Freeman Mk2 Petrol Engine (calorifier)

[MBA Marine]

Oh great oracles, I seek your knowledge.

Having trawled google (other search engines are available) I have conflicting options so here it goes.

On this old ford watermota direct raw water cooled (pre crossflow 1.5ish), where is best to tap out for a calorifier?

On an perkins I have used a plug just after thermostat and returned to the suction side of the raw water pump, this worked well, get the water to a good temp but doesn't overheat the engine.

But after web searches people say different things, including the method i have used before, tapping out before thermostat and using a circulation pump!

Its not my boat and is in the next week getting lifted and trailed away to its new owner, so i do not have time for trial and error methods, Water a bit below ideal temp i could live with but a cannot have a overheating engine.

I have pics but the will not upload as they are too big, I have know idea how to reduce there size!

[quo vadis]

Scissors!!!

[diesel falcon]

viewtopic.php?f=102&t=8682

ear you go

[MBA Marine]

it might be too small now but lets have a look

[MBA Marine]

Thanks to Diesel Falcon the pics are here!

[quo vadis]

No thanks to me then and my idea

[Hockham Admiral]

Good Lord! Looking at that I'd definitely leave well (??) alone!

[MBA Marine]

No thanks to me then and my idea

Scissors was defiantly an idea, but sadly im too tight to spend money on printer inc and it would take to long to post them to NBN towers!

[MBA Marine]

Good Lord! Looking at that I'd definitely leave well (??) alone!

There is nothing to be frightened of touching she is just a old somewhat crude looking engine by todays standards, and the copper pipes on it are not the neatest engineering ever!

Im thinking the plug on the side of the thermostat casing and returned in the raw water pump intake. fingers crossed!

[Guest]

I've got a calorifer on my raw water cooled engine, and this thread has stirred me to ask a question, now that kindred spirits are present !

Given the warnings against using plain brass fittings in sea water, (and the need to ensure that skin fittings and such are DZR or gunmetal instead), what is the effect of salt water on the brass fittings on the coil of a calorifer ? Or are marine calorifers already fitted with DZR compression fittings ?

Not a problem for most Broads based raw cooled boats I suppose, in mostly brackish water, but how do the salt side raw cooling calorfiers last, long term ?

[MBA Marine]

I've got a calorifer on my raw water cooled engine, and this thread has stirred me to ask a question, now that kindred spirits are present !

Given the warnings against using plain brass fittings in sea water, (and the need to ensure that skin fittings and such are DZR or gunmetal instead), what is the effect of salt water on the brass fittings on the coil of a calorifer ? Or are marine calorifers already fitted with DZR compression fittings ?

Not a problem for most Broads based raw cooled boats I suppose, in mostly brackish water, but how do the salt side raw cooling calorfiers last, long term ?

good question, and the answer to my knowledge is:

Regardless of what the fittings on the tank are i would expect the coil is copper, and when that goes you will get yummy raw water out of your hot tap!! in reality the salt water attacking the copper will be a relativity slow process, and after 'X' amount of years when the calorifier fails the boat gets a new one!

[MBA Marine]

Here is the solution i used, and the result is an engine that does not overheat and water still happily exiting the exhaust. Water temp at the tap is not exactly a nice 65 deg but it is a lot nicer to wash your hands with than cold.

The biggest down side is that if the owner was to plug shore power in and use the immersion then that tank of hot water will actualy get cooler with the engine running. As you can see in the pic there is a shut off valve the user can turn off the calorifier loop and the engine works just as it always did but I cant see people closing it to save a tank of hot water.

[ExUserGone]

Think I'd just buy a heat exchanger and go for split coolant/raw system, better for both water temp and engine.

[MBA Marine]

Think I'd just buy a heat exchanger and go for split coolant/raw system, better for both water temp and engine.

I have never seen one of these petrols with a heat exchanger manifold, cheaper to change the engine to a marinised diesel than have a custom exchanger made. you then loose the only benefit of the Petrol engine being quieter and smoother running.

[Guest]

I thought copper was relatively unaffected by salt water, (thinking of old woooden ships being sheathed with copper sheets o protect against Teredo worms).

I was more concerned with the ordinary brass compression fittings where the internal coil connects through the cylinder wall to the external hoses. A failure there could presumably sink the boat, leaking the cooling water into the bilges.

I fitted ball valves to isolate my cylinder coil whenever necessary, like during the winter, when I leave my calorifer empty and yet still use the engine occasionally.

I's look into the costs of fitting a heat exchanger to my raw engine, but as you say, it's well over a thousand, so the benefits are doubtful when the boat is used in freshwater mostly.

[ExUserGone]

I have never seen one of these petrols with a heat exchanger manifold, cheaper to change the engine to a marinised diesel than have a custom exchanger made. you then loose the only benefit of the Petrol engine being quieter and smoother running.

Could you not retain the existing manifold and still use a heat exchanger? Raw water out of heat exchanger into manifold, Bit of re-plumbing but not impossible.

[MBA Marine]

Could you not retain the existing manifold and still use a heat exchanger? Raw water out of heat exchanger into manifold, Bit of re-plumbing but not impossible.

one would need to find room for a header tank with a pressure cap, make sure the engine still has its own water pump and is not just using the raw water pump.

Nothing is impossible but still not cost effective, and how big would the heat exchanger need to be to keep the 1.5 petrol cool?