172 diesel engine balancing ?

I was reading some old posts about balancing this engine. How do you balance them aside from the counterbalance? Weigh each rod and each piston? Where do you remove metal on rods and especially pistons? Also do you balance all four pistons or rods to each other or the piston and rod assemblies to each other? Do you balance the crank or does the counterbalance do that? One final thing on the counterbalance. The manual states to slide the assembly to one side to get correct tooth clearance. I don't think they move too much to either side. Has anyone ever had the base shaved to bring the counterbalance into tolerance? It's a balancing act that keeps you on the tightrope. I think, that's all folks. Thanks for all the good advice on here.

In the last 10 years I have had 6 engines rebuilt and always have them balanced. About $125. Well worth it as they run much smoother. Just had a 27 Buick done. I think you could idle it down to about 400 RPM its so smooth.

I think you did an end run on me

River,
I have just got done balancing a chevy 327 for high rpm's for my coupe, and 2 stock 350's, one is going into my S-10, with corvette factory fuel injection, and the other on the shelf.

I have all the piston's taken off the rods. clean everything good. I then weigh each piston with it's wrist pin. I find the lightest one, then remove weight from inside bottom edge of the pistons, till they all weigh the same as the lightest one.

Then I have a setup that you would have to make. That holds the rods, by the rod bores (see pictures, I made mine like the center one), and the other end on the scale. Believe it or not, women are better at this then men, it's a fact.

Remove weight from the heavy ones down to the lightest one again, by removing (grinding) the weight from the very end of the rod. A very little at a time! Then do the same for the other end, but only after the first end is done on them all. It doe not matter which end you do first.

Your rods will all weigh the same when done.

Then I take them to my engine man, because I don't have a press, and have the pistons then mounted back on the rods, and then he balances the crank for me.

It is a lot better way of balancing any engine, then just having the crank balanced as most places do. It is a lot finer balance. I have been doing it since my racing days in the 70-80's, and I always will.

It takes time, but it's easy to do.

Pat

Hey there, old friend. Did you get your tractor up and running yet? I might just get someone to do the whole engine but I might try that balancing act. I couldn;t picture where you take it off the pistons. Are you talking about the bottom of the skirt? Does he balance the crank by itself or with the pistons and rods connected? How does he know where the sweet spot is with the crank?

River,
Nope, I'm still working on it. I just have to put the lift cover back together, then peak into the SOS, at the rate things have been going with it, I'm sure something has to be wrong with it! ;(. I have been wrong on everything else. I'm getting ready to pull my engine & transmission out of my S-10 truck. I put that @#$%@^@@@&%ing lucas into my transmission, to get rid of it, and now my transmission slips in every gear! I had just rebuilt it less then 5000 miles ago. So while it's out, I'm putting a 350 back in, and change it from throttle body injection to multiport injecting, from a corvette. Which means rewiring the engine & computer in it.

I have also been working on my coupe, I have not touched it in the last year. I have been working on the dozer, and my tractor.

I am getting the rearend ready to shorten it. I have to remove 10 5/8 from each side of the housing. Then I'll have to port & polish the heads, then put the engine in the coupe.

It's rained here so much. my toes are starting to web. I don't know if it's duck feet, or frogs feet! lol

You can remove it anywhere on the bottom of the pistons. I usually remove it around the wrist pin area. Inside & on the outside of it. I usually stay away from the skirts.

After I give him the pistons to put them back on the rods, he weigh them, and uses a what's called "Bob weights" on the crank in place of the pistons & rods, and then spins it up. The balancer tells him where, and how much to remove. He then removes weight from the crank where need be. They don't add weigh, just remove it.

Balancing of ant kind, makes a big difference in how smooth it makes it. I don't rebuild/build a engine without doing it!

Pat

Hey there, old friend. Did you get your tractor up and running yet? I might just get someone to do the whole engine but I might try that balancing act. I couldn;t picture where you take it off the pistons. Are you talking about the bottom of the skirt? Does he balance the crank by itself or with the pistons and rods connected? How does he know where the sweet spot is with the crank?