One of my favorite topics. Actually I find the lower radiator hose heater
to be fairly efficient, at least in terms of getting the job done. Maybe
not so good from an energy efficiency standpoint but the convection works
good. It usually only takes an hour or two to make a difference. Also, this
is on the lower radiator hose from the engine block, not the upper where
the thermostat resides. It heats by convection back to the block so the
thermostat is not really a factor.
The freeze plug heater is best if one can be found. Its closer to the area
you want to heat so the heating wattage needed is less like Blake says.
I agree that the dipstick heater is fairly worthless. Another heater I
found to be of little value was the heater hose in line heater. It has to
sit below the radiator water level to work and in theory it is supposed to
circulate the water through the heater line while it heats it. On my Toyota
Landcruiser, it did a great job heating a few feet of heater line and then
it would shut off until the temperature dropped and then repeat the cycle.
The problem with MGs (at least the Bs) is that there are no longer any
listings for engine heaters anymore (that I know of). My lower radiator
hose heater in my BGT was bought about 20 years ago but was dropped from
the listings not long after that even though it was a standard sized
heater, maybe because the fit was so tight. I was never able to locate a
freeze plug heater - the one that came on my 71BGT had been discontinued by
the manufacturer when I tried to replace it (it never worked for me).
Another one of my favorite topics is record cold weather starting
temperatures, unassisted. My original 65B started at 22 below once, but
anything below maybe five below was iffy. My 71BGT's record was 14 below
(temperatures being degrees F).
David Councill
67 BGT
At 11:02 PM 12/4/2000 -0800, Bullwinkle wrote:
>Now engine heaters.
>
>Now here is another topic to create a little discussion.
>
>FWIW: I know of four different types of engine heaters:
>
>1) Headbolt. Used by removing a headbolt/stud which was located so that the
>bolt went into the water jackets. Probably went out with Model A's and other
>flat head engines.
>
>2) Dip Stick. Easy installation, but it only heats the engine oil IN THE
>SUMP. How does it heat the engine as the oil is not circulating with the
>engine off. The oil on the pistons and bearings is not heated. The heat
>in the
>oil would only travel by convection through the sump walls to the rest of the
>block, or by heating the air in the sump above the oil.
>
>3) Lower radiator hose heater. Not very efficient as you're heating the water
>which passes through the radiator and gets cooled. Also, remember that the
>thermostat is closed until the water gets to operating
>temperature. Soooo, how
>does the heated water get into the engine block? These units are quite
>large in
>electrical consumption, some being as high as 1500 watts.
>
>4) Soft plug heater. IMO the best of the heaters. The are usually low in
>power
>consumption: 350 to 500 watts. They heat the water in the block which also
>warms the oil on the piston rings. I believe piston drag would be much
>greater
>than bearing drag. The bearings may get some heat. Basically, they warm the
>engine from the inside out. The warmed water around the heater rises in the
>block into the head, cools, and probably returns through the water
>passages near
>the front and rear of the block. I've used them on many vehicle and they
>make a
>bid differenece.
>
>Blake
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