Recently bought and installed a late model, low mileage 440 from a motor home. After running it a few days, I started hearing a very slight rattle on start up. As soon as it gets oil, it seems to go away, however, I now think I'm hearing an ever so slight noise at idle. It bothered me enough that I dropped the pan to have a look. The bearings look great. They are standard size, the rod journals are perfect. .0025 oil clearance. I can grab the rods and when I try to move them up and down on the crank, there is no movement, however, when I try to move the rods back and forth, perpendicular to the crank, there is a lot of movement. You can hear an audible clunk. I'm thinking this is where the noise may be coming from. Time to have the big ends resized?

Why do you think resizing the big ends is going to fix side clearance issues?

Get the FSM, read how to measure the rod side clearance, measure it and compare to the specifications in the FSM. FWIW, having side movement is not uncommon. Having too much can be an issue but you need to measure it.

Your ticking is probably lifters,

Perhaps I didn't make my self clear. I am not talking about rod side clearance, which is parallel to the crank. I'm talking about being able to move the rods back and forth across the crank journal PERPENDICULAR to the crank. There is no problem with rod side clearance. This is definitely NOT a lifter issue. This is a bottom end issue. I'm thinking the big ends are out of round.

I get it now. side to side sliding on crank (rod side clearance) Ok. Up & down (vertical, .0025) on crank OK . Sideways (perpendicular as you said) alot of play, Unfortunately yes it needs to come apart.

Ding, ding ding, we have a winner! lol Yes RR, I'm afraid so too.

Yeah I got one too (its coming out soon). EDIT I mean it is getting swapped to my 65 D100 MORE EDIT does this come out from the top or the bottom?

the 440 i pulled out of a motorhome i brought out the front,had to use the torch to get enough clearance,to get the motor and trans both out togeather

Alright, I will grab the hot wrench & get after it.

How much total side clearances do you have on the worst one?
I've seen stock Mopars have in excess of .040 that didn't make noise I could hear
Have you looked at all the rod bearings to see what they all look like? If not do that next
If your rods, or one rod, is out of round the rod bearings will show that

Ever check oil pressure !

If it's doing as you say then you've got an out of round rod journal on your crankshaft.

I replaced the oil pump before installing the engine, just to be safe. 60lbs of oil pressure, hot at idle. Oil pressure is not an issue.

I would think if the journal on the crank was out of round, it would only have extra clearance in just that spot. It seems to have clearance no matter where I turn the crank. Guess I'll have to pull the crank and rods and take them to the machine shop where I used to work. Perhaps they will give me the family discount. Typically they charge $125 to grind the crank and $88 to resize the rods. I was hoping to not grind the crank, because by the time I have that done and buy new bearings, I'll have more in it than what I paid for the engine. I'm not cheap, just broke!

Wait a minute, you stated above you have .0025 oil clearance on the rods and no up and down movement, now you're saying you have that movement anywhere you turn the crank. Sounding a little fishy now.

I am talking about back and forth ACROSS the crank, not up and down, not side to side. What is so fishy about that? I am stating the facts of this issue. Why is it every stinking time I ask a question or post a comment here I get at least 1 a$$hole that has to break my chops? I wasn't born yesterday and I have a fair amount of mechanical ability. Rapid Robert seems to be one of the only people that understands what I'm talking about here. Some people's reading comprehension just astounds me.

Wrong answer....Goodbye

If you could describe things clearly you would get better answers. Are you talking about front to rear movement? Across the crank is what most would call side to side. There is only three ways a rod can move. Up and down side to side or back and forth.

I don't know how much clearer I can say it. I have stated more than once that the movement is back and forth. I am not talking about rod side clearance where the rods slide from front to back on the crank. I am talking about moving the rod towards one side of the block to the other, which is perpendicular to the crank, not parallel, which would be side to side movement.

Maybe you should have included this !

Parallel lines have the same slope and will never intersect. Parallel lines continue, literally, forever without touching (assuming that these lines are on the same plane). On the other hand, the slope of perpendicular lines are the negative reciprocals of each other, and a pair of these lines intersects at 90 degrees.