Balance a Burtz

Spinning bob weights on the crank do nothing you cannot simulate the offset acceleration of the mass between tdc and bdc

The best you can do is make the rods equal weight and end to end
Pistons even weight and as light as you think you can get away with

Just an observation over the years is that hopped up motors will shake and those not familiar with them think it is out of balance

If your motor is only making 45 hp it should be smooth when you get to 200 hp it will shake

J
 
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Putting the bob weight issue aside for the time being, a trip to the balance shop will set you back $200-$300 depending on what needs to be corrected. Given the overall cost of a Burtz engine why would a person even consider not checking the balance? It's common knowledge that the rods need correction (the total weight garbage is just that- the crank will see any big end weight difference, and you will feel it) so just spend the $$ so you are confident that you have a good motor when you drop it in your car! pretty simple.......
 
Agree Dan when making changes such as lightning a flywheel or drilling crank for oil

The Burtz should be good out of the box
The crank and flywheel should be done to ISO standards
Rods and pistons easy on a gram scale

John
 
There are two sides to this coin. To be 100% accurate the all parts should be equal in weight, big end and small end of rods included, and the crankshaft dynamically balanced using correct bob weights. On the other side of the coin, I put my Burtz engine together without doing any balancing and it does not have any vibration problems.
 
nkaminar said:
There are two sides to this coin. To be 100% accurate the all parts should be equal in weight, big end and small end of rods included, and the crankshaft dynamically balanced using correct bob weights. On the other side of the coin, I put my Burtz engine together without doing any balancing and it does not have any vibration problems.
Click to expand...


nkaminar,

Thanks for your comment.

The moving parts are manufactured and balanced in factories that make parts for domestic and foreign engines.

The factories are not making engines for Ferrari, Lamborghini, Bentley, Indianapolis, Bonneville, or circle track racing.

The "Builders Guide" for the new engine mentions balance. Pasted below is from the "Builders Guide":
The connecting rods are balanced in sets to modern engine standards. Each of the 4 connecting rod weights are within a few grams of each other, but the center of gravity is slightly different for each connecting rod. If you are building a race engine or are a perfectionist, please see the YouTube video https://www.youtube.com/watch?v=QLpiF0E0EJU

It would be very unfair to 99% of our customers if we increased the price to accommodate the 1% that want closer tolerances and balance.
 
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from above: "should be equal in weight". If you all are good with that, then what can I say? I don't think that anyone in this thread advocated for Terry or John to be unfair to their customers, or change anything about their product.
 
Why even chance not balancing a 'Chinese' product. I don't care if they balanced them over there or not, I have them balanced again as a precaution. I agree with Dan McEaechern on that premise when spending all the extra $$$, why not spend the extra few bucks...


But with that said: Terry is right "Why increase the 99% to satisfy the 1%"?
 
If you want to spend the money that is fine, but it is not necessary. There are good and bad companies all over the world. Terry Burtz has picked a good company in China to do business with. This is the same company that makes engines for modern cars that are sold in the US.
 
China is in a transitional period in terms of manufacturing management as we speak. The Chinese government required (perhaps still do?) all foreign companies wishing to take advantage of the low labor costs to partner with Chinese companies. When the partner-manufacturer is able to produce global quality output, the newly learned expertise is cloned in Chinese-only companies, backed by the government, to compete with the foreign partnerships. China now makes first-quality electronics, based partly on the expertise taught to them by Apple. You can now buy clones of Honda motorcycles from China, as in, the Chinese engines are piece by piece bolt-up replicas. The quality isn’t the same - yet. And yes, there are still companies cranking out dreadful crap. They will not last.
I’m sure most of you recall in the 1960’s how “Made in Japan” was printed on little toys stamped out of cans. I mean this literally. If you pried them open you’d see the printed can label. Then Japan went wild for W. Edwards Deming quality control protocols. “Made in Japan” was no longer a Johnny Carson punchline. Americans bought Sony color TVs, even though they were very expensive. Honda went from piston rings to little motorbikes,to cars, and now the safest recommendation to a clueless car buyer is just pick whatever Honda you like. Chinese EVs (not even allowed in the US) generally cost way less than Teslas, yet beat the pants off them in every comparison test.
“Chinesium” will become a stale linguistic artifact of the current decade. China, Inc. is becoming the dominant global industrial powerhouse and the toughest business competitor America has ever faced. I believe when private equity gets involved it will just accelerate the change.
 
Here’s my 2 cents. I’ve done a bunch of these motors so far
and my take away is the pistons made now a days are usually with in 2 gr
The Burtz crank and flywheels are very close. But you should definitely have the rods balanced end to end. I haven’t seen a set yet that I would put in a motor.
This will get you a home built motor that runs very good. I check everything on every motor.
I don’t charge to check the balance on these motors but do charge to correct anything
I find.
 
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I agree with dodge. To meet the original model A ford spec of plus or minus 2 grams at each end of the rod builders should be checking rod balance. When I had my shop pistons where plus minus 5 grams. Now as he says probably 2 grams. I try to get them within 1 gram. It has been a while since I saw the Ford rod blueprint. I think I am correct on the 2 grams but it might actually be 1 gram. I try to get them all the same both ends and total. Maybe 1/2 grams variable.
 
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