Flame heater cutoff

[lawdog1623]

ive searched the threads and havent found this particular topic. im looking to see if anyone has actually placed a cutoff valve of any kind in the supply and return lines to the flame heater. my preference was to keep the system and replace it with new parts. ive replaced all the tubing and fittings; i then fixed the leak from the rear of the flame heater. The system is intact and looks great but i would like some added insurance to guarantee me that the seals on the unit wont fail without my knowledge and start dumping fuel into the crankcase. i figured i could just add some sort of manual valve that will cut off the gas flow to the heater. The only place i can see that i could splice one in would be in the area where the supply line runs between the valve trains. has anyone done this? do you have any suggestions? does anyone have any pics of their setups?

 

[cattlerepairman]

Reluctant to answer because I can only offer second-hand info. Yes, that has been done; I remember reading a post about it. Of note is that you need to shut off both supply and return lines to reliably prevent flow to the flame heater and uncontrolled leakage.

 

[doghead]

They do not dump fuel into the base. Think about this.

It would have to fill the turbo housing to the shaft level, to leak into the oil. That would mean that the steel pipe would have to be half full at the bottom. This would be about 1/2 a gallon of fuel. You think you would not notice that, in your intake pipe, when you cranked it over?

 

[Wildchild467]

I never understood how a flame heater can leak fuel into the crank case from the flame heater. The only place it can leak is at the flame heater injector and even then, the fuel would get burned. Correct me if I am wrong. It seems a lot of people say leaking flame heaters can dilute engine oil.... but i do not understand how. When I was working on my M109, I noticed that the fuel supply line from the fuel tank was hooked up to the flame heater supply port on the lift pump. I know that is a lot to think about in that last sentence. I am talking about the lift pump on the injection pump. So on the injection pump where the fuel should go in from the tank and where the line goes to the flame heater were reversed. The truck ran, but I switched them over anyway. Actually, I switched the fuel tank line so it goes in the correct port on the injection pump and just put a pipe plug in the port that supplies the flame heater. I have a separate tank of kerosene that supplies the flame heater on the truck now since I have used motor oil as fuel. So now there is no pressure at all on the flame heater nozzle. If I have a separate tank for the flame heater, and the “T” in the injector lines is replaced with a straight piece of line (the return line that came from the flame heater is no longer used).

 

[peashooter]

I also wanted to prevent anymore leaks from the manifold heater system. So after copying someone else's idea on here somewhere, I put a check valve on the flame heater nozzle return line ($11 from mcmaster) part # 7768K65 I think I used. I also bought a 24vdc diesel rated (supposedly) solenoid valve off ebay for $15 and will (havent yet) install that before the flame heater pump. I'll wire it to the pump so that when the switch is flipped for the flame heater it will open the valve and turn the flame heater's pump on.

 

[lawdog1623]

Nice...peashooter. I found a 1/4 inch cutoff valve and spluced it in to the line from the t coupler. The valve sits right between the two valve covers and is easily accessible. I tjink im going to add one on the smaller 1/8 inch return line as well. Can you send me more specifics about what you did with the solenoid and the pump? I dont mind a little overkill but its hard for me to visualize what you're talking about. The whole system is still new to me.

 

[peashooter]

Can you send me more specifics about what you did with the solenoid and the pump? I dont mind a little overkill but its hard for me to visualize what you're talking about. The whole system is still new to me.

Affraid I cant send actual pictures of my setup since its now dark by the time I'm home from work. But I'll try to explain it better. In the below picture titled "manifold heater Nozzle".... the larger 1/4" diameter return hose is what you would put the check valve on. The check valve would allow fuel to leave the nozzle and go back into the main return lines, but would not allow fuel to go backwards into the nozzle ever. I mounted my check valve between the nozzle unit and the brass compression fitting.
The other picture shows the backside of the manifold heater pump. This is what turns on when you flip the dash switch. It ups the in-tank fuel pump pressure to ?? PSI (cant remember, but its more). I am putting the 24vdc solenoid valve on right before the manifold heater pump. In the picture you can see the 1/4" fuel line entering the pump on the left side, that is where I'm putting the solenoid valve. The smaller red fuel line on the right side is the higher pressure line that runs to the manifold nozzle. I'm wiring the valve Im adding in parallel with the existing pump so they activate together.
Sorry I dont have actual pictures, and I'm not sure how to add text to the pictures at the moment.

 

[peashooter]

oh, also I've heard of many people finding leaks coming from the manifold heater pump itself, so if you decide to add another valve manual or solenoid to the 1/8" line side, you may want to do it ahead of the manifold heater pump to the 1/4" line going to the pump as I mentioned above.