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Freezing regulator - rich condition
  • jim_r
  • Indiana, United States
I own a 1945 Clark Carloader with a Conteniental L-Head 4 clylinder that was converted to LP. It has a Century regulator on it that does not have "heat fins" on it and is not plumbed with coolant. I recently installed a electronic distributor which made it run great for a short time but the regulator just continued to freeze up quicker and quicker. Now I'm lucky to get a minute or two of run time out of it. Do I just need to replace this regulator with one I can heat with coolant? Thank you!
  • Posted 2 Jun 2013 10:29 AM
Total replies: 27. Showing items 1 - 20 of 27 results.
If you have a regulator without any provision for absorbing heat, that regulator is probably not intended to be used with input of liquid propane to start with. Regulators that lack vaporizer capability are intended to be used with very low fuel consumption applications (usually less than 8 horsepower) and are plumbed from a tank configured to deliver propane vapor only.
I am getting a visual on this and I think your term "rich condition" is surely an understatement.
A J-model Impco regulator/vaporizer plumbed into the engine coolant (properly plumbed, of course) should give you dependable performance.
  • Posted 2 Jun 2013 11:22 AM
  • jim_r
  • Indiana, United States
Thank you, it never has ran very well but it was cheap. There are no provisions for plumbing in a regulator. The cap on my radiator is also bad, so I assume I should find a replacement for this also. How do I go about hooking up a new regulator to the cooling system. There is no water pump in the system. Thank you.
  • Posted 2 Jun 2013 11:28 AM
NO WATER PUMP? Surely you jest. I believe the presence of a RADIATOR with HOSES connected to it shouts "water pump somewhere in here".
At what level of expertise would you rate yourself when it come to actual mechanic work?
Not being sarcastic here, just wanting to know if you are just an owner of an old machine or if you actually have some working knowledge of what you are thinking about doing.
  • Posted 2 Jun 2013 11:56 AM
  • jim_r
  • Indiana, United States
No pump, the hot water rises and the cool water falls. Top hose comes out of the center/top of the head and goes to the top of the radiator. The bottom hose comes off the bottom of the radiator and goes into the side of the engine block. The tabs on my cap are broke off so I'm sure the system is building little or no pressure. I'm fairly mechanical. Have replaced the tires and entire electrical system on this thing, icluding switching the old mechanical distrubutor for an electrical one. I assume I would need to pull hot water off the top of the radiator and the cooler water off the botom and pipe it to the regulator. Im not sure about the best way to make these connections though. Can I get some type of in-line fitting to place in the hose or will I need to get fittings braised into my radiator?
  • Posted 2 Jun 2013 12:16 PM
I've seen them, old Carloader with no water pump.
The one of them I worked on had a J&S propane regulator mounted in a special radiator hose outlet that bolts on the head or it fit in the hose itself. That would require a different carburetor,though. Is there 2 bolts that hold what looks like a thermostat housing on the head where the hose hooks on? That might be the only way to go unless you can drill and tap for fittings in that hose housing and maybe find a drain plug in the block to use as a fitting hole. But the water flow may not be good enough. Your regulator probably needs a rebuild and that is causing it to frost up real quick due to running so rich.
I don't think the broken cap is causing any problem.
  • Posted 2 Jun 2013 01:06 PM
  • • Modified 2 Jun 2013 01:08 PM by poster
  • jim_r
  • Indiana, United States
Yes, there is a hose fitting bolted to the head. There is also some kind of repair "goo" all around that area so I'm not real excited about removing it. It would be great to find some type of in-line fitting to put in the radiator hoses. I was also worried about lack of flow. I wasn't sure if the regulator was going bad or not but I thought the freezing and thawing surely had to effect the diaframs inside it. I think I can buy a new one with water ports cheaper than rebuilding this one.
  • Posted 2 Jun 2013 01:16 PM
By the time I got finished writing this up (including a couple interruptions from wifey) you guys had carried on a good deal of dialogue, but I am leaving it as it stands. Thanks
I would think it would be more expedient to plumb a sort of "by-pass" arrangement into the hose rising up to the radiator so that naturally hot water could rise up through the regulator/vaporizer.
This is going to require that the hose in place now be cut at 2 places so a short section of pipe can be inserted into each radiator hose.
One pipe in the ascending hose near the engine head and the second pipe in the descending radiator hose somewhere near where the hose attaches to the block.
The coolant ports on the J-model regulator are 3/8" NPT and as such your 2 sections of pipe to "tap into" the radiator hoses would need to have either threaded fittings welded into them, or have 3/8" heater hose nipples welded into them, to transport the hot coolant to and from the regulator/vaporizer.
The regulator needs to be mounted above the point at which you are feeding coolant into it.
Because the net effect of the regulator absorbing heat from the coolant and transferring the heat to the liquid propane. the coolant temperature will be lowered in this process and will induce its own convection cycle circulation loop. Hot water in from top hose and cooled water falls back to the lower region of the engine block.
Ideally you would also add a VFF 30 vacuum operated fuel lock off valve between the LP tank and the J-model regulator to insure that no propane flows in the system if you forget to turn off the tank hand valve.
Legitimate LP engine fuel systems are required to have an automatic fuel lock off feature that senses engine vacuum or oil pressure so that the system automatically shuts of fuel if the engine quits running with the key still on. You can't just have an electric fuel lock off valve that is energized when the key is on, there must be an interlocking switch that senses engine vacuum or oil pressure before activating the lock off.
A direct vacuum operated fuel lock off such as VFF 30 does the job nicely without any electricity involved.
  • Posted 2 Jun 2013 01:16 PM
  • • Modified 2 Jun 2013 01:20 PM by poster
  • jim_r
  • Indiana, United States
With respect to the lock off valve, I don't have one and know I shoud have one. If I add one will this allow me to eliminate the current 12 volt solenoid that is in line between the tank and the regulator?
  • Posted 2 Jun 2013 01:24 PM
Yes, replacing the present electric solenoid valve with a direct vacuum lock off is practical.
If the electric solenoid valve on there now is activated by a vacuum or oil pressure sensing switch, it is legal and as practical as a direct vacuum lock off.
I just wanted to caution against simply wiring in a solenoid valve to a circuit that is hot with the key [url removed] that does not satisfy the requirement that fuel flow be automatically interrupted if the engine dies while the key is on.
  • Posted 2 Jun 2013 02:26 PM
  • jim_r
  • Indiana, United States
The current solenoid is wired to the on/off switch. Do all the model J regulators come with the VFF 30 lock off or is that an option? I'm going to order a new regulator, I just want to make sure I get the correct one. How does the vacuum hook up? What is used for the source of the vacuum?
  • Posted 3 Jun 2013 02:40 AM
  • • Modified 3 Jun 2013 02:44 AM by poster
  • jim_r
  • Indiana, United States
Sorry, I understand now that they are two separate parts. The VFF 30 has a 1/8" NPT vacuum port. Where or what does this get connected to? The intake manifold?
  • Posted 3 Jun 2013 03:04 AM
  • • Modified 3 Jun 2013 03:15 AM by poster
Yes, intake manifold. There should be some kind of threaded hole somewhere in the intake. It will likely be plugged and may require some effort and heat to loosen it. I can't say about back when this engine mas made but most engines have had at least some drillable and tapable extra metal areas in the casting that can be opened up, even if they were not originally drilled and tapped.
If you would rather not mess with adding the VFF 30 you can always resort to adding an oil pressure switch to control the solenoid that is in use now.
  • Posted 3 Jun 2013 09:21 AM
  • • Modified 3 Jun 2013 12:31 PM by poster
I want to add that placing the J-model vaporizer near the lower end of the ascending radiator hose will cause a convection loop to form passing through the regulator as first choice (instead of climbing higher to fall down through the radiator) if the coolant return hose from the regulator begins to descend immediately toward the engine block.
Because the new J-model circuit in the plumbing provides a sort of "bypass the radiator" [url removed] will want to keep an eye on the coolant/engine temperature to make sure that adding the vaporizer heat loop does not decrease flow volume through the radiator enough to cause engine overheat.
Ways of compensating and "fine tuning" the vaporizer heat loop could include adding a restriction orifice fitting into the vaporizer coolant plumbing.
But the easiest way to handle this would be to use an extra long length of 3/8" heater hose for the returning coolant line (going to the bottom of the engine block) and simply raise that hose to a higher elevation if it seems that the radiator is not receiving sufficient flow volume to affect adequate cooling.
Liquids will seek out the path of least resistance if given unequal elevation routes to flow through, so the return hose from the regulator would be the path the convection loop would want to use if it is lower than the loop path through the radiator.
You might want to set up your return hose out of the vaporizer so it rises to the same, or maybe 1 inch lower than the normal level of coolant in the radiator top tank.
I don't know from experience how much the flow rate of a convection driven cooling system is, but I'll bet it can't be all that much. Or in other words, adding a 3/8" alternative loop might "reroute" enough flow volume of coolant to decrease cooling in the radiator (despite the fact that the vaporizing propane will provide some cooling itself) so you really want to route that return hose strategically in regard to WHERE it changes from [url removed] [url removed] the scheme of plumbing.
  • Posted 4 Jun 2013 02:40 AM
  • MEngr
  • Missouri, United States
If my memory serves me you have an old Clark flat back and the style of Century was still being used in the Clark product lines as late as 1976.
  • Posted 4 Jun 2013 03:08 AM
  • cownd
  • Arizona, United States
this sounds like an old Y20 & I thought carloaders were electirc?
  • Posted 4 Jun 2013 04:42 AM
  • bbforks
  • Pennsylvania, United States
I have installed the air heated century regulator on a 4 cyl air cooled wisconsin manlift. Unit worked well- no issues.

I have seen the lift you have with convection cooling. Not sure if any type of liquid regulator will receive the volume of coolant needed to satisfy the heat transfer - keep us posted on the model J conversion if that's the route you take.

bbforks (at) Hotmail (dot) com
Customers love technology- until they have to pay to fix it!
  • Posted 4 Jun 2013 07:37 AM
  • kevin_t
  • Pennsylvania, United States
I think the first thing I have to ask after reading and watching this post [url removed] this truck EVER run right with this converted LP Regulator system on [url removed] if it did I have to ask what was changed/ done that made it start freezing [url removed]'t of been just a distributor change that made the freezing start????
  • Posted 4 Jun 2013 07:45 AM
  • jim_r
  • Indiana, United States
I would say that it never did run right. There were many things wrong with it when I purchased it. An example would be that the main seal was out and instead of changing the seal they painted "check oil daily" on it! Nothing else was changed. The engine ran great after the electrical tune up but the run time to freeze up just keeps getting shorter. I can only get a few minutes out of it now and the plugs are fouling out quickly.
  • Posted 4 Jun 2013 08:37 AM
  • cownd
  • Arizona, United States
I'd contact Manny at M&M forklifts in Phoenix AZ. I think he may be able to help you put that machine back so it works correctly. Just goggle M&M forklift salvage.
  • Posted 4 Jun 2013 08:41 AM
  • MEngr
  • Missouri, United States
jim r;
You have more then likely a M6 Century Carburation system which started on vapor and ran on vapor LPG until engine reached it's normal operating temperature and then change to liquid LPG. You can get good help if you contact Alternate Fuel [url removed] at 877-425-8383. They just be able to supply with what you need to restore what you have.
  • Posted 4 Jun 2013 11:48 AM
Total replies: 27. Showing items 1 - 20 of 27 results.

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