251b coolent issue

[68j6]

  I pick up a 1968  bombardier  j6  with  chrysler  251b  motor. I re did the   electrical  system.   All new gauges in volts.   And temp sensor and oil sensor   and voltage  gage installed. I Put in a master power  switch and 10 block fuse panel.  And  a new 95amp alternator.  I left the starter driver original.  I added  a electric  fuel pump  to.   I did  a carb kit on   the clark ball  and ball   carb. Which needs to replace cause  of corrosion and    possible crack. And  air leak through  through  the   throttle  shaft.  This machine  does have exhaust    governor  before  throttle  body.   I had the original  raditor. I hadit  Pressure  tested and new cap installed.  I replace the old  thermostat  that failed and  stuck open with 180° motorad/stant thermostat.  Replace the oringal water pump with GMB pump  and the water distribution  tube with a stainless  one all at the same  time a month ago.   The heater core is original  and works great.   With the new system.  I change  all rubber   radiator  lines and heater  core lines in this process.  And installed  a 1 3/4" cooolent heater on the down spout line to the thermostat  manifold.  I had issues where I  run this machine  and  my oil Pressure  45psi. My  temp sensor  will run  about 180° to 190°.  Then  the machine with burp coolent (approx 1ltr)into  over flow, when operating.  I did this  and run idle,  from when I filled it up the first time.  Radiator  was  full after 40mun of run time burp 1liter out.  Ran it  for another 30min no burping.   Shut it off let it cool brought temp back up  third time no  burping.  Heater works great putting  out very hot heat.  Test  drove  it today. Then burp out another  liter respectively  today.  Any issues? Or cause to this happening? Inside would be  great? 

 

[greg g]

The burping is seeking its own operational level.  Rule of thumb is cool expansion area at top of radiator should be mostly empty.  As long as the coolant covers the top of the cooling core you are good to go.

 

Where is the overflow outlet.  Inthe tank or on the filler?  If on the filler, is the opening below the radiator cap sealing gasket or above it?

[68j6]

  The level would be  lower then the core when is burp  out 2 liters. The  over flow is  is in the  fill spout. And above the seal ring. 

[Tooljunkie]

The cooling system ran with very low pressure, its common for coolant to push out. If you are using an overflow tank it will rise and fall from hot to cold. If its overheating thats a concern. If head gasket is leaking, there is a chemical test for that. Head gaskets typically leak under high engine load, usually followed with overheating. 
dirty engine block results in a plugged rad, something else to consider. 

[68j6]

What is the psi for  the coolent on  is motor? 

[wallytoo]

5 minutes ago, 68j6 said:

What is the psi for  the coolent on  is motor? 

 

it would vary by application.  in the chrysler/dodge cars/trucks of the 40s and 50s, the cooling systems were unpressurized.  i have no idea what bombardier used in 1968 for a cooling system.

[DJ194950]

Is a pressurized system?

 

Industrial motor of later years most likely were but how to know?.   A pressure test tool on the system would tell for sure .

Is the overflow tube in the filler neck above the seat for the radiator cap seat or below?.

 

While pressure testing leave the tester on on start up and warm up and see if it holds pressure say up to about 10 -12 psi  which if I remember correctly is about all even the later Mopar flat 6's ran in the industrial  uses-- it was only about 25+ years ago that i last worked with these , but-  ?

 

Add-- test the rad. cap for ability to hold pressure to the rated # psi stamped on the cap. What is it labeled. 

Info will help the forum members give you  answers- -

 

DJ

Edited January 8, 2022 by DJ194950
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[68j6]

 I don't have the Oringal cap anymore.  The  tester put  13psi cap on there.  I  pressured tested it at 13psi.  Would slowly  drop during  a 5min period.  To seven  pounds Then hold,  found a leak at the  heater core upper line?  and  the  heater core  shut off valve. I have tighten the line waiting on the valve to show up to put on. Then going to retest the system.

 

[TMG]

1 hour ago, 68j6 said:

 I don't have the Oringal cap anymore.  The  tester put  13psi cap on there.  I  pressured tested it at 13psi.  Would slowly  drop during  a 5min period.  To seven  pounds Then hold,  found a leak at the  heater core upper line?  and  the  heater core  shut off valve. I have tighten the line waiting on the valve to show up to put on. Then going to retest the system.

 

I have the 1971 and the cap has pressure valve.

Edited January 11, 2022 by TMG
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