I just put a cummins 5.9L piston/rod/bearing/rings/rod bolts onto a scale yesterday? Wow, It supprised me, its very similar to a weight of a new born. Also does anybody have an idea the weights on each part like the piston, rod, bearings and piston rings?

I'll post the weights for each part later on this week. These are stock parts right out of a stock virgin CTD engine

 

Piston tease !

 

If you guys only knew, would you rev the engine up to 5000 rpm's? Thats the real question. Hint, is its more than 5lbs...

 

I've got 4 piston/rod assemblies at my sisters place, so I'm aware of the weight, and I've got the 5k springs in my truck, so I think that answers your question.

 

I know that Tate, I've seen those spring in/out your truck a few times but haven't seen your truck rev above 4200 rpm's, yet. Of course the new 13mm CDS pump should fix that issue.

I think you should weigh the assemblies and see for yourself. It supprised me last night. I thought you guys would like some cummins trivia once and awhile. There ain't no little weight stuff in that motor.

Also, where was the crank, rods, pistons and wrist pins made at in your motor? The motor I have apart they are from Germany and England foundries. How many guys are running stuff from Brazil or Mexico?

 

No guess yet eh... Well its more than 8lbs?!!

 

12 lbs..

 

10.2 or 9.8 lbs.

 

How does 8 lbs 13 oz sounds. Right out a VE motor. I thought it would be around 3-4lbs. Been kinda thinking about putting together a data base on CTD info. Like rod, design, piston bowl, weights, what country that they come from. How the crank designed between years? How much does the large end and the small end weigh? Here's a picture of the complete assembly.

Any buddy have an idea why the balance weight on the rod cap is so large?

 

Not that I know, but I think I can make an educated guess

Is it because on a straight six engine the pistons move in opposite pairs and balance each other, so there are no counterweights on the crankshaft like you would have on a V8? Therefore you need enough weight on the big end of the rod to balance the piston?

 

An inline four would have the pistons opposing each other, 180 degrees out. On a straight six, they are 120 degrees apart.

 

My guess is that its old school thinking that you need abit of centrifugal force to keep the engine rotating at slow rpms. I think that the new CR engines dont have those big balancing. I saw a few pics of polished and debeamed rods on comp diesel. Those rods, all had that pad removed.

How much can you cut the rod (internal diameter), I guess resize the rods? I never really thought to much on this stuff before. I want to reduce the interia on each piston and rod as much as I can.

I have a few engines to rip apart, and I just want to document as much as what the factory did, just to do some reverse engineering.

 

common rails have a flat machined on the bottom but it doesn't really stick out like that at all. common rail rod are also that sintered steel stuff.

 

Anybody give a thought to how the small end of the rod (wrist pin) gets its oil lubrication from? The only way that the oil gets up there is from the oil cooler jet. The jet coats the cylinder wall as well as the piston bottom.

The CR rod has a smoother finish to it. These older rods are have more beef to them and are truely forged pieces.

Of course the crank will have to balanced for the weight changes.

 

What do you think that will happen to the HP/torque curve by removing weight from the rotating assembly? I'm hoping to lose some torque down low but gain more HP in the upper rpm. I guess that I'll find out.