thought I'd share this - I installed all the pistons yesterday, made sure all the indents in the piston edges were facing forward.




Checked for bearing clearance, thats all good & then I noticed a cap on #5 looking funny as I was checking the clearance between the rods. It looked like I had a bit of a tapered gap going from one side of the cap to the other.

so I pulled the cap & started to suspect the rods are backwards...



the large chamfers on the rods & caps are facing each other. I was also told by a guy whose rebuilt a few mopars that the groove on the cap is meant to squirt oil towards the opposite cyl wall, these are pointing to the block castings.

Pulled 2 more caps, 1 & 5 & you can see the bevels are facing one another.



I finally noticed the bold type paragraph in the FSM on pg 66 that says which way the bevels face for all the pistons. Ultimately it makes me assume the machine shop pressed the rods in backwards. It does spin over w/o resistance but now it looks like I gotta take them out, have them re-press the rods back on & do it all over.

I believe the bevels are there to clearance the casting parts of the crank to the L & R of the rod journals & I assume thats pretty important. Hate to do all this work & screw it up over something so stupid.

Are the bearing tangs / tabs supposed to be on the same side of the con rod when assembled? They'd be on the same bolt then - that's correct isn't it?

My problem is I didn't disassemble this motor as I could not get the dampener pulley bolt off so I took it to the machine shop & they disassembled it. Had I done it I've have many pictures - too bad

Anyone ever run a motor with the rods facing the wrong way - whats the end result?

Thanks all,Evan

The large tapper goes to the crank side... the anti-spin
tangs are on the same bolt/stud.... no I've never
ran them the way you are asking

Campher goes to crank side not together rod to rod. Groove goes toward cam. Numbers to outside of block. Tang and tang same side. Now if you will listen. If you are lucky you can get all this right and end up with piston notches towards rear of engine. It all has to do with piston pin offset for quit cold opperation. All of us old timers remember Chrysler telling us to reverse the piston. Worth some 15 hp and the engine will rev up way faster. Story I, I had a 69 factory 440 cuda. motor apart with 150 miles on car swapping pistons was on of the mods. Done car ran on the national record. When retired from racing car went over one hundred thousand miles with pistons like that and nver a problem

Yes, we did this alot back years ago and it still holds true. Back then we just took all the odd number rods and pistons and put them in the even number bank and and even number in odd number bank. As I said it was in the chrysler speed books. Made those engines rev up like a small block. Only thing you may notice is a little piston noise when cold although I never heard it with the factory pistons in a good snug bore and very slight with the trw's we used to use. Trust me the bearings arn't going to know the difference.

Just swap the pistons into different bores so the bevel
on the rods are towards the crank... keeping the
notch to the front... you'll be fine

thanks for all the ideas guy, its good to know I can resolve this w/o going back to the machine shop.

Weird screw up though...

Thx.
Evan

Yep, I agree, put the pistons in backwards. It depends on the pistons. If yours are stock types with the pin offset, there are a few horsepower to be gained by reversing the offset (having the indents point towards the back of the block).
What is the disadvantage? You will have slightly more noise on cold startup. That's all.
If they are high performance pistons with zero offset, there is no change at all.
The offset pin is entirely for reducing piston slap, nothing else.

Whatever you do, DO NOT take the pistons back and have them pressed off and pressed on. There is some risk involved and the pistons or pin bores may become damaged. It isn't worth it.
R.