What octane gas do you use in your HX ?

The radiator fan comes on at about 204F water temp. I like to keep just below that, to avoid the high power draw, but as warm as I can below that point. I'm working on a warm air intake for this winter, to bring the intake temps up to 80+ degrees.

I haven't actually heard my fan come on in my hx yet.:confused: Got it in early december. I replaced the temp sensor that goes into the thermostat housing cause I was worried it was the prob. No difference. The car temp gauge has never gotten above halfway.

Do these cars hardly produce any heat so the fan hardly ever comes on in the winter?

well... on my 10-mile commute this morning, mine maxed out at 161 F water temp. That's with a 100% grill block. So, yes. They put out very little heat.

The gauge sits at halfway when it's fully warm.

Whoops - sorry I was absent for a bit.
I use 87 octane.

My Scan Gauge usually shows about 182 deg. F. when warmed up. New thermostat installed this past fall.

The 182 deg. is with a nearly complete grill block, in New England winter. I have no idea if the rad fan is coming on or not. When the weather warms up a bit I plan to run a lead from the rad fan's power wire to a glow bulb on the dash. That will tell me when the fan comes on. Experience with the electric fan I put into my former daily driver (Volvo 240) shows that I can rarely hear the fan even if car is not moving, so I want a dash indicator.

PaleMelanesian,

Did you build a hot air intake?? I've thought about one but I'm not sure where and how to put it. I have some ideas but it's pretty crowded in that area. That is, the space between the air box and the exhaust manifold. I keep thinking the hot air tube (from manifold to air box) has to be right behind the radiator, near the rad hoses. You think so too? Or another idea?

You might want to check with this guy, he snuck one into a tightly packed engine bay:
https://www.gassavers.org/showthread.php?t=10103

I'm trying a warm air intake right now. I got a 2ft piece of 2" carburetor preheater hose at the parts store - the bendable aluminum spiral stuff, that holds its shape when you bend it. I connected it right to the air filter box, removing the stock intake entirely. It curves over/around the distributor to the left, then tucks in between the block and the exhaust manifold.

Does that make sense? My engine bay looks very much like this one: https://memimage.cardomain.com/ride_i...0077_large.jpg

It's too early to know if it helps. Only 3 days of testing so far, and I have to compare to similar temperature days.

Update: my car seems to like intake temps below 100F. Above that and it gets really sluggish. That might be good for long highway driving, but for my in-town driving it's a liability.

Things might be different with a lean burn, though. It's possible the higher temps would make lean burn happen more often.

I would imagine that 100F is near the top of the range of air temperature compensation programmed into the ECU.