overheating

[rbodell]

I am looking for some input as to what to look for and where.

I have a video camera on the engine so I caught the temperature guage raising in time to shut down the engine. I narrowed down the problem to the thermostat sticking. Ironic that it is one of the few American made part in the engine isn't it.

The temperature got up to 230 degrees. My opinion is that that was not enough to break any castings.

The Radiator showes some bubbles when I first start it up and they drcrease as the engine warms up. I still get a few bubbles though.

The head gasket is also american made which me think the head gasket may not be the problem, but if so, what would be the problem.

I have a head gasket ordered and am going to try that anyhow as I think it is the most probable answer to the bubbles.

I was wondering is any body else has has any overheating and what the damages were. Especially where you caught it before it got too hot.

[craig c]

Hi your head gasket is blown , that is why you have bubbles in your water.craigc

[sanchez]

hi,

you could have a gasket problem, but first answer a question, how many pound-feet of torque do you applied to the head nuts (the correct torque is 120 Lb-Ft. : 5/8" grade 5).
the cold engine's bubbles and reduced when warm up is a possible symptom of loos head (when metals expands seals). pay atention to the head torque.

[rbodell]

hi,

you could have a gasket problem, but first answer a question, how many pound-feet of torque do you applied to the head nuts (the correct torque is 120 Lb-Ft. : 5/8" grade 5).
the cold engine's bubbles and reduced when warm up is a possible symptom of loos head (when metals expands seals). pay atention to the head torque.

I checked wirt the distributor, they are torqued to 150. Also have american made head gaskets.

[rcavictim]

You may have a case where the cylinder liner is protruding above the cylinder block deck too much and the head gasket is not sealing the water jacket very well because it cannot get enough squish.

[hotater]

Bob--

Did the T'stat stick from start up so that the temp. rose steadily after starting?

Do you have a way to let the air out of the head like a vent hole in the T'stat?

It's not like a T'stat to fail unless it has air behind it instead of liquid, is the reason I ask.

The bubbles have to be coming through the head gasket which means coolant is leaking into the cylinder when the engine is not running.  Be very careful on start-up. If the piston stopped  down and there's water on top of it you can crack the head hydraulically.

The bubbles could be why it overheated and not the other way around, too.    Too many bubbles to get through  the vent hole force the water away from the t'stat and caused it to fail through insuffecient contact with the liquid.

Check the flatness of the head with a straight-edge and be sure to scrub the crusty stuff off the spot the gasket blew so it'll seal right next time.

 Check the protrusion of the liner above the block, too.  Should be .005 to .010" and be constant all the way around.

I'll bet the original problem was the leaky head gasket.  230F shouldn't be a problem, if the paint is still good the iron probably is too.

[Tom]

The nice thing about these engines is that with the compression release on any water in the cylinder will be purged before damage is done. Don't ask me how I know. 

[rbodell]

RCA VICTIM
I  kind of doubt that, It has over 400 hours on it. It was also assembled here in the USA. When the head gasket arives and I pull the head I will check that though.

HOTATER
It was running for a couple of hours then got hot. The gasket was off center and overlaped the thermostat a little. There was a tiny piece of gasket material in the thermostat. I had to force it open to release it. I believe it was just enough to set it at an angle and jammed it.

Yes there was a bleed hole in the thermostat. I haven't had a problem with that in the past.  I have used a couple ndifferent cooling systems since I got it and each time it has purged the air perfectly every time.

RCAVICTIM mentoned the head and tolerances. I will check them too.

Yes the paint is fine.

TOM
I haven't seen any water in the oil or heard any pinging noises when it is running.

[dmp]

Bob


I don't know if you have a pressurised cooling system or not.  Oil or other contaminants can cause bubbling.
Try flushing the cooling system with baking soda.  In a car or truck, a pound box works.  If you have 50 gals.,
well, use alot more.  Once cleaned out, add a can of Silver King boiler water treatment to your cooling system.
This will clean and drop any sludge to the bottom of the cooling system,  and it can stay there too.

Should you still have high temps and bubbling,  well, you know your cooling system is clean and can eleminate
that as a cause.  Still a clean cooling system is a good thing anyhow.

BTW, I've taken your approach to starting and am planning to start my Listeroid with a 5HP Honda. 


Best To You,
David

[rbodell]

Bob


I don't know if you have a pressurised cooling system or not.  Oil or other contaminants can cause bubbling.
Try flushing the cooling system with baking soda.  In a car or truck, a pound box works.  If you have 50 gals.,
well, use alot more.  Once cleaned out, add a can of Silver King boiler water treatment to your cooling system.
This will clean and drop any sludge to the bottom of the cooling system,  and it can stay there too.

Should you still have high temps and bubbling,  well, you know your cooling system is clean and can eleminate
that as a cause.  Still a clean cooling system is a good thing anyhow.

BTW, I've taken your approach to starting and am planning to start my Listeroid with a 5HP Honda. 


Best To You,
David

The cooling system not pressurized and is clean. I also have antifreeze in the system That is probably why it didn't boil. At least nto enough to tell. You should have sent he looks on peoples faces as I walked to the register with a full cart of gallons of antifreeze. One man asked what it was going into. I told him a 6 HP diesel. He looked a little puzzled so I added “The radiator holds 35 gallons.”.

Yeah that lawn mower engine is a winner. It is down in the 50's now and I still have 30 wt oil in it.

I did upgrade the idler pulley a little, It is now mounted on an arm. I just flip it over and lay my hand on it to tighten the belt.

I had a problem because both oil drains were unusable the way it was mounted. At first I removed the engine, but that was a hassle so while it was off I found a round recess at the bottom of the oil pan and drilled a hole out to fit a ¼ inch pipe and used JB weld to install it with. At first I was going to thread it but then I would get chips in the oil pan. The JB weld worked fine with the surrounding hole. I picked up the engine and shook it around with the pipe and it stayed nice and strong. Now I just put a pan under it and remove the plug.