1115 thermal cyphon cooling question

[dmarkh]

The drain cock threads on the engines I have fooled with are all 1/4"or 3/8 BSPT or British Standard Pipe Tapered.

It is for sure larger than 1/4. It even seems like it was larger than 3/8. I've had it out several times now, I just never thought I would need to know.
 

Are you thinking about returning the cool water to the drain cock? I have thought f that also but it would require that the hole be opened up to accept a larger pipe. Is there room in the casting for that? I have not explored it further.

Personally I would remove the thermostat and try it prior to using a pump. If it then thero's correctly at least you have a known point to work at. I have a gut feeling that your problems lie under the plate, not with the 'stat.

Yes, I'm thinking of returning water to the drain port as Bob suggested above, for reasons he described. It seems easy enough. Like I said in my last post, I also believe the siphon problem is not the TS alone but certainly under that utterpower plate. I am going to fix that no matter what. I also want to run in that goldie-lox temp range of 200-215 so will be a pressure cap of 6lbs. I have already run this without a TS (stuck open when I got it) and I won't be doing that. It took 20-30 minutes to get to 200d.

Why do you think a 3/8 (minimum) hole won't be large enough for the pump? An awful lot of water can pass through a 3/8" hole.

Mark

[mobile_bob]

the drain cock hole is 1/4 pipe thread, which will pass ~3/8" of water
with the bosch pump feeding return water from the bottom of the radiator the engine will have
ample cooling capacity.

iirc the little pump will move about 3-5 gallon per minute open flow, probably ~3 gallons min in this application.

pretty hard to heat that much water with anything less than about 25hp in my opinion, that is if you have sufficient radiator capacity (which is almost impossible have a problem with unless you are using some very small radiator and no fan)

my 195 holds a touch over 1 gallon of coolant in the system, i like this because it allows for fairly rapid warm up and i can apply full load to the engine in just a few minutes.

it might not seem that this system is enough flow capacity, however i would offer this

cummins made a series of 855cu/in engines back in the 80s and early 90's that made up to 400 hp and more that used 1" heater hoses for both the upper and lower radiator hoses!  and the tstats too were smaller than those used in most cars, albeit they used two of them.  the system was a reverse flow/low flow design that really worked well.

i figure if one can successfully cool 400hp with 1 inch hoses, surely we can expect no issues with 5/8" hose mounted over the one choke point which in this case is the 1/4 inch nipple assy. fitted to the drain cock opening.

one final thought

i like the idea of smaller capacities of coolant, it allows not only for faster warmup but perhaps more importantly a more stable coolant temperature once up to full load. by that i mean there is less thermal stress on the engine when the coolant reentering the engine is perhaps 190F and leaving the engine at around 210F as opposed to large thermosiphon tank systems where the return water might be considerably lower coming back from a 55 gallon drum.

besides i like a thermostat that once things are up to temp opens up and after settling down stays open. it just seems like the stat might last longer and present fewer problems.

anyways it works for me.

bob g

[dmarkh]

the drain cock hole is 1/4 pipe thread, which will pass ~3/8" of water
with the bosch pump feeding return water from the bottom of the radiator the engine will have
ample cooling capacity.

Is that BSPT (British Standard Pipe Tapered) or NTP?

Thanks
Mark

[playdiesel]

!/4" pipe is about 1/2" O.D.
3/8" Pipe is about 5/8"

A helpful chart

[mobile_bob]

the port on my 195's are all 1/4 NPT female

bob g

[dmarkh]

the port on my 195's are all 1/4 NPT female

bob g

I took it out last night and my 1115 is for sure 3/8 BSPT. I've got an BSPT to NTP adapter coming from MCMaster Carr. Will have it Friday.

Mark

[buickanddeere]

The drain cock threads on the engines I have fooled with are all 1/4"or 3/8 BSPT or British Standard Pipe Tapered. To my knowledge there is no metric "pipe thread" as we know it. The Europeans used the British system of pipe threads by and large however there are many different metric pattern tubing threads.
Most but not all of the BSP threads are one thread per inch different than the American standard version, bastards 
What this means when a person tries to mix and match them they start together OK, but get tight kind of quick, you put a wrench on the fitting to tighten it and it feels a bit funny but seems to be tightening OK. Then you put the joint under  just  a small amount of pressure and it leaks no matter how much you tighten it.

For anything under medium to high pressure you simply cannot mix and match. McMaster Carr has both adapters and fittings

For low head/pressure systems you have a few choices. If your not going to be taking the fitting in or out in the planned future clean everything up, mix up some JB weld and use it as thread dope, fixed. If that bothers you you can try regular thread dope but that hasn't worked for me. You can also run a regular US standard pipe tap into the hole if there is room but you take your chances with that. Too deep and the valve wont thread in far enough to seal and your back to JB Weld. 

Are you thinking about returning the cool water to the drain cock? I have thought f that also but it would require that the hole be opened up to accept a larger pipe. Is there room in the casting for that? I have not explored it further.

Personally I would remove the thermostat and try it prior to using a pump. If it then thero's correctly at least you have a known point to work at. I have a gut feeling that your problems lie under the plate, not with the 'stat.

Drill and re-thread to obtain the desired threads. Cast iron is soft.

[buickanddeere]

!/4" pipe is about 1/2" O.D.
3/8" Pipe is about 5/8"

A helpful chart

  When working with pipe and tubing. Always make certain the I.D. is smaller than the O.D. or the hole will be on the outside of the pipe.

[EBI-WPO]

!/4" pipe is about 1/2" O.D.
3/8" Pipe is about 5/8"

A helpful chart

  When working with pipe and tubing. Always make certain the I.D. is smaller than the O.D. or the hole will be on the outside of the pipe.

He He  ,
It's always the simple things............

Terry

[dmarkh]

Drill and re-thread to obtain the desired threads. Cast iron is soft.

The desired results are to be able to reinstall the original pet cock should I decide to revert to thermal siphon.

Mark

[dmarkh]

Got the pump plumbed in and a 1/16 hole with a cotter pin in the TS. Once the TS opened up (30 minutes or so no load) I hooked up to the house. Left the AC off at first. I was running 2 fridges, a deep freeze, a couple of ceiling fans on low, and the kitchen lights. I was drawing around 12 amps. I let this run for an hour or so. The coolant temp at the plate was steady at around 208. It was a hot sunny day and the rad was in the sun. It maintained that 208 for over an hour so the rad fans were not coming on at all. OK, I like 208. So I told her to go kick the AC on. The gen sputtered for 2 or 3 seconds with a little smoke, but the AC started. I was now drawing around 32 amps. No smoke. But not much wiggle room at 40 max.

Of coarse the temp started going up and when it reached 214 the rad fans kicked in. So far so good. However the fans didn't turn off until the temp was down to 194. And after that the temp went down another 4 degrees. The TS had closed. Crap.. It cycled just like that continuously  while the AC was running.

The thermal switch for controlling the rad fans is a 200 on 185 off surface mounted on top of the plate. But it has a 20 degree swing, not 15 as advertised. I really need something with a 10 degree swing. Fortunately that switch was only $10. I guess ya get what ya pay for.

I see these adjustable temp fan controllers that say their swing is 10 degrees.

Derale 16759 Adjustable Fan Controller - sensor pushes into rad fins
Derale 16749 Adjustable Fan Controller - sensor 3/8 NTP into top plate

Is something like the above what I should be looking at or is there somewhere I can find a surface mount sensor with a real 10 degree swing?

Mark

[BruceM]

Your idea of a more limited hysteresis on the fan thermostat is a good one.
Other considerations- limit fan power (different fan, dropping resistor, variable supply, clip blades on existing fan), limit water flow via ball valve, limit radiator area by masking some off.

[vdubnut62]

Why would you mount the thermal switch on the blockoff plate and not on the radiator??  Or did I just completely misunderstand/
Ron

[dmarkh]

Why would you mount the thermal switch on the blockoff plate and not on the radiator??  Or did I just completely misunderstand/
Ron

There was room for it there and the rad I have has no port for one.

Mark

[vdubnut62]

Why would you mount the thermal switch on the blockoff plate and not on the radiator??  Or did I just completely misunderstand/
Ron

There was room for it there and the rad I have has no port for one.

Mark

OK. Got it, but I would try some sort of workaround to get my sensor on the rad tank cool side, but that is just me. It would mitigate some of the temp swing.
Ron.