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Subject: Welsh (Freeze) Plugs on a 9N Engine

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Dan    Posted 11-08-2006 at 16:36:15 [URL]        [Reply] [No Email]  
  • Welsh (Freeze) Plugs on a 9N Engine
  • I have seen several references that say Welsh plugs did not show up on the side of the engine until 1940. I have a mid November production 1939 9N tractor serial number 9N 5429 that has two Welsh plugs on the left side of the engine. One behind the oil filter canister and one directly behind the starter. These are not just holes drilled in the side of the block, there are raised rings around the hole in the casting like you see around Welsh plug openings. Since these plugs are on the same section as the serial number, there is no way this is not correct.

    Welsh plugs ARE INDDED on the 1939 9N engines and showed up before 1940. Can anyone state their serial numbers and if they have these plugs? This way we can pinpoint about what serial number these plugs started showing up on the 9N engines.

    Dan

    Farmer Dan    Posted 11-12-2006 at 23:05:01 [URL]        [Reply] [Email]  
  • Re: 1604 - 1773
  • Sounds like they appear between 1604 and 1773.

    Would that be correct? Or should we wait for more verification?

    Joe T    Posted 11-10-2006 at 21:36:02 [URL]        [Reply] [Email]  
  • Re: Welsh (Freeze) Plugs on a 9N Engine
  • One thing I am curious about is are they really freeze plugs? It appears these blocks crack easily. Do they ever pop out to protect the block during a cold spell?

    Assuming the antifreeze isnt adequate.

    Joe

    Dan    Posted 11-11-2006 at 09:12:50 [URL]        [Reply] [No Email]  
  • Re: Welsh (Freeze) Plugs on a 9N Engine
  • Freeze plugs are the "common" name for these plugs. In theory - if water turned to ice and expanded in the block, some thought this plug would pop out and allow the expanding ice to have a pressure release. In reality - it does not work like that. These holes were put in place as a way to remove the required sand in the block casting process. These metal plugs just seal the hole back to watertight.

    HTH,
    Dan

    Dan    Posted 11-09-2006 at 18:32:26 [URL]        [Reply] [No Email]  
  • Re: Welsh (Freeze) Plugs on a 9N Engine
  • From another owner on another forum:

    "ser no 1773 and 2363 have the plug behind the oil filter and I"m sure behind the starter but I can"t verfy without removing the starter."

    Dan    Posted 11-11-2006 at 09:09:26 [URL]        [Reply] [No Email]  
  • Re: Welsh (Freeze) Plugs on a 9N Engine
  • From another owner:

    9N1604 has one plug on the back side of the block.

    Matt


    Gaspump    Posted 11-08-2006 at 19:58:30 [URL]        [Reply] [No Email]  
  • Re: Welsh (Freeze) Plugs on a 9N Engine
  • Can't figure how any N engine could have been cast without Welsh Plugs. How would they effectively remove the pattern sand without them?

    Farmer Dan    Posted 11-08-2006 at 20:35:51 [URL]        [Reply] [No Email]  
  • Re: Welsh (Freeze) Plugs on a 9N Engine
  • The casting plugs are on the end behind flywheel.


    I think.

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