Masato

Hello all,
I posted this over at tacomaterritory as well but so far, no one could help. Perhaps someone here can chime in. I'm in the process of installing a Zerostart tank style circulating coolant heater (8000 series). The instructions tell you to either tap in the system through the coolant drain hole on the block or use the rad drain plug for the input. The recommended output is the heater hose leaving the block and heading into the heater.
Here's the issue. the threads on the rad drain hole aren't standard so I can't find any kind of fitting that will work here. If anyone knows of anything for this location, please advise. I need an adaptor that would convert our rad drain hole threads to accommodate 1/4" pipe thread. I've plumbed my system using the block drain hole but because of the petcock style, even with my hose fitting in place of the drain plug, coolant leaks out of the drain hole. Presumably, this is because the new hose fitting doesn't have that 'collar' that recesses into the block to direct the flow of coolant past the drain hole. Does anyone know of a fitting I can use in here OR an alternate location to tap for the inlet to the coolant heater? Or am I dead in the water.
Thanks in advance.

mt_goat

I don't like the sound of messing with the rad drain. Why not cut the lower rad hose and insert a pipe in there with a hole drilled and tapped for the fitting size you need. Something like this was done on my upper hose for a water temp sender. Hardest part is finding a piece of pipe the right OD, IIRC mine is 1.5" and works great. Note I used water pump RTV to seal it up good.

okie81

Just curious, where are you going to mount the tank?

Dale, what I would give to look through the inventory of 4runner pictures you have. Seems like you've always got a good picture for every scenario

mt_goat

Actually I don't have many 4runner pics, I have a lot of my pickup though.

Here's where the public ones are all stored if you want to look through them: http://community.webshots.com/user/osufan1

Masato

Thanks for the replies. I will try to tap the lower rad hose just like you've done with your upper hose. As for mounting the tank, I've mounted it just below the battery using existing holes in the inner fender well. and I've run my return line up to hose that enters the cab to the heater. If this works, I should do a write up.
Thanks again for the replies.

Canadian Bacon

I've heard of these things but I've never seen them. Where did you pick one up?

I bet you wish you had that thing installed last week. I'm in Edmonton so I'm sure you had a solid week of -30 to -40 weather.

I kept my 4 runner plugged in to the block heater, and even then it would take a couple of extra turn to get the engine going.

mt_goat

As I see it the only drawback to that design is you are going to be circulating the heated coolant through the radiator all night, which in turn will be cooling it off. Too bad you can't take the radiator out of the loop, no sense in trying to keep it warm all night.

Canadian Bacon

How would the fluid cool. The rad fan will not be running, nor will there be any air flowing through the rad. The sheer friction of the flowing fluid alone should cause it to heat up.

RobD

Oye, my fellow Canadian...as the coolant heats at the bottom of the engine's lower hose, convection currents will carry it up the rad, where it will lose heat by radiating it through the fins. You don't need to be moving to do that.

I hate to explain simple heat transfer, but then again, you are from Edmonton.

dannomite

Just get your toyota a tim hortens in the morning. That should warm it up just fine.

mt_goat

Well if I understand it right, the coolant will be sucked in from the lower rad hose and heated up and slowly pumped into the heater hose. The heated coolant then will have to return to the lower rad hose by way of the upper radiator hose and through the radiator because the t-stat will close off the flow through the block to the lower rad hose. Just running heated fluid through the rad when its very cold will cool it. Even if there is little air movement thought the rad it is still a very effective heat exchanger. Now if you wrapped a blanket around it that would help LOL. Friction of coolant flow will be insignificant.

You could take most of the rad out of the loop if you could tap into the block for the coolant, another posibility is tapping the oil cooler hose but its kind of hard to get to and its much smaller than rad hose. The upper rad hose might be a little more efficient but if the coolant level was low at all it could burn-up the heater and pump and it might not heat the block up as much.

Masato

Cdn Bacon: I bought it from Canadian Tire here in Slave Lake and wished I had it in last week as it was indeed -30 to -40c here. It's not a product that's found on the shelf but they usually carry it behind the parts counter. I paid $80 for it.
Mt. Goat: You are correct in how this thing is to be plumbed. The problem with tapping the block directly is that I cant find a fitting that will bypass the drain hole. I plugged my fitting in place of the drain plug in the block but because of the petcokc design, coolant just leaks out the drain hole and this is why I was looking for an alternate location. I'm not sure which line is for the oil cooler but from what I can see (if I'm looking in the right place) it looks to be quite difficult to work in there so I think I'll have to splice in at the lower rad hose.
What kind of pipe did you use on your upper rad hose for your temp. sender? I've done a little reading which appears to suggest that one should stay clear of galvanized steel as the zinc may react with the coolant causing either precipitate issues or sludging. I have some old fencing material and wa about to use that but thankfully I found the references about staying clear of galvanized steel. Any other recommendations? Stainless? Aluminum? thoughts?

mt_goat

Mine is just a piece of scrap mild steel I had laying around, but aluminum or stainless would be good too. I guess I'd refer steel because the threads will be stronger. You'll only have a few threads to hold it so the stronger the better.

Masato

I wonder if I should get a nut welded on to serve as a bung? I was thinking about the water pump seal material you had used and was a little uneasy for some reason. I think there's a millwright here in town - I'm sure he must have something that would serve the purpose.

mt_goat

Yes its very hard to replace that hose with the engine in the truck, but it can be seen in this pic, its the hose that runs from the t-stat area over the oil filter to the oil cooler.

Masato

Thanks for the reference. I don't think I'll be tapping that line... Guess i'm stuck with the lower rad hose. There are no other ports on the block to tap are there? The dealer didn't seem to think there were.... but then again, I was talking to someone who sounded like they were 18 and working part time taking orders...

mt_goat

That oil cooler line would be an ideal place if you could get to a section of it. You could do a "T" something like this:

mt_goat

That would work, good idea.

Canadian Bacon

So if the rad is that efficient that the fluids will stay cool, why but in an inline heater in the first place?


Also, I'm not from Edmonton, I just so happen to live there. But then again, Edmonton is the largest city in newfoundland.

mt_goat

I think if you ran the inlet to the oil cooler hose it would bypass the radiator from the loop and keep the block much warmer. It would really be a waste of energy to try to keep the radiator warm all night and would have no added benefit that I can see. I bet if you remove your oil filter you could get enough room to slice a "T" into the oil cooler hose.