. I’m wondering if somehow the timing is off or valve timing is incorrect, engine is complete and looks like it was well taken care of, where can I get a factory manual for the engine and drivetrain? Any help I can get to diagnose the problem will be greatly appreciated, thanks Tony. Ossipee, NH

  • I’m  sorry yes carb # is 10-140
  • Geoff
    Geoff Senior Contributor
    There is no factory manual, apart from the Owner's handbook.  Do you have a timing light?  If so, point it at the rectangular slot in the right rear engine  plate and see if it aligns with the  D.C.1-6 mark on the flywheel at idle connected to No. 6 plug wire.   As an experiment, while holding the throttle open try winding the  knurled screw in and out and see if that alters the engine speed.   Is there any black smoke out the back?   it is unlikely valve timing would be altered, but it may be that the chains is stretched and jumped a notch.   Check with a feeler gauge in N o. 2 tappet (inlet on N o. 1 cylinder) and it should pinch just after t.d.c. Just a few suggestions.  You are welcome to email me at NZgeoffclark@xtra.co.nz  (leave off the front NZ) for further instruction.
  • barrysweet52
    barrysweet52 Expert Adviser
    Blocked breather hole in petrol cap, or blocked filter in top of vac tank?
  • I am wondering if t-chain jumped, or the garage messed with ignition timing. that is what it feels like to me the engine is just flat. The fuel is gravity feeding the carb i have the top of vacuum tank off and fill it manually, the fuel is free flowing to the carb the needle and seat is working and float is working, i haven't noticed any rich exhaust. The knurled screw on distributer adjusts the ignition timing? I will try putting the timing light on it and see where the timing is. where should the timing be at? thanks again Tony. Ossipee, NH.
  • lostmind
    lostmind Expert Adviser
    Check the point gap , they may have changed it.
  • rusty_apache
    rusty_apache Member
    edited September 2020
    Is the cork float still present?
    Ethanol fuel attacks rubber and the lacquer the factory coated the cork with. It can easily clog up the main jet. I replaced mine with one made from synthetic material. It’s about $50 for a chunk of plastic, but worth every dime! Also the air valve Venturi swelled up slightly on my marvel v, causing the air valve to stick. I carefully filed it back down just enough to allow for unrestricted movement. 

    Your fuel cap has no vent, the tank itself is vented at the the fuel pickup tube. 

    With the engine at idle, you should hear the float cycling through it’s operation with a slight click every few moments.

    Set #1 at TDC, and locate the timing mark, set your contact so that they are just beginning to open. Here’s a link to the instructions in the manual and a photograph of the timing marks on my ‘29. 

    It’s highly improbable that your timing chain jumped. That’s what timing belts do.
    Dont rule out an electrical issue either. Coils and condensers can do funny things at 92 years old.
  • Yes I understand but before garage touched it I had two adults and three kids in it doing 50 mph up my road which is a incline. they tried a 6 volt fuel pump and couldn’t make it work because pressure was too high they found a good working vacuum tank and installed it and from what they told my friend who owned it at the time that it only idles and has no power. My friend flipped out and used his trailer to get it home and put it up for sale the car was so beautiful inside and out someone had restored it to new like condition, I had to have it. It’s hard for me to believe that it isn’t something simple Because the way it was running before garage touched it. I have read a lot about how the pot metal the carb is made of deteriorates, swells, and crumbles, this carb is as clean and solid inside and out like the day it was built Venturi moves freely and the accelerator pump looks ok just a brass plunger Jets are clear sprayed carb cleaner through them to check them. But without some kind of instruction with this engine I am not familiar with. I do not want to do more harm than good. I will check the points and ignition timing and let you know what I find. thanks for All your help it is very appreciated If there anything you think I should check let me know thanks again. Tony Ossipee, NH.

  • Sorry, I read the entire thread and realize I was giving you redundant information. That can be frustrating! 

    Forgive me but I don’t know your level of mechanical abilities, but the beauty of these machines is their simplicity. I am convinced that you have a fine, solid engine with one small complication that has cropped up.
     These things happen when a consumer product has outlived it’s own life expectancy for several generations! 

    Coils, plugs wires and condensers can fail suddenly exactly like you are describing. Even under the loving care of a mechanic. 

    Even if they are new, or were new years ago.  
    ESPECIALLY if they are brand new. 

    Check the color and intensity of the spark and note the color of the spark plug ceramic. 

    Check the condition of the ignition contacts for pitting. A helper could have inadvertently left the key on and burned them. 
    Again, very basic, was the accelerator pump accidentally set to summer? 

    You’re going to figure it out soon and it will be a victory!
    Be of good cheer that you have no need to connect to a computer, buy $500 worth of ignition coils or carry around both metric and SAE tools!

  • Geoff
    Geoff Senior Contributor
    I'm talking about the knurled screw on the carburettor.
  • The air screw on the carb seems to be functioning, while idling when screw is moved A few clicks in either works direction there is a change in idle speed and smoothness of idle. Mixture screw seems to work like your typical mixture screw should, I have been working a lot lately I am off Sunday I will bring my timing light and dwell meter home from work and I will let you know what if anything I have found, thanks again for your help. Tony. Ossipee, NH

  • Having recently gone through the vacuum tank versus fuel pump, one thing I have found quite readily the idle  jet plugs...causing you to run the engine pretty flat at about half choke, you will probably be lucky if you can get the car to go more than 15 miles an hour  It will probably be easier just to remove the whole carburetor And then separate the bowl from the barrel and check the idle jet and the high speed jet.  Remove them completely and hold them up to a light and look through the barrel of the metering jet.  It is very surprising how a small piece of dirt can screw up a good Marvel carburetor. Give the air valve a good thorough cleaning with an oxide reducing polish,  mine gummed up in five days just sitting there. 

    As for the electric fuel pump, you need to include a pressure reducer and get the psi to under 1/2 pound. I mounted mine under the rear seat to help take advantage of any line drag between the pump and the carburetor.  Also include a filter prior to the pump. I adjusted my fuel bowl float down about an eighth of an inch for additional back pressure on the inlet needle.  

    I have a question here folks...having done away with the vacuum tank, do I still need to maintain any vacuum to the carburetor?

  • Geoff
    Geoff Senior Contributor
    There is no vacuum to the carburettor.  The only vacuum fitting is above the carburettor, and goes to the vacuum tank and the wipers. 
  • bob ward
    bob ward Senior Contributor
    I like the fuel pumps these guys make, their range includes a 6V +ve earth low pressure version, no need for pressure regulators. 
  • supersixer
    supersixer Member
    edited October 2020
    yes I have taken carburetor apart removed jets cleaned and reinstalled with no change. Tomorrow I will check for quality of ignition spark, ignition timing and engine vacuum, will let you all know what I find. Thank you all for your help, Tony Ossipee, NH.
  • lostmind
    lostmind Expert Adviser
    Check to see if your manifold is burned through , allowing exhaust to enter intake. It's common. Remove the square cover on top of manifold and inspect.
  • I will do a vacuum test to see if manifold vacuum is low, thanks for the info,Tony. Ossipee, NH.
  • Today I checked for a good spark and found no problem, cork float in carb must be saturated with gas, the needle and seat no longer seals causing carburetor to leak fuel when not running. I installed a nipple fitting on vacuum port and installed a vacuum gauge with choke on and engine running at idle with no power I have a very low reading 5hg surprised it even runs at that low intake vacuum. So I’m figuring it is either late valve timing or exhaust manifold is cracked or burned through. What do you think the more common problem with this engine is? timing chain jumping or manifold burned through? Thanks, Tony. Ossipee, NH.
  • The timing chain is a substantial beast, I have a hard time imagining that it would jump a sprocket cog.    Alignment with the TDC mark and spark to #1 cycinder should rule that out.

    You might try recoating the cork float with airplane dope found at any good hobby store. 
    are you getting any fuel from the vacuum tank?  (these things are particularly touchy,  that is why I went back to an Electric fuel pump)  A poor seal on the top gasket will cause you all sorts of misery.  With only 5 inches of vacuum you may not have enough to pull the fuel out of the tank even if everything was operating properly. 
  • You can get a new carburetor float for the Marvel carb, and gasket from Bob’s Automobilia in CA
    He sells Buick parts and has repro. Marvel parts. The new floats are made of a new material instead of cork.  I suspect that the Venturi tube in your manifold is burned out. I had to replace it on my 29.  Check with Then & Now Automotive in Weymouth MA for a Venturi tube. Talk to Tom or Lisa.
  • Geoff
    Geoff Senior Contributor
    Vacuum at idle should in the range 19-21.  If the intake was burnt through it would not run at all at idle.   Check the valve timing.  Intake valve should open just after t.d.c. 
  • Thank you for your response where is the venturi tube? and how can I inspect it? can you post a pic. i purchased a carburetor float made of modern materials 
  • I will check the valve timing and see where it’s at, to me it feels like the engine jumped time, if it was ignition timing being late my reading would have been low around the 12 to 14 hg only late valve timing or a severe vacuum leak would explain the very low reading I am getting. I will keep you all posted on the results of the next line of testing. Thanks for all the help. Tony. Ossipee, NH.
  • lostmind
    lostmind Expert Adviser
    Thank you for your response where is the venturi tube? and how can I inspect it? can you post a pic. i purchased a carburetor float made of modern materials 
    My 29 Hudson ran , poorly at idle with the intake burned through.
    I posted earlier that there is a square cover on top of the manifold ( 4 bolts?)
    Remove it and look inside , I was able to see it burnt through the side.
    I had a sleeve made and installed it from the top.
    This was in the late 1970's , but my memory is still fairly good?
  • Geoff
    Geoff Senior Contributor
    This is an Essex, not a Hudson.   The heat exchanger is completely different.
  • lostmind
    lostmind Expert Adviser
    Geoff said:
    This is an Essex, not a Hudson.   The heat exchanger is completely different.
    Sorry , I came in a little late and didn't read the first post. thanks for straightening me out. I can't help with this , but I'm sure you can.
  • supersixer
    supersixer Member
    edited October 2020
    I brought up #6 to tdc And cyl#1 intake valve ready to open, points just starting to open. the riser is solid no leaks, spark plugs carbon fouled, plugs were just installed before I purchased the vehicle. looks like I'm back to square one.