I have a 383 (SBC), with the 5694-intake installed. Running two 500 cfm AVS2’s. In front of the front carb are two pipe threaded ports. How are they different from each other. I’m using the one to the left for a mechanical liquid filled temp gauge. The one near the thermostat housing I use for my dash electric temp sending unit. My electric fan sensor is in driver’s side head. Is the correct????
Art Klein
303 949 0393
You are using the Offenhauser 5694 intake, which has two pipe-threaded coolant ports at the front of the manifold near the oil filler tube, just in front of the front carburetor. Here’s what you need to know:
- Both of these ports thread directly into the coolant passage of the intake and are essentially the same. There is no “preferred” one for either a mechanical or electric temperature sender—they both access the same coolant and typically read about the same temperature. Any difference you see between gauge readings is usually due to differences in gauge calibration rather than any meaningful difference at those locations. If you swapped the senders, you would likely still see the same difference between your two gauges.
- Using one port for your mechanical temp gauge and the other for your electric dash gauge is a perfectly acceptable setup and is how most users do it.
- For electric fan control, running the sensor in the cylinder head is also acceptable and commonly done. In fact, many engines will trigger the fan a bit earlier because the cylinder head reads slightly warmer than the intake, which can be helpful in protecting the engine.
So, your current setup—with a mechanical gauge in the left port, dash sender in the other, and electric fan sensor in the head—is correct for this intake and will function reliably.