cleaning beta heat exchanger stack - easy or not?

[PhillM]

Easy job. Buy a service kit from Beta.

 

[Praxinoscope]

With my previous boat, I never dismantled the heat exchanger stack for cleaning during the 20 years that I ran the Beta 10:engine, however at the end of every season I ran the engine for about 15 minutes with fresh water through the raw water sytem, finishing with a 25% antifreeze solution.
This flushing regime seemed to keep the stack clean, never had any overheating problems even after one long continuous 36 hour under engine run.
My new boat has a Beta 14 which had run for about 900 hours before I bought it, I have adopted the same flushing routine and as with my previous Beta have had no overheating, but will dismantle the the stack to check it just to make sure its clean.

 

[Thistle]

With my previous boat, I never dismantled the heat exchanger stack for cleaning during the 20 years that I ran the Beta 10:engine, however at the end of, every season I ran the engine for about 15 minutes with fresh water through the raw water sytem, finishing with a 25% antifreeze solution.
This flushing regime seemed to keep the stack clean, never had any overheating problems even after one long continuous 36 hour under engine run.
My new boat has a Beta 14 which had run for about 900 hours before I bought it, I have adopted the same flushing routine and as with my previous Beta have had no overheating, but will dismantle the the stack to check it just to make sure its clean.

Interesting. It does beg the question, just what is the stuff that collects in the heat exchanger?

 

[Refueler]

So I'm new to this and thus 'treading lightly' given the (very welcome) expertise of others here, but:

My reason for 15 mins in an acid bath was not to have the shiniest tube stack in Christendom, but to help get rid of large amounts of scale that risked stopping the tube stack (and end cap ports, and a few other bits) from doing their job. The stuff fizzed and foamed away like a dying alien on Doctor Who and the scale fell away. I do accept that I may lose a £10 engine anode a little faster as a result. However I'd much prefer that to losing engine power due to overheating, or perhaps damaging the tube stack by cleaning it only by bashing, whacking, scraping, drilling or other mechanical means.

My idea is that you could have removed the larger deposits by flushing while still installed on engine .. rather than dismantling.

 

[arcot]

While you're at it, it's worth removing the stainless steel tube that connects the heat exchanger to the salt water pump, and checking for limescale build up. I found loads this year at the pump outlet.

It's easy to do, on the Beta 20 anyway. Just hose clips and the plastic clamp on top.

Prob good to remove stainless part it it's touching brass or aluminum.....

 

[Spirit (of Glenans)]

Clean everything off with paper towel before refilling and then run a clean tissue round all the joints and check for dampness on it from any leaks.

Blue paper towel, such as they have on service station forecourts, shows up damp patches really well.

 

[Spirit (of Glenans)]

A bit shocked at those who run valuable and essential engines but don't source or download a manual and read at least the maintenance schedule..

Yes, I'm quite surprised. My previous boat came with a Beta engine and the relevant manual.

 

[unbusted67]

I’m totally lost on this. I’ve got a beta 25 with the single bolt configuration and the anode on the aft cap. From reading this thread it sounds like the o rings go on the inside of the housing but I’ve been putting them on the flange of the end caps and tightening until it “seals.” It just keeps leaking coolant and water and I can’t get a prime on my raw water pump. Help!!

 

[Keith 66]

I have a Beta 16 in our Sabre 27, Its been a good engine but frankly the design? of its cooling system in regards to materials is a disaster. Aluminium header tank, Bronze end caps & bolts, Copper engine pipes, Brass tube stack soldered with lead solder. It is an electrolytic mish mash designed to fizz its way to destruction from the moment it touches salt water. If you look at the tube stack end there is a 45 degree chamfer on the end, a matching chamfer is on the end cap, The O ring sits in the header tank bore between these chamfers & seals when they are tightened together. It uses two anodes a season without fail & the tube stack comes out once a year for cleaning.
One of the main problems is that when you shut the engine down the tube stack, end caps & pipes are left full of hot salty water which precipitates a lot of salt. I now flush a bucket of freshwater through it before shutting down which has helped somewhat.
Two years ago i was losing coolant & a new thermostat helped but didnt cure it, In the end i found it was the tube stack itself that had failed. I made a jig so it oud be pressure tested under water & sure enough the tube stack had about 4 holes in it, so tiny they could not be seen with the naked eye but leaked enough to let salt water into the engine & fresh water out!. It cost me a new tube stack & that was approx £180.

 

[unbusted67]

Yeah when i do this there’s about a half inch of play between the cap ends and the heat exchanger flange. It’s like it should have two sets of o rings or something, one for the chamfered ends of the tube stack and one as a spacer between he caps and the exchanger. I wish to god I’d filmed myself taking it apart.

 

[steve62]

My Mirage had a beta 16. I took the stack out once and it was a pain. As other have said, it was stuck. Thereafter, I unbolted the whole heat exchanger of the engine (couple of hoses and 3? bolts) took the whole assembly home and cleaned it there. It was also a hell of a lot easier to make sure the o rings fitted properly with access all round. New paper seal from Beta and it went back on in 15-20 minutes and no Skinned knuckles

 

[doug748]

I’m totally lost on this. I’ve got a beta 25 with the single bolt configuration and the anode on the aft cap. From reading this thread it sounds like the o rings go on the inside of the housing but I’ve been putting them on the flange of the end caps and tightening until it “seals.” It just keeps leaking coolant and water and I can’t get a prime on my raw water pump. Help!!

The tube stack "floats" in the housing. I find it best to clean and lubricate the end screws so they operate by finger pressure; clean and lubricate the tube stack so you can move it easily by hand in and out.

Then position the tube stack in the middle of the housing and push in a lubricated seal ( probably best to do the most difficult rear one). Then carefully align and screw in the bell a reasonable amount (making no attempt to tighten it).

Next do the same to the front bell, seal and screw. Then alternatively tighten the screws an equal amount ( It is possible to feel the bounce of the seal when it is seated correctly or even feel with a fingernail or wooden toothpick to check there is no pinching. This pressures the seals against the pressure of the two end screws and positions the floating stack in the middle of the housing.

Not a job to be done in haste but you get there in the end. Good luck.

PS

The tube stack has a location slot and will only fit correctly one way.

.

 

[unbusted67]

Thanks for this thoughtful reply. I’m thinking that beta may have sent me the wrong o rings as I just dug out the old ones and they are slightly thicker than the ones they sent. I’m wondering that is accounting for why there is so much play inside of the heat exchanger housing. As i said, when tightened down the tube stack and bell caps can move a half inch fore and aft and it doesn’t make a seal.

 

[doug748]

Sounds like you may have the tube stack the wrong way around?

 

[unbusted67]

Sounds like you may have the tube stack the wrong way around?

I don’t think so…the notched end of the stack is aft and fits into the cap. Lots of people I’ve heard from on here have 13hp-20hp. I wonder if the config is different from the 25 which is what i have.