beta marine heat exchanger tube stack problem

dave c

New member
Joined
18 Feb 2014
Messages
6
Visit site
Hi All,
I removed the tube stack from my beta bd722 - with a bit of trouble - and cleaned it out.
I put new o rings in, but it's leaking at the exhaust end.
I actually assembled it outside the heat exchanger to see what the problem was and the divider bar that goes across the exhaust end cap ( when it's fitted into the slot ) keeps the two chamfered edges about 3'16 of an inch apart. The o ring looks and feels slack as well.
Is there a thicker o ring for the exhaust end cap?
The other end cap fits right up to the tube stack and the o ring fits a lot better.

Anybody else done this?
THanks
Dave c
 

wrr

Active member
Joined
23 Oct 2001
Messages
282
Location
Solent
Visit site
On my BD1005, the two O rings are identical, both being fairly large diameter. I wonder if the stack in not properly in place? It can move forwards and backwards. If it too far aft, it may be preventing the seal between the cap, O ring and the heat exchanger casing. Beware of over-torquing the phosphor-bronze bolt, they can snap!
 

dave c

New member
Joined
18 Feb 2014
Messages
6
Visit site
Thanks for the info, mate.
I'll try re-positioning it.
It looks like the actual casing is badly pitted/worn at the exhaust end and someone advised me to use a metal epoxy filler to smooth it out a bit.
But every little bit of info helps!
Thanks,
David
 

DoubleEnder

Well-known member
Joined
27 Apr 2002
Messages
1,423
Location
N Hemisphere
Visit site
Hi All,
I removed the tube stack from my beta bd722 - with a bit of trouble - and cleaned it out.
I put new o rings in, but it's leaking at the exhaust end.
I actually assembled it outside the heat exchanger to see what the problem was and the divider bar that goes across the exhaust end cap ( when it's fitted into the slot ) keeps the two chamfered edges about 3'16 of an inch apart. The o ring looks and feels slack as well.
Is there a thicker o ring for the exhaust end cap?
The other end cap fits right up to the tube stack and the o ring fits a lot better.

Anybody else done this?
THanks
Dave c

How did you get it out? Mine seems stuck...I use a bottle brush but I'd like to take it apart really

Thank you

Graham
 

sailorman

Well-known member
Joined
21 May 2003
Messages
78,879
Location
Here or thertemp ashore
Visit site
Hi All,
I removed the tube stack from my beta bd722 - with a bit of trouble - and cleaned it out.
I put new o rings in, but it's leaking at the exhaust end.
I actually assembled it outside the heat exchanger to see what the problem was and the divider bar that goes across the exhaust end cap ( when it's fitted into the slot ) keeps the two chamfered edges about 3'16 of an inch apart. The o ring looks and feels slack as well.
Is there a thicker o ring for the exhaust end cap?
The other end cap fits right up to the tube stack and the o ring fits a lot better.

Anybody else done this?
THanks
Dave c
did u use silicone grease on the O ring
the end plate is designed to use the O ring as a spacer to hold the cap away from the h/e body
 

BabaYaga

Well-known member
Joined
19 Dec 2008
Messages
2,490
Location
Sweden
Visit site
Hi All,
I removed the tube stack from my beta bd722 - with a bit of trouble - and cleaned it out.
I put new o rings in, but it's leaking at the exhaust end.
I actually assembled it outside the heat exchanger to see what the problem was and the divider bar that goes across the exhaust end cap ( when it's fitted into the slot ) keeps the two chamfered edges about 3'16 of an inch apart. The o ring looks and feels slack as well.
Is there a thicker o ring for the exhaust end cap?
The other end cap fits right up to the tube stack and the o ring fits a lot better.

Anybody else done this?
THanks
Dave c

I have the 722. The o-rings are identical fore and aft, but I believe the o-rings for newer Beta engines (from 2011 or so) are different in size to the older ones. Could you have bought the wrong ones?
As already pointed out, adjust the tube stack lengthwise, so that it is positioned equal in regard to the flanges. When done up, none of the end caps should be in direct contact with the h/e or the stack, the o-rings should prevent this.
 

ballyabroad

Member
Joined
12 Aug 2012
Messages
212
Location
Boat River Deben, Suffolk. Home Nottinghamshire
Visit site
I had a similar problem with my Beta 25. Seems a bit of an art to get back together, but once done it makes sense. Double check that the heat stack is going in the right way round, mine definitely only goes in one way round, with the 'divider' tabs locating with the correct end cap. When I phoned Beta they were really helpful and talked me through the technique to locating. Only tighten the end caps up finger tight, swapping ends so the tubestack sits even in the Heat Exchanger tank. Double check the tubestack is sitting correctly before tightening and it shouldn't be over tightened. Silicone grease on the O rings helps as well. If it all doesn't sit correctly then the Coolant and Raw water go to places they shouldn't and as in my case a new tank was required.

Give Beta a call, a helpful bunch.
 

dave c

New member
Joined
18 Feb 2014
Messages
6
Visit site
Hi Graham,
With a bit of welly!

I replaced the end bolt with an old one and tapped it out with a hammer and a metal drift. I had to persuade it! Be careful tho' as it can cause damage.
If I were you, I'd leave it in position and push a bit of wire or whatever thru the holes cos it seems when you remove it, you are creating a problem with trying to get it to reseal.
P.S. the heat exchanger body is aluminium and can get worn/damaged easily which causes the problems with sealing.
 

dave c

New member
Joined
18 Feb 2014
Messages
6
Visit site
HI all,
Problem solved - eventually!
I'm lucky enough to be able to remove the cockpit floor and get in beside my engine so I could see what I was doing!
I tried the metal epoxy - but wasn't too happy with it. I thought the exhaust end casing lip was too far gone. The alternator end was like brand new.
Beta wanted £245 + vat + delivery for a new H/E case. About £325.
As I have room to remove the unit, I did.
All was going well till I snapped the heads off two of the exhaust bolts, leaving two studs in the H/E body!
I epoxied the lip as good as I could, but it still wouldn't seal.
I took it to a small engineering shop and the guy cut out the lip put an insert into it. £100.
He saw the end cap for the exhaust end and said straight away that it was out of shape - I hadn't noticed this!
I put it together - centred the stack , tightened the bolts evenly, etc - and it still leaked.
By this time I was looking for a length of rope!
I contacted beta and they reckoned I needed a new end cap. I ordered one.
What a difference!
I could tell as soon as I put it up against the tube stack and it fitted into the slots that this was not going to leak - the way the old one wobbled about, there was no way it was going to seal.
I also ordered 3 new exhaust manifold gaskets for between the heat exchanger, the exhaust gasket, and new nuts bolts and washers. About £35/40. ( including end cap at £25)
I got the broken studs out easily and put it all together.
Started her up today and it's purrrrrrfect!
Thanks for all your help.

P.S.
I take my hat off to all the guys who have managed to do this without taking the unit out!
 
Last edited:

ganter

Member
Joined
9 Dec 2013
Messages
290
Visit site
I'd beef up the o-rings, both ends, to take into account general wear, vibration and inevitable corrosion.
I'd also ignore the book about torque. You know when it's tight on a slightly worn engine.
Blue gasket has its uses here as well.
 

Scomber

Active member
Joined
17 Nov 2006
Messages
852
Visit site
i always dismantle tube stack annually and clean and replace with new o rings-just be careful as already stated to align / tighten carefully then each year there wont be problems extracting the stack and you'll be sure all is clear
 

alahol2

Well-known member
Joined
22 Apr 2004
Messages
5,841
Location
Portchester, Solent
www.troppo.co.uk
Why every year
I do mine every year (although I don't replace the o ring) because one year I found it chock full of seaweed. The very thin 'grassy' type weed. The weed had already gone through two filters to get that far. If you do it every year it does not allow build up of any calcium products which can make it hard to remove the core. It takes about an hour all told to remove, clean and reassemble. Quite therapeutic.
 

dave c

New member
Joined
18 Feb 2014
Messages
6
Visit site
I do mine every year (although I don't replace the o ring) because one year I found it chock full of seaweed. The very thin 'grassy' type weed. The weed had already gone through two filters to get that far. If you do it every year it does not allow build up of any calcium products which can make it hard to remove the core. It takes about an hour all told to remove, clean and reassemble. Quite therapeutic.

Do you renew the anode every year as well?
 

dave c

New member
Joined
18 Feb 2014
Messages
6
Visit site
I've replaced the anode three times since 2006 - and there has only been about a quarter of an inch wasted away, at the most. Yet the amount of white crud I scraped off the end of the tube stack and end cap ( to get it out ) was amazing!
Most was around the edge of the tube stack tho' and only about 4 or five holes were blocked.
My problem was - I think - that I was losing coolant thru the o ring ( because of the badly eroded lip at the exhaust end ) and out the exhaust as I was having to top up quite a lot. ( About a cupful every couple of hours )
Hence the overheating.
 

Scomber

Active member
Joined
17 Nov 2006
Messages
852
Visit site
I do mine every year (although I don't replace the o ring) because one year I found it chock full of seaweed. The very thin 'grassy' type weed. The weed had already gone through two filters to get that far. If you do it every year it does not allow build up of any calcium products which can make it hard to remove the core. It takes about an hour all told to remove, clean and reassemble. Quite therapeutic.
well said sir-exactly my thoughts!!!!
 

arenyi

New member
Joined
30 Aug 2014
Messages
1
Visit site
BD1005 heat exchanger

On my BD1005, the two O rings are identical, both being fairly large diameter. I wonder if the stack in not properly in place? It can move forwards and backwards. If it too far aft, it may be preventing the seal between the cap, O ring and the heat exchanger casing. Beware of over-torquing the phosphor-bronze bolt, they can snap!

Are you sure that the end cap bolts are phosphor bronze? On mine heat exchanger was simple iron bolts, and they are wry corroded. I plan to change them to stainless steel. Is it the right solution?

S. Renyi
 
Top