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...

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

That 1 gram becomes quite heavy at high rpm .

I

4 times champion 👌

No

@@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.

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

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.

​@@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.

.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!

Earle, why shouldn't they use imperial measurement?

@@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!

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

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?

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

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

@@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.

What is a D21 defect?

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

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

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.