Temperature sender


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By DryLakesRacer - 10 Years Ago
Replacing sender.

Should I put sealer on it or leave the threads in the head and sender clean.

Does it needed to have the body of the sender grounded to work properly?

Anyone ever attached an ohmeter to the sender and heat it up in water with a thermometer and see the value change? The new one is 46 ohms and the one I'm replacing is 41 ohms. The gauge was never very steady and I blamed it on the thermostat opening and closing. It is a high flow 160 degree unit.........Thanks
By paul2748 - 10 Years Ago
The sender is grounded by the threads.

Never did an ohm check
By Ted - 10 Years Ago
As a general rule, brass on brass does not need any sealer.  For those applications that are not brass on brass, then I like to use Teflon tape.  By lieu of the tapered thread design of the pipe threads, there will still be some metal to metal contact even when using sealer or Teflon tape on the threads.
By DryLakesRacer - 10 Years Ago
Installed the new one (46 ohms) and it took forever to come off the "C" . Drained down the coolant and reinstalled the original (41 ohms) I put Perm #2 on the top 2 threads just a precaution. Temp gauge stays near the mid range now without much movement and went up as the car heated up. As stated on another thread; reading with a infrared gun the brass on the sender reads about 15* cooler than the the thermostat housing and that's after 20 minutes of driving.

Now I need to go after the PS control valve leak since I fixed the pump leak...One thing after another......JD
By lyonroad - 10 Years Ago
Don't worry JD, it never ends.  That way you always have something to do and if you pay yourself you'll be rich.
By DryLakesRacer - 10 Years Ago
Since I mentioned the power steering leak after 2 years all of the P/S problems are hopefully handled. One thing I hate are leaks and the P/S seems to have plagued me for 2+ years. Originally the control valve did not work properly but was repaired when a small burr was found; then minor leaks showed up. The hoses were original or very old so they were changed and less oil was noticed. While doing othe engine work I noticed red oil under the pump when wiped with a white paper towel. So off it came and a new seal kit installed by a brake/steering shop near me. I was hoping the dripping would have stopped off the threaded end of the control valve, in my mind it was coming from the pump and going down the hoses. No such luck.
With a repaired pump the leak was still there. I had bought a seal kit from C & G so I took off the control valve and went back to the same shop to have it looked at. They are able to test all control valves before it's given back. I measured everything and even counted threads too to put it back where it was and now no leaks................:<Wink  

I wonder what will be next....not complaining just wondering...JD
By DryLakesRacer - 10 Years Ago
With all the above I believe I believe actually have my temp gauge/sending unit problem cured.  First the car looked like it heated up in stop and go traffic didn't think it was real but bothered me anyway with the sender bought with the car needle would go past the line aiming at the H. New sender installed read too low for me; 160 was just moving the needle. I remember the 56 we had new and it never had a temp problem. I got the idea to run the engine with the rad cap off and a thermometer in the rad. I would add and remove a piece of card board in front of the rad to assist the engine getting hot and take readings. I noticed especially in gear at idle when the temp on the thermometer was at 180-190 there was hardly any water movement if I put in neutral it would move some but not much; putting the carb high idle on the first spot made it much better and the temp would come down.

OK I gave up....I read back on other posts and went and bought a Mustang 5+" pulley to replace the 7+" stocker. Gauge still drove me bats but the water flow was great at idle after the thermostat opened and temp normalized. Had to add a 1/8" spacer to the pump and shorter belt The car is a cruiser rarely on the hyway for long periods.


To "fix" the gauge I swallowed my pride and bought a NOS 1956 Ford Temperature sender jn the original box. Installed it and much to my shagrin everything works as designed. 160* is about 1/4" left of center. 175* is straight up and 200* is just short of the end of the line. All checked with no cap and and a thermometer. 2 years ago i installed  a high flow thermostat and a plug in the bypass with an 1/8" hole drilled in it. All of that helped but I do believe the pulley was the real answer at least for me and that NOS sender .....What's next?

As a side note I bought a really nice ABS fan shroud from Southwest Thunderbird in Texas that I thought would cure my ills. Apparently the stock 56 Ford power steering pulley or pump snout has 2 different ones or mine is wrong; it is tapered and not flat and the shroud would not fit, I also had a problem because the shroud needs the fan mounted directly on the water pump pulley but when I tried this the fan hit the lower crank pulley. I never noticed but when the gentleman who built the car had a third pulley on the crank;  actually a 2 pulley mounted on a single pulley. This is OK by me if the heat problem is truly gone I can now add A/C which maybe why he did it. Anyway I spent a day sanding and filling the ABS to look like metal and now I have a nice "garage hanger" primered and ready to paint.


By 2721955meteor - 10 Years Ago
sounds like you have screwed up the design of the cooling system. ther is nothing wrong with 180degrees,blocking the bypas is bad,you creat cavitation,as when stat closed poor circulation  in the engine. i have 2 gauges 1 in the back of the head which always is a few deg cooler.the 1 wher henry put in was never toatly acurate. i drilled and taped int at therm (engine side of therm) on hot day it will hit 200. 200 is not a problem as that area is hotest part. but block the bypass and you realy do not know what the temp is as steam does not activat temp gauge properly. clean rad proper shrouding and fan will not over heat. with air cond you need more air flow in hot humid arias. this is a well discused blog ( just my opinion) buy a cheap heat gun and do your tests it will be interesting. elect guages ar not very acurate.
By DryLakesRacer - 10 Years Ago
Meteor..I don't believe I screwed it up. The 1/2" bypass is just too much in my opinion. Even after the thermostat opens too much water is bypassing the radiator and continues to heat up the entire system. I have been using a thermo gun the entire time and agree that the back of the head is never as hot as the crossover in front or the thermostat housing. I like the 175* right in the middle of the gauge but before I sped up the water with the new pulley the water would creep up to 200 and continue going up only reving a few hundred RPM in neutral would help. The rad is new and the max cool I could buy. I live a few miles from where they are made and discussed what was best for my use. I read everything I could here and thought of each of the remedies. I don't believe the Ford ever had a fan shroud so that would have been a bandaid too but it was going to look like something that Ford would have done.  As for adding gauges I would just rather not. As long as I know there is no air pockets and what the inside gauge reads to what the thermometer says directly in the water I'm happy. It also has a 7 pound cap which pushes the boiling point up a bit...I shall see as the summer goes on and I cruise in traffic when it's 90* out.....JD 
By 2721955meteor - 10 Years Ago
It may be benificiel if you read about heat rejection and the desighn of cooling systems. pushing water threw a rad faster does not increase the efficiency.the water is cooled by going threw in a controled time. Air flow is a major isue. the heat is rejected by air flow threw the rad.even 210 leaving the therm is not harmfull. it is posible your therm is slow to fulley open. that is wher the bypass eliminates cavitation ,the desighn is to keep a constant temp in the engine. my thery is from reading factual enjenering data ,and applying the info in many hot rod builds as well as several y block powered restos. plus 36 years in heavey equ repairs,with lots of heating isues.But if you are hapey with what you have acomplished that is all great .I should try not to be so abrupt and did not try to be rude ,just offer some help. have read a lot of miss info on cooling system cures on this as well as other sites,also some good info, especialy ifo from dyno results,but dynoes usually have huge cooling capacity,un like our old cars
By DryLakesRacer - 10 Years Ago
Meteor, I have read much concerning proper cooling, not normally in stock cars. Most of my research is for over 13-1 compression and I do understand what you are saying concerning the research and engineering done when these were built. My father bought a new 1956 Ford Victoria when I was 12 and that car never had any cooling problem no matter what time of year and where we were and we went to the desert a lot. The gauge was always near center and never heated while idling or stuck in traffic. Engine/trans combo in this car is identical to moms. The engine has 4000 miles on it and is stock except for an over bore. It is in proper tune but if you let it idle, the temp continued to go up until it was ready to blow. With the cap off 200*+ with a thermometer not a heat gun came pretty quick. This is when I noticed there was very little if any movement of water. A rpm increase of 200-300 started a water movement and the temp would slowly come down. My wife would ask why did I need to put the car in neutral at a long signal and she started to watch the gauge too; driving for the most part was good but no way would I take on the a freeway and hope not to get stuck in traffic.

This is why I sped up the pump. Some here say it's bad and others say OK. Even on the hyway I drive at 65 or under which is under 2400 rpm. If I had an AOD, the smaller pulley would be perfect.

As for the reduced bypass. In my calculations even with the thermostat open by volume 10-20% is bypassing the radiator at all times if you measure the opening of the thermostat at full open. the 3/16" hole flows a small amount of water so the pump does not dead head even tho that really does not hurt a centifugal pump. GM's have been working like that for years The car heats up properly at least to me and can now sit and idle for 10-15 minutes or more right at 175-180 which is fine.

I do appreciate your concern and I did not want to alter the original performance of any stock part but in my case I saw no other choice with what I saw and what others wrote on other threads. I've been struggling with this for over 2 years. For now this is working, others said it helped them too....JD.

PS: Greenbirds...:<Wink

 
By slick56 - 10 Years Ago
Here is a fan shroud on fleabay that would not look out of place.
By Ted - 10 Years Ago

In looking at the Ford parts catalog, there were six different water pump pulleys for the 1956 Fords with V8 engines.  The diameters are as follows:


6.35” (extra cooling fan and 60 amp generator)

6.82” (A/C)

6.88”

6.94” (3 blade fan)

7.37”

7.44” (4 blade fan)


Depending upon the gearing and accessories, FoMoCo deemed it necessary to vary the water pump speed for the various V8 applications.

By DryLakesRacer - 10 Years Ago
Thank you Ted..I'll bet the 6.35" would have also solved my problem...

Slick. That's the shroud I ordered. Like I said the fan needs to mount directly to the water pump to place the fan in the correct position in the shroud and if you have 3 pulleys on the crank the fan will hit it. If you have no P/S or the your P/S pump pulley is flat it will clear. By the pix on FleeBay you can see it's a little rough. The one I recieved was not that bad but I spent 3 hours sanding, filling and priming  just the top half.  It is ABS plastic and made by Southwest Thunderbirds in Texas. The owner said he had been making them for 19 years....Even if it fit my car I believe I would have still had the problem. JD
By 2721955meteor - 10 Years Ago
drylake you apear to have a rare problem. re by pass i went threw severl different engin cos,gm 8cyl engines al had by pass at the therm,some wher built in,all fords,except flat heads,early flat heads never had therms,so a constant water flowwas in play.we all know flat heads had history of over heat.my 47 ford pickup had heat isues esp at idel. cured buy drilling the back of both heads and ran a line to drain in both water pumps. end of problem. every diesel cat ever built from 1950s to 2000 had bypass tubes. most truck instalations had a small tank in rad with a shunt line to water pump as cavitation hapened when therms opened as pump could not get enough water for short time while flow changed. In your case i still feal ther is some other isue. cavitation does not damage the water pump but with bubles in engine block and heads lead to hot spots and cracked heads or blown head gaskets,as well as in acurategauges Hope you get to the botem of your isue and will make interesting read
By GREENBIRD56 - 10 Years Ago
Re- engineering the 292/312 cooling system to function at hot idle, especially for an automatic in gear - is the main complaint I've seen on here over the years. Engines with the older spark advance systems were more prone to get "retarded" and heat-up - which just magnified the problem. Some vehicles got the problem solved with a fan change (especially those with the full sized radiator) - some got a bit better water flow with a more free flowing thermostat, and still better with the throttled bypass. Changing the pulley ratio jacks up both the fan speed (air flow) and the pump flow when the motor is sitting loaded against the converter at 550/600 rpm - and getting the job done with little evil. Mine is up about 20% - meaning that water and air flow potential at hot idle is now the equivalent of 670/730 rpm which does not approach "cavitation" - but does do a decent job of maintaining temperature equilibrium. I put a fan clutch on mine to slow down the fan at road speeds (per Hayden it slips 10% at full engagement).

So what RPM do most of our cruising outfits run at highway speed - steady state? My money says virtually none of them would reach a point anywhere near "cavitation" and then stay there.   
By 2721955meteor - 10 Years Ago
just found a old book on all the facts re 1956 ford cars,page59 claimsall v8 engines in 56 came with  fords new4 blade ,silent spin fan. it goes on to say6cyl and the engines in thunder birds.use the proven3 blade type.page 61 goes on to say the cooling systems are deesighned to run13psi. it goes on to say externa bypass(internal in i-6) permits continuous recirculation of coolant when stat closed. also claiming top tank in rad has a difusor to eliminate bubles..
another old book from larrys tbird ofers a 6 bladed fan( part #t8600b) to adress cooling isues with air cond.. ford book has form #7574.it apears 55 models had heat isues being adressed in 56?? Just more on the site to discuss.
By DryLakesRacer - 10 Years Ago
Whow..I never thought this would stir so much especially since this has been discussed about 2 years ago.. Greenbirds PM'd me over a year ago on the changing of the pulley to the 289/302/351 of just over 5", I was reluctant to do it and continually felt my 292 as built would at some point prove to me it could run at 175* in traffic/idle for what I would think was a normal amount of time. I'm not talking of going to Reno NV.for "Hot August Nights" and cruising for hours I just want to sit at a long signal and not have it heat up. As stated above it wasn't until I saw no movemet of water in the rad at idle especially in gear that I knew I had to do something. A Ford NOS temp sender at least made my gauge "tell the truth" when matched with a thermometer.

Ted's reply really helped. I did not know there were so many different diameters available but it does stand to reason a car with factory A/C in Texas or Arizona with an auto trans may need to pull more air and and flow more water than one in Minnesota with no A/C and a stick.

As a side note the car came with a 6 bade fan and a 4 would probably work fine and get me better fuel mileage. I have installed a 57-62 distributor with a carb proper vacuum (Carter WCFB small base). Like I've said this car performs perfect with the exception of idle over heat. I took it out this weekend and the temp performed perfect for me 165*-170* when driving city streets or freeway. I left it idling in front of my house when I got home for 15 minutes and it was 87* outside. Engine temp went to 180* and never went up any higher. Drove around the block and it came right down to 165*-70* and I was happy. All I'm saying is what worked just from making sure I put the temp sender correctly.............JD
By 2721955meteor - 10 Years Ago
I cant help but wonder if the fan speed is the critical isue at idel in gear,as you need air flow to exchange the heat fromwater to air.shrouds ar very critical as well as pans and belting wher air flowes around the radcore.we wher told in trade school that the hoter the water the better the heat exchang is but most important item is air flow threw the core.so the thery waswater flow threw was not as critical as air flow.So when the top tank aproches the same temp as the botem pushing more water threw the core will result in no change.once road speed comes into play more air flow the  temp rise is controled.pump cavitation is likely as stat opens and closes as more waterchanges direction.the post on the experiment re the tbird seemed to confirm ther problem was solved re shroud and blocking lost air flow .It is getting hot hear i sure hope my ranchero does not heat up,as the crow hear is not verry tastey. cliff
By carltonvickey - 5 Years Ago

I have a 1956 ford heat gauge doesn't work, replaced sender, still does not work was going to trace wiring next. My wiring diagram shows on wire going from sender to gauge and one wire going to switch, my car has two wires going to gauge, what is the other wire for

By oldcarmark - 5 Years Ago
Should only be One Wire on Sender even though some do have 2 Terminals. Where does the second Wire go to if not the Gauge?  Maybe someone thought it should have a Ground Wire.
By bergmanj - 5 Years Ago
Wiring goes as so:

Battery "hot" to Ign. sw; ign. sw. to gauge; other gauge wire to sender; sender body is grounded through engine block back to battery "ground".  This completes circuit.  Other "tab" on engine "Sender" was for connection of "overheat switch" on right bank; eliminated due to "not found necessary" (read that "unnecessary expense" to Ford manufacturing = more profit).  Those switches can still be found [rare] and installed/wired to function as originally designed/installed.

That "extra" tab is NOT a ground; do not try that - it WILL burn-out your gauge in short order!

Regards, JLB