2550 Melting hood!

[Fordlords]

Here are generally acceptable temperatures for air cooled aluminum engines. These are not specific to any perticular engine, just general ranges with engine at operating temperature.

Oil Temp: 180-210 degrees, 230 degrees max. (This figure is most important, as overheated oil is what will damage bearings)
Cylinder Head Temp: 300-385 degrees, 450 degrees max.
Exhaust Gas Temp: 1000-1200 degrees

Now as for what Cub actually engineers or uses as acceptable figures, I have no idea. I have yet to hear of any issues involving overheating or engine damage with the Command engines in any year model of Cub 2500, or actually any model of Cub, ever.

Thermoformed plastic hoods? Simply put, they suck. They are used not because of scratches or dents, they are used to cut costs. They probably cost $10 each to manufacture, where a metal hood probably costs $50 or more between material, stamping, and finishing. That's $400,000 in savings on a run of 10,000 tractors. In essence your sucky hood pays for that new carpeting in the CEO's office and a really lame summer picnic for the employees with thermoformed coffee mugs as door prizes No matter what color it is, it's all the same.

-Fordlords-

 

[Dascro]

Got a question on my 2007 2550. The louvers in the hood are all open. Is there another "panel" in the center of the hood that can/should be removed to aid cooling air flow?

Also, while I haven't paid particular attention up till now, I can't say that the engine temp on the 2550 seems any hotter to me after mowing for a couple hours than on any other air cooled engine I have used in the past.

I have rebuilt and used old Cub Cadets up until I bought this 2550 (128 and 1650), and the air flow is exactly the same on the 2550 as it was on both the 128 and 1650. I do notice more debris on the 2550's screen though. But I also blow it clean after each use with a leaf blower.

Lastly, I have noticed that the air filter gets real dirty real fast (at least the pre-cleaner)!! But I have attributed that to the very dry conditions here and the amount of dust in the air during mowing. I'll have to watch that over time.

Anyhow, if anyone can enlighten me on any other louvers in the hood of my 07 2550 that can/should be removed, I'd appreciate it.

Dave

 

[Dascro]

Later this morning I got a chance to check the hood on my 2550 and answered my own question on the center hood louvers . There is a cover over the louvers.

But this leads me to another question. What is the best way to remove the fasteners on the pegs of the cover to allow the cover to removed?

Thanks,
Dave

 

[JSharp]

Here are generally acceptable temperatures for air cooled aluminum engines. These are not specific to any particular engine, just general ranges with engine at operating temperature.

Oil Temp: 180-210 degrees, 230 degrees max. (This figure is most important, as overheated oil is what will damage bearings)
Cylinder Head Temp: 300-385 degrees, 450 degrees max.
Exhaust Gas Temp: 1000-1200 degrees

Now as for what Cub actually engineers or uses as acceptable figures, I have no idea. I have yet to hear of any issues involving overheating or engine damage with the Command engines in any year model of Cub 2500, or actually any model of Cub, ever.

Thermoformed plastic hoods? Simply put, they suck. They are used not because of scratches or dents, they are used to cut costs. They probably cost $10 each to manufacture, where a metal hood probably costs $50 or more between material, stamping, and finishing. That's $400,000 in savings on a run of 10,000 tractors. In essence your sucky hood pays for that new carpeting in the CEO's office and a really lame summer picnic for the employees with thermoformed coffee mugs as door prizes No matter what color it is, it's all the same.

-Fordlords-

That earlier post of mine wasn't meant as a dig on you Fordlords, it was dig on the guys at Cub. I noticed a year or so ago when I first came here that you were one of the straight shooters on the board and knowledgeable. Maybe I should have used a few more in there somewhere...

Your listed temps are right in line with what I've always been told. Of course air cooled engine temps will rise on a hot day with high loads and fall on a cool day with light ones. But there are some upper limits as you've said that should be approached with caution.

Judging by my earlier 238ºF measurement on the oil filter end cap I think these things are pushing it. And it's my belief it's because of the inability of the cooling fan to pickup anything but already heated air.

I think we'll see reduced engine life on the plastic hooded 2500's vs. the previous ones thanks to this whole cooling issue. They're just too new yet to have anyone with enough hours racked up to notice. Time will tell.

Unfortunately the fix here may involve even more plastic. Something like a divider in the engine compartment or some other means of ducting cool air to the engine fan and separating it from the hot hair under the hood.

I'll see what the dealer says tomorrow, along with writing notes to Kohler and Cub. The GF and I talked last night and we both realized I'm going to take an absolute bath on this thing if I get rid of it. The dealer I got it from sells Case/IH, Cub and Grasshopper so they won't be able to offer me anything that might better. I like the additional features of the 3000 Series but I'm a bit sour on Cub at this point and the turning circle on one would be a problem in my use. And trading at the other local dealers that sell other brands I'm unlikely to get more than 1/2 of what I paid a year ago, if that. $2000 is a lot to lose for such short hours.

Buyer beware indeed...

Dascro - I'm glad you found the cover fasteners but don't expect removing the cover to do much. There seems to be little to no airflow in that area of the hood...

 

[TractorLarry]

Is it possible to send the exhaust parts out and get them coated with that ceramic stuff they use on car headers? From what I've read, it does a heck of a job keeping the heat in the exhaust system.

-Larry

I thought it was excessive myself.

The cooler is located on the shroud. You cut a rectangular hole in the shroud and mount the cooler to it. Then the engine fan blows cooling air through it. I'll see if can find a photo or take one if I can't. It has a massive amount of air blowing through it. Too bad it's the hot underhood air that the engine fan picks up instead of some cooler outside air...

Those temps I measured are telling us something about the oil temps and IMO they're plenty high. It certainly doesn't make me want to run inexpensive oil.

That might also explain why the Cub Cadet oil change interval is 1/2 ( 50 hours vs. 100 ) of what Kohler recommends in their engine manual...

There's a stainless steel guard over the muffler but I like the header wrap idea. That stuff always shortens header life but if it extends engine life it might be a good trade off...

 

[TractorLarry]

Is there anything about the 1864 I should be aware of?

-Larry

 

[Fordlords]

I'm curious if the way the 2006 2500's duct air is different than with previous horizontal engine Cubs.

The 682 I have ducts like any other Cub I have seen- cool air enters from underneath the tractor, right above the center of the deck where the drive shaft tunnel is. There is a metal screen there to prevent large debris from entering. I would figure this air to be fairly cool, and at least as clean as the air anywhere else around the tractor while mowing. It then goes through the "firewall" in to the engine fan, which is butted up to the firewall. It then exits off the engine shrouds, over the exhaust system and muffler, (which are also shrouded) and out through the front of the tractor which is a fully open grille and perforated metal section by the headlights- essentially wide open, but the heat is ducted upwards.

Where is the 2006 2500 actually drawing it's outside air from?

One thing I remember is the cooling air exit is supposed to be at least 4 times the area of the inlet air opening. On the 682, I'd say this is pretty close. I have had no concern for the Honda engine running too hot.

There may well be some mis-engineering on Cub's part with the 2006's that only time will tell if engine damage will occur. The melting hoods do tell me they are running the plastic hoods way too close to hot components, or are using materials not made to withstand the temperatures- all things that should have been recongnized during the initial development and testing of the design. Perhaps it's going to come back and bite them.

-Fordlords-

 

[Dascro]

I understand why others have serious concerns in regard to cooling air flow on the 2500 series tractors. And I am not arguing with those that have experienced problems with their hoods because of temperature. I have about 20 hours on mine and so far, so good.

But I am having a hard time reconciling the difference in airflow patterns from any other older Cub Cadet I have owned or seen (and older John Deere 140's too) with the air flow pattern on my 2550. And the fact that the side of the hood is open at the cooling air intake location adds to my question .

More to the point, I don't understand where such overly hot air would be coming from to be drawn into the cooling air intake? All airflow principles just seem to counter hot air build-up in that area. I can see it being warmer than ambient, but not that much more. Again, I am not challenging anyones experience or measurements. I'm just having trouble seeing how cool ambient air would not enter into the cooling air intake area.

Maybe its just that the plastic hood is too close to the engine?? Not that the engine is running too hot?

If I am missing something obvious (and it wouldn't be the first time ) please help me understand why the problem is engine heat and not the plastic hood too close to an aircooled engine.

Thanks,
Dave

 

[CCinCT]

The air is drawn in from a grill below the steering wheel and above the drive shaft, and from both sides of the rear engine compartment (basically above the driver's feet). The air is blown forward and exits through the front grill as best I can tell. I haven't put a thermostat to the oil filter or the engine compartment, but I've never felt any kind of heat anywhere that would make me concerned about longevity.

 

[Dascro]

Yeah, I agree CCinCT.

After dinner tonight I did a rudimentary, yet credible (I believe) smoke test inside one of our bigger buildings that can provide a still air environment (I was in there finishing up some work anyway and figured what the heck!). What I found confirms what you just stated. In fact, I found that the engine draws in ambient air from about 4 inches away from each side at approximately 1/2 throttle.

And while I haven't measured any temperatures (and probably won't) I am now less concerned based on my smoke test and my "feel" that this engine doesn't seem to run any hotter than any other air cooled engine I have used over the years.

Time will tell, but I feel pretty good about engine longevity. Plastic hood life may be a different story!

Dave