Air bubbles coming into colling water?

[Gordon Bryant]

Hello all, I have a original Lister 6-1 SOM. I use a thermal syphin for cooling and use clear tubing for the conections. I notice that there are consistant amount of air bubbles coming into the tubing when running the engine. My first thought was that I have a leaky head gasket. So I wanted to ask yall what yall thought before I started taring it apart. If it is the head gasket, does anyone know where I can buy parts in the USA. Thanks in advance for everyone input !!!!!!

Gordon

[contaucreek]

Head gasket or crack in head? Ebay for gasket.

[ronmar]

If it does it when cold, then yes, I would think it a leaking headgasket or a crack.  If it only does it when hot or at heavy load, it may be poor flow allowing the coolant to boil causing the bubbles...

[Stan]

There's a guy in Thailand (or one of those S.E. Asian countries) who has a business manufacturing custom gaskets.  I have used him in the past, fast shipping, great prices and his products are first rate.  He asks for samples and copies them so he would have most gaskets for Lister engines in stock now.

Do a search for lister gaskets on here.   Here he is     http://www.gasketstogo.com/
Stan

[LowGear]

Dieselman gets my vote.  He works hard to help people here at LEF and seems entirely knowledgeable.  He sells parts out of Kansas I think.

If you could get a few pounds of pressure into your water jacket you'd know a few things for sure.  I'm talking light use with a hand or foot pump to something less than 10 PSI with the engine shut down.  Is hot different than cold?

Casey

[Gordon Bryant]

No. Running it hot or cold makes no difference. I guess if I put pressure on the water jacket, the air leak would slow down or maybe stop???
I have ordered a head gasket off of e-bay. When it gets here, I will pull the head off and take a look. Does anyone know what the foot pounds
of torque is on the head bolts are? And what the torque patern is?

[ronmar]

Well there are only really 4 head bolts, so pick a pattern I guess:)    I think around 150FT/LB, someone please correct me if I am wrong...  ALong that line, have you ever confirmed/checked the head torque, yours might just be loose.  Always a good idea to have a spare head gasket on hand anyway...  Putting a little pressure on the system when not running may force water to leak at the weak points such as back into the cylinder, but I doubt it will retard air being injected from the combustion chamber as that pressure peaks in the hundreds...

[LowGear]

I wasn't suggesting with the engine running but rather thought you might hear or see bubbles coming out some place.  Bubbles in - bubbles out.

We all assume your oil is a nice translucent to blackish color.

Casey

[Gordon Bryant]

Well the oil does still have a good color to it. Are saying that there is a possibility that water could be getting into my oil? I guess it would have to be a cracked water jacket at the lower end for this to take place. But the crank case has a vacuum on it doesn't it? It would be pulling water in not giving me air bubbles. Well I will just have to take it apart next week and see
whats going on. At this point it looks like a head gasket.

Thanks,
Gordon

[ronmar]

A breech can go both ways.  Combustion gas eaking from cylinder to water jacket under combustion pressure when running.  Water leaking from jacket under static pressure(gravity),  back into the cylinder when shutdown.  Water that makes it into the cylinder will leak past the rings and enter the crankcase to contaminate the oil quite easilly... 

[Bottleveg]

Torque settings for the Lister 6/1 are 100lb/ft for the large nuts and 65lb/ft for the smaller ones. I tighten in three stages and go clockwise.
I had a couple of Indian made head gaskets a few years ago. They looked fine but let a constant stream of bubbles into the cooling tank.
I can recommend the composite gaskets from John at “Gaskets to Go”. These will take a higher water head pressure than the copper ones.
Have a careful look at the head for cracks. They tend to crack between the ‘eyes’ if the engine has been overheated.
   Mark.

[Gordon Bryant]

How does a 6-1 get over heated? There were a few times I did start the engine, during the project, without any water in it, but only ran it for a minute or so and shut it back down. Do you think that could have over heated it? Or is over heating topically done with high RPM at heavy loads? Is it true that you can safely get more hp out of a 6-1 if you adjust the governor
to reach 750 rpm. someone said you could get 8hp out of it. But is this harmful and would it cause the Lister to over heat?

Thanks,
Gordon

[Stan]

Lister (Dursley) prints very plainly in all of it's manuals, that you should never adjust the speed either more or less than the rated speed on the plant, more than a specific percentage.  My manual is at the new place and I can't get to it for a couple of weeks so I don't have the exact percentage but it's quite low, like 5% or something like that.  I wouldn't.  The speed regulation equipment on the engine is designed for a specific speed range and when you start operating outside that envelope you are asking for trouble. 

Unlike today's machines, the the Dursley folks expected you to understand their Listers in the '40s and '50s and didn't design double or triple the safety margins into them to account for some of the people who operate todays machinery with little understanding of what they are doing.

There are some scary examples of old machinery in "run away mode" on the internet that you can see that tells the tale of what happens when all that mass decides to take off with a mind of it's own.
Stan

[Gordon Bryant]

Thanks Stan, well said. Will heed your advice!

Gordon

[Bottleveg]

How does a 6-1 get over heated? There were a few times I did start the engine, during the project, without any water in it, but only ran it for a minute or so and shut it back down. Do you think that could have over heated it? Or is over heating topically done with high RPM at heavy loads? Is it true that you can safely get more hp out of a 6-1 if you adjust the governor
to reach 750 rpm. someone said you could get 8hp out of it. But is this harmful and would it cause the Lister to over heat?

Thanks,
Gordon

Hi Gordon,
Cracked heads on CS engines, that I’ve seen, have been caused by lack of coolant, burst pipes ext. I’ve had a few with the cylinder waterways full of sludge and that ends in a blown gasket due to poor circulation.
You won’t have done any damage by running yours for a couple of minutes.
You don’t give any history to this engine. Have you just had it? How long has the head gasket been on? Ext.
I take it you have the top coolant hose going strait up with no dips? The gasket will blow next to the exhaust port if the thermo syphon is inefficient.
It would be worth you checking the mating surfaces are flat and smooth on the head and cylinder; I’ve had some that look like they’ve been used as an anvil!

As Stan says, you will run into problems if you try increasing the speed too much.
Lister did make an 8hp CS and they run at 850rpm, but that has an aluminium piston, a different governor, smaller flywheels and other mods.
Another consideration is, as you have an SOM, the frequency of the genny will increase with engine speed.
      Mark.