I finally gathered up enough parts to put the thermal fan clutch system on my rig this weekend. The Hayden severe duty clutch is part number 2797 (a truck part) and the aluminum pulley is modified from a part I got from CVF Racing. I also fitted a six blade fan made to fit the larger clutch style bolt pattern.  

It proved impossible to find the smaller diameter, single V-groove pulley, with close to the proper "backspace" - except from Concours in steel - so I bought a less expensive, aluminum double groove from CVF (for a small block Ford) and had it modified. By cutting off the second (back) groove, reducing the outer diameter to 6.0 inches (down from 6.2), and opening the remaining V-groove to fit the earlier fan belt size - it works well. I had to move the pump pulley/fan mounting flange .1 inches toward the radiator (to align it with the crank pulley). CVF has reasonable pricing for their aluminum pulleys and they are American made. Try.....   cvfracing.com  

I heard that it is possible to make a double groove steel pulley (302 Windsor) into a short single, by chopping off the second groove and dressing everything smooth - I haven't tried this. There are pictures of the modification on the internet - so there must be some Windsor applications that need the short length single groove pulley. You probably will have to use a puller or press on the waterpump mounting flange to get everything back in line on a Y-block.

 

 

  

 
 Steve Metzger       Tucson, Arizona

Thank you sir.....

Hey Pete;;   Water Pump Pulley   #8509-SP.  Hope that does it!!!   Sure helped our car!!!   Good Luck   Eddie

Eddie

Lake Forest, Ca. 92630

Mr. Paskey

I want to buy a smaller diameter water pump pulley like you have. You mentioned that you got it from Concours but I can't find it in their catalog. Do you have a part # ?

Pete

Valve would likely have to be tested/marked to calibrate approximate restrictor flow (they tend to be non-linear) to insure air escape from timing cover (total closure locked out also). Since thermostat would still need to be modified (?), warm-up should remain slower than OEM. So unless you live in Alaska and drive in winter (defroster needed quickly), why bother? Best rig might be plumbed manual heater valve with inside control (quick heat/max cooling)?

6 VOLTS/POS. GRD. NW INDIANA

I have no experience with restrictors, but trying to change that short piece of hose requires some flexibility when trying to install with the water pump nipple and thermostat housing still installed (trying to save gaskets).  Adding a tee would just about take all the flex out of the hose and make it even more difficult to install.  I believe it would be much less difficult to change the hose with a plug it.  It would be easier of course if you removed either the water pump nipple or the thermostat housing (or both) before installation, but you will most likely need new gaskets.

My second thought is the adjustability of the bypass flow would be good with a shutoff tee, but the amount of restriction would be difficult (if not impossible) to measure.  However, a little trial and error might dial it right in to suit your current needs. 

Charlie Burns Laton, Ca (South of Fresno)



BurnsRacing981@gmail.com

Couldn't you just use a shutoff tee with a stub of hose on either side (instead of a drilled plug)? That way you could open or close it to suit the ambient temperature (?)

I really like Duck's idea and think I might look into doing this myself. Is there a downside?

Cheers

Richard

Just ordered a thermostat from Stewart. I ordered a # 304 (160 degree) and they are going to drill the holes. So the answer to the question is there is no current part # for a modified thermostat for a Y block.

Pete

Couldn't you just use a shutoff tee with a stub of hose on either side (instead of a drilled plug)? That way you could open or close it to suit the ambient temperature (?) Just my .02's worth- /Duck

BOO- YA!!!

Machining the plug just a bit larger than the hose and pressing it into the hose middle is one way.  Putting an additional clamp around the middle of the hose so the restrictor is held tight is another.  As long as the restrictor is 5/8” diameter or larger, it’s not going to get past the hose nipples on each end of it if a clamp is not used.

Lorena, Texas (South of Waco)