Should you even bother with Crankshaft Balancing or save your money?

[@shawnwieser7101]

Ben, Love your channel and plan to attend some of your classes some day (have to fund it out of personal money not in the industry) . One thing to consider is over and under balance... In racing it may be nice to have a car that idles smooth (well balanced at idle) I think some racers will tell you when you over balance to the rpm range the engine is running at during the race that's even more important as the engine is not trying to shake itself appart (some racers can feel at high RPm when it come into balance) . I notice they still drill into the crank to reduce weight to get in balance, many years ago i read an article on someone turning down the counterweight to get the crank in balance rather then drilling holes and affecting the aero of the counter weight

[@dr.michaelbennett8597]

Actually, the standard remains the same. It’s the assembly that changes. As Randy has explained, OEM is approach racing standards from 10 years ago. Having run the old Stewart Warner, Balance Technologies, Winona Van Norman, Hines, and a CWT Multi-Bal 5000 I bought in 2007, the CWT is a quantum leap above anything else on the market. The old machines I listed were nowhere near today’s. Imagine using a timing light to identify the upside unbalance. The Hines and the Winona at least had degrees for position.

[@michaelgunning347]

There’s a very good sae paper on balance affecting oil clearance

[@GlobalMediaInc]

You Were Already A Leader In The Industry, Now Your Unstoppable! Looking Forward To What Your Testing Reveals...

[@scotts439]

not junk science, but "Imperfect science". Randy Neal is the industry leader in marketing. He does a great job of dazzling folks with tolerance and before and after force charts.... stuff that has always existed, most guys dont pay much attention to. To a customer it sounds impressive and makes it easier to write the check. The bobweight is still an educated guess, hence the imperfect science.

[@EFIU_Ben]

There is still so much to be learned before we can call a lot of this stuff "science"

[@jeromeallisonii8253]

Love it

[@darylmorse]

Like the others, I'm surprised that you thought crankshaft balancing was junk science. Glad you saw the light. I have always wondered how the 50% factor of the connecting rod mass was arrived at. It seems to be an estimate, rather than a hard and fast amount. I would be interested to see a test of an actual short block mounted with accelerometers with a variation from 45% to 55% to see if balance really is optimal at 50%. Has CVT ever done such a test?

[@flinch622]

There's a term for unbalanced reciprocating mass: vibrator. In the drilling industry, they call it a shaker. In proper application, the business of sorting solids [as in grading sand], or separating cuttings from fluid uses a purposed imbalance to create a force vector: it makes things jump. It is... very severe duty where bearings are concerned, and equipment failures are common, even with careful regular maintenance.

[@dr.michaelbennett8597]

I have done it with a vibration meter on my iPhone. 50% works mathematically. The other percentages fall into the voodoo category like 1% over or under balance. When you exceed the yield strength of the components, all bets are off. This is why Top Fuel cars have $10,000 crankshafts and they (if they live) change bearing between runs.

[@ComputerCapone]

Your shop is absolutely geared up for aerospace components. You should have a small aerospace contaract to pay the bills. They pay good and are consistant in workload. Small job help pay for the machines and put a few dollars into the business.

[@CHMichael]

Out of the box thinking that gets you to the top. Might also open some great doors.

[@falconhouseos]

Fantastic

[@michellee8369]

Junk science is the attempt of measuring the valve train behaviour without pistons rods combustion and temperature and so forth . Junk science

[@EFIU_Ben]

There is a reason that ALL OEM's and Professional Race Teams use Spintron testing for Valvetrain development! Because it WORKS!

[@CHMichael]

Hope you are thinking about EV. Mechanics will have to be able to work with some new technologies and chemistry.

[@coltonholiday4872]

This group/channel is geared towards builders, not mechanics. They are two entirely different groups of people. And as much as we all know that the EV revolution is well underway, ICE will live on for hobbyists and lovers of motorsports for a long time to come (due in no small part to said EV revolution). These people are the audience this channel targets.

[@ComputerCapone]

Im suprised you thought balancing is junk science....never ever heard anybody relevant say such things. As you get above 7500 rpm its very important. If it wasnt we wouldn't have balancers on our motors. Even the NHRA requires approved balancers, thats how important they think it is. This balancing is very important in motors that sustain long runs like boats. A boat motor wont last long at speed without a well balanced rotating assembly. Transmission included. 2 stroke engines have a 2 piece crank shaft, they have to be trued and balanced or you will have serious power loss and broken skirts. The rotating weights can actually work againt each other and be counter productive. And you hit on that. To keep centripetal motion. Nice machine. Good luck. Should produce some high quality parts.

[@coltonholiday4872]

The reason many people refer to it as "junk science", is that, at the basic level atleast, the math is only an estimate. Your % figure for reciprocating weight is a very loose figure, which isn't always the best number for any given engine. Some engines like a higher percentage than the standard figure (i.e. 50% for 90⁰ vee engines), some don't. Also worth noting, on your balancer comment, most super dampers that I've seen, will affect your balance pretty significantly. I generally balance all crankshafts (even stock rebuilds) within .5g. If it's easy enough I often shoot for .1g. Every time I've had the opportunity, I've put balancers and flywheels on cranks just to get every bit that I can. Super dampers alone generally put the balance 1-3g out if you install them after the crank is already balanced.

[@ComputerCapone]

@@coltonholiday4872 thats why the balancer needs to be installed during balancing. Most 0 balance flywheels are on the money. And all the high dollar convertors are balanced perfect. Thanks for the input.

[@georgedreisch2662]

Think the statement of crankshaft balance being, “junk science”, was intended as a overstatement to emphasize the inexact nature of percentages of balance applied and the interest to research a scientific approach to it.

[@Ron-j3t]

Maybe less harmonics