That's pretty much the responses I expected. "How Dare You question my religion? If you don't do it exactly as I say, the sky is going to fall and a giant 9600rpm Kraken will come out of the sea and eat you!"

The plain and simple truth is the V8 balancing formula isn't mathematically derived. It's just what seems to work the best. The ESTIMATE on oil weight is in that same ballpark, it is true.

To amplify, I think matching component weights is simply good engine building practice, and also for an initial build, balancing by the formula is a good place to start.
I also believe that Vizard has a pretty good handle on things. He's also done a ton of dyno work.

I remember years ago when Grumpy Jenkins was being paid by Chevrolet to develop one of their V6s for racing he complained that the counterweights were in the wrong places. It blew my mind. Factory engineers had sweated the details on the engine, but Bill Jenkins was no dope. Sometimes the conventional wisdom isn't wisdom, just conventional.

The simple fact that engine builders are fudging the percentages on the magic formula tells me that it is at best a very good guess of what will work, and logically a difference of 2-3 grams per piston which is in the order of 0.2% of the bobweight will make absolutely no difference, even at 10,000 rpm.

Now, what other sacred cows are ready to be speared?

R.

I have a question, everyone throws a few grams in for oil sticking to everything. My engine is dry sump and pulling 17 in/hg, with that being said everything is in a vacuum wouldn't that affect how much oil sticks to the bottom end?

What counts even more is if your using a crank scraper..
but Dog knows that.. I'm sure he runs engines into the
high 9500+ range ... why not have it balanced as close
as possible and save your mind and a engine

My first drive in my Gen III it had some weird harmonics. It was balanced locally and has an ATI "blem" balancer on it. After a few hard runs it smoothed out and is smooth now? Has anyone else ever experienced this?

The oil factor is just a guess. I am not sure it is a factor at all, more of a fixed value. It should not be related to weight, but surface/windage/shearforces in the crankcase. In practice it is a slight overbalance, 0.5-1%, obviously something that works well. When you add the oilfactor to all sorts of engines it just shows that the formula could be improved upon, as dogdays mentions.

The engine builders I have used have never asked what
weight oil I plan on running... be it 10 weight or 50 weight
and I'm sure that weight will be different

Same deal on bearing and lifter bore clearances on how much oil leaks down into the rotating assembly A guy can drive himself crazy worrying about some things Not me though, put it together properly and beat the dog doodoo out of it

Heck, yeah, run those 318s right up to 10K rpm except the switch on the back of the tach is pointing at the 4 on number of cylinders!

R.

No oil from the lifter bores leaking down in this engine. She's all closed up. The crank was just balanced for this assembly. So it's not like it'd be 40 grams off.

I'm still contemplating even taking anything off. When my $27 spark plug comes tomorrow that will really sway me one way or the other. If this plug hits, then I have no choice. If it clears, then I can go with a $150 spark plug change, out go with my other options I find out about tomorrow morning.