Torker289--can I drill and tap a plug hole here...?

When I put in my temp sensing relay on the radiator fan, I had to "concoct" this ugly setup to put the temp sensor in line with the water flow. My T289 did not have any extra holes tapped for a plug.

Anyone think putting a small hole in the HERE area would hurt the manifold, mainly would it weaken it so it wouldn't seal to the heads well?

It would only have to be a small hole, I think it is 3/8" pipe, that the last piece with the nipple hanging down from the brass crap would have to fit into.

 

I would either put it in the front water manifold near where you indicated, or drill and tap straight into the flat on the backside so it protruded straight into one of the rear ports.

Where you have it marked, is too close the center, and may interfere with the distributor. I would move it over to the driver side end of the water manifold, fairly close to the head.
I like the idea of into the intake flange in the back more... but that is personal pref.

 

Hey, after thinking, that top of the water manifold is probably too thin.
If you look at the factory bosses, they are thickened.
You might be best to drill the hole a tiny bit oversized, then have an aluminum bung with proper threads weld on where I mentioned.

The flange itself is thicker, so now I lean heavily to drill/tap the rear flange over the coolant passages. No welding there.

 

I have seen thermostat housings with a boss on the top that could be drilled and tapped.

 

You mean right here... Durned good idea. I noticed that one of my old ones had a plug in there. See if I can find it. Already drilled and tapped. If not, this used one has the hole ready to tap and drill the rest out.

Thanks for pointing that out.

Ratio, My flanges at the back are already worn pretty good, maybe 1/3 of the way through. Good idea though.

Do you think I should fill the rough water eroded parts with an expoxy or something?

 

Just found my old one, and I was right, drilled, tapped, and plugged, plus, the entire casting is about 3 times heavier than the one in the picture:bananaman

This one feels like cast iron, the one in the pic feels like cast aluminum, the one I have on is chrome plated, and I could never get it to seal correctly.

The heavy one with the plug is the one I had on when I bought the car.

 

One thing about the housing,,,your on the closed end of thermostat.

 

DK, what are you getting at? Being on the cold side until the thermostat opens, or the thermostat physically hitting it?

The electric fan does not kick on until 190, and off at 175. I use a 160 thermostat, so it should open up in time for all of it to work together, if that is what you are getting at...

 

I'm thinking the fan will run a bit erratic. Not on the hitting of t-stat, just turn off an on. Where you are,,I guess it should work pretty good, with the 160 stat an 190 fan Give it a try.

Can't remember when you said of the fan,,,but do you have a switch to over ride? Always a good idea to be able to turn fan on as a option.

 

Would that be a problem for a fan switch being that you dont want the fan to come on anyway until the water has at least had a chance to do its job.

I too have an interest in this for my own project.

 

I moved it to another spot anyway. I had a temperature gauge sensor in the top just in front of the carb, but it is lower than the one on top of the thermostat housing. If one isn't going to work (due to being too high in the system or having an air bubble get into the hole), I would rather have the gauge not work, and keep the fan working. So, I put the fan in the low spot existing hole in front of the carb, and put the gauge sensor in the top of the thermo housing. Beside, the gauge sensor has a deeper probe so it should still be touching the water, even at the highest point in the water system.

Still, thanks for pointing out the drilled hole in the top of the T-stat housing. Saved me from having to do a hole where it wasn't engineered to be.

 

Guess we'll have to have a tester on this! That "hole" was there for the emission vacuum ports, which makes me think (after first post) it probably will work, well maybe er sorta er I don't know!

 

Should work fine,temp guage may fluctuate a bit though.(not a biggie)

 

I would rather have the temp gauge reading incorrectly than the fan relay sensor...

 

I don't see it.
That port is so close to the stat it shouldn't matter.
You can mount the temp sender right on the back side of the stat and it will still fluctuate as the stat opens and closes.
My vehicles do it (ones with gauges)...
If the water temp didn't fluctuate on either side of the stat, it wouldn't open or close. There must be fuctuation there.