When taping with a pipe tap I always stop and trial fit to make sure I get the fitting, sensor, etc. the depth I want.  I learned this when taping the front of engine blocks for screw in plugs instead of welch plugs.  There's one in both Fords and Chevys that if you go too deep you block an intersecting passage and disaster ensues.  The fear of that taught me pipe tap discipline.  Its like cutting a board.  I can always cut it again if its too long, but I just can't cut it longer if its too short. 

How has the Sniper efi performed for you ?  have been looking at the SNiper and the Fitech but have just stuck with carbs to avoid potential headaches
 

I've thought about going to electric fans but the thing holding me back is the 'fan logic'. As long as the radiator is cooling properly the thermostat keeps the engine below its rated temp. This means that the best way to monitor the temp would be to have the sensor in the radiator itself. That way when the coolant in the radiator drops below the sensor rating, the fan(s) switch off. It should remain this way until the thermostat opens and exchanges block water for radiator water, when the temp rises above the sensor rating. The problem for me is putting a hole in a perfectly good radiator before it needs a rebuild.

Sensing off of the engine temperature would be a bit of a problem because you aren't sensing the actual state of the coolant in the radiator. Sensing at the water neck presents the same problem. Sensing it in the radiator tank would be the most accurate for fan control. When I tried an electric fan setup back in the late 80's the kit came with a temp probe/relay pack that you inserted in between the radiator fins to sense coolant temp in the radiator. It was adjustable and had a connector for the A/C (if equipped) for fan override. It never cooled well (but the fan controller worked OK) so I pulled it and went back to old school. I still have the controller and I'm thinking about giving it a try again now that there are much better electric fans available today.

But the best thing would be an in-tank sensor, IMO.

351MooseStang wrote:

I've thought about going to electric fans but the thing holding me back is the 'fan logic'. As long as the radiator is cooling properly the thermostat keeps the engine below its rated temp. This means that the best way to monitor the temp would be to have the sensor in the radiator itself. That way when the coolant in the radiator drops below the sensor rating, the fan(s) switch off. It should remain this way until the thermostat opens and exchanges block water for radiator water, when the temp rises above the sensor rating. The problem for me is putting a hole in a perfectly good radiator before it needs a rebuild.

Sensing off of the engine temperature would be a bit of a problem because you aren't sensing the actual state of the coolant in the radiator. Sensing at the water neck presents the same problem. Sensing it in the radiator tank would be the most accurate for fan control. When I tried an electric fan setup back in the late 80's the kit came with a temp probe/relay pack that you inserted in between the radiator fins to sense coolant temp in the radiator. It was adjustable and had a connector for the A/C (if equipped) for fan override. It never cooled well (but the fan controller worked OK) so I pulled it and went back to old school. I still have the controller and I'm thinking about giving it a try again now that there are much better electric fans available today.

But the best thing would be an in-tank sensor, IMO.

Agreed. That's why I posted the link to the in-line temp sensor above. I think it's a much better way to set it up.  If your fan sensor is measuring the coolant temp at the engine and BEFORE the coolant goes through the rad, it is always going to reading "hot" and will always want to kick on the fan, whether it actually needs to be on or not.  But by having the fan sensor measure the coolant temp as it exits the rad, you will get an accurate reading of the actual temp of the coolant after it's had an opportunity to be cooled by the air going through the rad and your fan will only kick on if the exit temp of the coolant is above the temp you have designated.  It's not only a more accurate way to measure the coolant temp, but will also save a lot of unnecessary wear and tear on the fan because it's won't be running nearly as much as it would be if you are taking the temp reading at the engine. 
 

I was just at an IA airplane mechanic renewal seminar where one of the speakers was from Cam Guard. One of the things he pointed out was that they had the most trouble with direct fuel injection systems contamination around the valves. He didn't elaborate.

Bolted to Floor wrote:

351MooseStang wrote:

I've thought about going to electric fans but the thing holding me back is the 'fan logic'. As long as the radiator is cooling properly the thermostat keeps the engine below its rated temp. This means that the best way to monitor the temp would be to have the sensor in the radiator itself. That way when the coolant in the radiator drops below the sensor rating, the fan(s) switch off. It should remain this way until the thermostat opens and exchanges block water for radiator water, when the temp rises above the sensor rating. The problem for me is putting a hole in a perfectly good radiator before it needs a rebuild.

Sensing off of the engine temperature would be a bit of a problem because you aren't sensing the actual state of the coolant in the radiator. Sensing at the water neck presents the same problem. Sensing it in the radiator tank would be the most accurate for fan control. When I tried an electric fan setup back in the late 80's the kit came with a temp probe/relay pack that you inserted in between the radiator fins to sense coolant temp in the radiator. It was adjustable and had a connector for the A/C (if equipped) for fan override. It never cooled well (but the fan controller worked OK) so I pulled it and went back to old school. I still have the controller and I'm thinking about giving it a try again now that there are much better electric fans available today.

But the best thing would be an in-tank sensor, IMO.

I like your thought process. To add more questions than answers, is there something like a thermocouple that can be secured to the tank or fins?? For those running a standard transmission with a trans cooler in the radiator, could that trans cooler be used. One end would require an adapter to get from the inverted flare to the temp sensor. On the other end, add a valve to allow the cooler to be filled with antifreeze. Would the heat transfer be quick enough to maintain proper operation?? Food for thought.
 

I'm sorry for not responding sooner! Family & work, the usual... I dug up the controller that came with the fan I bought in the late 80's because it's like what you are asking about. It was made by Genelco (looks like still in business) and the model code is: MOD 14-8635. It's a small rectangular box (about 2" x 1-1/2" x 1") with two small mounting tabs (mine are broken off long ago) that has the electronics potted inside with five 1/4" male terminal connections, a 2" long x 1/4" diameter thermocouple on a 2' lead coming out of it, and a small potentiometer to adjust the trigger temperature. The five terminals are marked: IGN. COIL, GROUND, +12 VOLTS, A/C CLUTCH and FAN. I used it to trigger a more powerful relay to turn on the fan and while it worked, I never could get the fan to cool enough to know if it would hold and cycle correctly.

I'm thinking about adding another try at electric fans to my long list of things to do on the car. The tech is better now and this controller might be worth trying with better fans.