I got my rotating assembly balanced

[Cartel]

and they didnt add any weight. It must have been close from the factory?
I see one spot they took down a sharp corner that was there, is that ok?
I see 2 other spots where a tiny bit was taken off and thats it

It had std cast pistons and now has forged L2315NF +30

I have little knowledge in this department so I'm asking now before I find out the hard way it may not be correct.
"The weight of the piston and pin of the L2315NF30 is 786 grams"

stock piston and pin 995 grams
new pistons and pins 1000 grams
so I guess really close.
Also arp rod bolts replaced the stock ones

crank was polished only as it passed tolerance at STD r&m

 

[MONC440]

With a forged crank they usually don’t have to add weight and after market pistons are usually lighter than stock. What you are explaining sounds totally normal to me. Be thankful that they didn’t have to add weights because they increase the cost of balancing.

 

[413]

Sounds like a good job. Can you see ginding marks on ends of rods? On pistons under pins can you see marks like some were cut in a lathe?

Sometimes adding weight is partially filling inside the 1/2" holes the factory drilled. Look inside the holes, is it smooth or have welding inside them?

The Mallory metal is the expensive part when they need to add a lot of weight.

 

[CBODY67]

I would say you "got lucky" with that piston/pin combination. My observation is that many aftermarket pistons are heavier than OEM items, as OEM items are the same weight all the way to .030+ sizes, whereas aftermarket pistons are not. This OEM weight allows rebuilders to replace just one piston, if needed, without affecting engine smoothness, at the dealership level. Or in the case of a DIY rebuilder that gets the block bored/honed for 8 pistons on a worn block. Whatever.

My late machine shop operative had a brother that was in the core engine business. Whenever Tommy needed a set of rods, he's always call up his brother for a "factory balance" set of rods. On all of them, the balance pad at the piston pin end would always be much less than any OEM replacement rod I had ever seen, plus all the same height.

I suspect the engines that Alan had were just salvage yard engines, so their internals were "seasoned" as the block was by years of hot/cold cycles and such. so just a retouch of the bearing caps and end-size was all that was needed, other than cleaning and inspection.

Enjoy!
CBODY67

 

[Cartel]

The rods do look like they took some weight off. the bottom and top look machined. I'm afraid to take them out of the box I dont want to contaminate anything.
The pistons were really close out of the box.
The shop did resize the rods or clean up the big end whatever they do

 

[cudamark]

Looks good to me.