Troubleshooting with a DYNO

[Ranch_Hand_Supp]

As some of you already know we are a general repair shop that services and repairs most all makes and models of tractors 80 horse power down and also a importer of Jinma tractors and other implements.

We have always felt we could benefit our repair business by owning a PTO tractor Dyno (dynamometer) and at the same time trying to justify the cost of the machine. It's hard if not impossible to get a tractor to full field operating temperature setting in a shop running trying to duplicate a engine over heat problem, governor performance problem, injector, fuel delivery, noise under load , PTO problems, testing engine repairs / rebuilds, engine break in (seating the rings) etc, etc ...... the list goes on and on.

Well about two weeks ago we bit the bullet. We now own a PTO Dyno !

I have been playing with the Dyno hooked to a Jinma 254/284 with the Y385 engine getting familiar with the machine. Most people know that is in or have been in the repair business professionally that a piece of equipment is no better that the guy using it.

We have always been proud of our PDSA (Pre-delivery Service and Assemble we perform on all of our new Jinma tractors prior to selling them .......... and now they will be sold Dyno tested & tuned with the engine already broke in and truly ready to put to work.

As time goes by I will post some of the PTO horse power ratings I find as I twist there tail.


Ronald
Ranch Hand Supply

 

[Wombat125]

Congratulations on your new purchase.

My dealer is going to run my tractor on their dyno before delivery for precisely the reasons you stated. I asked him if I could watch. He said it really wasn't all that exciting, but he agreed nonetheless. So any day now, I'm going to get "the call" to come and watch.

So just be prepared to deal with goofballs like me.

 

[dfkrug]

......... and now they will be sold Dyno tested & tuned with the engine already broke in and truly ready to put to work.

Sounds like you have a useful tool to add to your shop, Ronald.

When you say you will sell the tractors with the engine already broken in....
What constitutes "broken in" from your perspective? 50 hours is commonly
used as the break-in period for new Diesels. How do you reconcile that with
your break in procedure?

 

[Ranch_Hand_Supp]

Congratulations on your new purchase.

My dealer is going to run my tractor on their dyno before delivery for precisely the reasons you stated. I asked him if I could watch. He said it really wasn't all that exciting, but he agreed nonetheless. So any day now, I'm going to get "the call" to come and watch.

So just be prepared to deal with goofballs like me.

Thanks,
I think the more mechanically inclined find it more exciting. It's not a real quick process if he is going to seat the rings, verify injection timing under load etc.etc.

If he is just going to warm it up and check horse power ???? that is pretty quick and that also depends on what he considers warmed up?

I grew up with a dyno in my Dad's tractor shop and always liked to hear them pull at full load.

Congratulations on you new tractor !

Ronald
Ranch Hand Supply

 

[Ranch_Hand_Supp]

Sounds like you have a useful tool to add to your shop, Ronald.

When you say you will sell the tractors with the engine already broken in....
What constitutes "broken in" from your perspective? 50 hours is commonly
used as the break-in period for new Diesels. How do you reconcile that with
your break in procedure?

That's almost like asking what's the best oil........... lot of different opinions.

My opinion, a new engine has to be broke in. mainly the piston rings have to be seated. There are many opinions on how that should be done. I think you will find most engine rebuilders will recommend a light load, no load, heavy load, low throttle, full throttle, med throttle, back and forth with different loads and with rpms.

The roughness in the cylinders left from the hone will be gone in 50 hours for sure but, does not mean the rings are seated or seated properly. Load is what pushes the rings against the cylinder wall. Being able to control load and rpm at will allows you to control how the rings are seated. Most owners manuals have a throttle & load recommendation along with there 50 hour statement.

Depending on the type of material the rings are made of dictates how quick they will seat. Cast iron seats pretty quick..... Chrome molly not as quick. Just to name two.

That Jinma with the Y385 gained 4 horse power in about 45 minutes and lost about a pint of engine oil ( I already had it a full operating temp). Let it cool down, top off the engine oil, warmed it back up, ran it at full load, throttle wide open, 30 45 minutes, no more HP gain and no loss of oil.

I think a new engine that has been properly ran on a dyno and lived through it should be considered a good one.

If you want ??........ you could do a Google Search using, seating piston rings and or engine break in and get more opinions.


Ronald
Ranch Hand Supply

 

[Bob Rooks]

......... that is pretty quick and that also depends on what he considers warmed up?

"Warmed up" is when the engine and operating components have reached thermal equilibrium. In other words, the engine has quit "growing"; all of the engine components, lube oil and coolant included, have expanded as far as they are going to and operating tolerances are met. The amount of time it requires to warm up an engine is in proportion to it's mass.

Not sure how many people actually do that before they climb into the seat though.

 

[Wombat125]

I think the more mechanically inclined find it more exciting.

Yes we do.

It's not a real quick process if he is going to seat the rings, verify injection timing under load etc.etc.

The sales guy said they would run it loaded for about an hour. That seems pretty reasonable to me.

My other secret agenda is to make sure they actually do warm it up, and more importantly let it cool down for a while. I'm feeling very protective of my little turbo.

 

[dfkrug]

That Jinma with the Y385 gained 4 horse power in about 45 minutes and lost about a pint of engine oil ( I already had it a full operating temp). Let it cool down, top off the engine oil, warmed it back up, ran it at full load, throttle wide open, 30 45 minutes, no more HP gain and no loss of oil.

Those are interesting measurable results. So you put about 1.5 hr on the
Jinma as your break-in. You are right that there are many opinions out there
on what should constitute the break-in hours/load/RPM/etc.

 

[Ranch_Hand_Supp]

So you put about 1.5 hr on the Jinma as your break-in.
.

I don't know yet ?? I just got the Dyno and still playing with it on different tractors. .... when time allows.


Ronald
Ranch Hand Supply

 

[3RRL]

Ronald,
That Jinma you were referring to which gained the horsepower, have you done more than one?
And how do you find their horsepower rating compared to actual horsepower (and torque) when measured on the dyno?
Both engine hp and PTO hp.

 

[Ranch_Hand_Supp]

Hey Rob,
I have not hooked it up to another Y385 as of yet.

My Dyno is a PTO Dyno so I will be looking at /reading PTO horse power only. It does have another shaft where you could run a engine directly off the crankshaft.

Once actual pto horse power is seen / known then a percentage factor can be used for actual engine horse power.

All the feed back that I have ever read, seen, heard is that Jinma rates there horse power at/off the pto shaft.

To me what is not known from / about Jinma is what pto rpm do / did they rate it at. The engine rpm rating is on the engine tag which is considered high idle, no load.

Other than me personally wanting to know the actual horse power of the Jinma's ......... I want to be able to break the engines in,and put then under a working load to help ensure my customers are receiving a tractor that has been serviced, prepped and tested. A lot of these tractors are sold to people that will only be used lightly like, pulling a drag/spike harrow, PTO 3 point spreaders, driveway maintenance box blade work, mowing somewhat short grass, move a round bale etc and will never really pull hard or get loaded. Some think they are pulling, loading the engine when they are actually lugging the engine. I feel it is going to be a great tool for day in day out tractor repair, diagnosing, testing.

I hope to have some time this coming Saturday afternoon to verify pto rpms and calculate the gear ratio between the engine and pto.



Ronald
Ranch Hand Supply

 

[Ranch_Hand_Supp]

"Warmed up" is when the engine and operating components have reached thermal equilibrium. In other words, the engine has quit "growing"; all of the engine components, lube oil and coolant included, have expanded as far as they are going to and operating tolerances are met. The amount of time it requires to warm up an engine is in proportion to it's mass.

True and only then as you know.... you can start looking at some real numbers.

On that second run.... the cyl head temp was a lot lower. ( rings seated)

Ronald
Ranch Hand Supply.