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Adding a Calorifier to a BMC 1800.......


TheSaintlyOne

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Hi everyone following on from a previous post we now have the BMC 1800 runming and the Calorifier ready to go in currently in place but only situ. 

 

I remember some of you saying I needed a few specific bits for the engine to connect the Calorifier can you remind me what those are and where best to get then. Screw threads etc

 

Picture of our engine before install for reference. 

Screenshot_20210826-222617_Gallery.jpg.d9e5a31e0aa075930e1b7f80b2fc2701.jpg

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The flow tapping is on the top head near the gearbox end, close to the rocker box, 1/2" BSP tapping, will have a plug in it at the moment. This goes to the BOTTOM of the coil in the calorifier.

The return from the TOP of the coil goes into the water pump via a tee piece in the hose on the port side under the heat exchanger/exhaust manifold. Stick a vent tee on the pipe to the calorifier at the highest point, usually on the top connection itself.

!5mm pipe will be sufficient for these pipes unless the calorifier is over 10metres away from the engine.

Edited by Tracy D'arth
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Just now, Goliath said:

 

It crossed my mind, but there’s not the strength in them two bolts, is there?

 

Yes there is.

 

I used to use brackets like that to lift a BMC engine.

 

But it was an A series in a Mini. And that included the gearbox too, which was attached beneath the engine, so quite a weight.

 

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It wasnt my engine at the time this photo was taken so cant comment on the suitability but the guy that sold it to us is apparently an expert at BMCs and this wasnt hos first one so presume he knows his stuff

2 hours ago, Tracy D'arth said:

The flow tapping is on the top head near the gearbox end, close to the rocker box, 1/2" BSP tapping, will have a plug in it at the moment. This goes to the BOTTOM of the coil in the calorifier.

The return from the TOP of the coil goes into the water pump via a tee piece in the hose on the port side under the heat exchanger/exhaust manifold. Stick a vent tee on the pipe to the calorifier at the highest point, usually on the top connection itself.

!5mm pipe will be sufficient for these pipes unless the calorifier is over 10metres away from the engine.

Os it just a standard 1/2 inch BSP or do I need something specific 

 

Regards 

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41 minutes ago, TheSaintlyOne said:

It wasnt my engine at the time this photo was taken so cant comment on the suitability but the guy that sold it to us is apparently an expert at BMCs and this wasnt hos first one so presume he knows his stuff

Os it just a standard 1/2 inch BSP or do I need something specific 

 

Regards 

Its just 1/2" bsp on the  1.8 D so you need  male  1/2" bsp to whatever pipe you use adapter and ptfe tape the thread.  The 1.5 D BMC is 20 mm conduit thread.

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1 hour ago, The Happy Nomad said:

 

Yes there is.

 

I used to use brackets like that to lift a BMC engine.

 

But it was an A series in a Mini. And that included the gearbox too, which was attached beneath the engine, so quite a weight.

 

 

They were standard Austin and then BMC fitments and no, they may not really be strong enough. We had one on an A series petrol that snapped the rocker shaft fixing stud and crushed the mechanics small finger and hand. After that, we always roped/stropped them.

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16 minutes ago, Tony Brooks said:

 

They were standard Austin and then BMC fitments and no, they may not really be strong enough. We had one on an A series petrol that snapped the rocker shaft fixing stud and crushed the mechanics small finger and hand. After that, we always roped/stropped them.

 

Interesting.

 

Obviously we never had this happen.

 

But then we were not doing it commercially and I think we did only about a half a dozen lifts over the years with different family and friends cars. We always used a spreader bar too, not that Im suggesting you didnt.

 

I never knew them as being 'standard fitment' though, we had to buy a pair from our local BMC dealer, Watsons of Saltburn by the sea.

 

Obviously as I am talking minis predominantly there wouldnt be the room.

Edited by The Happy Nomad
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4 hours ago, Tracy D'arth said:

The flow tapping is on the top head near the gearbox end, close to the rocker box, 1/2" BSP tapping, will have a plug in it at the moment. This goes to the BOTTOM of the coil in the calorifier.

The return from the TOP of the coil goes into the water pump via a tee piece in the hose on the port side under the heat exchanger/exhaust manifold. Stick a vent tee on the pipe to the calorifier at the highest point, usually on the top connection itself.

!5mm pipe will be sufficient for these pipes unless the calorifier is over 10metres away from the engine.

More or less the same as mine but I took the flow from the tapping next to the stat housing. That was 20 years + ago And still works perfectly.

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26 minutes ago, Slim said:

More or less the same as mine but I took the flow from the tapping next to the stat housing. That was 20 years + ago And still works perfectly.

Taking the water from the back of the head prevents the rear cylinders running hotter than the front ones. Its where the cab heater took the hot water off in the van engine.

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1 hour ago, Tracy D'arth said:

Taking the water from the back of the head prevents the rear cylinders running hotter than the front ones. Its where the cab heater took the hot water off in the van engine.

Noted. I suspect that was more relevant in a vehicle where the front cylinders were cooled more by airflow. 

 

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19 hours ago, Tracy D'arth said:

The flow tapping is on the top head near the gearbox end, close to the rocker box, 1/2" BSP tapping, will have a plug in it at the moment. This goes to the BOTTOM of the coil in the calorifier.

The return from the TOP of the coil goes into the water pump via a tee piece in the hose on the port side under the heat exchanger/exhaust manifold. Stick a vent tee on the pipe to the calorifier at the highest point, usually on the top connection itself.

!5mm pipe will be sufficient for these pipes unless the calorifier is over 10metres away from the engine.

I'm surprised, I would have fitted the hot flow from the head to the TOP coil connection and the cold return from the BOTTOM of the coil.

Is there a reason why you've chosen the opposite?

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7 minutes ago, Mikexx said:

I'm surprised, I would have fitted the hot flow from the head to the TOP coil connection and the cold return from the BOTTOM of the coil.

Is there a reason why you've chosen the opposite?

Feeding the hottest water into the coolest part of the store creates more heat transfer and is approx 5% more efficient. But the main reason is that air will rise so it is better to displace it upwards rather than try an drive it downwards. If you understand ?

If it was gravity circulation it would have to be the converse of course.

Edited by Tracy D'arth
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6 minutes ago, Mikexx said:

I'm surprised, I would have fitted the hot flow from the head to the TOP coil connection and the cold return from the BOTTOM of the coil.

Is there a reason why you've chosen the opposite?

 

So would I initially, but often that allows the calorifier to cool at night by thermo-syphon back through the engine. Doing as Tracy says very often, stop that.

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6 minutes ago, Tracy D'arth said:

Feeding the hottest water into the coolest part of the store creates more heat transfer and is approx 5% more efficient. But the main reason is that air will rise so it is better to displace it upwards rather than try an drive it downwards. If you understand ?

If it was gravity circulation it would have to be the converse of course.

 

When the water initiailly enters the calorifier I would agree, but now the the water leaving the calorifier would be hotter than if it left the bottom.

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7 minutes ago, Tony Brooks said:

 

So would I initially, but often that allows the calorifier to cool at night by thermo-syphon back through the engine. Doing as Tracy says very often, stop that.

 

Mine has a flap valve to stop the thermo-syphoning.  Whether any syphoning action takes place will be determined by the relative heights of the calorifier vs engine. I can't see it makes much difference whether a connection is made to the top or bottom of the calorifier.

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3 minutes ago, Mikexx said:

 

Mine has a flap valve to stop the thermo-syphoning.  Whether any syphoning action takes place will be determined by the relative heights of the calorifier vs engine. I can't see it makes much difference whether a connection is made to the top or bottom of the calorifier.

 

Experience tells me it does. It also varies between horizontal and vertical calorifiers and which coil you connect to the engine. A flap vale is the certain way as long as the engine water pump can open it and it does not stick shut over the winter. However, a clout usually sorts the latter.

  • Greenie 1
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6 minutes ago, Tony Brooks said:

 

Experience tells me it does. It also varies between horizontal and vertical calorifiers and which coil you connect to the engine. A flap vale is the certain way as long as the engine water pump can open it and it does not stick shut over the winter. However, a clout usually sorts the latter.

 

I bow to your experience, however even you own training website advises differently:

  http://www.tb-training.co.uk/17Bdomwat.html

 

I believe the flap valve I have is unsprung, it hasn't failed me yet! They are a little specialised and not the sort of thing to find in your local Screwfix.

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23 minutes ago, Mikexx said:

 

Mine has a flap valve to stop the thermo-syphoning.  Whether any syphoning action takes place will be determined by the relative heights of the calorifier vs engine. I can't see it makes much difference whether a connection is made to the top or bottom of the calorifier.

Well 45+ years of experience would suggest I am correct and if you have to shift air locks  you would then agree.

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59 minutes ago, Tracy D'arth said:

Well 45+ years of experience would suggest I am correct and if you have to shift air locks  you would then agree.

 

We'll just let you and Tony fight it out then...

 

"To minimise this risk connect the HOT (away from the engine) pipe to the higher calorifier "coil" connection and the return to the lower one. Try to ensure both connections run horizontally at the calorifier end to prevent thermo-siphoning of water from the coil, backwards through the engine once the engine has been turned off."

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4 minutes ago, StephenA said:

 

We'll just let you and Tony fight it out then...

 

"To minimise this risk connect the HOT (away from the engine) pipe to the higher calorifier "coil" connection and the return to the lower one. Try to ensure both connections run horizontally at the calorifier end to prevent thermo-siphoning of water from the coil, backwards through the engine once the engine has been turned off."

No fight ensued.  Tony is an expert on boats, I on the other hand spent a lot of my working life as a technical plumbing and heating services consultant, different experiences.

Edited by Tracy D'arth
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22 hours ago, Tracy D'arth said:

Its just 1/2" bsp on the  1.8 D so you need  male  1/2" bsp to whatever pipe you use adapter and ptfe tape the thread.  The 1.5 D BMC is 20 mm conduit thread.

 

Hi just found the old thread and on this you said it was NPT 

 

Just want to make sure I get it right 😎

 

Head tapping on a 1.8D is NPT thread, on a 1.5D its 1/2" BSP.  Calcutt can provide the NPT one.  Some heads are reworked ones from the factory so check first, BMC were fond of making unannounced changes!  NPT is the same thread as electrical conduit if that helps.

Edited June 29 by Tracy D'arth

 

 

 

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3 hours ago, Tracy D'arth said:

No fight ensued.  Tony is an expert on boats, I on the other hand spent a lot of my working life as a technical plumbing and heating services consultant, different experiences.

 

I have no intention of arguing with Tracy on this and in other topics I have mentioned using a flap valve. What I don't understand is why someone thinks this:

 

"When the engine-cooling thermostat opens it is possible for water flow through the calorifier to stop because heat exchanger/skin tank/keel cooler provides an easier path. To minimise this risk connect the HOT (away from the engine) pipe to the higher calorifier "coil" connection and the return to the lower one. Try to ensure both connections run horizontally at the calorifier end to prevent thermo-siphoning of water from the coil, backwards through the engine once the engine has been turned off.

If you find that the engine room calorifier pipes/hoses are still hot some time after turning the engine off and only cool water in the morning it will be because of thermo-siphoning. The best thing to try is swapping the upper and lower connections over. This usually cures it, but you might lose calorifier operation when the engine thermostat is open – only experimentation will tell."

 

In any way contradicts what I said in my reply about calorifier connections. Maybe they did not read the second paragraph.

 

Personally, I would rather fit an air vent at the high point in the calorifier engine circuit but if for any reason you keep getting air locks then alternatives have to be investigating, one of which could be to do it as Tracy describes or if there is a remote header tank with a suitable connection an air bleed hose could be fitted at the high point to vent any trapped air into the header tank.

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