Coolant level in block

[55 Fargo]

Unlike modern vehicles which have in many cases the radiator mounted eve with or even below the top of the engine, our cars are not very suseptable to trapped air in the coolant chambers. If the coolant is covering core of the radiator, the engine must by fluid dynamics laws be full.

When I worked in the food industry, we needed to check termometer accuracy and log the results on a weekly basis. The standard procedure was to fill a container with ice and add water to fill. Thremometer needs to read 32 degress when imersed in the water or when shooting the water's surface. If off they were adjusted. We had some early version of the infra red deals and they were notoriously incorrect. they had a card in the case withthe varience noted and readings were supposed to be corrected by the operator.

I was checking my infared this morning, I did use a pail/bucket it was full of water, but had an ice berg in it, temp was 33 f, so out maybe 1 degree, gonna go and try it right now and report my finding...

[55 Fargo]

This time it read 30f, after the infared gun had been in the house in warm air for a number of hours, not sure if is a piece of junk, or a battery going dead, will try a new battery and see.....

[55 Fargo]

Hi all, not trying to prove anything 1 way or another, but I did a test, with my hand held laser temp gun. this test was performed on my 47 Chrysler flathead 6, and stock gauge, as well as a stock rad.

Engine warmed up to 160, t/stat opens, coolant flow goes through rad, and re-circulates through block.

The outside ambient temp is somewhere between 35 and 40 f, and tons of snow, so balmy at best.

The stock temp gauge read about 140, after the coolant flow began through the cold antifreeze in the rad, the laser temp at the sender, was displaying 142, the top of the rad, was 113. As the the coolant was very cool, and the t/stat is most likely just partially open, and my engine was only at a fast idle, the temp did not even up close as it would in warmer weather or if I was out driving fora 1/2 hour.

I could not verify the laser gun against my meat thermometer, as it is not working at all, so will need another to verify sometime.

Here are 3 pics of my findings.....

[Joe Flanagan]

This is why my temp gauge did not work:

I removed it and found that it is broken. When I bought it, I noticed the bulb was longer than the original and I worried about bottoming out against something inside the head. Installed it anyway and it never worked.

Here is a comparison between the new gauge and my original:

You can see how much longer the replacement is. I've looked at a couple places and can't seem to find one that's got a bulb as short as the original. I suppose I could use a couple of adapters arranged so that the bulb does not protrude as far inside the head.

[Jerry Roberts]

Just wondering , when you place the bulb into the hole , do you feel it bottoming out like there is an obstruction ? I guess you could somehow make the gland nut protrude from the block a little .

[Joe Flanagan]

No, Jerry, I didn't feel it hit anything when it went in. But I found that in order to seal it I had to tighten it pretty good, which brings it farther into the head. I got a replacement today and found a couple of washers that looked like they should keep the bulb from going to far into the head when I tighten it down. That one is inoperative, too and I suspect the same thing has happened. This second replacement had a shorter bulb than the first one I broke but still a bit longer than the original.

[Niel Hoback]

Joe, maybe stick something in the hole and see how deep it is before you put the bulb in to it.

[Joe Flanagan]

That's next. I'm going to try to come up with some kind of adaptor that holds the bulb out a little farther.

[Joe Flanagan]

As I understand it, these things seal when the flange on the ether bulb is hard up against the nut itself, is that right? When I've installed the replacements, they kept leaking from around the capillary tube until I tightened it to a certain point and that might be the process that is damaging the longer bulbs.

[55 Fargo]

As I understand it, these things seal when the flange on the ether bulb is hard up against the nut itself, is that right? When I've installed the replacements, they kept leaking from around the capillary tube until I tightened it to a certain point and that might be the process that is damaging the longer bulbs.

Are you using teflon tape or thread sealant. I have used the teflon tape, it works well....

[1941Rick]

Just loosen the nut that hold the bulb in the head....this will bleed any air....

[Joe Flanagan]

Fred, I'm using thread sealant but the coolant doesn't leak from around the threads, it wants to leak from where the bulb and capillary tube enter the nut. Comes out from around the capillary tube. Only way to stop it is to crank down on the nut. Am I missing something here?

[Merle Coggins]

Joe,

Are you using the bushings that came with the gauge or are you trying to install the bulb into the existing adapter bushing that was used with the OEM gauge? The bulb may not seat properly into the old bushing. You should change out all fittings to use the bushings that come with the new gauge.

Merle

[Joe Flanagan]

Thanks, everyone, for the advice. I figured out what the problem was. When I got the temporary gauge, I took out the original gland nut and replaced it with the one that came with the gauge. As it turns out, the new gland nut allows the bulb to protrude pretty far into the head before it seats. I compared the new gland nut to the original. That was the solution. The original lets the bulb seat long before it ever gets far enough inside the head to contact anything. I switched back to the original gland nut, threaded the new bulb in, and everything worked. I now have a working (temporary) temp gauge.

Merle, I agree with your reasoning on this but this particular problem was a bit unusual. I had doubts that the new bulb would seal against the old gland nut but it did. In any other application, I'd use all the stuff that came with the new kit.

Anyway, I ran the engine for another half hour today. Runs and sounds great. Temp stayed at a steady 180 at idle. The only leak I have is a small oil leak at the front of the engine somewhere.

[Alshere59]

So wheres the video?

[Joe Flanagan]

I'm technologically challenged in that department. How are you guys doing that? My digital camera has a video function. I accidentally activated it one time and took a video of my gas tank sitting on a pair of sawhorses. Tried it again after that but couldn't get it to work.

[greg g]

should be a little icon that looks like a movie camera. set it there from auto and push the shutter once to start and again to stop.

[RobertKB]

Yep, need video with sound. Love to hear those flatties run. You and aero3113 are getting me excited about the engine in my '53 original survivor Plymouth. Motor has 98,000+ miles on it and has a couple of noises I am not really keen on hearing. It had rings and a quickie valve job 25,000 odd miles ago. I am thinking that next winter I will pull this motor and rebuild it. It is original to the car and I would hate to detonate it. I think I would do the R & R but have a professional rebuild it. However, you two guys have been an inspiration!