312 temperature gauge

[Steve's Autobody]

Working on a 312 for a customer .I'm trying to install a mechanical temp gauge. The head is threaded 1/4 pipe. Gauge won't fit and doesn't register if I use adapters. Probably air lock. Other option is on water pump. I don't think that's a good idea. Will it work? Thanks

[RKS.PA]

Steve, what type of mechanical gauge are you trying to install? Looks like you might not quite have enough posts to send us a picture? The 312 heads came with two different diameter threaded pressed inserts for the original electrical gauge sensor. Is your pickup bulb extending deep enough into the head?

[Gene F]

How did you decide on mechanical for the water temp? My car has been converted over to the "electric" sensor, and it seems to work just fine. I do have a tube kit (copper) that I will be hooking up to my oil pressure soon. I took an under-dash trio for a hotrod that I converted over to factor style gages, and used it on my 57 Y-block. That fitting is more like a pressed in type of thing (like a freeze plug)

If the customer is concerned about heat in traffic; 1) check the ignition advance functions, 2) add a shroud to the radiator. A decent temp gage with numerical values sure is nice.

[KULTULZ]

What is the size of the gauge sensor fitting?

FORD had two sizes of coolant sensor bungs for the cylinder head, one 1/4in and the other 3/8"

The sensor bulb has to be fully immersed in the coolant.

[paul2748]

Up to and including 56, the bung for the temperature sender was 3/8 pipe. In 57, this went to 1/4 pipe. The removable bungs are available aftermarket.

[miker98038]

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As a last resort you can drill and tap the intake on the drivers side of the TStat. You’ve got to look close, I’ve seen some mechanicals where the bulb is too long (deep) to fit in that small passage. It will also read a bit hotter than the rear head location. But with the bypass from the stat housing to the water pump, it get good flow and shows proper temps as the engine warms up.

[KULTULZ]

What they are referring to is the ECZ-B intake had an enlarged carb pad and the pad was moved forward on the intake. If one uses a wide mouth thermostat (HI-FLO), it may not open fully if it comes into contact with the HTR HOSE OUTLET fitting pickup tube.

The same would apply as to the install of a temp sensor on the coolant crossover. You would have to determine no contact.

BTW-

ENGINEERING's placement of the TEMP SENSOR on the driver's side cyl head only gives a coolant temperature coming off the left cylinder bank and not the right.

Correct placement (IMO) would have been in the front intake coolant crossover as to read both banks/heads.

[paul2748]

I think is a WIDE MOUTH thermostat instead of open mouth.

[rotorwrench]

Look up a radiator hose adapter for sending unit or temp bulb. It requires cutting the hose and two clamps to secure it but they do work. They are available in different hose and fitting sizes. Autometer has them just for that purpose. There are several sources.
https://www.summitracing.com/parts/a...RoCsx8QAvD_BwE

[KULTULZ]

Well, the trouble with those is that the sender bulb has to be placed before the thermostat to read correct engine coolant temp.

If it is placed in the top hose, it will show correct temp only after the thermostat has opened (will not show overheating w/ thermostat closed). If placed in the lower hose, the coolant has been cooled by the radiator.

The early 1958 FORD FE had the sender placed in the WP BY-PASS HOSE. But that would restrict by-pass coolant flow. Taking a chance there.

The earlier FLATHEAD has two sensors, one on each cylinder head. Seems like that didn't work well either as it was not carried over.

[paul2748]

The reason for that was because the flathead actually has two separate cooling systems (one at each side of the block) that mixed at the radiator. There was no cross flow in the block. The two temperature sender set up actually worked very well (lasted for 21 years) . This set up was not needed with the YBlock because there was water cross flow in the block.

Originally Posted by KULTULZ

The earlier FLATHEAD has two sensors, one on each cylinder head. Seems like that didn't work well either as it was not carried over.

[Gene F]

I wonder if we will hear back as to the result(s).

[KULTULZ]

This set up was not needed with the YBlock because there was water cross flow in the block.

Because of where engineering placed the FYB temp sensor, you had no idea of what was happening in the right cylinder bank.

So you could have a cooling system failure there and would be difficult to diagnose as both banks after running through the heads met at the manifold front cross-over showing a reduced coolant temp.

FORD had a lot of trouble with the FYB cooling system, except yourself of course.

[miker98038]

My comment kind of hijacks the thread, but the cooling discussion rang a bell.

Doane Spencer’s 55 bird had a modified cooling system. The story goes that Ford developed the water piping for NASCAR racing with the F code motors in ‘57. I don’t know what’s true, but I’ve not seen this piping anywhere else but the pictures of Spencer’s bird.

[KULTULZ]

... hmmpf ...

I wish I could find more info as to how coolant flowed through the heads.

[RKS.PA]

Not necessarily germain here, but to Paul's #11 post above about the two separate cooling sections on the flatheads, I put two separate temperature gauges on my '39 to monitor each side...belts and suspenders...funny how close the temperatures were, but the right side always ran a little cooler.

[KULTULZ]

Originally Posted by RKS.PA

Not necessarily germain here, but to Paul's #11 post above about the two separate cooling sections on the flatheads, I put two separate temperature gauges on my '39 to monitor each side...belts and suspenders...funny how close the temperatures were, but the right side always ran a little cooler.

Germain or not, I have been inoculated and have no worry ...

See attached (if shows large enough) and see if it sounds correct -

[paul2748]

You are correct. I got 2 YBlocks, both 312's with a little better cam, stock heads and pistons. Do not have a heating problem with either. No oil leaks with either one (knock on wood ).


To add about the two senders on a flathead. Both were not the same so I understand. I do not know the engineering on how they worked, but somehow they gave some type of ( I guess) average temp. I did have a flathead at one time, but it was a hot rod and I used two identical senders to one gauge, using a two way switch so i could monitor each head. And they seldom were the exact same.



And your right about the Y sender in only on side,. I guess the engineering was that since you have a crossflow within the block the temp will even out

Originally Posted by KULTULZ

FORD had a lot of trouble with the FYB cooling system, except yourself of course.

[KULTULZ]

I was never interested in FLAT-HEADS so have no experience with them. I started with FE GALAXIES.

I remember the first time I saw an H4000. I was horrified. That and a 54 FORD 'ASTRA-DIAL' instrument panel.

The first time I worked on a 56 FORD, I was mystified as to how the engine compartment was laid out.

I bought a 55 BIRD in 1970. Didn't keep it long as it was during the MUSCLE CAR days and just didn't cut it on the street. Upgraded to a 64 FALCON SPRINT and all was well.

A 57 FORD with an FE upgrade was a cheap way of getting around insurance costs of a new late sixties muscle car.

If I had kept it (and a 67 GT-500), I would be rich.

All of us have had different experiences I guess.

[KULTULZ]

Originally Posted by miker98038

Doane Spencer’s 55 bird had a modified cooling system. The story goes that Ford developed the water piping for NASCAR racing with the F code motors in ‘57. I don’t know what’s true, but I’ve not seen this piping anywhere else but the pictures of Spencer’s bird.

I tried to chase down this plumbing with GIGGLE. I came across a reference it was a design for BONNEVILLE if you are interested.

Came across a few photos (of the BIRD and system) and none showed or explained the design. I think it was mostly eye-candy.

Thanx for showing that. Learn something new everyday.