LD340 and mechanical temp gauge

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autopar3000

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So I got myself an LD340 intake manifold. It's not bad... there's about half of one of the thermostat housing bolts broken off in the hole, but I should be able to get that figured out. I'll probably drill it out and re-tap it.

My question for the gurus is regarding my Autometer mechanical temperature gauge. Looking at the manifold, I'm thinking that I might have to downgrade to an electric gauge becuase there's no hole for me to stick my probe into (please excuse the expression). Is there a workaround for this problem?
 
I don,t know if they make a thermostat housing that you can install your sensor in?If not drill and tap temp gauge in your housing?
 
Down grade? Better think twice on that. The newer guages are not yesteryears gauges and, alot safer.

I thought I did see a thermostat housing with a outlet on it for various reasons....AKA, emmisions. A Chevy stat housing will work well should the case arise.

Can you use a tap on the rad?
 
It`s always a drag when you don`t have a hole to stick your probe in. In all seriousness, I`ve read where somebody screwed a small nipple (ha ha) into the hole with a fitting to cap it, then tapped a hole in the top for the sending unit.
 
Down grade? Better think twice on that. The newer guages are not yesteryears gauges and, alot safer.

I thought I did see a thermostat housing with a outlet on it for various reasons....AKA, emmisions. A Chevy stat housing will work well should the case arise.

Can you use a tap on the rad?

Ha ha, I knew someone was going to take me to task on that! I know the modern electric temp gauges are good (especially an Autometer piece). I'm just trying to avoid buying a new gauge.

I could probably tap the stat housing or the rad, but then the sensor would be on the wrong end of the cooling system, wouldn't it?

The hole used by the heater hose looks tempting, but the heater is my friend in late September and October.

Can anyone tell me why mopars have the little bypass hose that goes from the water pump to the intake? That would be a might convenient spot for the probe if I didn't need the bypass.
 
Here are two pictures of a brass fitting designed to accept a mechanical temp sender on an LD340 intake (Mine).

Any pipe fitting and hose end store should have soemthing similar.

P1010011.jpg


P1010010-1.jpg
 
OK,
I went out to the garage and took a look at mine and there is only the small hole for the electric probe. If you are not going to delete the heater you need to drill and tap into the front of the manifold to the left of the bypass hose. One thing that needs to be kept in mind, is that you need to position the probe so that the coolant flows past it, putting it in a static location such as moparmal has can give you an inaccurate reading. Not that you can't compensate for that, but if accuracy is what you are after keep it in the flow.
The bypass hose is there to maintain sufficient flow when the thermostat is closed.
Andrew
 
I had the same issue and instead of messing up an LD340 I just went ahead bought a Performer RPM, which of course has the appropriate hole.
 
The hole for the original temp sender is not only too small but too shallow for a mechanical probe in most cases.
Many have found pipe fittings needed to get the probe attached at that location. Others will chime in with their solutions. Also keep in mind that heat naturally rises so the probe doesn't absolutely need to be in a cross flow.
The bypass hose allows the water to circulate within the engine while the thermostat is closed. Without the bypass hose you would have a small amount of back pressure on the water pump which is not an issue really. Pouring the system full of water is much more difficult without the bypass hose also. A tiny vent hole can be drilled through the thermostat flange to cure that. GOod luck.
 
I am in the middle of this too. What I came up with is to take the heater nipple out and put in a short nipple and a tee and then put the heater nipple back in the top of the tee and the gauge in the side of the tee with another short nipple,this only raised my heater nipple up about 3" and once you put the air cleaner on you really have to look to notice. Lou
 
So I got myself an LD340 intake manifold. It's not bad... there's about half of one of the thermostat housing bolts broken off in the hole, but I should be able to get that figured out. I'll probably drill it out and re-tap it.

My question for the gurus is regarding my Autometer mechanical temperature gauge. Looking at the manifold, I'm thinking that I might have to downgrade to an electric gauge becuase there's no hole for me to stick my probe into (please excuse the expression). Is there a workaround for this problem?

I went to an electric gauge. I had the same problem. works great but a little more $$.

65 Vart 002.jpg
 
Hmmm... lots of great ideas here. I went to the parts store today to pick up my gaskets for this swap, and the guy there tells me to look on the cylinder head to see if I can plumb the mechanical gauge in somewhere on the head. I don't remember ever seeing a home for the probe on the heads, but maybe someone here knows different?

In case my final decision is to walk away from the LD340 I got him to quote me on both an Eddy Performer and an electric temp gauge.
Performer = $280
Gauge = $80

This means that I could save $80 if I spend $280 and get a new intake! Then I could sell the LD340 and be even further ahead!!
 
You can get really good deals on performer intakes on e-bay if that is the route you want to go.
 
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