1115 thermal cyphon cooling question

[dmarkh]

My thermostat is the NAPA 253 (190 degree). Should I use a normal radiator cap (11 PSI) or should I go with one that has had the spring removed (0 PSI). I've read somewhere the seals were not designed for pressure. It appears if I go with 0 PSI cap I will need a much larger over flow tank. Which is the best route?

Regards
Mark

[Ronmar]

You don't have to remove a spring, you need to remove the little disc and rubber sealing ring in the center of the part of the cap that is inserted into the filler neck.  It is the part labeled as "vacume relief valve" in this linked pic.

http://www.team.net/www/morgan/tech/CoolingSystem/RadiatorCap-2b.jpg 

This is the valve that allows coolant to flow freely back into the system from the expansion tank when the system pulls a vacume.  Removing this disc will allow coolant to flow freely to-from the expansion tank. It can usually be removed easilly by clipping or drilling/grinding the center pin or rivet that retains it.

Unless you have a hundred gallons in your system, you are not going to need very much of an expansion tank.  my coolant system uses 2 gallons and the expansion tank level changes about 1/2" from 30F to 200F   in a tank like this one linked below, napa P/N 730-4514, which is a great little expansion tank that has a bottom feed option, you just have to drill out the bottom hose barb to start using it. 

http://m.napaonline.com/Tablet/parts/ProductFinder.aspx?k=730-4514&interchange=false

The tank really needs to be above the radiator cap to insure the radiator is kept 100% full all the time.  That is the weak spot in thermosiphon, the upper feed line into the radiarot must remain completely full/submerged to maintain thermosiphon flow...

[playdiesel]

X2 on everything Ronmar said.
If your chosen radiator and cap uses the top seal such as the link he posted you can gut the cap and water will come and go freely through the overflow hose. If you are using an older type radiator and cap that seals only at the bottom of the neck then you will have to add a tube to the top tank that will serve to both vent the radiator and all a path for coolant to coma and go.  I tried the pressured system with my 1115 and that lasted one start up as it shoved coolant past the head gasket.

A viable alternative for all the adapting are the radiators designed for thermosyphon systems. They are distinct in that they have a large reserve capacity above the top hose designed into them. These are  now my choice instead of converting and the associated tanks and lines. The ones I like to use are both common ( in farm country) and cheap. This is a John Deere LUC power unit radiator on a 6/1 'roid. Other than hot days at full load you dont even need a fan.  I placed a few ads and bough up several of these for $75 or less. The necks are too large for our usage but I simply turned some adapters on the lathe and epoxied them in place. Lowes or Home depot has clamp on adapters that will work in the plumbing section.

[dmarkh]

Thanks for that Ronmar and Playdiesel. When I inherited this thing, the rad and cap were laying on the ground next to it. It was not in good shape. At the wifes request, I ended up buying a new one (she likes shiny things) but didn't inspect his original cap closely until today. It was a newer type radiator and I replaced it with basically the same one. This morning I noticed the original cap did have the vacume relief valve removed. So I also removed it from the new one this morning.

But last night, before realizing the vacume relief valve had been removed, I removed the spring from it, put it on and brought it up to temp using a clear gallon jug as the overflow to see what would happen. Before the tstat even opened I had a half gallon in the jug. But shortly after the tstat opened all but an inch of the jug went back into rad. It seemed to be working as I can see the siphoning through some short clear hoses next to the rad in/outs. The fans came on at about 217 degrees and went off at around 195. I didn't let it cycle more because the dinner bell rang.

I'll test again this evening using the new cap with the vacume relief valve removed.

Thanks again.
Mark

[Ronmar]

Your description is not uncommon for a first system run/coolant system purge.  It may have had some air in the system(upper radiator tank) that pushed a bunch of water out as soon as the hot water heated it to expansion. In an unpressurized system, the air expands a great deal more than the fluid.  As soon as it was expelled, the system drew all the fluid that would have occupied the expanded airspace, back into the system...  I would guess that it will not expand nearly as much the next run...

[dmarkh]

I would guess that it will not expand nearly as much the next run...

Yep, you were right. There still seemed to be a little air but much better now. I can probably even live with my original expansion tank. It's about half the size of the one you recommended. I went ahead and picked one up anyway just in case for$8.00.

Man when that tstat opens up all hell breaks loose for a few seconds.

Regards
Mark

[mobile_bob]

no reason for the system to not be able to stand up to at least 10psi

if the gskt is leaking under very little pressure, replace it with a good gskt and double check
things like liner protrusion.

my testing has been on the 195's admittedly, however i can see no reason why an 1115 would be any different in its capability.

i run a 7lb cap in order to run between 205 and 214F without issues.

the cylinder liner orings can surely handle the pressure in my opinion.

as for thermosiphon systems, i am not sure having a pressurized system would have a detrimental effect on its operation.

thermosiphon certainly has its place, however the 1115 really lends itself to a radiator/pressurized system and a coolant pump.  efficiency goes up with coolant temperature in my experience, and once you get over about 195 relying on thermosyphon can be problematic, at least in my opinion.

another point worth mentioning, the engine being of horizontal design, makes it a bit more difficult to get sufficient circulation via thermosiphon through the cylinder head, the cyl head temps will be quite a bit higher than that which is measured in the main part of the block.  it is not unusual to see temperatures in the 240d F range in the cylinder head. at these temperatures air bubbles are likely to form in copious amounts, these bubbles can cause issue with thermosiphoning.  this is the primary reason the engine's are rated so conservatively because you can't get much more power out with an antiquated cooling system design (read that thermosiphon)

as an example the 195 is rated at ~12hp continuous, with thermosiphon and you can push it to ~13 for a 1 hour rating owing to the need to add copious amounts of makeup water. however with an inclosed system the same engine has no problem developing 15+ hp continuous without any issues save for replacement of the cheap oem head gasket with one supplied by the "gaskets to go" guy.

the efficiency is significantly improved at the higher temperatures and higher output levels.

back to bed, been sick for over a week now and its  getting really old!

bob g

[Ronmar]

When you say all hell breaks loose, what exactly do you mean?  

I can take a guess that you see some rapid cycling out into the expansion tank, perhaps even some bubbles?

If so, I will take a guess that you do NOT have a small bypass hole drilled in the thermostat, and the thermostat is not right at the water outlet from the cylinder?   That or your thermostat is a little sticky(unusual). Your description indicate this to me.  

If the thermostat is not exactly in the cylinder water(up a short length of pipe), the hot water must slowly exchange up the pipe to reach the thermal bulb that opens the thermostat.  By the time the temp there reaches the opening temp, the temp below that alongside the cylinder may actually be much hotter, perhaps even starting to boil. As soon as the thermostat cracks, this super hot water flows by the bulb jerking the thermostat to wide open, maybe even allowing steam to flash and all this roars up the pipe to the radiator untill temps/flows stabelize.

I need a new HG on mine also.  The factory one weeps coolant untill it reaches full op temp...

In a cooling system with a circulating pump, the bypass hole is not so important as the pump circulates the heat around better so it reaches the thermostat in a timely matter and it opens smoothly to modulate the flow.  In a thermosiphon system, the bypass hole drilled in the thermostat plate/disc is very important, as it allows water to start flowing past the thermostat bulb as soon as you start making heat in the engine.  This steady flow allows the hot water to reach the thermost much faster, so it opens much more gently to modulate the flow, before the water around the cylinder reaches boiling...      

[dmarkh]

no reason for the system to not be able to stand up to at least 10psi

if the gskt is leaking under very little pressure, replace it with a good gskt and double check
things like liner protrusion.

my testing has been on the 195's admittedly, however i can see no reason why an 1115 would be any different in its capability.

i run a 7lb cap in order to run between 205 and 214F without issues.

the cylinder liner orings can surely handle the pressure in my opinion.

as for thermosiphon systems, i am not sure having a pressurized system would have a detrimental effect on its operation.

Interesting. I didn't realize that. Looking back, I probably should have changed he HG when I had it down and opened up. If I had known that the HG gasket from the "gaskets to go" guy. would have allowed me to safely run pressurized I may have done it. The "gaskets to go" guy. could not provide the gasket until I had mine out so he could get it's dimensions. I though it strange he didn't already have the info to make one. I didn't want to open it up without a gasket in hand.

thermosiphon certainly has its place, however the 1115 really lends itself to a radiator/pressurized system and a coolant pump.  efficiency goes up with coolant temperature in my experience, and once you get over about 195 relying on thermosyphon can be problematic, at least in my opinion.

Eventually I may have to back track and consider this. We'll see. The guy that built this didn't do it and I didn't want to make any changes I wasn't sure about until I got it back up.

another point worth mentioning, the engine being of horizontal design, makes it a bit more difficult to get sufficient circulation via thermosiphon through the cylinder head, the cyl head temps will be quite a bit higher than that which is measured in the main part of the block.  it is not unusual to see temperatures in the 240d F range in the cylinder head. at these temperatures air bubbles are likely to form in copious amounts, these bubbles can cause issue with thermosiphoning.  this is the primary reason the engine's are rated so conservatively because you can't get much more power out with an antiquated cooling system design (read that thermosiphon)

as an example the 195 is rated at ~12hp continuous, with thermosiphon and you can push it to ~13 for a 1 hour rating owing to the need to add copious amounts of makeup water. however with an inclosed system the same engine has no problem developing 15+ hp continuous without any issues save for replacement of the cheap oem head gasket with one supplied by the "gaskets to go" guy.

the efficiency is significantly improved at the higher temperatures and higher output levels.

back to bed, been sick for over a week now and its  getting really old!

More good info, thanks and I hope your feeling better.

Mark

[dmarkh]

When you say all hell breaks loose, what exactly do you mean?  

I can take a guess that you see some rapid cycling out into the expansion tank, perhaps even some bubbles?

Actually it's just rapid cycling in and out of the rad. Sort of like it had an orgasm. A tremendous amount of cycling through the rad takes place in a few seconds then calms down. Like I said earlier, I have about 4 inches of clear hose on both in and out of the rad. I can clearly see what's going in and out of the rad. The bubbles are pretty much gone now but yes still some during those few seconds after the ts opens up.

If so, I will take a guess that you do NOT have a small bypass hole drilled in the thermostat, and the thermostat is not right at the water outlet from the cylinder?   That or your thermostat is a little sticky(unusual). Your description indicate this to me.  

If the thermostat is not exactly in the cylinder water(up a short length of pipe), the hot water must slowly exchange up the pipe to reach the thermal bulb that opens the thermostat.  By the time the temp there reaches the opening temp, the temp below that alongside the cylinder may actually be much hotter, perhaps even starting to boil. As soon as the thermostat cracks, this super hot water flows by the bulb jerking the thermostat to wide open, maybe even allowing steam to flash and all this roars up the pipe to the radiator untill temps/flows stabelize.

Right again. I do NOT have a bypass hole drilled in the thermostat. The ts is right on the plate at water level though.

http://s1273.photobucket.com/user/dmarkh/media/DSC03701_zpsc09fb578.jpg.html?sort=3&o=0

I need a new HG on mine also.  The factory one weeps coolant untill it reaches full op temp...

In a cooling system with a circulating pump, the bypass hole is not so important as the pump circulates the heat around better so it reaches the thermostat in a timely matter and it opens smoothly to modulate the flow.  In a thermosiphon system, the bypass hole drilled in the thermostat plate/disc is very important, as it allows water to start flowing past the thermostat bulb as soon as you start making heat in the engine.  This steady flow allows the hot water to reach the thermost much faster, so it opens much more gently to modulate the flow, before the water around the cylinder reaches boiling...      

As I told bob, I may have to back track and make some changes. If/when I do, I'll drill me a hole.

The only way I seem to be able to reach the 200-215 temps is to block off the rad from the wind. I'm in central FL and it is HOT here too. I've only had a 10-12 amp load on it. I'm planning to hook it to the house on Sunday for the day. I'm hoping a load on it will get me in that range. I suppose it's a normal thing to get a 6 pack and sit by the gen all day? She thinks I'm nuts.

Mark

[playdiesel]

Bob, I sure hope you dont have the same crap that I and all of my family had. From May 1 to mid July I went from chest congestion to sinus to flue like symptoms to diarrhea on a 5 day cycle over and over agin and that got REAL old let me tell ya.

Bob has vastly more time with these engines than I do so listen carefully when he speaks.  My "powermart" 1115 leaked with no pressure as delivered and still weeps a bit with the G-to-go replacements gasket which it is on #2 of those. I have model 180, 190, 192  and 195 Chanfa branded engines with factory radiators and all have pressure caps and dont leak. Due to the flow problems Bob spoke about I have to wonder about the long term viability of running one of these engines under such load that the system must be pressurized to keep the coolant from boillin? No science involved , just opinion.   What Bob spoke about in power vs operating time rings true when a person studies the ratings of the more reliable builders. These engines will literally pull their own guts out if the rack limiter is set to allow it and the operator is willing to let them do it. All of the better builders   rate them at some HP continuous and another higher HP for intermittent  loadings.  My 1115 Laidong engine is rated much more conservatively than the "Powermart" branded engine on my stand by set in spite of the fact that it is of superior build quality and the Laidong also has a circulating pump in order to insure coolin at the rated loads. The rack limiter on the Powermart engine was backed all the way out and it has something like a 24 HP rating and would blow coal until I backed it down. Meanwhile the Laidong is rated at 20 HP and will not blow smoke except under acceleration.  Laidong is a ISO 9001 builder so claims of HP and durability must be backed up with something other than a decal. other brands? you take your chances.
Sorry If I am rambling here, but a subject I like to talk about. The China horizontals are good engines but most of them have pump delivery settings that are just plain insane for continuous duty.  If your going to put a lot of hours on the engine my experience is that that if you can see even a hint of smoke that you have much more load than is healthy over the long term,, regardless of the ID plate rating and how many KW your are pulling.

[dmarkh]

The China horizontals are good engines but most of them have pump delivery settings that are just plain insane for continuous duty.  If your going to put a lot of hours on the engine my experience is that that if you can see even a hint of smoke that you have much more load than is healthy over the long term,, regardless of the ID plate rating and how many KW your are pulling.

I'll pay special attention to the smoke on Sunday. I've only seen it once and that was the very first time I started it after bringing home. It was my first time throttling up and I didn't know yet the feel of the throttle. I've noticed that with no load, running at 240volt and 60hz, I have all kinds of throttle left.

Mark

[dmarkh]

Bob has vastly more time with these engines than I do so listen carefully when he speaks.  My "powermart" 1115 leaked with no pressure as delivered and still weeps a bit with the G-to-go replacements gasket which it is on #2 of those. I have model 180, 190, 192  and 195 Chanfa branded engines with factory radiators and all have pressure caps and dont leak. Due to the flow problems Bob spoke about I have to wonder about the long term viability of running one of these engines under such load that the system must be pressurized to keep the coolant from boillin? No science involved , just opinion.   What Bob spoke about in power vs operating time rings true when a person studies the ratings of the more reliable builders. These engines will literally pull their own guts out if the rack limiter is set to allow it and the operator is willing to let them do it. All of the better builders   rate them at some HP continuous and another higher HP for intermittent  loadings.  My 1115 Laidong engine is rated much more conservatively than the "Powermart" branded engine on my stand by set in spite of the fact that it is of superior build quality and the Laidong also has a circulating pump in order to insure coolin at the rated loads. The rack limiter on the Powermart engine was backed all the way out and it has something like a 24 HP rating and would blow coal until I backed it down. Meanwhile the Laidong is rated at 20 HP and will not blow smoke except under acceleration.  Laidong is a ISO 9001 builder so claims of HP and durability must be backed up with something other than a decal. other brands? you take your chances.

What kind of 1115 have I got?

http://s1273.photobucket.com/user/dmarkh/media/DSC03754_zpsc3ece064.jpg.html?sort=3&o=0

Mark

[playdiesel]

What kind of 1115 have I got?

http://s1273.photobucket.com/user/dmarkh/media/DSC03754_zpsc3ece064.jpg.html?sort=3&o=0

Mark

I think?,,, you have  what most people call a genuine "Changfa" 

My "Powermart" 1115 engine is a clone of that one, the photo copied manual even says Changfa on the cover, LOL. Dont have any pictures of it handy. Do have a video of the 1115 Laidong, notice it is sitting on a little rubber tired cart and running smooth. Quality speaking they are a cadillac.

[Ronmar]

That does indeed look like a genuine changfa by the label.  Mine is also a clone, changchi and I am still running the installed box radiator in place of the hopper.

Keep an eye on those clear lines you are running, especially the one on the upper radiator.  They get pretty rubbery when exposed to high temperature.

Nice group on youyr target/airflow block!