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Discussion Starter · #181 ·
Bob - I'd rather not run with no t-stat honestly. Simply because it would change to a lot of water flow through the radiator, and not a lot through the engine. Engine oil temp would probably go up yes. Based on my data, I am confident that the flow through the radiator is good as is (small change in temperature). As we know, the 332 is very sensitive to debris covering the side screens and such, which indicates it is air side deficient. This is confirmed by the very large temperature difference between air temperature into the radiator, and air temperature out of the radiator. It means that the air is traveling slowly (relative). I'd bet my hat if I ran with the hood open, the temperature difference on the air side would come a little closer together, and the water side temperatures would separate (more airflow, more cooling). About the engine oil, more time is the only way to know for 100% certain, which I can do next time to be sure.

Tom - I thought about engine RPM data aq as well. I can do it, but it'd take some more finagling. Not out of the realm of possibility.

Dan - I use the pre mix 50/50 from Deere. I considered this as well, running a stronger water mixture. I seem to have several options to eliminate the symptoms, but I'm convinced that there is a problem to solve still.

Randy - I actually have the TinyTach, but it kinda crapped out on me. Sometimes it works, sometimes it does not. Unsure how reliable it is anymore. With regard to anti-cavitation additives...as I understand it, the Deere coolant Cool-Gard II includes these additives already. The main reason that I decided to go with it was to eliminate(?) that as a problem.

I think what I'll do next is run around with the hood open to test the airflow hypothesis. Based on my empirical data from testing in the fall, I think it'll work. After that, I'll probably hook up the MCS and see how much hotter everything runs.
 

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I can envision your fix on the airflow problem...Two large chrome semi air filter canisters hanging off both sides of the tractor with those fat chromed rubber tubes going in through the side screens...after that you'll be put 8" diameter chrome stacks out the sides and sticking up ten feet for the exhaust... :ROFLMAO:
 

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knockknock - I sent you a PM. Don't forget, in that vintage engine, roughly only 1/3 of the BTU in the fuel goes into making hp, About 2/3 of the BTU content is wasted as heat - roughly 1/3 out the exhaust and the other 1/3 through the radiator. Don't underestimate the cooling effects of good clean cool unrestricted combustion intake air and unrestricted exhaust that does not get recirculated back into the intake. Forgive me if this was discussed in one of the previous posts, but is the air filter clean and stock? Is the muffler stock and unrestricted? I sent you some ideas about measuring exhaust temps.
 

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This is a fascinating thread. I just recently put my 332 into mowing service after 15 years as a dedicated loader machine. I have seen over the years many posts about the limits of these cooling systems, but don't recall anyone talking about intake air temps. I never got too involved in those threads as the way I used it, overheating wasn't really a concern.

When I was looking things over yesterday after my first mow it occurred to me that the air intake is directly above the radiator. Started thinking about rerouting the intake to get to cooler air, and based on the chart knockknock posted think I may get serious about that as it seems the intake air may be close to 200*. As Mike U points out, good cool intake air is a very good thing.

Anyone thought about a "cool air intake" for these machines?
 

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I've thought about it some. I thought about putting some type of air intake thru the hood.
Maybe something using louvered aluminum, so it wouldnt look to strange.
But, I dont really want to cut the hood.
 

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I have a n Ebay Donaldson air filter housing on my 140, that I have been thinking about in regard to the 332. (Mine is the original style air cleaner)

Instead of the rain cap, a guy could route another hose off the housing to where the air is cooler. The 455's have an "elephant trunk" looking hose that goes off to the side.

I agree with @Skwirl don't want to cut any hoods.
 

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Discussion Starter · #187 ·
Minisub - Intake air (at the inlet to the air cleaner assembly) is likely closer to ~100F. I can wire up another thermocouple for such a purpose if there is interest in this. It is sort of a bummer where it breaths from, but there's not really any better way of doing it in the packaging space. Short of blowing a hole in the hood of course, which none of us will do lol.

I forgot about something, can't imagine it'd make that much of a difference though. I've got the leaky inlet to the fuel filter on the side of the engine. Every time I clean it then run the engine, there's more dampness. Not sure the exact location of the leak, I assume the little fitting, though it is tightly in place still.
 
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So, can this type diesel run lean? Lean will definitely create extra heat inside the cylinders. What little I knowof diesels is that there are all kinds of paths to run a cooler engine, excess fuel to cool the piston tops, extra oil to pull the heat away from the top end better, and the others have already been discussed. Obviously the oil isn't a huge influence, but every BTU counts. The fuel going into the cylinder actually does a a little too depending on the type of combustion the diesel has. A pre-chamber is a big help but direct injection does help a some. And an incomplete burn may waste a small amount of fuel but it helps cool the exhaust considerably from what I understand.

Is there a screw that can bump up fuel delivery?
 

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Knockknock, I've got a 4 channel bbq/oven thermometer that I can log on my phone. I think I am going to stick one of the ambient probes into the intake on my next mow just for grins and giggles. I'll post the findings here, but suspect you are right and that it will be much lower than your rad out temp but a good bit higher than ambient.

The chrome plumbing trap intake through the hood would be kinda fun in a pulling truck hood-stack kinda way, but yea, I'm not going there. 😄
 

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Discussion Starter · #190 ·
Randy - there is a screw for turning up the fuel. I used to have it turned up a skosh, but have since turned it down. This did decrease the temp some (turning it down). It is an IDI diesel, and it will run lean all the time. More fuel is added by the governor as load increases (until a set amount) in order to maintain the set engine RPM.

A co-worker and good friend of mine came over today, and we walked around the tractor for 3 hours. We discussed the engineer's design intent of the cooling system given the packaging limits and requirements of the 332. We came out of the discussion with a few possibilities, that I will test...

First off, my theory on running with no thermostat is entirely wrong. It may be the case for some other cooling systems, but not the way this one is designed. The water pump basically dead heads against the thermostat (OK, so there's a tiny bit of bleed through the thermostat, and a little hole below it in the pump housing for it to circulate). This means that when the thermostat is closed, there is VERY little flow through even the engine. A very odd design choice, but explains why the pumps are known for cavitation, and why people haven't had problems running without a thermostat. So that said, running no thermostat would definitely help if you needed extra cooling. At the expense of...hopefully the pressure at that part of the system is less than the 15psi rating of the cap. Normally there would be a pressure drop across the thermostat that you no longer would have. I'm measuring coolant pressure below, so I'll be able to find this out.

Airflow stuff. I have all of the factory intent foam in place that is around the radiator (except the one with the mylar on the firewall below the radiator, but I have some tape over the leak paths*). 1) The one by the hood latch on the hood (M89367) is a little tired, but it's there. This one exists to either filter or prevent air from coming in over the top of the radiator (indicated in photo). It seals from the dash, to the little firewall above the fan shroud, and all the way around the sides as well. 2) Little cubes on either lower corner of the radiator (M89366). These ones are there so that hot air from the engine compartment doesn't recirculate back rearward past the radiator and get sucked back in. 3) The pieces below both side covers (not the engine covers, the pedestal covers, M90124). I think these are supposed to be there for the same reason as #2. In addition to this, I also added more sealing around the top of the radiator in order to discourage recirculated air. I found last year that opening the hood was the biggest knob to turn with respect to cooling the engine down. What I don't know is if that's because of relieving pressure under hood, the additional unrestricted air getting sucked in from the top area (indicated in photo), or a combination of the two. Easy enough to test, but I guess that still won't tell me if there is a problem with what I did, or if it's something else. I'll have to ponder that some more.

I think things will start to fall into place some once I start getting more data. Will be interesting to see if it still spits coolant out the overflow with the latest and greatest cap I've got on...
 

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You mentioned above that you had turned the fuel up at one point, then "since turned it down". Did you turn it down a "skosh" or put the fuel delivery back where is was originally? I would suggest you start with the factory settings on all things being tested and monitored, then see if the issue is present.
 

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Discussion Starter · #192 ·
332 Guy - Yes, I adjusted it per the manual back to factory spec, or at least as close as anyone can get it. There is a mark on the fuel rack that you have to line up. Making this adjustment last fall did have an impact on the temperature (lower) at the time, but I ran out of weather to get a good data point.

Sidenote - anyone with a Tachometer (or maybe a 655!). How much do y'all think the engine RPM ought to drop while the mower deck is running, or when that plus the PTO MCS is running? When my tach was working, I seem to recall it being about 3400 unloaded, then dropping down to like 3100 or 3200 RPM when loaded up. Maybe closer to 2900-3000. It'd be nice to know what others are running at. More RPM means more heat into the engine oil, but also higher coolant flow and more air from the fan. As we know, we need to run the engines at full whip all the time. Maybe I need to turn the RPM set screw up a bit? I doubt it's that sensitive. Thoughts?
 

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When I start the deck on mine, I'm at 1/2 throttle or so. Deck gets going and full throttle it goes.
I dont know the actual rpm of the engine though, I dont have a transducer type thingy, lol.
But, it sounds darn close to 3400/3600 rpm.

I can tell you this, theres extra rpm/power available from the engine. While pushing snow this winter, I'd hit a frozen part and the engine growled a little puff of smoke and few hundred rpm and kept right on going. That told me the governor was working correctly.

At this point it may benefit you to check/adjust the valve lash. Pay special attention to the exhaust lash. I dont know if these are hyd cams or solid.
While rotating the engine over, check that valves all move same amount.
Next would be the injectors, I would crack each line and listen for the rpm drop.
Replace/rebuild any that fail. If they pass, I'd get them tested anyway. They should pop off at 3500 lbs or so, with a fine spray mist.
I think your chasing a symptom with the cooling sys, not the cause.
But, as always, ymmv.
 

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Discussion Starter · #194 ·
Skwirl - I've experienced the same while plowing snow, which I think is a good thing. I did check the lash too, twice actually just to be sure. It's adjusted right on the money. And the injectors...before I installed the engine into the current tractor I had sent to an injection shop. They tested and rebuilt for me. I can't imagine they'd crap out on me after only 6 months(?). About the cooling symptom, I tend to agree as well to be completely honest. I've got several ways to massively increase the cooling ability (by means of removing t-stat, or opening hood, ect... I can find out with actual hard data how much. I keep going back to the fact that it was spitting coolant when it was at 200F, which there's no way that is right. Makes me think there's something else wrong.

On the other hand...when I ran the other day at 79F out, the coolant was 204F at the end of my mow, and it did not spit coolant. I'd like a hotter day, and I'd like to test with the MCS rollin', and I'd like to test for repeatability. However, even if I added say 11 degrees to the ambient, and translated that directly to coolant temperature, that'd mean 215F coolant on a 90F day. I can't really fault it for that right? It's not overheating, and that is quite a hot day. Really need to hook up MCS to see how much hotter it'd run with vs without. I expect that the hottest day I could run with the MCS would be lower than without it, that is obvious, but there's no way to know what the system was designed to. I just feel like if the hottest day you can run the MCS is less than 80F outside, there is likely a problem someplace. Probably.

It is entirely possible that everything is working now, and I'm chasing my tail. Reference back to having bad radiator caps and the radiator leaking at the inlet. If it was only generating a few psi at the cap (say 4 or 6psi), then just spitting it out early, the local boiling point at the cooling jackets would be lower, which would be bad, and could explain the problem. That's why I wanted to add pressure gauges.

Give me some warm dry weather so I can run some tests!
 
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Discussion Starter · #196 ·
As I was digging for more information, I stumbled across a lot of good stuff in the service manual for the 6/7/8/955 series. I suspected, but now confirmed that the engine is rated at 3200 "at maximum engine load." I should make sure the engine speed is where it ought to be, I can check that today if I can get the TinyTach to work. Additionally, the manual for the 655 states that running the 50" mid-mower is 75% engine load. I see no reason that can't be applied to the 332 running a 50" mid-mower and the same engine rated at the same output. It's supposed to be about 80F out today, so I think that's good enough to get some good A-B tests in.
 

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That engine load % seems to be a lot for a deck.
Couple that number with running the hydro, there isnt much left. I wouldnt want to run any engine near 100% load for any length of time.

I wonder what the mcs unit runs at?
You could very well be at 100% or more.
 

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Belt drive, shaft drive, or hydraulic drive on the deck? I would think the shaft drive would put the most load in. Lot of friction there.
 

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Discussion Starter · #199 · (Edited)
Deck is belt drive off of front PTO on crankshaft. MCS is belt drive off if rear PTO clutch that is splined to the back of the hydro (through shaft to engine crankshaft).

Busy day today. I spent all day testing. Unfortunately, I lost my last bit of data due to computer crash. But coolalnt temp was stabilized at 225F with the MCS going at 84F outside. Engine oil stabilized 275F. Radiator air out temp was 176F, and raidator coolant out temp was 217F. All that in 23 minutes.

I found that it is highly sensitive to raidator air inlet temp. I found riding into the wind, the air inlet temp increased by up to 10 degrees, and RadIn temp started to increase. Against the wind, the rad air in temp was basically equal to ambient temp, and RadIn started to go down.

I'll write another post with the data that I did collect.

Sent from my SM-G781V using Tapatalk
 

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Discussion Starter · #200 ·
Also, I tried to adjust engine RPM, but had 2 problems. 1, my TinyTach no longer works. And 2, I found that when I move the idle speed control to rabbit ALL THE WAY, it leaves a little bit to go on the lever on the side of the engine. I can give it a little shove with my fingers and it moves enough to being the RPM up proper. With no amount of adjusting the cable could I get it to pull to maximum.

Would be good to know the engine RPM, as it should be running at close to 3200 while loaded. Add that to the list of things to do. Anyway. Did that this morning, then started running my tests.

Sent from my SM-G781V using Tapatalk
 
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