breakin rpm's

[redhawk]

breakin rpm\'s

got my b7500 delivered sat. afternoon. i looked through the
manual but cannot find a recomended rpm for breaking in the
engine.

 

[chuckp]

Re: breakin rpm\'s

Redhawk:
My Tractor manual does not make any recommendation for engine RPM except when using the PTO/w3tcompact/icons/crazy.gif. But my FEL manual recommends 1700-2200rpm for nominal operation/w3tcompact/icons/smile.gif. My Tractor is also new, however, it has a Hydrostatic Transmission and I was having problems with it when under a heavy load coming to a complete stop without loading up the engine or spinning the tires./w3tcompact/icons/mad.gif I talked to the Service Manager and he came out today /w3tcompact/icons/smile.gifand after driving it, he said I have to run the throttle wide open for it to work correctly and to seat the rings/w3tcompact/icons/shocked.gif.

Chuck

 

[Harv]

Re: breakin rpm\'s

Redhawk -

Sounds like we received our tractors at exactly the same time (oh-oh! I thought heard Rod Serling's voice...)

I, too, have perused the owner's manual, as one might expect of a new owner. Under the chapter on "Operating The Tractor" it just says "don't operate the tractor at full speed for the first 50 hours". If you're anything like me, full speed is the farthest thing from your mind right now, anyway.

I think they're just saying "take it easy for a while". Just don't rev it up to where unidentifiable pieces of metal start flying out of the thing. That's the way I read it, anyway.

 

[PaulB]

Re: breakin rpm\'s

I arbitrarily decided top keep my rpm's under 2200 (rated pto rpm is 2600) during breakin period, and was mindful to vary it frequently, between 1200 and 2200. I also changed oil and filter at 25 AND 50 hours. Don't know if what I did was right, but thats what i did.

 

[chuckp]

Re: breakin rpm\'s

Harv - My service Manager told me that all Tractors have a Governor that controls the Engine RPMS and is set such that the Max RPMs cannot be reached. He said that HST Tractors are designed to run at max mechanical throttle setting (which is not max RPMs).

 

[TomG]

Re: breakin rpm\'s

At least with a gas engine, the main break-in things are don't load the engine until it comes up to operating temperature, and don't operate for prolonged periods at the same power level.

Taking your foot off the gas while going down hills is good. The intake manifold vacuum goes up which draws more oil into the upper engine area. Diesels have low intake manifold vacuum, but the idea still may help and certainly won't hurt anything. It'll still probably help seat the rings, which is what you want to happen during the break in. Periodic bursts of power help the rings to seat.

The reason for giving a new engine a good warm up before moving it is that engine parts are designed to fit to tolerance only at operating temperature. Pistons actually fit cylinders, and piston rings end gaps are closed, only at operating temperature. It's not a good idea to be running a new engine at power with parts that actually don't fit before the cylinder walls are run in. For example, the shape of a piston at room temperature is pretty complex. They are tapered toward the top, because the top gets hotter and expands more. They also are oval with the wrist pin across the narrow side for the same reason.

Improper break-in may prevent the rings from seating, and the engine may become a permanent oil burner. I imagine good break-in practice is similar for gas and diesel engines.

 

[art]

Re: breakin rpm\'s

There was a lot of good info in Tom's post on the design of a good engine. The break in period and how you run it does make a difference in the life of the engine. Properly warming any engine before applying full load conditions does help the engine life old or new. Varying the throttle is a plus, not exceeding 50 to 75% throttle for the first 5 hours and then for the next 5 hours to run at 75% to full throttle is all that is needed to break-in a new engine. That is more than enough run in time to seat the engine in after that you should run the tractor as you need. A little thought on the hydro's, they run by oil, to put full load on a hydro at low rpm is not good because the pumps are not at there peak at low rpms. This could cause starvation of oil for the hydro unit. Hydro's have been used for years in tractors both farm and home use and have proven to be very reliable with proper applications but when missused they can have there problems just like anything.

 

[DVerbarg]

Re: breakin rpm\'s

This thread regarding break-in rpms has been a eye opener for me. My TC40D only has 30 hours after a month of use and I have been trying to "baby" it like others have mentioned. On another thread regarding traction I had mentioned that I did not need extra ballast because my engine dies instead of wheels spinning when doing FEL work. Well, I just tried increasing my RPMS (I have a HST tranny) to the reccommended 2600 (was running 2000 - 2200) and now see the need for ballast! Those R4s can really dig a hole fast /w3tcompact/icons/shocked.gif when spinning! Hmmm, just ordered a toothbar, now ballast, what's next guys? Does the cash flow ever stop?!

DaveV

<P ID="edit"><FONT SIZE=-1>Edited by DVerbarg on 9/27/00 10:28 AM.</FONT></P>

 

[gerard]

Re: breakin rpm\'s

The cost of tractor ownership is only limited by your imagination to invent justification for being able to do something yourself as opposed to paying to having it done.
Confucius 620 AD (He was a very farsighted individual)

 

[TomG]

Re: breakin rpm\'s

Couple of things I should have mentioned. You may already know about warm up and cool down. I didn't when I first got my used 500-hour tractor--I didn't have to break it in.

Bringing a tractor up to operating temperature before loading the engine will prolong engine, transmission and hydraulic life. Warm up is good practice even after the break in period. However, diesels, unlike gas engines, do not warm up at idle rmp. After a short period at idle, most diesels should be run around 1500 rpm to warm them. On the other hand, excessive idling time gums up an engine and reduces oil life. Balance is needed.

Another good practice is to cool down diesels for 5 minutes or so at idle rpm before shut down, especially after a hard run. There are stories of people warping heads and valves by shutting down a hot diesel.