JustJeff

iTrader: (13)

I'm stuck between two sets of advice.


I'm doing a taurus efan with a 200 degree on switch I bought from Summit Racing.

I'm getting conflicting info about the best place for my efans thermoswitch. The thread of the switch matches a closed port on the bottom driver side of my koyorad.

My thinking is that bottom of the radiator is going to be where it's the coolest. Friend advised NOT to use that bottom port for the fan switch because of that. However the machine shop says the bottom of the radiator will be same temp as the engine.

Based on the machine shops advice I left it with them to open the that bottom port. Is this sound advice? Should I call the shop and tell them NOT to open the port?

RotaryEvolution

iTrader: (30)

i wouldn't use that machine shop if they don't know how a basic radiator works, the water at the bottom of the radiator is in fact cooler than the engine... that is the point of a radiator, the top is full of outgoing water from the engine and the bottom feeds the engine with cool water after it has passed through the radiator core, giving you inconsistent temp readings at the bottom outlet during various outside climates.

the thermostat neck is a good spot for a temp switch or the back of the waterpump.

whenever i have to use the radiator for a thermal probe activation device i ALWAYS use the top of the radiator for the probe since it gets the hottest most accurate temp readings off the radiator, but anywhere on the radiator is still not ideal.

this may be splitting hairs but if you want consistent temps then i would disregard their advice. it won't make a huge difference but it will still be a noticable one, especially in colder weather as the cooling fan will bounce your water temps up and down a bit more with a much wider range of on off time for the fan than needed. even in the proper top radiator location, in colder weather my fans will kick on at 200*F and pull it down to 170*F, in hotter weather it will go from 190*F to 180*F, assuming the fans are keeping up well. on very hot days even the black magic will run 100% duty cycle to hopefully keep it at 200*F.

with the above i'm sure your spread would be even wider during cold weather operation with the probe at the bottom of the radiator.

JustJeff

iTrader: (13)

^thanks

canonize-ryda

Whats a switch cost for the efan?

JustJeff

iTrader: (13)

^depends on the switch. I bought mine through Summit Racing and it was $30 for the switch and $9 shipping.

I did not catch the shop before they closed for the day. They only had the radiator for an hour or so so they may or may not have opened up the port. I'll find out tomorrow if I need to plug that hole or try to use it.

If it's too late I can test at what engine temp the efan will turn on. I have a temp gauge with the sensor/sender on the water pump housing. It wouldn't take too much effort to simply test. Or I can exchange the 200 deg switch for a 185 deg switch and still use the same spot on the bottom.

If it hasn't been opened up then I'll simply get an adapter for the upper hose.

But for now I need to head to work and earn my millions.....

RotaryRocket88

iTrader: (7)

I tested out the location at the bottom corner with a 195º switch, but the fan did not switch on until about 215º. Not exactly ideal. It makes sense since that's the "cold" half of the radiator. This was also without the hole being drilled through to allow coolant to reach the sender. It was reacting to heat transfer through the metal.

I'm using the pre-drilled hole in my S4 TII thermostat cover now. It was the same thread pitch (just smaller diameter), but I chased it with a tap to fit my new temp sensor (for my SPAL PWM).

jackhild59

iTrader: (7)

I put my VDO temp sender in that spot to monitor temps when I first went E-Fan. My intent was to perhaps put a 175* switch in that spot. The temps are very erratic and do not track engine temps. They tracked road speed and fan usage but the spot was essentially useless for temperature control.

Summit has a 3/8" aluminum weld-in bung, bout $8 that I welded into the supply tank on my aluminum Griffin rad for the temp switch.

Good luck!

Jack

JustJeff

iTrader: (13)

Thanksf or the feedback, the machine shop didn't open the bottom port.

I've found that the Summit switch matches diameter of the S5 OEM thermoswitch on the back of the water pump housing. However the threads do not match. I had plans to stop in a different machine shop about tapping the OEM port for the Summit switch. My concern is retapping with the same diameter switch will create a leak and poor threading. I thought I could simply use some teflon thread tape or sealant. But I came across this tidbit of info in a related thread:

One thing to remember with single pole switches is that they use the body of the switch to ground, so you CANNOT use teflon tape to help protect against leaks or it will affect the reading of the switch.

Is this accurate information I stumbled upon?

JustJeff

iTrader: (13)

^another question

Can I create a ground using a ring terminal and use it as a washer? I'd really like to use the OEM spot but don't own a backup turbo water pump housing. If I rethread this and it doesn't hold water I'm in a bad spot.

RotaryRocket88

iTrader: (7)

If the desired location has a different thread pitch, don't try to tap it to match your sensor. You'll just ruin it. The spot I used had the same pitch, but it was slightly smaller diameter, so I was able to just enlarge it.

If you buy 2-wire switch, one of the wires can go to a ground terminal. If your switch has one wire, it has to ground through the body. Teflon tape should be avoided.

JustJeff

iTrader: (13)

^I"m about frustrated with all this. Starting to wonder if an electric fan is worth all the hassle.

j9fd3s

iTrader: (3)

you can do a few things, easiest would be to run a temp sensor that threads in, argx7 has a thread about that, there are several stock temp sensors.

second would be a helicoil

third would be to weld up the hole and redrill

JustJeff

iTrader: (13)

Edit...

jackhild59

iTrader: (7)

Your frustration is noted as there is much info that is based on mis-info, slightly incomplete info etc. They just that they know so much that isn't so.

I read the same thing over and over regarding the sensor and Teflon tape. Now, I have personally use *hundreds* of rolls of Teflon tape in various construction projects over my life. I have used Teflon tape on 1/8" senders up to 4 inch pipe. I learned how to correctly use Teflon tape and was converted from 'pipe dope' in 1983 while plumbing a privately drilled gas well into a steam boiler at a nursery where I worked.


Nevertheless, I followed the 'advice' and used no Teflon tape when I started out with the efan project. I was unable to fully seal my temp sensor without Teflon tape. I subsequently taped the threads *properly*. I solved my seeping and have no grounding issues with the Summit sender. I also taped my VDO temp gauge sender with no grounding problems.

Proper Teflon taping technique? The tape is wrapped in the same direction (clockwise) as the threads. Only *one* layer is required, with minimal overlap, starting at the starting threads and wrapping up. Stretch it tight as you wrap. When you cover all the threads, stretch it to break. The tape should remain in place, stretched into the threads. Thread the sender into the hole, tighten to seal.

If you use this method, there will be plenty of contact for grounding purposes and you will not have any leaks.

Improper techniques include wrapping the wrong way, applying multiple layers (more is not better)

JustJeff

iTrader: (13)

Thanks again for feedback.

Alot of my problems are self-induced. This is a project I put on the shelf over the winter. I was going largely by memory and found that my memory sucks. That combined with gearing up for my long awaited rebuild..and my first rebuild. So I have alot of car related things bouncing around my head at any time.

What this has taught me is to go back to square one. Take notes, make checklists and to-do lists.

One thing I thought and was incorrect was that s4 and s5 threading is not the same. They are in fact the same threading (M16x1.5). I had not pursued a Starion switch because I thought the threads did not match.

I'm looking into returning the Summit switch. There is no restocking fee and other than return postage I can get a full refund. BUT I may have thrown out the envelope and Summit may not accept it without that envelope.

I'm currently looking into 89 Starion switches. I found them at several sites, but I also found some confusion. Rockauto has several different switches listed all for an 89 Starion.

My first choice is to not make any permanent modifications to my water pump housing. Get the right Starion switch. If I go with the Summit switch my thinking is just what Jackhild said about wrapping properly. I'll have the OEM spot tapped and see what happens. If it leaks or I get poor grounding I can then pull the housing. Have it welded shut and redrilled/tapped.