292 Stat Housing Question

[Short 3/4]

I'm replacing a mechanical water temp gauge on my 292 and am thinking of also re hooking up the old idiot light, kind of a belt and suspenders thing. I did that on my oil pressure line years ago to help avoid disaster, and figure it would be a good idea for the temp as well.
I have the later style housing, with 2 ports on the pass side- one for heater, other for temp sender. On the drivers side is the large outlet for the bypass. They make a top outlet elbow with a threaded hole on top, but want the sending units on the engine side of the thermostat.
Best I've come up with so far is to 'T' into the heater port and install the idiot sensor there. I have the standard heater without a water valve, so water always flowing in that loop.
Anybody out there have a better idea I'd love to hear it.
Thanks,
Tom

[vince1]

When I got the truck going with the 250 I bought that original type sending unit with the two spades and hooked it back up as original, one wire for cold and one for overheat. Since then it got transferred to the 350.

I remember it as having quite a large thread, maybe about 1/2 NPT or larger. Is this the type you are referring to?

[Short 3/4]

Originally Posted by vince1

When I got the truck going with the 250 I bought that original type sending unit with the two spades and hooked it back up as original, one wire for cold and one for overheat. Since then it got transferred to the 350.

I remember it as having quite a large thread, maybe about 1/2 NPT or larger. Is this the type you are referring to?

Yes that is the type sender I want to add. Problem is I need three 1/2" ports on the pass side: idiot lite sender/mechanical gauge sender/heater outlet. Looking for a clean way to get that many holes. Thought I remember seeing an aftermarket part that would work, but now can't find.

['68OrangeSunshine]

Some years ago, after I'd just broken the cast aluminum GM thermostat housing on my 292 L6 ['68 C/10 Stepside]. I went in to a close-by Pep Boys, and asked for that part.
He didn't have a GM one, but looked in his bin and came up with a Toyota 4.8L [? Landcruiser] cast iron housing that also had a 1/2'' opening at the top for a temp probe.
Still have it.

[Short 3/4]

Originally Posted by '68OrangeSunshine

Some years ago, after I'd just broken the cast aluminum GM thermostat housing on my 292 L6 ['68 C/10 Stepside]. I went in to a close-by Pep Boys, and asked for that part.
He didn't have a GM one, but looked in his bin and came up with a Toyota 4.8L [? Landcruiser] cast iron housing that also had a 1/2'' opening at the top for a temp probe.
Still have it.

I've seen that type housing with the plug on top, in fact I have one that has the flat spot on it to drill and tap a hole if needed. What I don't understand is what good it would do as its down stream of the thermostat. To be accurate shouldn't the probe be on the engine side of the stat?
Looking at your picture I'm wondering where the probe for your gauge or light sender is. Is it going to the plug on the manifold side of the head near the front? Is that the stock location for your year of truck? I had a machinist tell me that that wasn't a very good place for a temp sender due to being so close to the exhaust port. Any opinions on that?
Appreciate any help, thanks

['68OrangeSunshine]

You make a good point. I never used it for a temp probe. I have a sensor capsule in the drivers side of the head that reads out on a mechanical gauge under the dash. I disconnected the idiot light probe years ago. Not sure what happened to it.
Something pointing down inside there might interfere with the action of the thermostat too.
If it did work with both elements together, you would read the temp of the water from the radiator, and it would radically drop when the thermostat kicked in.
Still you asked a question, and it made me think of that piece.

[Short 3/4]

Thanks for the info and especially pictures Orange. Looks like a nicely set up 6 you have there. So I see where you have your gauge plugged in at, was that the factory location for the old idiot light sender you took out? If that location works, then you have answered my question. I have a pipe plug in that location, so could use it for my 2nd sender, problem solved!
Since I have your ear and living where you do you know about keeping a 292 happy in the heat, maybe you can answer another question that I've always wondered about. How the heck do those engines stay cool in triple digit heat with that huge bypass hose shunting all that water past the radiator? The old Triumph engines had a similar set up (they are another sick obsession of mine) but the original thermostats they came with had a sleeve that blocked the bypass when the engine warmed up. As far as I can tell the Chevy's never had such a feature. Been pondering that one for the 30 years I've had this old big six and would love to know the answer.
Thanks again,
Tom

['68OrangeSunshine]

Yes, I believe that's the stock Temperature probe port.
Thanks. I like it. I've been running a hotrod L6 since 1978.
Adaptation for desert heat...
1] I use a Flex Fan. I know they're controversial now. Mine's US-made, 43 years old and still under warranty. Never failed. The fan has curved blades which scoop more air at low RPMs. As RPMs increase, the pitch of the fan blades flattens out. Not sure what the controversy is? Usually the opponents are in favor of fan-clutches. Too many parts to fail with that configuration, IMO.
2] I now use the wider-based V8 radiator core. Three tier. HD. Since the L6-sized radiators are no longer available, going to a V8 radiator is inevitable. You get a bonus of frontal area. The Passenger side radiator mounts must be moved out to the 3 - 5'' width. New brackets may be needed. Well worth it.
3] I keep the heater core in the loop also, as it's that much more cooling area to help. If my temp gaue is pushing 212*F, I will turn on the heater and keep both windows open, until it drops. [Hence the slang term ''Hot Rodders''.]
4] Thermostat is 195* I think. Don't eliminate it.
5] Coolant mix. I buy Prestone [green] full strength and mix down with distilled water. Two gallons = 4 gallons 50/50. I start with the half-n-half and then add water or coolant mix as necessary. With polypropylene glycol/water coolant, your boiling temperature goes up from 212F -- more coolant: higher boiling point. Always keep 2 or 3 gallons of spare water for emergencies. Five if desert off-roading. Flush the system annually if a daily driver. Watch the color. You don't want brown rusty water. Use the attached Prestone Tee till you get clear water, then drain and add coolant mix until green. Remove the Tee when satisfied.
6] I used to mount a Desert Water Bag on the front grille in extreme off-road conditions, but they've gone extinct for the US [LA] -made flax evaporative 1 Gallon bag. Too bad. Kept an extra for drinking water. It was always cooler than ambient and tasted sweet. Insane prices on EBay for them now.
7] Keep the engine bay clean with degreaser and frequent spraying off of the engine at the car wash. A greasy coating of road grime and oil retains heat.
8] Park in shade whenever possible.
9] Run at night if you can. Tucson cools off about 20 - 30* when the sun goes down because of the surrounding mountains. Phoenix is not so lucky and can stay hot all night.
Compared to the V8, the Chevy L6 is almost air-cooled for a start.

[Short 3/4]

Thanks for the info and the hot weather tips. I also have had good luck with the Flex Fans. Started using them when I lived in Sacramento many years ago where it can get quite hot and now use them in all my old junk. I think the issue most people have is fear of blades flying off. I admit I had one come off at speed in the past. Was in my 65 Mustang and somehow it flew out on the highway without touching anything under the hood. Installed another and it's still going strong all these years later, just like the 35 year old one in my truck. I agree simple is better, and less moving parts equals more reliability. (Why you would want 8 pistons when you can get just as much power from 6 is a mystery to me)
Thanks again,
Tom

['68OrangeSunshine]

I once had a '61 Mercedes 190B sedan [4-door] with an L4 <2L motor, 4-on-tree shift,
Blaupunkt AM/FM/SW receiver, sunroof, factory fogs.
One day on the freeway, the fanblade broke off the front of the engine and one blade sliced its way out of the hood like a stray .50 Cal slug. The Originalersatzteile fan was white nylon instead of an aluminum/magnesium ally.
Direct drive instead of a clutch.