Questions on engine rebuilding, rod placement or location.

[Brad S.]

Do the rods need to go back in the same cylinder where they came from???
Pretty sure I'm not going to balance the motor.
Machine shop will just bore it out however much it needs, then new pistons etc.
I did mark the rods with the cylinder number they came out.

 

[franklin2]

I would keep them in the same order. Not so much that it matters, but on most engines the pistons have to go on a certain way, they have a mark that needs to point to the front of the engine. So you have a left set and a right set when they are installed. Thats because the pin in the piston is not exactly in the middle, it's offset.

I hope you marked the rod AND the rod cap. That does matter, the cap needs to go back on the same way it came off.

 

[Brad S.]

Yep the rod caps are on the rods.
It looked like to me that the rod caps could only get put on one way...????

 

[franklin2]

Yep the rod caps are on the rods.
It looked like to me that the rod caps could only get put on one way...????

That's possible. I have rebuilt many different brands of engines, most you could put either way though. I have never torn one of these particular diesels down.

 

[icanfixall]

Heres the deal with pistons and rod placement in the engine. Every piston MUST have the flame trench at the top of the cylinder. Thats so the precup flame has a place to flow thru. Now look closely at the big end of the rods. See the chamfer on only one edge of them where they connect to the crank. That MUST POINT TOWARDS THE CRANK BEARING RADIUS. In simpler words the beveled edge points to the outside of the crank rod bearing journal or to the crank throw walls. The inside of each rod that rubs the other rod on that same bearing is much sharper looking. This takes concentration so look it over several times. As you place the rods and pistons in the cylinder remember the piston flame trench is up top and the chamfer is on the outside of the crank bearing journal. These rods have a slight offset to them. Lay a rod on a flat surface and press down on the big end. You will see the small end lift off the table. Try it on both sides to see this.

 

[riotwarrior]

They need the pistons to bore and hone the block to correct tolerances. They need the rings for the pistons to hone the bores with the correct grit and cross hatch as well.

It's a good idea to retain the rods as they where, however if you are getting it balanced then it's NOT the end all be all however it is preferred.

Now with NEW pistons and such it could be a good...no IT WOULD be a good idea to have the Rod small ends re-bushed and sized accordingly to the new wristpins as well. If your in for that penny, go for the pound and have the big end resized as well.

Are you having the block align honed? It's a great idea too, this sets the bores correct to the mains and the deck surfaces too.

Generally once you have it all together you can mock up each piston rod and with crank in block check all your clearances and measure your pistons deck height and if you need to get the deck height of pistons crowns all machined to same as well.

There is tons of info and suggestions available. Blue printing that engine is worth while and provides for a basis to work from for any issues that may come up.

Hope that helps, got more ??'s now than answers I bet rofl

 

[idiabuse]

no balancing? ! and your asking for advice? !

 

[racer30]

Balance the rotating assembly...It will be the best money spent on the Job....My pistons were more than 8 grams out of balance and the rods were worse than that... 7 grams out of balance at 4" from center of the crank is 28 pounds of force at 4000 RPM....

 

[Brad S.]

First things first, Garys answer on rod edges, here are some pics

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Rods #3 left, #1 right

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#3 rod close up, look at the edge

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#1 rod close up, again edges
Gotta run now, will answer some questions later.


I will be talking with the machine shop about all of the above.
I know that a balanced motor performs/wears better, but I doubt if I rev mine much above 2500 rpms a couple time a year.
Maybe I should post the pics of the main bearings, don't think they were out of the normal, plus I don't think the stock engine wasn't balanced....????
Do most rebuilds get balanced???? Even rebuilt engines that come from a "rebuilder"????
My problem was a stuck ring(s) plus wore out rings, PO I think pulled livestock trailers.

 

[racer30]

There is only one way the rods will fit....The chamfered side of the rod goes toward the counter weight of the Crank and there really is no way to get them wrong just remember to put the square rod end weight towards the outside of the block when installing the pistons on the rods. The manufacturer only builds them to within 10 grams or so. stock piston weight is about 1000 grams (without rings) so 10 grams is 1% stock rods 1160 grams. Check into balancing you wont regret it.

 

[idiabuse]

There is only one way the rods will fit....The chamfered side of the rod goes toward the counter weight of the Crank and there really is no way to get them wrong just remember to put the square rod end weight towards the outside of the block when installing the pistons on the rods. The manufacturer only builds them to within 10 grams or so. stock piston weight is about 1000 grams (without rings) so 10 grams is 1% stock rods 1160 grams. Check into balancing you wont regret it.

We both know people will install rods backwards and start up the engine.

 

[riotwarrior]

We both know people will install rods backwards and start up the engine.

Yes we both do know such people, who have done such things, and I"M NOT one of them.ROFL

 

[Brad S.]

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To quote Jack Nicholson from Batman back in the 80's,
"I don't know if it's art but I like it"

Crank back from the shop, standing on the top of the basement stairs, checked out ok, standard sizes.
BTW the shop owner was very much for balancing engines.
He made a statement that much vibration comes in around 1500 rpms, so I think I'll have them balance it when the time comes.
Thanks all.

 

[FarmerFrank]

I wish i knew of a shop around me that balaneces, seems they are all a coupe hours away

 

[Brad S.]

I wish i knew of a shop around me that balaneces, seems they are all a coupe hours away

Have you ever figured out what it would cost to ship engine parts to a machine shop for balancing???
Then figure how much it would cost you to drive it over...???