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Engine block heater

Discussion in 'Gen 2 Prius Accessories & Modifications' started by bobc, Feb 21, 2005.

  1. bobc

    bobc New Member

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    Hi all,

    This past weekend, I installed a block heater that I ordered from a Canadian dealership. From our Canadian counterparts, these come standard on Canadian vehicles.

    I have to say, that I can't recommend installing one tho. The installation isn't that hard but I question the efficiency of this heater. From the first and second photos, the arrows point to the hollowed out cylindrical area in the engine block where the heater element is inserted. The block heater does just that: It heats the engine block. It does not heat the oil.

    The concern I have is that the heating element doesn't go "into" the block. The heating element isn't in the bowels of the block whereby all the heat generated can be put to good use heating the block. The hole is cast such that it runs parallel with the side of the block. Thus, maybe half of the heater is exposed and that heat is lost to the elements. While the aluminum in the block does transfer heat quite well, only half of the heater is in true contact with the block. So, this isn't a particularly efficient block heater.

    The heating element is rated at 400 watts, BTW.

    I hope you find this of some help.

    PS. If someone can tell me how to draw arrows in Photoshop, I'd appreciate it!

    Cheers,
    -bob
     
  2. jayman

    jayman Senior Member

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    Well, I didn't expect that.

    Every block heater I've ever seen has fit inside a frost plug, so it heats the coolant in addition to the block. I've never seen a "block" heater that clamps to the side of the block. I suppose it's better than nothing.

    I still think the best block heater is a thermo circulation coolant heater. It plumbs into the heater hose and as the coolant heats inside the little chamber, it expands then is forced past a spring-loaded valve. Cold coolant is drawn in and the cycle begins anew.
     
  3. jayman

    jayman Senior Member

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  4. hdrygas

    hdrygas New Member

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    03 or < or 04-5? You could get an electric blanket and open the hood and drape it over the engine and do better, and for a lot less I would guess. Is that really it?
     
  5. DanMan32

    DanMan32 Senior Member

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    Electric blankets don't put out a whole lot of heat, they don't need to for their intended purpose.
    Not to mention the inconvenience of having to remove it and re-install it every day. With a block heater you usually have a plug sticking out of the grill. All you need do is connect it to an extension cord. Nothing else to remove.
     
  6. bobc

    bobc New Member

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  7. jayman

    jayman Senior Member

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    Dan:

    Oh boy, have you ever seen what happens when you *forget* to unplug the extension cord and attempt to drive off??

    A million years ago when I was a teenaged boy, I saw a frail little granny-looking woman with a Dodge Dart driving down Portage Avenue here with the extension cord still hooked up.

    The cord was whipping around behind her like an angry snake. Despite passing motorists using frantic hand gestures and honking horns to get her attention, she seemed oblivious to it
     
  8. DanMan32

    DanMan32 Senior Member

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    But imagine if you forget to remove the electric blanket! Especially if it is draped over the engine.
     
  9. jayman

    jayman Senior Member

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    Dan:

    The scary thing is, that happens around here too. You even see folks who put an indoor-rated baseboard electric heater under their oil pan to help with cold starting. I guess we as a society really are getting dumbed down.

    I'm not sure a regular electric blanket would do any good though. You can purchase industrial blankets for specific applications, such as barrel heaters for 55 gal drums. Some process fluids and oils are like taffy at room temp, so you really have to heat them up to get them out of the drum.

    OTOH A blanket heater for the battery is a great idea. Even a new battery, fully charged, can freeze at -40 or colder.
     
  10. bobc

    bobc New Member

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    In my old Subaru,

    I had both a block heater and battery heater. The latter was like a heating pad we use for our aching joints. It wrapped around the 4 sides of the battery and was semi-permanently attaqched. It wasn't removed in the AM.

    Regardless of the temp, when using both of these, the car started just like it was summertime. The rpm's even went immediately to low idle. There's no question that using these saved wear and tear on the engine and the battery...

    Thus, the reason for installing the block heater in the Prius...

    -bob
     
  11. Frank Hudon

    Frank Hudon Senior Member

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    how much heat transfer do you get?
    over night plugged in full time 53-57C approx 130F,
    2 1/2 hours on a timer 35-41C approx. 100F it totally depends on OAT, the numbers stated are approx. 0C OAT 2 1/2 hours at 400 watts
    cost me 6.1 cents a day to have heat at start up worth every penny.
     
  12. jeepien

    jeepien Member

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    I'm surprised to hear that someone would want to install a block heater.

    Has anyone EVER had a "cold starting" problem with a Prius?
     
  13. Frank Hudon

    Frank Hudon Senior Member

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    "has anyone ever had a cold starting problem with a Prius?" yes me, I don't start well cold and the sooner that the heater blows warm air the better I like the Prius. I ues it for the better gas mileage factor about 3MPG better day in and day out. 4 warm starts out of 8 per week give me 3 mpg better milage. ymmv. That costs me 6.1 cents a day to use, and gas is 93.2 cents a liter. My electricity bill goes up 97.6 cents a month. On average I doubt that I'd notice the increase in the Hydro Bill. Oh Hydro, our electricity is generated by HydroElectric dams.
     
  14. jayman

    jayman Senior Member

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    Gary:

    I think you're missing the point. Many cars will now reliably start even at -40, thanks to HV ignition and fuel injection. Many drivers figure since the car seems to start fine, they can forget about plugging in.

    In many cases, especially below -20 C, you get cabin heat much faster and minimize the MPG drop in cold weather. At the very least, if you break even (Cost of power to plug in vs fuel savings) at least you're getting heat much faster while minimizing cold start wear.

    I even see it around here. Manitoba has about the cheapest power in North America, with a service charge of around $7 a month and rates of around 5.4 cents a KW. So it is *very* inexpensive to run a block heater here, yet folks still try to get away with not plugging in.

    I'm like Frank, my cranky 'ole bones don't like the cold either.
     
  15. bobc

    bobc New Member

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    Frank,

    Thanks for the temps.

    out of curiousity, when you took the temp readings, where was the thermometer?

    Do you happen to remember what outside ambient was when you got 53-57?

    -bob
     
  16. Frank Hudon

    Frank Hudon Senior Member

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    The temps are taken with a MiniScanner that reads the temp of the engine via the temp sensor in the block. The temp for the 53-57 readings were taken at about 0 -3C before I put in the timer. Our winter over night temps usually hover around freezing or slightly above. I've been using it (timed heater) since November and that has supplied the data for the MPG's. The one thing that I wanted to try was a sheet of cardboard in front of the rad to see if the ICE over heats but we didn't get cold enough to try it this winter. The MiniScanner gives a constant temp readout so it's easy to watch and see if it would over heat. Unfortunately the scanner isn't available for the 2k4-5 Prius.
     
  17. ezongas

    ezongas Junior Member

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    I live in a fairly moderate climate, but if I lived further north, I would seriously consider purchasing a oil pan heater instead of the Toyota block heater. This is a less expensive and IMO more effective solution. There are many vendors selling this type of product, but I have included a link for your convenience: http://www.etipinc.com/universal.asp?cat=maint
     
  18. jayman

    jayman Senior Member

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    There is continuing debate up here about the oil pan vs coolant heater. IMHO both are right.

    Oil pan heater: proven to dramatically reduce start-up wear, especially in temps -40. Allows you to run a cheaper mineral oil instead of a synthetic. For HD trucking applications, allows the operator to use a 15W-40 year round. Provides little if any benefit to faster warmup, faster heater performance, or initial starting ease.

    Coolant heater: especially a circulating coolant heater will provide much quicker heat from the heater. The spark plugs, fuel injectors, cylinder heads are at least partially warmed, so cold starts especially at -40 are much easier. Provides only partial if any benefit to warming the oil for reduced cold start wear.

    Since most mineral 5W-30 oils only have to be "good" at -30 C / -22 F, it's important to use either a synthetic oil below that temperature or to use an oil pan heater.

    Immersion oil pan heaters don't have to be huge. Most HD truck pan heaters are 150 watts or less, and that will easily heat +30 litres of oil. Stick-on external heaters are much less efficient.
     
  19. Frank Hudon

    Frank Hudon Senior Member

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    it would be interesting to see what the 125HWD unit would do on a Prius. 3" diamater by 1/2" thick shouldn't stick down too much lower than the oil pan on a Prius already is. Draws 92 watts so it and a block heater would be best of both worlds. Perfect for you jayman!
     
  20. tomdeimos

    tomdeimos New Member

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    <div class='quotetop'>QUOTE(Frank Hudon\";p=\"67146)</div>
    I've stuck an indoor-outdoor carpet mat from Home Depot in my 2005. Had to cut out
    two pieces and stick one in each side. One side is harder, so that piece is smaller.
    Overall I blocked 3/4 of the radiator.

    Unfortunately it imeediately warmed up here so don't know if it helps much but I drove it
    for an hour or so at various speeds and stopped to check and the radiator still felt
    cold. Engine was warm but not too hot to hold my hand on. Air temp was maybe 20 F.
    My Radio Shack infrared thermonmeter also showed everything pretty amazingly cold.

    If it gets over 50 I will start watching it closely or remove it for the summer. Be nice when
    we can read the temps with a scanner. Then I might dare block a bit more.