Sabre Perkins still overheating

[stuartwineberg]

Which exchanger?

Stuart,

Spent the weekend with owner of marine services company who had stong ties with Sabre in Poole.

As soon as I mentioned your problem his response was immediate. Ten degree rise in operating temperature, Problem well known to Sabre guys..........Strip the heat exchanger, and take tube stack out. You will find engine coolant side of heat exchanger coated in a gooey slime. Apparently slime results in long term reaction of coolant with chemical treatment used by the foundry who cast the heat exchanger body. Once the tube stack is 100% clean and cooling system completely flushed engine operating temperature return to normal and issue never returns.

Good luck

Very interesting. However we did strip the raw/fresh exchanger down, took the coppoer tube stack out and gave it all a good clean. I don't recall this goo. There was more gunge in the air charge cooler for the turbo and I still think I may not have cleaned the fins on that one out as thoroughly as I would have liked basically cos it was so big. We definitely checked no blockage in the tubes on both and cleaned out the castings completely - have I missed something?

 

[volvopaul]

If it's the outside of the tubes I can understand why, though the thermo gun readings would confirm the heat exchanger isn't doing it's job.

I had this recently with a yanmar owner who had done everything to his engines to combat the overheat, stripped tube stack, left sinking in rydelime fir 24 hours, refitted all ok. In Stuarts case I do wonder why it's only one engine.

 

[stuartwineberg]

Thanks again

If it's the outside of the tubes I can understand why, though the thermo gun readings would confirm the heat exchanger isn't doing it's job.

I had this recently with a yanmar owner who had done everything to his engines to combat the overheat, stripped tube stack, left sinking in rydelime fir 24 hours, refitted all ok. In Stuarts case I do wonder why it's only one engine.

Thanks for your patience and constructive comments Paul - as I say, weather permitting I should have some temp readings under load soon

 

[Latestarter1]

In Stuarts case I do wonder why it's only one engine.

Exactly my question, answer was variability in the process at the foundry, some engines affected, some not.

Just conjecture on my part, but typical of some of the side affects seen when switching to propylene glycol from ethylene glycol based coolant on large high speed engines.

I have promoted use of Rydelime for years, however after reading papers on large engine heat exchanger cooling, like the classification societies starting to consider ultrasonic cleaning using Scruffite Marine as the most effective and reliable long term process.

 

[tico]

Just a thought, as its many years since I made engine coolers for Sabre/Mermaid and similar (Serck).
Is the heat exchanger of the 2-pass type (both connections at one end)?
If so, then the seal between the end tank baffle (cast rib on the inside of the tank between the connections) and the tube plate is critical.
In the past I have seen this eroded, thus allowing a small amount of bypass of cooling water directly from inlet to outlet without passing through the tubestack. This will affect the cooling ability to a noticeable degree. Often there is a 'U' shaped rubber seal that fits on the rib to improve the seal between rib and tube plate, if this is missing or distorted this will have the same effect.

If however, the cooler is of the single pass type, then disregard the above!

 

[burgundyben]

A useful thing to do when cleaning tube stacks is weigh them before and after, the weight loss tells you how much gunk you've removed.

 

[stuartwineberg]

Good thought

Just a thought, as its many years since I made engine coolers for Sabre/Mermaid and similar (Serck).
Is the heat exchanger of the 2-pass type (both connections at one end)?
If so, then the seal between the end tank baffle (cast rib on the inside of the tank between the connections) and the tube plate is critical.
In the past I have seen this eroded, thus allowing a small amount of bypass of cooling water directly from inlet to outlet without passing through the tubestack. This will affect the cooling ability to a noticeable degree. Often there is a 'U' shaped rubber seal that fits on the rib to improve the seal between rib and tube plate, if this is missing or distorted this will have the same effect.

If however, the cooler is of the single pass type, then disregard the above!

It is indeed a 2 pass with the connectors as you describe and a cast rib inside and as far as I remember there is no rubber seal on the rib - I guess that would mean a new end cap if it is the problem and again i think the problem would show up on temp checks - thank you

 

[stuartwineberg]

No real gunk

Exactly my question, answer was variability in the process at the foundry, some engines affected, some not.

Just conjecture on my part, but typical of some of the side affects seen when switching to propylene glycol from ethylene glycol based coolant on large high speed engines.

I have promoted use of Rydelime for years, however after reading papers on large engine heat exchanger cooling, like the classification societies starting to consider ultrasonic cleaning using Scruffite Marine as the most effective and reliable long term process.

My problem with this proposed solution is that the tube stack was extremely clean. It had only been serviced the previous year by Paul and when we took another look this year there were just a few grains of chalk in he botom tube. I think Paul can vouch for the fact we aren't looking at a typical limescale horror that ridlyme seems to be used for

 

[tico]

OK, may not need a new end cap. The usual repair involved 'Plastic Metal' applied to the rib and then machined/filed back to the correct level.
The seal is simply a 'U' shaped rubber extrusion, or sometimes part of the sealing gasket.

Something to go on anyway..

 

[volvopaul]

My problem with this proposed solution is that the tube stack was extremely clean. It had only been serviced the previous year by Paul and when we took another look this year there were just a few grains of chalk in he botom tube. I think Paul can vouch for the fact we aren't looking at a typical limescale horror that ridlyme seems to be used for

Indeed we did check the tubes for limescale blockage, but this was the sea water side only stuart.

We are now talking about the outside of each tube where the internal( cylinder block water) passes over the cold tubes to be cooled, which is the heat exchange process.

As said the cooler will need to come off and be stripped down, cleaned, resealed refitted and new coolant added.

As said a WOT sea trial with the laser gun pointed in all the right places will reveal all.

Have you also considered the cost in fuel by going out on sea trials? Fun I know, I was out yesterday on andydent2000 boat, the Hamble and its surrounding area was beautiful, but very crisp!.

 

[carlhardlabour]

Was a resolution ever found for this problem? My starboard engine does exactly the same as described.

 

[Greg2]

Was a resolution ever found for this problem? My starboard engine does exactly the same as described.

Thanks for resurrecting this old post because it is of interest to me too and I have learned some things that I didn’t know.

We had a Broom 41 with the Perkins M300TI and had a similar issue with one engine running warmer at higher revs. We now have the same boat/engines that Stuart had (Hardy Commodore 36 with Perkins M265TI) and whilst all seemed okay on sea trials and subsequent cruising during the summer it is helpful to know what to look for if a problem arises.
.

 

[oldgit]

Had a noticably higher temp on one of a pair M135 Sabres.
Nothing fatal just annoying.
Tried all the usual tricks flushing for ages with Rydlyme etc.
Eventually stripped down the heat exchanger and removed core stack.
Removed end caps and "O" rings and gently tapped out core with piece of wood.
Course it was the engine with the exchanger on the "wrong" side, however simple to dismantle device, if awkward to release hoses and end caps.

Bit fed up with forking out for expensive magic potions .
Cut the top off an old fender and marinated the tube stack in Wickes brick cleaner .**
Problem solved.

Boat health Warning.
**At your own risk

 

[stuartwineberg]

Was a resolution ever found for this problem? My starboard engine does exactly the same as described.

Sorry, it’s several years since I sold the boat and at that time the purchaser was happy with the temp increas. Never did resolve it. Now a raggie again

 

[harvey38]

Interesting posts, if nothing was found untoward with the engine, I'd be thinking along the lines of maybe the engine was having to work harder eg fouled prop, something binding in the tube shaft.......

 

[carlhardlabour]

Sorry, it’s several years since I sold the boat and at that time the purchaser was happy with the temp increas. Never did resolve it. Now a raggie again

No probs, thanks for the reply. I'm leaning towards a head gasket, been through all the normal stuff and even with a clean bum @2000rpm I'm getting steam/ white smoke. Never had any problem before and engines only have 2500 hours on them, owned from new and serviced every year or 400 hours.

 

[volvopaul]

No probs, thanks for the reply. I'm leaning towards a head gasket, been through all the normal stuff and even with a clean bum @2000rpm I'm getting steam/ white smoke. Never had any problem before and engines only have 2500 hours on them, owned from new and serviced every year or 400 hours.

Blocked exhaust elbow

 

[fisherman]

I bought a boat with a Mermaid 135hp. The outlet water (dry exhaust) was about 6in above the water, and hit the surface 6in out. After 18 months I refurbed the pump. The water hit the surface 3 feet out. The engine never over heated before or after. So, overprovision of raw coolant.