Block Heaters

[David Dunlop]

Hi Guys.

Not so much worried about what to use. I’m just suspicious that, across the board, manufacturers of these things have quietly been reducing the wattage output of them, to make them more energy efficient. Haven’t a clue what they are rated at today but 40 years ago I think they were running 400 to 500 watts in an iron block engine.

David

[Tony Smith]

I don't know where on a Ford V8 you could fit a block heater, considering the lack of freeze plugs, but the original GM accessory freeze plug was 400W 115v:

https://www.ebay.com/itm/CHEVY-GM-W-...BZ0sJk&vxp=mtr

[Phil Waterman]

Hi David

I have one of those heater hose type heaters that have a one way flow check valve you connect it in line with the heater hose or some other convenient point in the cooling system. Then mount the heater as low as you can vertically. The unit heats the coolant and the thermosyphon draws the heat through the system.

I use one of these when I'm testing new engines to bring them up to temperature two torque the heads. Unit I have is relatively small 110v plugged in over night in 40F air temp in the shop it will take the engine up to 180F.

When I'm first starting a new engine with system on the test stand will take the engine through a couple of heat cycles to re-torque the head. Then when I'm ready to start the motor do the oil prime with the drill and pumping the oil into an already warm block warms the oil quite fast.

When used in a car in the winter it has the added advantage that you get heat out of the cars heater almost immediately.

With the weather we have been having may be looking for one to put on the plow truck.

Cheers Phil

[rob love]

One of my favorite block heaters to use on the older vehicles was the one that spliced into the lower rad hose. I used to use on a M38, and on a Manitoba winter morning, there was actually heat on startup. But when I went to buy one about 15 years back, I noticed a change. They had now included one of those little thermostatic switches on the heater to turn it off at a certain temperature. Now whether that was a conservation measure, or a safety measure, I knew I didn't want that style. Those little thermostatic discs seem to be the thing that will fail.

Re the flathead Fords, there were the blockheaters that would install in place of a headbolt.

The block heaters Phil talks about that go into the heater line are also a winner in my books. You can get them in wattage up to 1500W. I installed one years back on a HLVW wrecker that would be called on for crash duty in Moosejaw. The truck would start immediately on the coldest of days. Only problem was that you had to change the heater hose every 2 years. Even the silicone hoses I used for it would rot off form the heat, but it was a small price to pay for reliability.