HRW3 heat exchanger

[Kris9128]

Evening all. Does anyone know how to get the end caps off the heat exchanger.  

I undid and removed the centre nut. 

Tried twisting the cap off, Tried pulling it, tapping it with rubber hammer, shouting at it, swearing at it even resorted to praying to a diety I don't believe in for some divine intervention but the little sod refused to budge.

 

Any help, advice would be greatly appreciated. 

 

Thanks, kris

 

 

[magnetman]

I don't know but if the cap is threaded then maybe a strap wrench is needed. 

 

One of those things to open jam jars with could work. 

 

Just a theory until someone who knows about it comes along. 

 

 

 

 

[MtB]

1 hour ago, magnetman said:

I don't know but if the cap is threaded then maybe a strap wrench is needed. 

 

One of those things to open jam jars with could work. 

 

Just a theory until someone who knows about it comes along. 

 

Not me, but I had an HRW3 and I took that end cap off to find out why it was overheating and I don't remember having any particular difficulty.

 

Maybe once the nut is off you need to apply some old fashioned BF&I.

 

 

P.S. It was an ex lifeboat engine I bought. 30 years old but virtually never used. It overheated when test run up with jury-rigged cooling. All the tubes inside were clogged solid with that protective wax stuff they use to protect new steel products. Must have been like it since new. It was apparently test-run every six months for the 30 years but clearly not run for long enough to reveal the blocked HE. Good thing it was never needed for real. 

[RLWP]

It needs violence to remove it - and be careful. The cap will probably be OK, if you strain the heat exchanger you'll make the tubes leak, and the shell is alloy and probably corroded. Don't be surprised if the flanges come off

 

Why do you want to dismantle it?

 

Richard

[Kris9128]

1 hour ago, RLWP said:

It needs violence to remove it - and be careful. The cap will probably be OK, if you strain the heat exchanger you'll make the tubes leak, and the shell is alloy and probably corroded. Don't be surprised if the flanges come off

 

Why do you want to dismantle it?

 

Richard

Over heating issues. The boat i bought was used by an old boy (sadly passed away last year) and hasnt really had much use in the last 8 years. I've stripped and cleaned everthing else, including the skin tank. The amount of crud that came out was quite suprising. The feed pipe into th eheat exchanger was clogged with crud and other stuff. 

[RLWP]

Flush it through a few times in alternating directions to make sure it isn't blocked. Also flush the tank out as much as you can

 

If the boat has a skin tank you don't really need a heat exchanger.  I presume the rubber pump rotor is OK?

 

Richard 

 

 

[Kris9128]

Thanks for the advice, everyone.  

Just got back from the boat, what a dirty messy job that was. 

End caps came off reasonably easy in the end. Used a small knife edge chisel and a small pin hammer. Took my time chasing the gap around. Few squirts of wd40 and they both came off with no issues or damage.  That was the easy bit. 

The exchanger was absolutely gummed up with gunk and jizz.  Spent 4 hours with lengths of 2mm wire poking all the tubes out. 

Washed it through a few times and bolted back together.  Washed through a few more times and all clean. 

Need to order about 3 miles of coolant hose and 300 clips. Then job finished and test run on the weekend.  

 

Again, thanks for the help

Kris