Block heaters
 

Anybody around here installed one of the freeze-plug types? Like this one:


https://cimg7.ibsrv.net/gimg/www.mia...76bce780fd.png

I have not used those, but I do have experience with the pad style that go on oil pans. I can confirm that those are not as dangerous as one would lead you to believe.

I do have to ask why Joe. What are you getting into? Don't want to let the Miata idle for 48 hours when it's -32f again?

Curious: are they in any way effective? I've looked at them, and the wattage ratings seem quite low for those in the general size range that I can imagine fitting onto the sides of a Miata oil pan.



To be fair, it was only -22°F, but yeah, that's the general idea.

I put the pad style on the oil pan of my Miata. It seemed to get things plenty toasty. I went with the pad on the oil pan because I was concerned about cold start wear and wanted warm oil ASAP. The freeze plug style seemed less effective for that since it's primarily heating coolant. That said, I think every factory installed heater I've seen has been the freeze plug style.

How many watts do you want / need? The ones i've used are 400w and are PLENTY enough.
The two i have personally used are the moroso one . https://www.summitracing.com/parts/m...BoCXqkQAvD_BwE
And this amazon one. (well not exactly this, but very very similar)
The moroso one i've used on personal vehicles. The dry sump tank on the boat has one currently.
The proheat one i've used on equipment at work. Specifically a generator. I've also used them to wrap around chemical pipes that poke through a wall for bulk deliveries. Sodium hydroxide freezes at like 56f so it's important to keep it warm.


On part 2: I cold started the NB when it was below -20(and in hindsight i should have let it run). Top end chatter was there, for longer than it should have been. And i didn't even know trans and rear diff fluid could freeze.

Edit* If you go with pad style, just make sure you affix it with more than just the adhesive it comes with. Or at least check it every so often to see how well it's still attached.

Didn’t we have this conversation last year?

Maybe not, could only find this

Yes, and I wound up purchasing a heater which goes inline with the lower radiator hose. I wound up not installing it, largely because of laziness, but also because the more I thought about it, the less this seemed like a good idea given the design of the cooling system on this engine. Specifically that the closed thermostat would tend to prevent any significant circulation from occurring.

Given the size, it seems those would need to be applied to the bottom of the oil pan. Beyond the fact that it is ribbed (thus preventing good contact), that's also a location where I'm pretty sure the pad would be destroyed quickly. The alleys are not plowed in my neighborhood, so after a snowfall followed by a partial thaw and re-freeze, the drive out from my garage to the street consists of a lot of small icebergs scraping against the bottom of the vehicle.



Yeah, I figured that one out the first morning that I pulled the shifter to the side (call it left-neutral), released it, and it just stayed right there rather than springing back to center.

The one I used was very similar to the amazon link but it was small enough to only fit on the smooth area of the bottom of the pan. After installing it I used an infrared temp gun to check the temperature of the ribbed area further back. I can't remember the numbers but I remember being impressed with how well it heated the rest of the pan.

Joe, I think the lower hose heater would work better than you are imagining. However, the idea of heating the oil seems quite sensible.

In the end, any of the three wold beat nothing.

Read the last post from the thread I pointed to. The guy is from Alaska.

DNM

Fwiw diesel guys around michigan all swear by the bottom of the pan method

I wouldn't stick it on the ribbed section of the pan. Put it on the smooth part above the subframe. So it doesn't get ripped off. The thermal conductivity of the aluminum should be enough to heat the sump.

?
Hot water will rise in both directions, through the radiator and through the block (heater core is still wide open) from the lower radiator hose. Thermal conductivity of the block is pretty high so the whole engine should be warmed. And the transmission, to a lesser extent.

But unless there's a problem with plugging in two devices, why not use both the pad and the lower hose element for increased effectiveness? Quicker warmups and increased comfort are a good thing.