What thermostat would you run for a low speed crawler, I'm town driver, 160 or 180?

Discussion in 'General IH Tech' started by winchested, Sep 28, 2020.


  1. winchested

    winchested Y-Block King

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    Currently running an NOS 370-195 Rob Shaw.

    It's too hot, I think this is the cause of my dieseling and run on issues at shutdown.

    Heads are getting too hot.

    What's the preferred temp especially for low speed crawling.

    I'm running the HD clutch fan.

    Not currently overheating. My gauge runs at 1/2 way most often.


    I'm getting either the Milodon 16405 or 16406.

    I can get the 16405 for $57 Cdn on amazon but they don't have the 16406 that on is $70 Cdn shipped from summit.

    IHPA has no stock of the 160 or 180s only 195.



    [​IMG][​IMG]
     
  2. scoutjason

    scoutjason Farmall Cub

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    Not sure what the best one is for crawling, but I found some NOS Robertshaws on ebay for a good price. That's where I got my 180.
     
  3. Ron A

    Ron A High Wheeler

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    I have 180s in both Scouts. Not sure if that is best, just what I have.
     
  4. mporter52

    mporter52 Binder Driver

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  5. winchested

    winchested Y-Block King

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  6. Mark Aycock

    Mark Aycock High Wheeler

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    Just checked Super Scout Specialist. They have Robertshaw 180° thermostats for $24.99.
     
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  7. mporter52

    mporter52 Binder Driver

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    Oh, I missed that.
     
  8. winchested

    winchested Y-Block King

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    I'll call em if I can't get one up here.
     
  9. Greg R

    Greg R Lives in an IH Dealership

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    You're going the wrong way for Stop'nGo around town driving. You want to keep the temp up to help the PCV system evacuate the blowby and unburned hydrocarbons out. Chances there's some carbon in there. Rich mixes from idle settings, accelerator pump shots, and fast idle speeds all contribute to dieseling. Make sure your fuel mix is as lean as possible without upsetting drivability, and look at the air filter while you're at it. I would try a Seafoam treatment, and a fast drive on the freeway. One range cooler plugs may help if it continues, and see if she is sucking a little oil too. The idea is reducing carbon buildup and hot spots.
     
  10. winchested

    winchested Y-Block King

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    I also posted this on Dan Hayes Facebook- Ih Truck Scout Mafia page, most stated that 180 degree t stat is the sweet spot. Another guy had the exact same symptoms and dropping from a 195 to 180 solved it all.

    I've tried every type of fuel, from reg to premium with a octane booster. No change. I'm running 1 step colder plugs, no change. 1" phenolic spacer on the carb, no change. Idle is great, not rich, 650 rpm. Accel pump is set up 100% correct. Heads were rebuilt and fully cleaned 3500 miles ago. There was no carbon in them before nor is there now.

    After the other guys success and Dan Hayes stating they put a 180 t stat in all their builds and trucks, I am going to go that route before trying anything else.

    It's the easiest thing to try next.
     
  11. 72soa

    72soa High Wheeler

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    We use a 180 degree t-stat. We use fixed fans. In FL it is hot! Very hot almost all year long. A lot of low speed driving in both what little woods are left and in the tons of traffic here in FL. Don't overheat.
     
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  12. Ron A

    Ron A High Wheeler

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    Which fan, or configuration of blades are you using? Simplicity goes to the fixed fan, no doubt. I used nothing but fixed in my Scouts until just recently. The 345 in my SS always wanted to run warm, but previous owner had a plastic fan installed, Maradyne type or similar. You can still get these dirt cheap. I replaced it with a 7 blade flex. It was loud but that seemed to fix the problem and I ran it that way for a long time. Years go by and I install a 392, Then I needed a new radiator. So I pulled the flex fan, partly because of age and all the stories of blades cutting peoples heads off. Only trouble I ran into is I could not find a new, non flex fan, in 18" with 7 blades. So I went with a fixed 6 blade Derale fan, 18". Worked fine 97 percent of the time, but it had swept up edges on the fan tips. I suspect this was done for noise reduction. But long slow climbing, or idle in traffic on the hottest of days, the temp would climb. I was not over heating but was headed that way. As soon as I would start moving at any kind of speed temps would drop back to normal. Obvious airflow problem. So I went to a Heavy Duty clutch so I could run a 7 blade 18" fan, without the tips swept up at the ends. It has not been in long, but I can't seem to get the temps to climb no matter how long I sit in traffic, or on the slow hill climbs. First impressions are good, but if I could have found an 18" 7 blade fixed, without the swept tips, that is probably what I would be running.
     
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  13. Greg R

    Greg R Lives in an IH Dealership

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    Most of the air through a propeller fan is about mid-blade between 2-4" inches from center and about 1-2" from the tips. The curved ends cut down vortices at the tips to reduce noise from air cavitation. The big deal in volume or capacity is pitch or blade angle. I'll bet there was at least a couple of degrees in pitch difference, probably not too noticeable unless you had a pitch gauge. On an IH options charts, most fans for larger engines such as the 392 or increased cooling had fans with a 40* pitch, just a bit more bite than the 35* used on packages with smaller engines or no automatics or air conditioning. The trade off is a bigger bite eats more horse power and a clutch really saves Hp at higher speeds.
     
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  14. Ron A

    Ron A High Wheeler

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    Looks like most aftermarket fans run around a 28* pitch. If IH was using a 35* pitch that would explain why some IH engines run warm. Add water pump impeller clearance issues, T-Stats that don't don't block the bypass, no shrouds, crappy gas, timing issues, 50 year old gunked up engines, etc...
     
  15. winchested

    winchested Y-Block King

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    Ya I am running a stock fan. I'll get the part number off it in the morning.

    Maybe that is worth upgrading too.
     
  16. winchested

    winchested Y-Block King

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    Just ordered the Milodon 16406 as it would cost more with duty to get the RS 180 from any scout vendors. Still cost me $70. (canada sucks)
     
  17. Brandon A.

    Brandon A. High Wheeler

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    I have run 180 in all my scouts! Works well when fan is right and radiator is in good condition. I tried 195 for better mileage but did not notice any difference in mpg's.....
     
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  18. Patrick Morris

    Patrick Morris Lives in an IH Dealership

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    I've never understood the purpose of the 160 thermostats. Sure, they start opening sooner. But they don't open any MORE. And once the engine temp reaches 200F (which is perfectly fine) when running it hard, I don't think that the earlier opening made any difference at all.
     
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  19. winchested

    winchested Y-Block King

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    This is the one I've got not sure what year it was originally off. Originally had a fixed fan but I think I scrapped it. [​IMG]

    Only places I can find reference are from ISAsIH and SSS, list it as a 6 blade aluminium HIPO fan.

    The only similar fan I can find is a flex-a-lite on summit. Wonder if the blade angle is different.
     
    Last edited: Sep 30, 2020
  20. Ron A

    Ron A High Wheeler

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    I went with a reproduction of a GM 7 blade, listed for mid to early 1970s Camaro, Nova, etc... Just because I wanted to try a 7 blade. Don't know if it is better than your 6. It cost more, but it is working. One thing about our vendors like SSS, I doubt they would sell it if it did not work. Biggest challenge that fan has is overcoming the air resistance of a fairly tight engine compartment. Venting the inner fenders and such would help. Would be nice to have a cooling system overbuilt enough so you could cool an SV on the worst of days, without a shroud, but I doubt that is going to happen.
     

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