Coolant Expansion Tank: Where to Buy ?

[SV Demeter]

I am installing a hot water heater and the heater has to be located above the engine. I am going to replace the exisitng coolant cap with a non venting cap and plan to install a remote header tank above the water heater with a 7lb cap. I have tried some searching online but have not been able to source a tank. I would prefer a metal tank with 1/2" or 5/8" NPT openings.

[thinwater]

Originally Posted by SV Escape Plan

I am installing a hot water heater and the heater has to be located above the engine. I am going to replace the exisitng coolant cap with a non venting cap and plan to install a remote header tank above the water heater with a 7lb cap. I have tried some searching online but have not been able to source a tank. I would prefer a metal tank with 1/2" or 5/8" NPT openings.

* A very small air compressor tank (Grainger). Down to 2 gallon, but several hundred $$. Too big, anyway. I doubt you'll find any thing that small that isn't custom.

* Build something from pipe fittings.

* Go to an autoparts store and ask. Why re-invent? Hose barb is fine and plastic is fine. I don't understand why you want metal.

[SV Demeter]

Had one on my last boat that was aluminum made for westerbeke. Figured it would be available someplace. I guess plastic would be fine as long as it could handle being pressurized. Usually these plastic tanks are stricly overflow and not for a pressurized system with a cap. I did find this one

Westerbeke 24177 Sailboat Engine Parts and Boat Parts-Torresen Marine

But for that price I have a metal fab guy who will build me a gorgeous anodized one.

[Uncle Bob]

Hey try a car wrecker or recycler many cars have the type of tank you are looking for. Volkswagen Golf has a small plastic tank which is pressurised. Should be cost effective way to do it. Cheers
Rob

[never monday]

Originally Posted by Uncle Bob

Hey try a car wrecker or recycler many cars have the type of tank you are looking for. Volkswagen Golf has a small plastic tank which is pressurised. Should be cost effective way to do it. Cheers
Rob

those tanks have a high failure rate. I'd spend the money on an aluminum tank.

[ggray]

I was looking for one a while back, and found a number of aluminum tanks like this one.


Moroso Coolant Expansion Tank - Lightning Motorsports - Made with Bits of Real Lightning, so you know it's good ! AEM-ARP-Competition-Skunk2-Walbro-more

[SV Demeter]

Thanks that looks like it would work well. Im guessing they have standard female NPT fittings? Price seems fair enough too.

Ok looked a little closer and the tank has female NPT fittings however one is 3/8 the other 1/2. Im a little concerned that 3/8 would be restricting flow and could lead to engine over heating. This is on a perkins 4-154 and the coolant line is more like 5/8 ID IIRC and comes from the engine to the hotwater heater then to the expansion tank then to the heat exchanger. Need to look at this circuit again...

[SV Demeter]

Okay here I go again answering my own posts... I went back to and old thread on installing the water heater on the 4-154.

http://www.cruisersforum.com/forums/...4-a-41840.html

I see that only a portion of the coolant flow passes through this circuit and not the entire cooling system. With that in mind I think I am more comfortable with the 3/8 restriction. Alhough I may just ask my metal fab buddy to replace the 3/8 port with a 1/2" port.

[anjou]

Volkswagen, - fail?,

I dont think so.

Shame on you. The Bosch didnt lose the war cos of machine failure.

Ive got a header tank from the scrap yard. A billion cars cant be wrong.

[NCboatrx]

Coolant header tanks are readily available for only $200 with the mounting brackets. I have attached 2 photos of the ones that we keep in stock and I know that these are available at many different suppliers.

[SV Demeter]

Thanks I ended up ordering an aluminum one. Now I need to find a replacement cap for the heat exchanger since the header tank will be where I want the cooling system to vent from. Trouble is the cap is for a 2" filler neck and most radiator caps are for 1 1/2" filler necks. Im waiting to hear back from a dealer for the heat exchanger (Bowman) to see I can either get a non venting cap or one with a high pressure rating so I can use one with a low pressure rating on the header tank.

[NCboatrx]

Take your old pressure cap to a Napa store. They should have no problem providing the correct size. The large caps were common on the older Lehman marinisations and are common here as truck pressure caps.
Stanley

[SV Demeter]

Tried that this morning. Thinking I need to try a radiator shop maybe? Maybe I can search online for truck radiator caps for 2" filler necks? Tried searching yesterday online to no avail.

[NCboatrx]

I believe the correct Napa number is 703-1418 for the 7lb version and 703-1422 for the 10 lb version. Your cost should be about $10 or a bit less. If you have trouble getting one, I can get from our local Napa store here.

[SV Demeter]

And this is for a cap that will fit a 2" filler neck? Not a standard car size cap for a 1 1/2" Diameter neck?