legacycentral bbs

Trying to fit a circulation pump to circulate heated coolant through the engine for easier starts and faster heat .

www.carlor.com

makes a nifty one but at 499.00 USD it is a bit out of my price range. The car already has a 500w block heater but i am pretty sure circulating the water would give much better results in the morning when i start up. The pump i am thinking of is a Wilo Star series , 115V, 25W , continuous duty impeller pump and would circulate the coolant all around as it is being heated. I was told the best place to put in inline with the system was the inlet heater core hose as this would also bring some heat into the cabin and return back into the engin. I am in northern Canada and it is -27 C today...

The car is a 2001 Legacy GT with the EJ25 non-turbo version, what is the size of the heater hose ID and OD.

thx

stephan

Welcome to the BBS.

I am not sure the ID & OD of the hoses. I've got my motor out now for my 90 Legacy and could give you that information, but I'm not sure if it's going to be the same for your 2001 Legacy. The hoses are metric hoses, (which may not be an issue for you since you're in Canada) but standard 5/8" or 3/4" heater hose is probably going to be what you need.

My only concern about putting that pump in-line would be that it will likely be a restriction once the engine's water pump kicks in. What I would probably suggest doing is installing some type of swing check valve (which offers low flow loss) inline with the stock heater hose, and then install tee fittings before and after the check valve so you can run those lines to the circulation pump. This would allow the circulation pump to circulate the coolant around the engine when off, but when the engine is on, the check valve would open and the engine pump would operate and provide normal flow rates to the heater core.

If that's a little confusing I can draw up a little sketch which may help explain things better.

That is exactly the kind of info i was looking for. The part number for the inlet hose is 72411AC020 , i got that from Subaru over the phone (the dealership is 2.5 hours away) but they didnt know which size they were... Well at least i tried . Under normal circumstances i would just crawl under the car and pull one off to find out but in this kind of weather this has not been very appealing. So, please, if you can mic the ID of the hose or the OD of the metal barbed it goes onto, let me know the size , metric or inches.

I have the same concern you do in regards to possible impedance to the flow. I was thinking of trying it out inline, and see how it performs, keep it simple and reasonably cheap so to speak, but yes, i do see a possible issue with restriction there. I dont think it would affect the engine as much as it may lessen the amount of coolant going into the heater core and therefore the efficiency of the heater once under power.

I understand perfectly the rigging of what you talk about, but there isnt a whole lot of space around the engine for too many extras...

So the reason i need the hose ID size ( or the barbed end near the pump) is that i am talking to Wilo and trying to get the pump i need with the right fittings on it. Once the pump arrives i can plug it into the system and not have to disconnect the coolant lines twice (once to check the size, once to hook up ). In a perfect world...

I'll give myself a reminder to look this evening and let you know what I find out.

I measured the piping on the coolant crossover going to the heater core and it's 5/8" OD, so 5/8" ID heater hose should work for you, assuming the newer cars have the same diameter piping.

Thx Josh, I will go with 5/8 because that is what it looks like to me as well and it seems that some of the aftermarket hose sold for a number of the Subarus is 5/8. I wanted to confirm though as it could have been some odd size metric. I have emailed the pump distributor with the sizes and i am waiting for an answer from them to see if they have one with the barbed ends , otherwise they have one with 1/2inch npt for sure but that would complicate matters...

Temps warming up from -25C to -4 C in the last 24 hrs. We got 40 cm of snow over the weekend, loving the Subaru.

stephan
PS and thx for all the trouble. I will let you know how things all work out, bear with me sounds like Wilo was not in a rush to email me back today or yesterday... I also have a OBD reader that will let me see the difference between block heater only vs block heater + circ pump when it is all installed.

later

stephan

Sounds good. Let us know how things turn out.