Need help with a temperature guage

[COMETGALAXIE]

ok so i was gunna put the temp gauge on my comet today it has a straight six 202 i took out the old temp guage on the back right hand side i tried puttin the adapter and it was to big so i went looking for a smaller one and no one had it i went to 5 different places and they all had one but it was a little to big any one know were i can find an adapter so i can put the temp guage

 

[gearhead138]

Try a hydraulics shop or a plumbing store. Other wise you might have to buy a different gauge set up with the proper size. I had the same problem with my 300 six. I tried to modify the fitting until I totally destroyed it then I bought the right one. That's the way I learn

 

[COMETGALAXIE]

OK IMMA TRY SOME PLUMBIN SHOPS OR HOME DEPOT THE THING IS THE ADAPTER I HAVE TO PUT ALSO HAS TO PUT THE SENSOR THRU IT

 

[fordconvert]

IIRC early 80's corvettes used that size. Most people seem to be putting sensors in the later model stat housings, I believe the threads in those fit the typical gauges.

 

[Stubby]

The thermostat housing will work, but it will show a different temp.

 

[Ranger_gone_straight]

When I put the big six in my ranger, ran into same thing. I had aftermarket gauges in Ranger with other engine and the alternative adapters that came with the gauges had long since disappeared to some rusty coffee can someplace and dont know there was right one amoung them anyway. I found a pipe bushing that fit the hole, then cut the threads off the incorrect adapter I did have off the other engine and welded the two together, then drilled out the hole in the bushing so the sensor would fit down through it. My welded adapter still short enough the sensor stuck into the water jacket like its supposed to. Fiddly sort of welding with a stick welder but I got lucky and no leaks.

These little things like this are what will drive you crazy and take an inordinate amount time to track down or re-engineer. Yesterday dont know how much time I spent looking through junk to find a fitting that would screw into Wilwood clutch master cylinder so I could connect remote fluid resevoir. Finally happened to see an old all metal valve stem off some old truck wheel. It screwed in perfectly and the rubber washer on it sealed perfectly too. And the rubber hose from the OEM resevoir fit the other end snuggly. Pure luck.

 

[Drumhead_Dan]

There are typically two types of oil holes, one in NFT(National Fine Thread) and one in NPT(National Pipe Thread). The NFT is a strait hole based on a fine threaded bolt, where NPT is tapered to squeeze shut as you tighten and generally has a coarser thread. More than likely you have a NPT hole, so I'd start at the hardware store. Don't force anything; you should be able to screw it in at least three turns by hand. Most tap/die kits have a thread guage that can tell you what thread you're looking at.

Edit: Later aftermarket stuff might be in metric.

 

[fordconvert]

I believe typical mechanical temp gauges come with a 3/8" npt sensor end. They all seem to come with a 1/2 adapter. Some come with some metric options that the 3/8 threads into. I believe the OE 200 was an 1/8". I have never seen an aftermarket mechanical gauge with 1/8". Electric gauge / senders seem to come with the proper 1/8" sender and sometimes with the 3/8 and 1/2" adapters.

http://www.autometer.com/cat_gaugedetai ... 2453&sid=1

Napa has it for around $35 #BK 3011103 Im sure summit and jegs also have them.

 

[COMETGALAXIE]

SO wat do you guys recomend i do tap the hole to try and put a new fitting on it or wat should i do im so confused

 

[fordconvert]

What gauge or type of gauge are you trying to install?

 

[Drumhead_Dan]

Don't try to tap the hole except as a last resort, you'll get metal shavings in there. A thread gauge looks like a tiny little feeler gauge with teeth on the side. It will help you find out what you have, so you don't have to guess when you go to buy the parts. A simple adapter is all you need. It might be easier to take the old sending unit and the new sending unit to the parts store and they can fix you up with a solution.

 

[fordconvert]

Im guessing like everyone else here but I suspect he has a typical mechanical aftermarket gauge. All of them I have seen have the probe as a integral part of a 3/8"npt fitting. The probe is almost the size of the 1/8" npt hole he is likely dealing with so its not as simple as an adapter unless he wants to get crude and make parts to make it fit like some one else mentioned earlier in this thread. Electrical gauges are pretty common with 1/8" npt senders, just like the OE ones were.

 

[Drumhead_Dan]

Brass fittings will probably look better than the 1/8th inch black plastic line running strait out the side of the block into the firewall . I think a brass street 90 with a step up adapter is about as good as its going to look short of putting the electric sender back in.

 

[fordconvert]

Plastic line? This must be one where the copper is covered with plastic rather than that coil look that is more typical?

The probe on a temp sensor has to be in the 'flow' to get a proper reading. Putting a 90 in there will not tend to give you a usefull reading since the coolant will just be flowing past the hole and not around the probe. Yes you will get a reading since it will conduct some heat through the coolant but you are going to get air cooling on the outside off the fitting that will likely keep the gauge reading low. I think when people put the senders in the T stat housings they keep the factory gauge (or light) in its original location as a backup in case you were low on coolant and not getting a reading at that location. Pressure gauges you can T off and elbow all you want within reason.

 

[COMETGALAXIE]

IM puttin a temp guage iv tried everything i think the size of the hole is a 5/16s i bought i think its a 3/4 or 3/8ths the one i bought is a lil to big wat to do wat to do i tried home depot and they didnt have the fittin that small should i just add it to the t-stat housing i know if i put it there but i know im not gunna b gettin the right readin know wat im sayin its not gunna b the same as if i put it in the stock temp guage on the back of the head

 

[Asa]

please take the caps lock off, there's no reason for you to use it with your thread titles every time, and the few times you might actually need it, no one will actually pay attention to it since you've used it up

i edited your thread title to reflect this
thank you

 

[Drumhead_Dan]

Doh! I was thinking oil. I am full of epic fail today. The thermostat housing isn't ideal because if your thermostat sticks the engine could overheat and you would not know it, but its still better than a sharp stick in the face. You can also take a look and see if you have a engine block drain plug, that should be about a 1/2" hole. I don't know that there would be a lot of flow there, though.

Edit: The original used as a backup is definitly a good plan.

 

[COMETGALAXIE]

ok so im gettin very desperate iv tried all kinds of things should i just bore out that littl hole and make it to a bigger size or should i just put it on the t-stat housing wat do you guys think ill let u guys make the last say so t-stat housing or bore wat do you guys think

 

[fordconvert]

Why do you think you need a new gauge? Im not saying thats a bad thing just what to know your reason so I am better able to help you decide what to do. Does your car have a light now?