I must fit a coolant reservoir to my 8-year old Beta 13hp.

Old Rhodie

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I must fit a coolant reservoir to my 8-year old Beta 13hp because other efforts have not prevented overheating at prolonged high revs.
The reservoir now supplied by BETA as an option is far, far too big to fit into the space I have, or can create above the engine. ( long keel sloop)
I have tried car breakers, but can't find a tank small enough. BUT - some motorcycles use them ?
Any m/cycle experts out there with ideas where I might look ?
My old BMW is an R90S and doesn't do fluid cooling - so I have no experience to draw on.
Thanks,
Ken
 
I am following this thread as I have a similar problem. On my engine, if I fill the header tank on the manifold to the top, there is a spillage from the overflow the first time the engine is properly warmed up. It does not seem to lose any coolant for the rest of the season as the level stays the same, but well below thw level of the overflow. In fact it is just below the top of he exhaust tubes so I would like it to be higher. The cause of the problem is probably that the engine is at a slight down angle and the expansion capacity is not enough to allow for the volume of coolant in the system. As I want to increase that volume bu incorporating a calorifier coil, I need to provide for expansion.

I have been looking for such a tank for years. I have ordered one twice from ASAP when I have been getting other stuff but the order has arived with that item marked "out of stock at present." I see on their web site that the item they describe as "currently unavailable, we are hoping to have a replacement available shortly."

I also want another one to replace the cr4ppy painted mild steel one that was installed as part of my heating system.
 
There are hundreds for sale on Ebay. Look for "motorbike expansion bottle" instead of coolant reservoir.
Most of them are odd shapes to fit in a small space, so they wont hold much fluid, but there are a few "square" ones.
I'm not sure how useful they will be. Surely the expansion bottle has to match the volume of coolant in the system and the running temperature, so that you can calculate the expansion volume required?
 
I am following this thread as I have a similar problem. On my engine, if I fill the header tank on the manifold to the top, there is a spillage from the overflow the first time the engine is properly warmed up. It does not seem to lose any coolant for the rest of the season as the level stays the same, but well below thw level of the overflow. In fact it is just below the top of he exhaust tubes so I would like it to be higher. The cause of the problem is probably that the engine is at a slight down angle and the expansion capacity is not enough to allow for the volume of coolant in the system. As I want to increase that volume bu incorporating a calorifier coil, I need to provide for expansion.

I have been looking for such a tank for years. I have ordered one twice from ASAP when I have been getting other stuff but the order has arived with that item marked "out of stock at present." I see on their web site that the item they describe as "currently unavailable, we are hoping to have a replacement available shortly."

I also want another one to replace the cr4ppy painted mild steel one that was installed as part of my heating system.

So we are talking "expansion tank" as in a car & my Nanni.
This will not cure over heating at all it is purely a reservoir to take up expansion of the coolant
 
So we are talking "expansion tank" as in a car & my Nanni.
This will not cure over heating at all it is purely a reservoir to take up expansion of the coolant

I am not sure whether the OP's problem (overheating) is caused by loss of coolant but it could be. If it is, catching the expanding coolant so that it can automatically return to the engine whne it cools again may cure the overheating. My own problem is slightly different and I contributed to open up the discussion in hope that a source of such tanks may be exposed.
 
I am not sure whether he OP's problem (overheating) is caused by loss of coolant but it could be. If it is, catching the expanding coolant so that it can automatically return to the engine whne it cools again may cure the overheating.
even without the expansion tank the system will "find" its own level as your post 6.
the only other way he can loose coolant is buy the system being over pressurized as in a blown head gasket.
If the system is just over heating due to high load, then its the H/E that cant cope.
 
I am following this thread as I have a similar problem. On my engine, if I fill the header tank on the manifold to the top, there is a spillage from the overflow the first time the engine is properly warmed up. It does not seem to lose any coolant for the rest of the season as the level stays the same, but well below thw level of the overflow. In fact it is just below the top of he exhaust tubes so I would like it to be higher. The cause of the problem is probably that the engine is at a slight down angle and the expansion capacity is not enough to allow for the volume of coolant in the system. As I want to increase that volume bu incorporating a calorifier coil, I need to provide for expansion.

I have been looking for such a tank for years. "

Yes - quite so Wight dawn - I believe that it is the slope which exacerbates the problem as the filler is actually below the highest point of the cooling system ( thermostat) and one can never fill the entire system with coolant. Hence the air expands, blowing water out.
However - a removable stud above the thermostat can be replaced by a pipe to an overflow tank and this would then keep the system full of coolant ?
Thanks, creakydecks.
Ken
 
I have exactly the same problem with my Beta 20 which I have been trying to solve for the past couple of years without success and adding a coolant expansion tank is my last resort which I think im going to have to take.
I have expanded my inlet seacock to a 1.25 inch inlet and completely cleaned the heat exchanger and replaced the coolant.
After doing all this I went out on the boat the week after and was getting loads of water coming out the exhaust but it still overheats!!!!!
Oil pressure alarm is always going off when revs are reduced as well due to the over heating.
 
I have exactly the same problem with my Beta 20 which I have been trying to solve for the past couple of years without success and adding a coolant expansion tank is my last resort which I think im going to have to take.
I have expanded my inlet seacock to a 1.25 inch inlet and completely cleaned the heat exchanger and replaced the coolant.
After doing all this I went out on the boat the week after and was getting loads of water coming out the exhaust but it still overheats!!!!!
Oil pressure alarm is always going off when revs are reduced as well due to the over heating.

My 37.5hp Nanni has a 1" seacock & doesnt over heat
 
I would like to understand what "overheat" means. Alarms? Engine damage?

If "problems" have been experienced for a couple of years then it does not sound like an urgent problem if a problem at all.

My boat has a Lister Petter engine and the engine space is very small. It has an engine blower installed. I don't really understand why as happily runs when I forget the turn on, but it does bring the temp down. Just once after prolonged high engine revs I had the alarm go off but that was because the oil pressure dropped (I believe).
 
"Or insufficient flow of seawater."

No pvb - plenty seawater.
ken

It's difficult to know just how much flow is 'plenty'. When I replaced my Bukh 20 with a Yanmar 3GM I retained the 1/2 inch inlet seacock for the first season. The flow appeared good but the engine showed signs of overheating. Next season with a 3/4 inch seacock, as specified, the coolant temperature was clearly lower.

Looking at the ASAP catalogue of thermostats yesterday I saw that for my motorsailer BMC engine the normal one is rated at 82C but there is one at 74C for use in warmer waters. Is such an option available for your engine, or could you find one to fit?
 
Could well be. We've only just discovered that there's apparently plenty of seawater flowing.

Er .... not really pvb ...... I did state in my posting "other efforts have not prevented overheating at prolonged high revs" and clearly asked for help from the motorcycling fraternity - not a general reply on how a beginner might solve an engine overheating problem.
Nevertheless - thanks for your input.
Ken
 
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