1rino56

Can anyone running spal fans help with the location you have used for the thermostat? Block? Water pump? Head? Also using Dewitts radiator and wiring harness. Any wiring issues to know about?

fauxrs

I have mine in my thermostat housing - I have a replacement copper brass radiator bought from We-be-radiators-n-**** (i.e. backwoods radiator ) the spal fan assembly I got at the long beach swap meet for $80, and I wired it up manually using a Derale controller.

1rino56

I guess I meant the temperature sending unit. It has 3\8 threads.

fauxrs

Yes, thats exactly what I was talking about, my thermostate housing has two ports - one for the temp vacuum switch and one appropriately sized for the 3/8" thread sensor.

72LS1Vette

If your thermostat housing doesn't have 2 ports you can by one for a 79 at the chain parts stores really cheaply.



Rick B.

fauxrs

This is actually what I did, during the install of the new thermostat I found my cheap chromes pot metal thermostat housing was dissolving!!! so off to O'rielleys (sp?) and a new aluminum housing with 2 ports was like $8

The Money Pit

I'm in the process of doing my Spal fan,...if I ever get the chance to actually work on the Vette....Plan on using a 3/4" to 3/8" reducing bushing and install the sensor in the waterpump top fitting. I wanted to keep the billet Tstat housing I already have, and not penitrate the new Dewitt radiator I just replaced.

noonie

That location will not give you engine temp.
Head or intake manifold if you don't want to use the tstat housing.

The Money Pit

The location will be a little cooler than the engine for sure, because it is feed from the return side of the radiator. If the fan switch is 195 degrees, how hot will the engine get before the fan kicks on? 210-220?

I don't want the fan running full time for sure, but if this turns out to be too high a setting I can alsways replace the fan switch with a lower value like 180 degrees or so. I plan to also add a manual override switch I can turn the fan on from inside the car if need be.

Anyone have info on what temps actually are present at the waterpump, if the engine is at normal operating temp?

Ganey

The sensor can go in the head or intake. It can be done in the rad.

noonie

I thought you were talking about the temp sensor for the temp gauge.
If you are referring to the temp switch for the electric fans, then the water pump is a good place for it.
You can expect up to 30° cooler at that location versus coming out of the engine at the tstat housing. A little less difference if you are using the block recirculating feature in the pump.
Let the tstat control the engine temp and let the fan switch control the coolant temp out of the radiator.

The Money Pit

With my Griffen aluminum radiator I usually ran 180 degrees water temp, (sending unit in the intake), so I guess what you suggest is that the water pump port would be about 150 degrees,..give or take a few. If the new fan switch is rated at 195 degrees, the engine temp would hit 225 degrees before the fan turned on....give or take a few. (fan switch located in the water pump.) The fan should turn off at engine temp of 205 based on the switch rating.

In the past my temps would only creek up if dead stopped in traffic on 95 degree days, and as soon as I started to roll,..the temps would drop like a rock. I am expecting the bigger Dewitt radiator and Spal fan to be able to cool even better than the old Griffen did.

noonie

You would have to use a much lower temp switch, you don't want a lot of swing in the coolant temps.
A lot of the exotics use this method for activating the fans.