Engine Overhaul Kama 554

[dcyrilc]

Cyril,
I have read several threads about the injector pump timing and also talked to Chip about it. He said as long as I mark (exactly) how it was assembled before, where the gears line up, and if I put it back together the exact same way, I should have no problems. So that's what I plan to do.

Sounds like you have it covered. Enjoy your week.

 

[dfkrug]

Taking all the geared and timed stuff off the front of the engine will be new to me. I suppose I will mark the mating gears tooth for tooth how it sat together before removing them completely.

If it is like all the Yanmars I have done, there will be letters or numbers
stamped into the gears to get the cam/crank/FI timing right. You do have
to turn the crank a number of revs before they line up. I have no idea
what Kama does. It was disconcerting when I opened up my latest
engine when I saw the letters as expected, but also some slots for the
FI pump bolts. These bolts had to be removed, so I marked where they
should be in the slots as best I could. No way did I want to change the
FI timing.

I looked at a number of those Youtube videos about rod balancing. None
seemed to deal with right-left big end imbalance that could exist or be
caused by uneven material removal during static longitudinal balancing.

 

[IH3444]

"I looked at a number of those Youtube videos about rod balancing. None
seemed to deal with right-left big end imbalance that could exist or be
caused by uneven material removal during static longitudinal balancing."[/QUOTE]


Please explain how this right-left rod balancing could apply to a slow speed diesel tractor engine.

 

[SPYDERLK]

It took me a little while to get through all the connecting rod instructional links, but I pretty much understand now. I'll have to buy the 1000 gram scale and make a fixture for the connecting rods.

I noticed all the fixtures in the examples had the same chain set up for the big end. I looked to me that one of the fixtures used a different locating device on the big end rather than a spud with a dowel through the center. Ultimately, it achieves the same thing as long as each rod end locates in the exact same place.

Many thanks to all for taking the time to share all this information with me.

Rob, until today I had missed those links in my visits to the thread. I thot you were referring to a PM or something.

Do not do it like the 1st link - the uTube one. That one is wrong. It is substantively different from the others in that it never weighs the big end. Those rods may weigh the same, but the big ends dont and theyre the most important to keep the same as you home in on an equal weight set. Since the small end only [[~]] reciprocates, its weight is of little importance and the only reason to take weight off there would be to adjust a heavy rod with light big end. The key is repetitive end to end weighings ending with big ends and total weights the same. ... The truth of this is borne out by the below excerpt from the last link [hiliting mine].

"The requirement for equal linear and angular acceleration of the connecting rods is met by the symmetrical movement the engine provides to the rods. If all rods have the same center-of-mass and that mass is of identical amount, then by Newton's Third Law, acceleration forces caused by translation motion will equal.
The requirement of identical moment of inertia (rotational inertia about an axis of rotation) means that the way the mass is distributed with respect to the axis of rotation is important. All rods need to have identical radius of gyration. This is achieved by having identical mass placed at the identical distances from the axis of rotation (piston end). "
larry

 

[MtnViewRanch]

Just my opinion here, but all this micro balancing just is not needed for an engine that turns 3000RPM. You are not building an 8-10 thousand RPM race motor. Yes check the pistons and rods to see if they are close. Are you sending the crank out to get it balanced? How about the flywheel and pressure plate. For that matter, what about the drive shaft and the tires for goodness sake. How far do you want to really go, after all it is a 3000RPM tractor engine.

What Mark and I have found is that if you take a little care in building an engine, it is well within spec for everyday use.

Just my two grains of salt.

 

[SPYDERLK]

Just my opinion here, but all this micro balancing just is not needed for an engine that turns 3000RPM.
What Mark and I have found is that if you take a little care in building an engine, it is well within spec for everyday use.

Just my two grains of salt.

Yeah... last comment post #135. Good for technical discussion... , but doing it is fun and entertainment here - - not necessity. A mental gain

I did this to a 9krpm Honda 750 motorcycle engine once. On a trip to Daytona my brother and I traded bikes on a stretch of Rt 100 in Fla. We were traveling aroud 100 on the average - we confused the signs. My brother said as soon as we hit 80 he thot something had gone wrong, but it was just that the engine seemed to disappear.
larry

 

[MtnViewRanch]

I did this to a 9krpm Honda 750 motorcycle engine once. On a trip to Daytona my brother and I traded bikes on a stretch of Rt 100 in Fla. We were traveling aroud 100 on the average - we confused the signs. My brother said as soon as we hit 80 he thot something had gone wrong, but it was just that the engine seemed to disappear.
larry

I have an old 1967 Ford 427 engine that I have had in a couple of different cars. Now it is only an 8Krpm motor, but man does it ever run between 6500 and 7800.

 

[IH3444]

I balanced my Volkswagen diesel Jetta with the beam balance, as described in the video, and my engine machinist coaching. Small end first, then overall weight from the big end. Both pistons and rods were made to weight the same. This engine runs smoother than the engine I built for the Volkswagen diesel rabbit, which I took to the balance shop, and had all components balanced, and the crank, flywheel, pressure plate spun dynamically. The balance shop then marks the crank, flywheel, PP, so it goes back together balanced. It did run smoother than before I took it apart, just not as good as the Jetta engine. My buddy at the Volkswagen dealer told me he had drove hundreds of diesel rabbits, and that this one was the smoothest running. Go figure, the Jetta engine is smoother than the rabbit diesel. Maybe they were having a bad day, and I had a good day. They surely had a good day when I paid them. Anyway, the KAMA engine is a slow speed diesel engine as I have stated before. If you can get all piston/rod assemblies to weight within 1 gram, I'm sure that will be fine. All I did to the Porsche 2.7L 911 engine is swap components around such as wrist pins, and went by Bruce Andersons recomendations as to where the heavy set went, closes to flywheel. Understandably Porsche components from the factory are already balanced pretty well. My Honda V65 red lines at 10K rpm from the factory.....I have over reved it on numerous occasions to 12K rpm. Never a whimper, or feeling of out of balance. Hey, it's a Honda!: That's how you can break the national speed limit (55) in first gear. 2.3 seconds......faster than you can read this sentence. That was their advertisment, and looks to be true in my opinion.

 

[MtnViewRanch]

Is there a link for information about this Ag Fair you guys keep talking about?

Here ya go. Lots of info, tractors, food. Plan on going at least 2 of the 3 days. This late in the game, you will most likely only be able to get a hotel about an hour away.

Welcome to the 2010 World Ag Expo: Tulare, CA

 

[dfkrug]

Please explain how this right-left rod balancing could apply to a slow speed diesel tractor engine.

It doesn't apply, no question. Balancing the rods (or even the pistons
and crank) any better than the factory did is just an exercise.

 

[psj12]

I have rebuilt hundreds of diesels and only balanced the rods on one. This was a special case where the rod for that engine (foriegn) was unavailable and a rod from a different model, similar engine was modified to work. We sent it and samples of our existing good rods to a balance shop. When we got them back they didn't even weigh the same much less balance the sam end to end. I ended up doing it my self using a very accurate scale and I am proud to say that engine is still running.

 

[Bob Rooks]

Gentlemen, FYI, this is considered a medium speed engine because it's rated HP is over 600 r/m. Slow speed engines develop maximum HP between 50 and 600 r/m, such as the Sulzer RT-flex60C. And I agree that the balancing exercise is unnecessary because the inertia forces just aren't there with this engine, but it's fun to watch.

 

[MtnViewRanch]

While it may be fun to watch, so much of it simply is not needed. Hopefully we will have a reality check before Rob actually starts on the engine and he ends up doing what is needed and not a bunch of unneeded race engine stuff.

 

[Bob Rooks]

While it may be fun to watch, so much of it simply is not needed. Hopefully we will have a reality check before Rob actually starts on the engine and he ends up doing what is needed and not a bunch of unneeded race engine stuff.

I agree Brian. He could blueprint, port & polish, CC, and balance and it won't make a noticeable real-world difference on this engine. Rob is a very capable person, and I'd hate to see any expectations shattered. But if he really wants to do it, he should go for it, but realize that there will be no payback for the extra time spent.

 

[PAGUY]

Guys - Maybe Rob wants one of those tractors that are turbo charged with two smoke stacks on either side of the engine and the capability to bring the front end off the ground when he gives it the juice.

Think how fast he could get his projects done with a tractor like that the work done in half the time it normally takes him.

What say ye Rob? Are you up for high powered tractor that burns rubber?

 

[3RRL]

lol...
My goal is to have end up with a good running and very reliable engine.
I don't want to build a "race motor". I'm going to do most of the balancing just because I know the stock motor may not be set up close to what it really should be. I've seen this time and time again on my inexpensive Chinese tractor. You do "get what you paid for" and I'm aware of this. A lot of this is because I don't mind going through with some of these things just for my own satisfaction.
It can't hurt.

I'm still waiting for the new crank to arrive.
I also ordered a gram scale online so I presume it will arrive this week too? I will have to make up that balancing fixture though. I've decided to balance the weight of the pistons and cranks pretty much the way that first video showed. Although you guys are probably right that the results might be indiscernible or even unnecessary, at least I'll know it's been done.

I'll be tearing down the tractor more this week.
Hopefully, I should have some photos by the end of the week some to show the progress. My main goal this week is to at least have the engine out of the tractor and mounted to the new engine stand. It will be a lot easier access to removing the rest of the engine parts. If the scale arrives in time, I can build the fixture for it too.

 

[TBDonnelly]

Rob, The West Coast Nationals tractor pulling event taking place during the World Ag Expo is calling YOUR NAME!

splash ｻ West Coast Nationals

You have four weeks to pull it all together. You can do it!!

Don

 

[greg_g]

...I know the stock motor may not be set up close to what it really should be. I've seen this time and time again on my inexpensive Chinese tractor.

Operative word being tractor. But consider that the FeiDong 95 series engine is licensed from Isuzu. Chip pointed out quite some time ago how impressed he was with quality of the FD95 series components. He should know, they were in his parts room right alongside the YangDong parts. My feeling is that you may have reached the point of diminishing return here.

//greg//

 

[SPYDERLK]

Rob, until today I had missed those links in my visits to the thread. I thot you were referring to a PM or something.

Do not do it like the 1st link - the uTube one. That one is wrong. It is substantively different from the others in that it never weighs the big end. Those rods may weigh the same, but the big ends dont and theyre the most important to keep the same as you home in on an equal weight set. Since the small end only [[~]] reciprocates, its weight is of little importance and the only reason to take weight off there would be to adjust a heavy rod with light big end. The key is repetitive end to end weighings ending with big ends and total weights the same. ... The truth of this is borne out by the below excerpt from the last link [hiliting mine].

"The requirement for equal linear and angular acceleration of the connecting rods is met by the symmetrical movement the engine provides to the rods. If all rods have the same center-of-mass and that mass is of identical amount, then by Newton's Third Law, acceleration forces caused by translation motion will equal.
The requirement of identical moment of inertia (rotational inertia about an axis of rotation) means that the way the mass is distributed with respect to the axis of rotation is important. All rods need to have identical radius of gyration. This is achieved by having identical mass placed at the identical distances from the axis of rotation (piston end). "
larry

I've decided to balance the weight of the pistons and cranks [pretty much the way that first video showed]. Although you guys are probably right that the results might be indiscernible or even unnecessary, at least I'll know it's been done.

Not a very good way, but it will be easiest.. and almost definitely closer than they are now.
larry

 

[dcyrilc]

Rob, The West Coast Nationals tractor pulling event taking place during the World Ag Expo is calling YOUR NAME!

splash ｻ West Coast Nationals

You have four weeks to pull it all together. You can do it!!

Don

Thank you! I needed a good laugh tonight.

...and I'm still chuckling.