Great thread, and I don't feel like a "high-jacker," since we're discussing a number of engine "pre-heaters."
However (at the risk of repeating myself, but to save typing, because I'm LAZY--LOL) here were a couple of questions that I'd like to re-ask, as they seem to have gotten missed, given all the good, healthy debate:
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"2. ....
Does that Katz, in-line heater have an internal pump, or does it simply rely on convection, to circulate the heat?
And if the Jeep's thermostat is CLOSED (i.e., it's normal position, when engine is cold, right?) how can the Katz-style heater circulate warm coolant throughout the entire block, even with (an electric) pump (which I doubt it has)? (Not that anyone in this thread claimed it could--I'd just like the idea of being able to partially
warm up the entire engine, first, if possible.
I've had block heaters on (non-Jeeps) that went into one of the mis-named "freeze plugs" in the block, and looked like a small
"water heater-style" heating element. So, at least
that was warming the coolant within the engine block itself, not out in the hoses, or in the heater core--which I admit is a nice advantage for the
passengers, but perhaps less-so for the engine, than the in-block heater I'm discussing.
The problem with one of the
"in-block" heaters I had is it caused the "freeze plug" it replaced to begin leaking. Happily, I caught it in time, carefully refilled (the running) engine, and limped home."
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That said, I'd like to freely acknowledge that the point made (in
bold red, below) by ADee1 had
completely escaped my notice, despite my lifelong automotive passions--to wit:
ADee1 said:
I bought a used PU with a heater installed in a radiator hose, I took it out after it started leaking about 6 months after I bought the truck. I installed a pan heater, way better for cold starts than the heater in the hose was. No worries about leaks either. if its fast heat you are after the hose heater is better. If its better cold oil flow for a faster easier start and cutting down on engine wear nothing beats an oil pan warmer.
I'm actually embarrassed to admit I'd never considered the (perhaps MOST important?) benefit of an oil pan heater, as so eloquently described by ADee1, above.
However, I remain concerned about (cold) piston/cylinder fitment, and, thus, it seems to me that BOTH a magnetic, oil-pan heater AND and internal, engine block-water (heater) style, block heater, would be the best setup.
But can ANYbody please explain to me how the "Katz-style," i.e., in-line, heater-hose style of *cough* BLOCK heater, can possibly heat more than the passengner-compartment's HEATER CORE, when the engine's THERMOSTAT IS CLOSED, as it would be in cold temps, with the engine sitting, overnight?
IOW, it seems like the in(hose)line, "Katz-style" heater can ONLY heat the water in the coolant lines running to the heater core--or is the argument that the "Katz-style" heater is SO hot that it actually causes the engines THERMOSTAT to OPEN, allowing THERMOSPYHONING to occur, i.e., the natural process of heat cycling through an engine, that the early models of Ford Model T's used? (The early "T's" had NO water pump, and relied on the thermosyphoning princple, with decent results, obviously, though Henry later added a waterpump).
My point is--IMO,
a "Katz-style", in-line heater--especially if it has no built-in water pump (a question no one has yet addressed--is ONLY going to heat the water in the Passenger's HEATER CORE), which is [physically] HIGHER than the Katz heater) and NOT heat the water in (much of) the engine block, for two reasons:
1. Much of the lower block is BELOW the typical location of a "Katz-style" heater, and;
2. THE THERMOSTAT ON A COLD ENGINE IS CLOSED, meaning there CAN BE NO HOT/WARM WATER
CIRCULATING INSIDE THE ENGINE'S WATER JACKETS.
ALL of which makes me think the Katz-style heater presents a warm passenger compartment, but an (initially) cooler engine, than would the "water heater-style" heating element inserted into one of the (mis-named) "freeze plugs" in the engine block itself, as the latter is ALREADY HEATING WATER INSIDE THE ENGINE'S WATER JACKETS, DESPITE THE FACT THAT THE ENGINE'S THERMOSTAT IS CLOSED.
So...since I'm clearly biased toward an IN-block, electric water heater-style block heater,
CAN ANYONE RECOMMEND THE BEST BRAND/MODEL OF THIS TYPE OF BLOCK HEATER?
Help? LOL
Thanks,
Y-Yes