I've got this big old honkin timer that has a big dial with hours and days so you can set it for a whole week just by putting little screws in where i need. I got it from my grandpa and wired it up, but then decided I wanted a smaller timer so i bought one, I guess if the little digital one fries, I can use the dinosaur ha ha

 

Nearly all of the Ford/International heaters are 1,000-Watts, which figures out to something like 8.7 ampere.

I have read somewhere here that the Dodge/Cummins heaters are 1500-Watts, which is getting in the 13 ampere range.

One company manufacturers probably 95% of all block-heaters.

I have been using the same little 15-amp hooded outdoor Walmart timer for several years; it is the kind that has the little GREEN and RED plastic pegs that you place wherever you want.

 

I do 2 hours, usually after that the grid heaters don't even turn on.

I think the wattage is like 750-1000 watts.

 

I hadn't even given it a thought until you mentioned your's, but I know just where such a heavy-duty timer as that can be had for a few minutes with a screw-driver.

Way back in 1976, when we opened our shop for business, my father had a huge 110-volt timer installed to operate the big flashing sign out by the highway.

It was supposed to turn the sign ON just before dusk and OFF around first light and did so wonderfully for about two weeks.

Then, some of the local punks burst the sign into pieces by slinging beer-bottles at it from passing cars; and, then, some little old lady side-swiped the sign-post, stripping off the electrical conduit that came up through the concrete.

That wonderful timer has just been hanging there, screwed to a floor-joist above the basement stair-well, ever since our country's bi-centenial.

I may just commandeer it tomorrow and put it to better use.

 

According to this :

http://scheiddiesel.com/display_part/1149.php


750-Watts it is.

 

From 20* above to about -25* I give it 4 hours. Colder than -25* I leave it on constant.

 

Thanks, guys. I think I'ma go for 2 hrs to start.

My timer is a 1500 watt unit, which is left over from my reef tank days. Should do the trick!

 

I'm with the two-hour consensus, ... last I read into it the block heater max temp is reached at four hours, and at a nickel an hour give or take for hydro we're not talking big bucks. The best hour for block heater warming efficiency is the first hour (delta T and all that), and uses the most hydro (elec resistance lower when colder). So after four hours the hydro draw rate is least, which otta be solace for the plug-in-all-nite crowd. Either way it's better bang for your hydro nickel than an elec interior warmers IMO

 

Would all depend on the ambient temps/conditions. Up here when its -40F plugging in all night is usually the best option, especially if its windy.

If its not that cold, 3-4hrs does plenty.

 

my (what i believe to be factory) block heater pulls between 6.5-7.0 amps with an amp probe. at 12* i plug mine in as soon as i pull it in the barn and shut the door, .50 cents a day i can take.


Darwin