Harley engine balancing, reverse engineering, and balancing

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saddlebagrail
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Re: Harley engine balancing, reverse engineering, and balanc

#16

Post by saddlebagrail »

Cotten wrote:If I may in the meantime, Folks,

Please allow me to explain my position on mutilating the female rod top.

Imagine these rod tops sawn off. One is a male rod, the other its mate.
It is obvious that their masses would be nearly the same.
These are the major portions of the rods which travel in different directions.

The hanging method of determining mass of rod tops, however, includes mass from the bottoms of the rods.
That's why we hang them: Some of the bottoms are moving up and down, thus reciprocating mass, but not traveling divergently, like the tops.

The huge female rod will alway have a heavier top than the male, unless you carve it to an extreme, pointlessly attempting to make the bottoms equal by altering the tops.

Now imagine Ray's rod tops sawn off.
The hardware that actually travels in different directions is now dramatically un-equal.

How ironic that in search of a mythical ideal of equality, the rods should be contrived to be different.
One can only wonder how it affects its rigidity, etc.

But since the inherent design of the motor can absorb it,
it is much a do about nothing!

....Cotten
Jealousy can be that bad,I have to agree yes :mrgreen: ,more please I want more :mrgreen: ,why keep arguying your idea is set on a thing, and I have mind,I will not make you change your mind and I really don't want to ,please would you do me a favor ,TAKE THE TIMES TO REALLY POST SOME REAL TECH THREADS WITH PICTURES INSTEAD.....
1950EL
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Re: Harley engine balancing, reverse engineering, and balanc

#17

Post by 1950EL »

I do not have the knowledge, education, training, or experience to validate (or even completely understand) either of the differing opinions here. I enjoyed reading the original post and felt a little more informed after doing so and seeing the photos. I will never be doing this but I have a better understanding of one man's way of doing it and I thank you for that. I also appreciate knowing that this is not necessarily the only way to do it. I thank you both for taking the time and trouble.
Mike
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Re: Harley engine balancing, reverse engineering, and balanc

#18

Post by saddlebagrail »

1950EL wrote:I do not have the knowledge, education, training, or experience to validate (or even completely understand) either of the differing opinions here. I enjoyed reading the original post and felt a little more informed after doing so and seeing the photos. I will never be doing this but I have a better understanding of one man's way of doing it and I thank you for that. I also appreciate knowing that this is not necessarily the only way to do it. I thank you both for taking the time and trouble.
Mike
Your Welcome Mike

For sure it might not be for everyone, but at least now you know the basic on how parts works together inside of your engine ,it is a plus for you,and if you want to try it by yourself sometimes in the future, then you will have all the basics.

There is other ways of making it, everyone have different opinions on this subject,my goal was to educate those, like you who never completly understand the Harley balancing thing,with a complete story like I just did, with clear explanations and pictures it is way easier to understand,I thank you for taking the time to post your feeling about the original thread.

....For the time and trouble I guess I have the large parts of the cake here :mrgreen:

Ray
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Re: Harley engine balancing, reverse engineering, and balanc

#19

Post by ingram »

Great article and fantastic pictures. :!: :!: :!:

Thanks for sharing Ray.
saddlebagrail
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Re: Harley engine balancing, reverse engineering, and balanc

#20

Post by saddlebagrail »

ingram wrote:Great article and fantastic pictures. :!: :!: :!:

Thanks for sharing Ray.
Thanks Mike,.....Are you making cams for any Harley V-Twin ?
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Re: Harley engine balancing, reverse engineering, and balanc

#21

Post by clunker1 »

Thanks so much for this great article. It is very well documented. Looks like it took a lot of time to do.

I have a question. Balance factor. Would you also use 60% for a roller bearing case panhead motor? The LH flywheel is quite thick and heavy. Any advice on the balance factor on these older motors?

I was also wondering if a lead slug held in with a threaded plug would be ok?

Thanks
Dennis
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Re: Harley engine balancing, reverse engineering, and balanc

#22

Post by saddlebagrail »

clunker1 wrote:Thanks so much for this great article. It is very well documented. Looks like it took a lot of time to do.

I have a question. Balance factor. Would you also use 60% for a roller bearing case panhead motor? The LH flywheel is quite thick and heavy. Any advice on the balance factor on these older motors?

I was also wondering if a lead slug held in with a threaded plug would be ok?

Thanks
Dennis
Dennis

I have balanced my own 67 Shovel with a 60% balance factor and it is really smooth even if my flywheels are among the heaviest of all Harley,Ray

Lead plug are soft compare to Tungstene/Mallory and if you are using a threaded portion at the end do not crush the lead plug by overtorquing them or the thread could move.

To make sure you are using brake cleaner,Loctite primer and Red Loctite to make sure thread do not move after it is set.
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Re: Harley engine balancing, reverse engineering, and balanc

#23

Post by Flathead80 »

I use the identical system to balance old flatheads as does Ray. What Ray did to the rod end does not weaken it as implied by Cotton. Old flathead racers used to drill holes the length of the rod to lighten them. I have a set in one of my engines that was raced for years and is still going strong. I used to use Jahn's racing pistons, which were heavier than stock, and put them on polished and shot peened rods that had more metal removed that those shown by Ray. I have never had a rod fail - ever. I am rebuilding two ULH's this very minute. One is a 0.020" OS and the other a 0.030" OS with a small increase in stroke with lightened flywheels. If you don't think equalizing the small ends of the rods makes for a smoother engine, you just haven't balanced many engines. It works and works very well. I can't imagine why anyone would not do so. I have been riding Harleys since since 1959, and some of them would vibrate you into numbness within 20 miles. Nothing I know of smooths them out better than a good static balance job. Some of the Bonneville guys go to amazing lengths to balance their engines as they lighten the reciprocating mass (and rotating mass in some cases). I go with what works, and Ray's method works.

Just my opinion. Your choice.

Jim 8)
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Re: Harley engine balancing, reverse engineering, and balanc

#24

Post by saddlebagrail »

Flathead80 wrote:I use the identical system to balance old flatheads as does Ray. What Ray did to the rod end does not weaken it as implied by Cotton. Old flathead racers used to drill holes the length of the rod to lighten them. I have a set in one of my engines that was raced for years and is still going strong. I used to use Jahn's racing pistons, which were heavier than stock, and put them on polished and shot peened rods that had more metal removed that those shown by Ray. I have never had a rod fail - ever. I am rebuilding two ULH's this very minute. One is a 0.020" OS and the other a 0.030" OS with a small increase in stroke with lightened flywheels. If you don't think equalizing the small ends of the rods makes for a smoother engine, you just haven't balanced many engines. It works and works very well. I can't imagine why anyone would not do so. I have been riding Harleys since since 1959, and some of them would vibrate you into numbness within 20 miles. Nothing I know of smooths them out better than a good static balance job. Some of the Bonneville guys go to amazing lengths to balance their engines as they lighten the reciprocating mass (and rotating mass in some cases). I go with what works, and Ray's method works.

Just my opinion. Your choice.

Jim 8)
Thanks Jim for your input,I know that it is among the smoothness you could achieve the way I did my balancing job, but some tend to be reluctant the way I do it,some say rods may be weaken,I have done strocker that way and feeling was incredible after the balancing job ,and never have one failed or never had any come back,Ray
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Re: Harley engine balancing, reverse engineering, and balanc

#25

Post by Cotten »

You people just don't get it...

Look at the photo I posted of the pair of rod tops, and who can tell which is the female, and which is the male?

If you chopped them off at the bottom of the photo, they would, for all practical purposes, weigh the same, and that is a good thing!
The tops of the rods are the parts that move in different directions. Their bottoms rotate in unison, like the rest of the rotating mass.

But the bottoms of the rods are not equal, as the forked female bottom is much heavier. Yet they too, move up and down through the stroke, reciprocating proportionalely.

So the applied technique is to weigh the top half of the rod, as it will also weigh a portion of the bottom. The top of the female rod will always read to weigh more than the male, because it is half of a much heavier rod.

Thus the inequality of the two rods is accounted for, without making the actual part of the rods that fly in different directions horribly unequal.

It worked for a century, and there are serious reasons why female rod tops were never whittled into toothpicks.

Just the basics, not armchair conjuring.

....Cotten
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Re: Harley engine balancing, reverse engineering, and balanc

#26

Post by Flathead80 »

No offense Cotton, but I doubt you have ever balanced a Harley engine. Re-examine your little dissertation, and see if you can spot an error in your statements.

I just finished balancing an old flathead 80 that vibrated so badly, the owner would have to ride with one hand at a time to avoid numbness. After balancing, it was obvious the two flywheels were not a matched set from the factory. I used a balance factor of 55% (flathead), and discovered one of the wheels was in balance within a single 0.25" deep 1/2" hole opposite the rod pin. The second was way out of balance and required way more drilling. I also had to remove 12.54 grams from the end of one of the rods. Got any idea of the volume of 12.54 grams of steel? It was a polish job. I used up my last set of Jahn's pistons (hint, hint) as this engine will make a cross country trip this fall (Wilmington to LA), and one of the points of the trip is to demonstrate the reliability of the old flatties. I will bet my next check that this old beast will run as smooth as silk and that lightened rod won't fail. If we make it, you will see that bikes (and engines) in one of our biker rags. My name will appear as the engine builder of two of the three bikes. There will be no chase vehicle. It's a wait, but maybe we can continue this discussion after the trip and demonstrate some real world results (or not). Incidentally, I decided to rebuild my Green 80 for the trip. It is converted for electric start as I don't like kicking over 80 ci+ engines every time I want to go somewhere. The Green 80 is a big time relieved flattie bored 0.030" OS, tricked out drive bearing setup (INA bearing running on a later model CH'ed output shaft), ported intakes, warmed over (reground) intake cams, ceramic coated piston tops and exhaust ports, hand fitted oil pumps (both), and hand matched gasket surfaces breathing through a 40mm Mikuni. It will break the century mark in a heartbeat and run at 80mph all day long. Guess what? It is balanced using the method recommended by Ray.

I don't understand why you are attacking Ray, as Ray is correctly assuming the reciprocating forces dominate the rotational forces at the end of the rod. The rotational forces are maxed at the rod pin and zero at the piston pin. The reciprocating forces are maxed at the piston pin and minimized at the rod pin. A difference in reciprocating force will produce a more noticeable vibration. Try it yourself sometime.

Jim
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Re: Harley engine balancing, reverse engineering, and balanc

#27

Post by Cotten »

facepalm-triple.jpg
facepalm-triple.jpg (16.17 KiB) Viewed 3947 times
It never ceases to astound me how the gullible can be impressed by bell an whistles, Folks.

Motor balancing has nothing to do with handlebar vibrations, and total flymass has nothing to do with factor.

Learn the basics, first Folks, and then play with your toys.

....Cotten
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Re: Harley engine balancing, reverse engineering, and balanc

#28

Post by Flathead80 »

What are you talking about? Where are you getting your information? Superman comic books? Anyone who says an unbalanced engine won't induce a vibration in the handlebars shouldn't even be in this conversation. I have seen a Panhead that was put together with parts off eBay that (before balancing) was almost unrideable due to a vibration that would shake you hands of the bars. After balancing, the bike wasn't like new, but she ran smooth at highway speeds. A Harley is made up of many rotating and reciprocating parts in differing planes that all contribute to the final ride. The entire mass is connected by bolts, pins, etc. that pass along whatever vibration is imparted to them. You can't eliminate all unbalanced forces, since even ignition timing (and ignition) can impart a change in felt vibration at differing rpm. Vibrations have different amplitudes and frequencies that can change due to outside forces (wind) or changing rpm, or varying accelerations. You can idle a top fuel dragster up to the line with ease, but hammer that sucker and you will discover vibration takes on a whole new dimension.

I am fairly new to this forum, and know no one on the forum. I am a retired engineer (no trains) who would enjoy an in depth discussion on this subject, but I suspect you are reading stuff on the net between posts and not quite understanding what you have read. Balancing an engine doesn't mean it will feel the same over the entire rpm range, and for lack of a better description, the Balance Factor can be viewed as a means of moving that "sweet spot" up and down the range. It is very easy to sit back and arrogantly pontificate on what makes an engine run faster/better/smoother/etc.; but a totally different world opens up when you are the guy who has to physically produce the desired result.

I am going to bow out of this intercourse, as it is too one sided for my tastes. Keep on trucking, Ray. The system works for you and it works for me, and the third party doesn't appear to work at all.

Jim :D
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Re: Harley engine balancing, reverse engineering, and balanc

#29

Post by Cotten »

Jim!

Please don't ask a question and then leave.
You might benefit.

Here's a source of theory basics: http://virtualindian.org/1techflywheel.htm
(Please note that I only moderated, and the valuable information that you really aught to grasp isn't mine.)

And you really need not throw personal attacks.
(I suspect that you may not have even been born yet when I was toiling in a speed shop on a Stewart-Warner, balancing Harleys, autos, and even Caterpillar hardware as well.)

The theory I endorse worked for a century, made these machines the icons we revere, and Mother Nature's laws of physics haven't changed. Ask yourself why Harley rod tops were always the same size. And Indians. And all V-twins.

....Cotten
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Re: Harley engine balancing, reverse engineering, and balanc

#30

Post by john HD »

Gentlemen,

We strive for civil conversations here. This is not a tribal chopper site.

Jim, since you are new here i'm cutting some slack. However, when you start a post with "no offense" and follow with an insult i suspect you ment to offend in the first place. Prove me wrong...

Cotten, i think you have gotten your point across. Let's please move on.

This thread is locked until further notice.

john
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