Found out something about my coolant plumbing

[David Anderson]

When I had to run the engine with the radiator out last week to find the tranny hose leak,  I found that the coolant that diverts from the water pump through the oil cooler, then the tranny cooler and back to the bottom of the block does not go back to the radiator unless the t-stats open.  I could tell this by the fact that my pvc pipe loop I rigged up stayed cool and the oil cooler plumbing began to heat up, but never enough to open the t-stats.   

It's the OEM configuration and works fine, except when I come down those Rocky Mountain passes and hang on the retarder, the tranny oil temps can get as high as 230, while the oil temp drops to 180 and the water temp drops to 170 and the t-stats are closed.  The coolant is just making the circle through the engine block.

If the coolant from the tranny cooler and oil cooler went back to the radiator it would cool the oil faster.  However, diverting water from the engine block might disrupt the cooling of the engine when running normally under power.  We sure don't want that problem.  The plumbing return line of the oil cooler circuit to the block is at the lower quadrant in the hole where a block heater could be installed. 

Is this something that might be considered or left alone as is?

David

[DMoedave]

you may have to do the air to air cooler route, then back thru the reg oil coolers. I would not try to modify the coolant plumbing unless i had some expert advice and a harbor freight air compressor! We have the problem going up the hills! You will have to decide how often this happens to make it worth while or not.

[luvrbus]

David, a good set of Jake's will solve that problem your Metro Eagle didn't see many mountains in Houston,those 4 coolers inside the housing are not very large to start with 8x4x4 but they do a fairly good job as water goes into the bottom cooling the bottom 2 then goes over the top 2 and exiting into the block,still trying to figure out what you talking about a return plumbing line ?



good luck

[David Anderson]

David, a good set of Jake's will solve that problem your Metro Eagle didn't see many mountains in Houston,those 2 coolers inside the housing are not very large to start with but they do a fairly good job,still trying to figure out what you talking about a return plumbing line ?



good luck

You're right. No mountains in Houston, but I have been all over the west in this coach.  I bet I've done Wolf Creek pass 10 times.  The retarder works fabulous but generates copious amounts of heat into the oil, all the while my engine oil is cooled down and the water temp is 170 or even less.

I figured my description was poor.  On the water pump there appears to be two outlets, one to the engine block the other to the oil cooler which is a 2" pipe.  After it goes through the oil cooler, it travels through the tranny cooler, then back into the lower side of the engine block.  It then makes its way through the combustion areas then up to the top at the t-stats.  

If the tranny cooler can't transfer 220 degree oil heat fast enough into the coolant to heat the water above 170, changing the plumbing to send that water straight to the radiator probably won't accomplish much anyway.  

I'm sort of thinking out loud here.

How hot does the oil get in an Allison with a retarder when braking while descending long passes?

David

[luvrbus]

I am not real good at this explaining but the bottom 1/2 (2) coolers are separated from the top 2 they are in a separate compartment the water has to go through the bottom 2 first then over the top 2 and I don't see how rerouting the water would help you any



good luck

[David Anderson]

Thanks, Clifford.

David

[Melbo]

I kind of like this discussion

I just installed a larger trans cooler and talked to the Cummins people who said to separate the rads

One for the trans cooler and one for the engine ( the cummins rep said one was large enough to cool the L10 --- we shall see) with a pump for the trans cooler

I am just finishing up and a test drive this week.

I can't figure out where to install the hf compressor

Melbo

[zubzub]

I can't figure out where to install the hf compressor

Melbo

This just keeps on being funny.