440 assembly !! I Need help! Rods or piston mix up! NEED HELP!!

[wjaholic]

Alright, long story short. I had my old pistons pressed off of my 440 "LY" rods for another set that didn't pan out. So the old pistons were pressed back on.    I recently had my crank, rods, and pistons balanced (entire rotating assembly). I am going to put it all back together now and I don't know which rod goes where. I don't see the rod number cast or stamped any where one them.   Can some one help!!! I know the big chamfer the "big end" goes toward the crank but..... Since they have balanced can any rod go in any cylinder as long as they oil correctly? No way, that cant be right. HELP!

The pistons have an F stamped on one side... does that go to the front of the engine?

ohh god, i am freaking out! 

I am starting to think my '73 440 will never get back together!

[AprilsPink72Cuda]

I moved this to the engine section, as Chryco will probably see this here first. 

If you pulled the connecting rods and pistons after the bottom end was balanced, in my opinion, you should have stamped the connecting rods before you pulled them out so you would know which cylinder each rod belongs to.  If I am understanding what you wrote, I think you may have to have the entire rotating assembly balanced again.  I could be wrong, as I am not too much of an engine chick, but I am sure someone else will chime in if I am wrong.  Best of luck to you.  I hope it isn't too much of a hassle.   

[Hot_Rodder]

To my knowledge, the rotating assembly is balanced to an assembly, change the assembly, change the balance. Also, each connecting rod is supposed to be fitted to a crank journal, so, I would say each piston/rod assembly has a place of it's own. From here, I think I'll let a professional engine builder take over before I say something that's probably wrong, or going maybe to far, like having to have everything redone to match up in it's own place........

[Moparal]

Well, the rods should weigh the same both on the big and small ends. They weigh them seperate and get them down to 1 gram of each other. The pistons will be the same story. They are weighed and then drilled or cut down to weigh the same.The oil suirter holes (chamfers) on the rods go to the inside to lube the cam lobes. You will be just fine. The balancer is of course is neutral balance and the same as the fly wheel. Build it and enjoy it. You really shouldnt notice any viberations. If it was balanced all the same. The f is for front.

[ntstlgl1970]

I agree with moparal on the balance issue, the only question I have is that if the rods use pressed pins, you said you had the pistons/pins pressed off, then the same pistons pressed back on(same pins/new pins???) Check with chryco or moper, they seem to be the engine guys around here, but I thought that pressing the pistons off the rods usually damaged the pistons skirts and/or pin bores to where you wouldn't use them again. At least that is what I have been told before. Also, depending on how the engine was machined, if the machinist honed the pistons to fit a specific cylinder, then (in my opinion) you would want to mike the pistons and bores to match the cylinders to the pistons.

This sounds like a lot of stuff, but it can be sorted out pretty quickly at any trustworthy machine shop or if you (or a buddy) has some micrometers

[Chryco Psycho]

The rods make no difference which cylinder they go in , the pistons do however , so each piston should have been stamped on the way out so you know which bore to install it into , each cylinder is fitted to match the piston when bored & with the pistons pressed off the rods & back on there is no way even if the rods were stamped that the piston would be in the right cylinder , you would need a set of both inside & outside micrometers to measure each piston & bore to sort it out 

[moper]

Like CP and Al said. When it's balanced, the weights are matched. But, valve releifs and rod orientation means it fits or not. I dont press pins on. It's rea;;y a misnomer, because the small ends of the rods are heatedto expand them. Then the pins are inserted cold, and in a second or so, the rod cools and shrinks and locks it in place. The problem is when they are pressed off, unless the shop is very careful, the pistons will get squished in the pressing operation. I dont re-use presssed pin pistons for that reason. No, you will wan tto orient your rods first by the crank position. The chamfered edge always faces the crank throw. So the two rods on the crank in that throw are "flat to flat", and the bearing is positioned so the radius on the crank (if it has one) will not pinch the bearings. I mark the rods with the cylinder with a permanent felt marker. Then you need to orient the pistons. Stock type pistons have a notch on the edge that marks front. Some makers use an arrow stamped in the dome. Most of what I use you use the valve pockets to orient them. On mopars, that means looking don on the bank of pistons, it goes EIIEEIIE. E being exhaust, I being intake valve pockets. I have found several times that shops have the pistons right, and the rods wrong. I've also caught myself doing it too. So dont feel bad. Everyone's human...Mostly.

[wjaholic]

Thanks! thanks for all the help!