Hey guys I recently acquired an oil temp gauge to replace the nonfunctional clock in the 81. The gauge went in without any problem. I also picked up an oil temp sensor from the auto parts store and got underneath the car to install it above the oil filter. I noticed a plug in the port where I was going to install the sensor.

I have no idea how to remove this plug since it is flush with the side of the block. Are these press fit in or are they threaded in? I didn't want to drill it out in fear of getting debris in the engine or breaking the plug off inside the engine. The engine is not the stock engine and is actually a 350 out of a 74 Camaro, if that helps.

What is the easiest method to remove this plug? I know that there is another port for the oil galley in the back of the intake manifold near the distributor but that is being used for the oil pressure gauge. Any help would be appreciated.

here is a pic to show what the plug I'm dealing with looks like

 

What's the hole above it for, clutch pivot?

It almost looks to me like the boss hasn't been drilled. You might just have to drill ind tap it.

 

That's the plug for the oil gallery that leaves the filter and enters the oiling system. It is a press fit. If you want to remove it you just use a small drill bit to make a hole in the plug, then thread a puller into the hole and pull it out. But you did write "oil temperature" right? Oil temperature is normally taken from the sump. Oil temperature will vary throughout the engine since oil carries heat from the engine just like coolant and putting the oil through the pump does add heat. I don't think the contact exposure will be sufficient to give you a stable reading and the reading you get will be higher than what you'd see at the sump.

 

I'm about to do this conversion as well. I'll be installing a sensor into a 350 H.O. when it arrives next week. You are correct, the sensor goes above the oil filter. I don't know if the block casting for a '74 Camaro would have been identical to the casting for an '81 or '82 Corvette. I hope someone with a late C3 will offer up a photo of the exact location of the temperature sensor.

 

I might be able to supply some info. The 81 I bought had a engine that was from a 70s truck. The port shown was factory tapped and the oil temp sensor was installed in that location. The wire looked untouched and was really not long enough to locate anywhere but above the filter. That 70s engine went bottoms up so the new engine I got was from 80s camero. The port on that 2 bolt main engine was plugged as shown in the picture. I was sure that drilling and tapping would be straight forward and I could install the temp sensor in the same location. Once the pressed in plug was removed I found there was a sleave installed that the plug pressed into. Had a dickens of a time getting the sleave out. The temp sensor has 1/4" pipe theads. With the sleave removed the hole in the block is slightly larger than spec for a 1/4" npt tap. I tapped it anyways and the sensor bottomed out in the threads. My next thought was to redrill the hole for 3/8 npt and use a 3/8x1/4 bushing. That extra length of the bushing puts the probe of the sensor out of the oil stream and I was not sure the probe would sense the oil temp. I used the 1/4" tapping and was forced to add extra wraps of Teflon tape and some sealer. The probe still bottomed out in the thread tapping but did not leak. This work was all done with the engine on a stand and not in the car. If a person was to install a oil temp sensor with the engine in the car I would find a better location, like the oil pan as suggested. Hope this info is helpful.

 

correct, It is the oil temp sensor that I am trying to install. This is the stock location for the sensor on later C3 models equipped with this gauge. I have considered putting the sensor in the oil pan but am concerned about clearance issues due to that fact that it has been lowered. I don't want to run the risk of it accidentally being ripped off.

What exactly do mean by a puller? Like threading in a bolt into the plug and using that to pull it out?

 

To be honest I'm not sure what the hole above is for. I thought it may have been for the stock exhaust manifold or something. I know that it is not part of any oil or cooling passage.