We reveal our connecting Rod & piston balancing SECRETS…

[@Avemech01]

I overhaul aircraft piston engines (opposed) and weigh our rods, pistons, etc as well. The only difference we have is that I'm not allowed to remove material to get the assemblies to match. I have to put lighter and heavier components together (within 2 grams) in order to balance the assemblies from side-to-side. I'm like you, i always check the measurements even when the parts are new from the factory. Most the time things check out, but every once and while something odd comes out. Thankfully with today's tighter manufacturing processes (at least in aviation) we don't have a ton of variation. Thanks for the video!!

[@ChiefCabioch]

Trying to get perfection is impossible, the biggest variable is the oil under the piston on the way up, verses oil under the pistons on the way down, and in a radial it's even more pronounced...

[@brentadler9539]

It's as easy as that.... thanks for the tutorial, well needed. Always a good watch. Cheers from New Zealand 🇳🇿

[@stephenmiller5004]

I’m 74 now, but I remember quite vividly going to a workshop as an apprentice and they were building a bike engine for racing in the Isle of Man TT. The owner had just received a set of pistons for his Norton bike and he set about them with a vice and a hacksaw, naturally I asked him what the hell was he doing. He was lightening them he said, so that the engine could rev higher without coming apart. Obviously, things were not so precise in those days. He also never won a race at the TT, but I guess he had fun.

[@robbateman7987]

Perfect timing for me. Am balancing some conrods for my spare Kawasaki Z500 engine this week. Home built jig, am using small roller bearings to get rid of much friction as poss in the balance on a free floating arm. I am balancing to 0.5 g or better. Also would not take material from the bottom web but from the side of the big end. Your jig does get good consistent results. Nice one.

[@eddieMurphy11111]

a great video and take no notice of what others say in a negative way you know what you are doing and that's all that matters

[@AR3n3gad3]

Love the Jig Setup! Thanks so Much!!!

[@rixward5475]

ive seen other shops have 2 scales with a jig as some rods weight is heavier/lighter on one side of the rod , so you weigh the rod one way then flip it upside down to weigh it the other way , normally blueprinting an engine you measure & weigh every possible way multiple times to reconfirm everything is precise , tolerances are spot on for each cylinder , adjust & readjust

[@jasonsardie8085]

Great video. Thanks for sharing.

[@frenchie7206]

Absolutely outstanding once again methodical in every aspect of your engine building Business My Cossie lump will definitely be coming to you guys at some point Brilliant vid once again keep them coming 👍

[@sidwainhouse]

My father in law has used the exact same method for the last fifty years for a major motorsports engineering company.

[@doncodman913]

Thanks ...Never knew this sort of thing happened . Interesting ! rgds Don

[@theessexhunter1305]

what are you like at the village fate at not setting the buzzer off on the curly wire ?

[@BarumEngines]

4 times champion 👌

[@magnusdanielsson2749]

I found weighing rods to be a work of patience. Getting consistent readings demads exact placement every time.. I built an arm with a razorblade that goes in the big end. Taped all the stands down so nothing moves. I have one odd rod among 6. Its the same weight in both ends but lighter total weight. Assume its some casting imperfection causing density difference.

[@jacquespoirier9071]

on any production engine, weight matching is a notable improvement at about zero cost, From what I've saw when doing that operation on my engines, the connecting rod is the component that needs the most part of the correction.usually, pistons and pins are very close match so a little or no corrections are necessary.

[@bostedtap8399]

Very interesting.

[@johnnyholland8765]

Only thing I would do is on the round pieces of your jig I would create a knife edge for the rods to rest on. The least amount of contact surface you have the more accurate your measurement will be. But if your satisfied with your setup and it works for you then that is fine. Just my two cents worth...

[@vg23air]

Here's an idea, weigh them, if they are off, send them back, tell them you want matching rods. If they cant provide matching rods, go somewhere else and let them know you are telling others you went somewhere else.

[@stephensaines7100]

'Manly Comrods'...and thus the glorious Revolution!

[@petershepherd6889]

So if you add the two figures together does that give you the total weight of the Conrod.?

[@m638csi]

No

[@petershepherd6889]

@@m638csi so if the big end and little end figures for two Conrods were different but the totals were the same would the two rods be balanced.

[@madeljacky]

It should give you the total weight of the rod in theory, when I used to weigh a microlight for its certificate of airworthiness every 5 years (that rule was scraped in 2015) I used one set of digital scales and took the reading under each of the three wheels and add them together, that gives you the total weight of the aircraft. I had two wooden blocks the same height as the scales under the other two wheels at the same time to keep the aircraft level of course. Another example is when VOSA weigh the weight of a lorry, they only weigh one axle at a time as you slowly drive over it, then they add all your axle weights together which lets them see if your total weight and as well it lets them see if you are overweight on any axle but still could be under your total weight

[@stephensaines7100]

Not necessarily. Balance in the horizontal plane would have to be absolute to achieve that. That would be impossible in practical terms with this set-up...not that it matters for this purpose. I think what's shown is an excellent and easy way to achieve the needed outcome.

[@robb1165]

​@@petershepherd6889 The big end is mostly rotating mass, the little end is mostly reciprocating mass, and the material in between is a mixture of rotating and reciprocating. So, if there were differences between rods the characteristics would be slightly different and considered out of balance.

[@steve5x565]

I like this kind of content, although I did worry about the vagueness about where material gets removed. Where you remove material from is actually really important, probably not for the kind of race engines you build, but for extreme performance engines it is. Those components you showed are top line for 99% of people who will watch this, but I live near Northampton and know retired Cosworth engine builders who would be apoplectic! These guys would polish every casting mark (or forging imperfection) before even beginning to weigh them. I’m sure you will find the internet is full of people who know better than you… I don’t I am an amateur (with a small amount of knowledge). Your are spot on though, it doesn’t matter the method you use for measuring, the actual number means nothing, as long as it is repeatable and consistent. I would like you to purchase a better scale though, 1 gram is quite a bit when it comes to moving components, it’s probably why you never see any differences in the bearing weights, there is nearly a 1 gram range that scale won’t measure. 1.5 - 2.4 grams for example will measure as 2 grams, that’s potentially 0.9 gram you don’t need to remove from a rod or piston to make it all balance. Great stuff, keep it coming, glad you changed the previous one, you don’t deserve to be robbed. 😘👍

[@JasmineJDMgirl]

Well you ask about material to remove well top of the range stuff realy is already done like as in H rods but as for pistons an there assembles the gudgon pin gets turn out from each end on the inside in a lathe an the pistons gets material removed from the side recesses the rings no ofcaues but as for the rods all standard rods from the factory will have a lot of meat on the small end as a casting on the end and the big end will have the same on the bottom cap as most people who have seen stock rods will know this is the aerea on the lump of casting you remove no where else both ends get done in the same way as by the use of a metal sanding belt for accuracy each part gets weighed an sanded several times for complete same weighted rods so they all end up the same weight but as I said top notch like manly rods dont need this done it's more for standard OEM rods due to the extra meat on each end I hope this helps oh one more thing this is done with the bearings added to each big end and no not assembled in the big end just added to the scale balance plates we did not use the bearings as such we would make a up a peice of thin sheet metal bearing weight to be clamped in between the big end caps just hand tight this thin sheet we put a curve radius on one side as to help set the big end on the scale plate so it only touched in one spot on the radius Jasmine JDM girl from Sydney

[@ronniecox109]

That 1 gram becomes quite heavy at high rpm .

[@mikemilanowski8827]

I

[@davidteixiera8398]

Awesome jig setup 👌

[@who-gives-a-toss_Bear]

I've worked in a tool room for years, not the automotive industry. Please educate me, which term displays the highest accuracy. “Bang on” or “Cock on” 😇

[@BulliKid]

My wrist pins won’t fit the rod small bore out of the box. Any advice

[@mikegross3800]

They are most likely to be pressed into the rod.

[@wilburt6131]

Local gravity can account for the discrepancy in Conrod weights. I read on net a100kg person would weigh 200g more in Tasmania than they would in Queensland due to gravity fluctuations

[@davidoldboy5425]

Great video as usual, very informative thank you.

[@kianward5999]

that is just great content love the channel keep up the good vids pal

[@TheMxrrab]

Well I learned something new today

[@1donniekak]

You guys ever try different ratios for different layouts? For example we do anywhere from 50-65% balance factor with 60* split pin v6's.

[@m638csi]

Would like to know one thing. Let’s say that non oem Conrod/piston combo is 100g. Lighter then oem one. What do you do with crank counter weights?

[@BarumEngines]

Doesn’t matter on an in-line 4 cylinder, would matter on a v8. Counter weighing would be needed 👍

[@m638csi]

@@BarumEngines what about in-line 6? Thanks for reply

[@mikehunt8968]

@@BarumEngines That's why they often run different harmonic balancers on modified V8 motors, to fix the dynamic balance... They even try different firing orders to get the power characteristics they want. Yamaha R1 X-Plane cranks being an example of that type of thing.

[@earlebacciochi9796]

Yes always check! Once had a sports camshaft from Yosimura Racing, One of the cam lobes was exactly 100 thousands of an inch smaller than the rest !Never really understand why Japanese company was using Imperial measuring?

[@geoffgreenhalgh3553]

.100" ? that's almost 1 eighth of an inch. (2.54 mm) Never in a million years would Yoshi produce a cam that far out of tolerance!

[@iareid8255]

Earle, why shouldn't they use imperial measurement?

[@earlebacciochi9796]

@@geoffgreenhalgh3553 No one more surprised than me! It's exactly a 10th of an inch. Which is why i noticed it ,before I even measured it!

[@earlebacciochi9796]

@@iareid8255 It's just that Japanese nuts,bolts, owners manuals and technical books are Metric!

[@iareid8255]

Earle, OK, are you saying that Yosimura Racing give their camshaft specifications in Imperial? If so it's unusual if Japan uses the metric system?

[@hipstarchild]

The amount of money people pay for new pistons and rods, you'd expect the manufacturers to get them absolutely spot on

[@trevormansfield6740]

Good video. I learned a few things there 👍

[@RalfyCustoms]

Proper job bud

[@GarageNation353]

I'd love to know what I'm doing wrong. I've made up similar jigs, but keep getting different readings.

[@LuckyBaldwin777]

Interesting. I wonder why the 11g difference.

[@phillipthethird42]

Spot on, always measure.

[@JasmineJDMgirl]

Well I used to work for lynx engineering on parramatta road many yr ago doing such a job complete engine balancing an we used 2 sets of scales one set for the big end an the other set for the small end both sets of scales where side by side to give a accurate measurement I never seen it done like this as there is or could be a discrepancy on the weight figures due to a incorrect placement on the jig but if done precisely I dont see why this would not work Jasmine JDM girl from Sydney Australia

[@therollintoolbox3547]

Great info i would add maybe driling oil hole a bit bigger to cut weight but it would also require a lil biger oil pump to keep up

[@CR3W1SH03S]

Trying to understand the purpose of the line on the jig on the scale.

[@AndrewDrapper]

Manly con-rods that are “ cock on!” Is it safe to watch the rest of this video?

[@cw2126]

👍👍👍

[@davevaughn7057]

Always check and double check to make sure it’s always right.

[@1magnit]

Have you ever dynamically balanced a 60 deg V6? What's your secret for bobweights for these?

[@eliotmansfield]

jewellery scales go down to fractions

[@tomhamilton9140]

We had a motor that would wipe out main bearings after a pressure plate change. Every thing has to be checked now days.

[@slowcountryboy476]

You twok fonney, but I did understand you and you make much sense. Thank you!!

[@FOSTERSFARMGARAGETV]

Just take material from the piston pins

[@kevinsmith1044]

Those rods and pistons are works of art. Side note: cock on is now my favorite saying

[@DEATHWISHVQ]

cheers from silent hill

[@jasonsardie8085]

Your jig is fine.

[@fuzzayd4601]

" zubaru impretza" 😂

[@spacedust2270]

Number 3 piston has a D21 defect

[@ohboy2118]

What is a D21 defect?

[@richardperry21]

FYI: There is NO balancing SECRET here,,, in fact you should probably have little rollers with a bob at the bottom to be more precise. We have been doing that since the mid 1960's

[@PeggyParrow]

Dont weigh small end first ..! I LEARNED from professional engine builders and balanced engines for years...first. weigh big end and correct them because they are most critical because they are reciprocating.. next weigh the total rod and get all total weights the same by removing weight from small end. Why ? Just 2 things matter...reciprocating weight and total weight ! Hope this helps .

[@666kty3]

UH....OTHER THAN THE FACT MANLEY H BEAMS COME ALREADY WEIGHT MATCHED AND BALANCED....CHECKING IS A GOOD POLICY. NICE TO SEE SOME CONTENT THAT ISNT ABOUT BEATING SOMEONE OUT OF A WARRANTY CLAIM.

[@vg23air]

if you are competing against me please use the methods in this video to balance stuff lol

[@riccocool]

No one is grinding my rod.

[@Choober65]

Well, I know what brand of Conrods I'm going to use.

[@SamsungGalaxy-bk1vf]

When you remove from edges it will be un ballenced the other way leave it to the experts

[@MrGuvEuroman]

Your not balancing you’re weight matching.

[@WarlordMarty]

It's all part of balancing. If the rod weights are out, the balance of the rotating assembly when running would be too.

[@BarumEngines]

Weight matching piston and rods (balancing end for end) is all part of balancing the rotating parts of the engine 👍

[@bcr1818]

I don't mean to disrespect you, but there are so many mistakes in this video. You never remove weight from the ribs on the big end. You should always remove them from near the bolt area. Pistons is the same, never near the skirt, but aroudn the pin end area, chamfer that a bit. Depending on what you do you want to balance closer then let's just say 1gram (what your scale can measure to).

[@stevenbelue5496]

Don’t think I would use a jig like this, the prop end of the rod should be on a pendulum for unbiased tension for accurate measurements. Also should measure tenths of a gram at least, if your rounding to the gram after just 3 measurements you could be off more than 1 gram. For a street engine that might be ok but for a serious engine you must at least do tenths.

[@mightyeagle]

2 words for customers Plasta gauge

[@gibsonandpickett]

There is no need to weigh bearings on that type of engines

[@ema1671]

Cockon? WTF is that?

[@simonchang3929]

More talk than action