Hello...I want to install OEM 6V temperature sensors in my '57 292 heads and get the dash temp guage to work. The car came with a freeze plug in the passenger side hole where the temp sensor is supposed to go. The driver side has a threaded insert installed for an aftermarket sensor that is too small to accept the OEM sensor.

I've not done this before. Can I buy threaded inserts that press into the freeze plug holes...or do I need to thread the existing hole in the passenger side and drill-out & thread the hole on the driver's side? Thank you for your response in advance...Bob 

Factory Y blocks do not use a temp sensor on the passenger side, only on the driver's side where the threaded hole is.  You can re-thread the existing hole, or buy a new bushing from one of the part suppliers like Carpenter or Concours, or Macs, etc.  The early cars had a 3/8 pipe thread, after '57 they went to 1/4 pipe.

John - "The Hoosier Hurricane"

John...appreciate the reply...I think you are correct. I should probably tell the whole story as to why I am trying to do this. The '55 fairlane I have came with a 272 engine. The 272 came with two sending units as I read in my '55 Ford service manual. So...somewhere along the way, someone swapped-in a '57 292 as indicated by the casting numbers on the block.

I am not very knowlegeable on engine designs. I think the 272 & 292 have similar engine heads, I could be wrong....probably am, but there is a freeze plug in the 292 passenger side that I have that looks to be the same spot that exists on the 272. So, I guess I am trying to retrofit '55 parts on a '57 Y-Block.

I guess that would also explain why the bushing threads are so small on the driver's side...probably took a smaller 12v sending unit...Bob

Redline,

As I recall from very many years ago, the earlier '55's had a thermal sensor on the passenger's side wired in series with a thermal (overtemperature) switch on the driver's side. Normally, only the thermal sensor is active (with the thermal switch held closed) and controls the operating current to the dash gage; however, if the driver's side gets too hot, it actuates the switch to open, which lets the gage go all the way "hot", indicating a problem.

It was changed quite early-on to a single thermal sensor in the driver's side only, with no switch opposite.  This King-Seeley gage system (both temperature and fuel gage are similar) is very simple and can work very reliably and well when in calibration.  It is an "oddball" system of which not many people clearly understand how it actually operates (search for earlier posts of mine which describe the system  -  this will also explain why both the fuel and temp gages are at their 'top' with the ignition key off).

The '54 & '55 system is uniquely a 6-volt only system, with the '56 & 57 being uniquely 12-volt only (the parts will not work well together if mixed), with '57 & up being a completely different design and totally incompatible with earlier systems.

I am trying again to briefly explain, because I've seen numerous incorrect statements here regarding these particular gage systems  -- with the apparent result of perfectly good parts being scrapped as a result of mis-information  --  makes me cringe!  I'll get off my soapbox now!!!

I hope that this helps you and others.

Regards,   JLB

55 Ford Crown Victoria Steel Top

Folks,

I misspoke: The '56 is uniquely 12-volt, with '57 & up being totally different!

Regards,   JLB

55 Ford Crown Victoria Steel Top

You can get new bungs with the correct size holes. The TBird parts suppliers have them, Mac's might have them as well. There was no sending unit from the factory on the passenger side. Since 54, the temperature sender was always located in the drivers side head. 53 was the last year Ford had the two temperature senders.

54 Victoria 312;  48 Ford Conv 302, 56 Bird 312
Forever Ford
Midland Park, NJ

Hi Guys! This topic was discussed back on April.The topic # is 42652.If you find that discussion I think you will see that in the end only the one in the left head is required.The one in the right head when installed is a "thermal switch":Not all 55 's had the second sender installed.Before you go to the trouble of installing one in the right head you may want to read through this previous post.

  

Here’s the link.

http://www.y-blocksforever.com/forums/Topic42652-3-1.aspx

Lorena, Texas (South of Waco)

Hi, I'm new on here and don't want to start an argument but my fuel gage goes to M/T when the switch is off, not "both the fuel and temp gages are at their 'top' with the ignition key off". My In fact every '55 I have owned the fuel gage goes to M/T and the Temp goes Hot (or Top as you say)

"The Master Cylinder"

Enjoying life at the beach in SOCAL

M. C.,

I don't take your comments as an argument - always open to more enlightenment; I put my comments in here only to try & help other's: I'm really interested to know of other's experience with '54, '55, and '56 guages' response to "key-off", as the only ones I've ever seen (100's of them - mostly at Crown Victoria Association meets) have all "topped-out" with key off (the King-Seeley system).

I'm now wondering if there was an alternate system issued from the factory with some cars; or, if there were other systems used in trucks-vs-cars, etc.  As I asked in a previous post about this some months ago, what are others' experiences with car guage systems of those years?

Old Cars Weekly had an article about the same King-Seeley system last year (?), which corroborates my experiences: The answer to this question may very well be that there were multiple systems used.  Anyone else???

Regards,  JLB

55 Ford Crown Victoria Steel Top