Cooling the Beast, question?

[jcussen]

Originally Posted by joeplazek

Water Spray would be an elaborate set up. Imagine the engineers that came up with that configuration. I hear you on the air flow when you need it most. This has been an interesting subject and its making me think.

I actually used one on a 64 GMC 4106 with a 8v71. 6 sprayer tips,[like the ones on patio coolers] around the radiator, a solenoid valve hooked to coach fw system. Solenoid valve opened by a switch on dash, and mist was sucked through the radiator by the fan. When I saw 200 f. on the water temp gauge, would open valve and temps would drop fairly quickly. Because it was a fine mist, only used about a 10 gallons a day when climbing in the mountains.

[Old Scout]

JC--probably telling you more than I actually know, but believe the wax valve is graduated with little or no RPMs when engine/coolant is cold and gradually opens as the coolant in the radiator warms...[just like a common engine thermostat]...what I was suggesting is that most diesels are pretty cold-blooded an don't need much cooling, except in hot weather and/or on long climbs....however, the CAC may need fan cooling right away to keep the intake temps down....I freaked out the first time it happened in Van Horn but once I installed SilverLeaf, I was able to watch coolant and intake temps rise in concert....then at 185 coolant temp, fan speed increased [apparently] and intake temps drop dramatically....suspect CEL is a warning parameter that occurs prior to engine de-rate??????….many winter trips to Q-site over the years and I was able to replicate this situation over and over.....

[Windecker]

Old Scout,
The Wax valve actually gradually shuts as it warms, not opens.

There should be a small orifice in one of the fittings going into the Wax valve itself for the control line, that orifice size is what gives the fan it's low heat RPM. I think on the ISM-11 they wanted 300 RPM's as the base number.

As the original poster mentioned without stating exactly, swap the hoses and the fan goes to full speed (assuming everything else is working correctly).
Windecker

Originally Posted by Old Scout

JC--probably telling you more than I actually know, but believe the wax valve is graduated with little or no RPMs when engine/coolant is cold and gradually opens as the coolant in the radiator warms...[just like a common engine thermostat]...what I was suggesting is that most diesels are pretty cold-blooded an don't need much cooling, except in hot weather and/or on long climbs....however, the CAC may need fan cooling right away to keep the intake temps down....I freaked out the first time it happened in Van Horn but once I installed SilverLeaf, I was able to watch coolant and intake temps rise in concert....then at 185 coolant temp, fan speed increased [apparently] and intake temps drop dramatically....suspect CEL is a warning parameter that occurs prior to engine de-rate??????….many winter trips to Q-site over the years and I was able to replicate this situation over and over.....

[jcussen]

https://www.irv2.com/forums/attachme...1&d=1586903275

OS, not much on the ISM and M11's online anymore but found this screenshot from an old m11 manual.
Did talk to Newell [series 60] and Foretravel [ISM] and they said original design was a 2 speed fan with fan on low until engine coolant temp required high speed. Have heard of wax capsule modification, but always thought the fans ran slow, and ramped up gradually as temps rose. Pretty sure high intake temps will reduce power, and if fans not running a little bit, and boost is high, temps will be very high. I know on my Newell when engine coolant temp low, and I put my foot down with fan off, only got about 25 instead of 30 psi of boost. As soon as coolant temps came up and high speed fan came on, I, like you saw manifold air temp drop, and boost come up to normal. Could be the engine derating because of the high intake temps.

[Old Scout]

Interesting--max boost on my 2003 era non-variable pitch turbo 400ISL is about 23PSI....typical ambient temp in Van Horn TX on a sunny January morning is 25-30 degrees….following the diagram you found, that means max target intake temp would be around 55-60 degrees…don't recall but seem to remember intake temps around 70-80 once engine fan is running....totally agree that higher intake temps means less horse power--just don't know what the ideal temp differential is but don't recall any appreciable loss of boost or power while climbing the hill.
PS--the VH morning hill climb is the only time I have ever seen a CEL with higher intake temps--17 years and 185k miles on this rig?????

[Old Scout]

Windecker--agree, more WV restriction means more fan RPMs.....I did hear there is supposed to be a baseline but my fan actually has 0 RPMs at engine start-up...[OEM wax valve replaced 10 years ago for no reason--mechanic recommended--I didn't know any better]….Have never had a cooling issue other than VH winter hill climb.
PS-- during the WV replacement, I experimented with plugging and free-flowing the control lines to see what the impact was on fan RPMs....even installed an WRV recommended solenoid valve to integrate dash AC cooling needs with wax valve--eventually moved condenser coil and added electric fans.....
PSS--back to the OPs question, I offered this WV observation to show that engine cooling wasn't the only perimeter to consider when modifying the engine fan.....

[jcussen]

OS If intake manifold air is 50 over ambient when fan running on high, might check out your intercooler. My 500 ism and 505 series 60, both run over 30 psi at full boost and maintain less than 30 F. difference when fan on high. This discussion comes up often in the Foretravel and Newell forums, Think you should do what I did, call Cummins and get the straight story.

[jcussen]

Originally Posted by Windecker

Old Scout,
The Wax valve actually gradually shuts as it warms, not opens.

There should be a small orifice in one of the fittings going into the Wax valve itself for the control line, that orifice size is what gives the fan it's low heat RPM. I think on the ISM-11 they wanted 300 RPM's as the base number.

As the original poster mentioned without stating exactly, swap the hoses and the fan goes to full speed (assuming everything else is working correctly).
Windecker

That is what I understood, I have the ecm controlled one that bangs in high at a certain water temp, but have a friend that did the wax valve mod that keeps fan at low rpm, and ramps up as engine temp rises. Is that how it works?

[Kurt Averill]

Originally Posted by joeplazek

This is a M11. Cummins changed the engine a few years after dad bought the coach because of fuel economy not what it should have been. It was the fans being plumbed wrong from the factory all this time but no one could figure it out. The engine specs from the tag on it reads, serial 34888478 family VCE661EJDARC manufacture date 11/97 model M11-450EPLUS 661cu in . 10.8 litres . 450HP rpm idle 650-800 1450 PEAK TORQUE So I would say this is a 1998 engine

Interesting... My "99" is ser#34899066, family WCEXH0661MAA, DOM 2/98, M-11 450E+, etc. pretty close to the same.
What do you get for boost pressure? mine was rarely over 22-23, turns out the CAC was leaking pretty good. When I fixed that, I also rebuilt the turbo, I put a billet compressor wheel in it - now it gets up as high as 30-32 depending on conditions. Not sure if the billet wheel helped or not.

[Windecker]

JCussen,
Can't say I have seen every combination out there but yes, should ramp up fan speed as temp increases, then full on at a specific temp which is slightly adjustable.

Kurt,
I rebuilt my CAC also, tested it with regulated air to 40 or 60 PSI in the shop before reinstalling (can't remember what that spec was). I typically saw 30-32 PSI on my little mechanical gauge in the dash after re-installation.
Sounds about right to me.

One thing to consider, the M-11 is non wastegate and pretty sure this vintage has a mechanical gauge connected between the engine and gauge with a long tiny hose!
Windecker

[joeplazek]

Originally Posted by Kurt Averill

Interesting... My "99" is ser#34899066, family WCEXH0661MAA, DOM 2/98, M-11 450E+, etc. pretty close to the same.
What do you get for boost pressure? mine was rarely over 22-23, turns out the CAC was leaking pretty good. When I fixed that, I also rebuilt the turbo, I put a billet compressor wheel in it - now it gets up as high as 30-32 depending on conditions. Not sure if the billet wheel helped or not.

That's interesting. My boost is about 20lb max. My CAC is in now for a new core so lets see what happens after it gets back. Do you find more noticeable power with the increase in boost?


joe

[joeplazek]

Originally Posted by Windecker

JCussen,
Can't say I have seen every combination out there but yes, should ramp up fan speed as temp increases, then full on at a specific temp which is slightly adjustable.

Kurt,
I rebuilt my CAC also, tested it with regulated air to 40 or 60 PSI in the shop before reinstalling (can't remember what that spec was). I typically saw 30-32 PSI on my little mechanical gauge in the dash after re-installation.
Sounds about right to me.

One thing to consider, the M-11 is non wastegate and pretty sure this vintage has a mechanical gauge connected between the engine and gauge with a long tiny hose!
Windecker

My boost pressure comes off the computer and I read it on the Silverleaf glass dash.


joe

[Windecker]

Oops, yup your right Joe, it was 20 and sometimes a bit more, not 30 plus. Sorry. I would have bet $100 on 30 but I doubled checked my records and sadly, I was wrong
Windecker

Originally Posted by joeplazek

My boost pressure comes off the computer and I read it on the Silverleaf glass dash.


joe

[Old Scout]

JCussen--agree that it might be time for a CAC inspection but what would I be looking for?....Boost, MPG, and power seem to be in "spec" and no smoke....had CAC rebuilt [new gaskets] about 10 years ago--back then, boost was lower, MPG was off and it was making some smoke on acceleration....Have owned the rig for 17 years and 185K miles so like to think I know when things aren't quite right--like an old pear of slippers??????