Topic: Isotropic surface finishing aka super finishing - anyone doing it?

[turboguzzi]

2-3 gp on a 120 hp supersport 600 would equal 1-2 hp on your 70 hp CB750 (correct the numbers according to your actual dyno readings....), so I tend to agree with simon, looks like low return on investment, if any.

DLC, TIN and other surface treatments that actually increase surface hardness rather than just polish the micro ridges are of course another story.  Wide spread in motogp etc.

In what type of applications does NASA use it? Relevant to internal combustion engines/gears?



 

[kmb69]

Hard to imagine why most of the top F1, Nascar, and NHRA teams waste their time and money to use it if it doesn't work! 

I guess people use it when every ounce of advantage counts and cost is secondary to ANY performance improvement. 

My understanding is there are differing treatments used for optimizing specific applications.

[slikwilli420]

Again, not just about power gains but I'll gladly take 1-2hp for the cost involved. Considering what it costs to get 80+ out of a 750cc motor already it is really icing on the cake. Things like smoother shifting and a rotating assembly that spins more freely are no brainers. Longevity of parts by decreasing stress risers sounds good too. It seems these are uncharted waters for our motors and I'm more than willing to give it a try. I have a few more things cooking that will be very different from other racers engines.

[kmb69]

Again, not just about power gains but I'll gladly take 1-2hp for the cost involved. Considering what it costs to get 80+ out of a 750cc motor already it is really icing on the cake. Things like smoother shifting and a rotating assembly that spins more freely are no brainers. Longevity of parts by decreasing stress risers sounds good too. It seems these are uncharted waters for our motors and I'm more than willing to give it a try. I have a few more things cooking that will be very different from other racers engines.

+1
The potential "dependability" factor, reducing possible crack propagation, when pushing these old parts, is of real value to me.

[754]

 That and ANYTHING lasting even a little bit longer can help win a race..

[turboguzzi]

well, you guys got me curious. and yes, nasa tried it, just not with the results you'd think

here's the original article, but who knows, maybe it's faked you can never know these days...

https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20070022618.pdf

Conclusions
For the results attained the following conclusions can be made:
1.
Superfinishing   provided   no   measurable   performance   
benefit to the high speed gearing system under study. The
film  thickness  to  composite  surface  roughness  was  2  or 
greater for most of the tests conducted.
2.
Increasing  lubricant  inlet  temperature  provided  the  most 
beneficial effect to the performance of the drive system. 
3.
Thermocouple   rakes   and   arrays   installed   in   the   test   
gearbox provided data that the fling-off temperatures vary
with location across the face wi
dth of the gears as well as
the  location  within  the  gearbox  where  the  temperatures 
were  measured.  The  idler–idler  gear  meshes  typically 
produced   the   highest   rake   and   array   temperatures   
measured in all tests.
4.
The  change  in  flow  rate  (due  to  lowering  the  lubricating 
jet  pressure  from  80  to  60  psig)  had  only  a  very  minor 
effect on power loss. 

[simon#42]

exactly the results some would expect yossef !

[crazypj]

I think you lose almost 6 oz by drilling a 1/4" dia hole through axle.
 Front is dead easy to do but rear is easier to find something from mid 90's  'sport-bike', either swing arm pivot or axle.
 I have various 'weight loss' on XL spreadsheet 'somewhere safe'
From memory,  2mm overbore' lightens' block by more than half a pound.
It's all relatively simple stuff that takes time but minimal resources if you have a mini mill and mini lathe ( it's just faster to do with larger machines plus set-up's don't get so 'creative'  )

Very interested in your list if you're willing to send it along.

That wouldn't be a problem but  FINDING list may be.
I did find an old envelope with wheel rim weights a few days ago (being used as a bookmark in a service manual) Steel rims were at least 2lbs heavier than Borrani's and 1970's Borrani's were heavier than modern 'Borrani copies' by about 1/2 lb (WM3 x 18")

yoshimura was one of the brands we tested .

Not that I outright don't believe you, but it is odd that there are MANY accounts from people who have done this and felt smoother shifts, observed cleaner oil, and have dyno tested with measurable (though small) gains on power. I like data from all sources, convince me this isn't worth doing.

 You need around a 10% difference for 'seat of the pants' dyno to be able to tell any difference. Majority are using psychology to kid themselves