Your cylinders have a lot of burnishing, that's metal that's been folded over, which is why it looks dull and matte dark spots in the light. When light reflects well, it means the surface finish is uniform, because all the light rays are reflecting uniformly. The light reflection tells you a lot about surface finish.
If you want to do a cylinder finishing right, you need a rigid hone, and a profilometer to see the actual surface finish. Ball hone will work, but it won't last, or work as well as doing real precision machine work. It's not to say whatever you do with a ball hone will be bad, it's just that you're leaving a lot of performance on the table. You don't know how much your peak roughness is, which is what annihilates rings in the long run.
Your correct but the amount of times I refresh and rebuild this small engine it does not make sense to take it to get a rigid hone every time. For someone that won’t want to take the engine apart for 5-10 years sure but I tear down at least once a year.
@@onebads2kracing Race engines are meant to be torn down and re-built. Still would be nice to not lose any performance over a season. Your engine has held up pretty well for the years you've ran it, keep up the good work.
I honestly think the issues with the cylinder burnishing comes from too much cylinder pressure, the top rings are forced outward by the power of combustion, the combination of ring hardness and cylinder surface finish is, in my slow opinion, the root cause of the burnishing. A stronger cylinder bore material will hold up better than the sleeves you have in there now. However a stronger cylinder wall material is also harder to hone properly, and is expensive to apply.
This never happened until moving to methanol, that’s why we are thinking it’s lack of lubrication on the cylinder walls that’s why I tried a harsher hone.
As always, great video. Eventhough your car is at a racing level and mine is just a Sunday driver. I still enjoy watching your video and knowledge. I do have a question. Did you notice any oil consumption prior to the engine teardown?
Your cylinders have a lot of burnishing, that's metal that's been folded over, which is why it looks dull and matte dark spots in the light. When light reflects well, it means the surface finish is uniform, because all the light rays are reflecting uniformly. The light reflection tells you a lot about surface finish.
Can't wait to get mine together and work with you tuning it. Great video thanks
Hell
Ya!
If you want to do a cylinder finishing right, you need a rigid hone, and a profilometer to see the actual surface finish. Ball hone will work, but it won't last, or work as well as doing real precision machine work. It's not to say whatever you do with a ball hone will be bad, it's just that you're leaving a lot of performance on the table. You don't know how much your peak roughness is, which is what annihilates rings in the long run.
Your correct but the amount of times I refresh and rebuild this small engine it does not make sense to take it to get a rigid hone every time. For someone that won’t want to take the engine apart for 5-10 years sure but I tear down at least once a year.
@@onebads2kracing Race engines are meant to be torn down and re-built. Still would be nice to not lose any performance over a season. Your engine has held up pretty well for the years you've ran it, keep up the good work.
I honestly think the issues with the cylinder burnishing comes from too much cylinder pressure, the top rings are forced outward by the power of combustion, the combination of ring hardness and cylinder surface finish is, in my slow opinion, the root cause of the burnishing. A stronger cylinder bore material will hold up better than the sleeves you have in there now. However a stronger cylinder wall material is also harder to hone properly, and is expensive to apply.
This never happened until moving to methanol, that’s why we are thinking it’s lack of lubrication on the cylinder walls that’s why I tried a harsher hone.
@@onebads2kracing It will increase the RVK, but it will also increase the RPK.
nice keep it up ..
Thanks
As always, great video. Eventhough your car is at a racing level and mine is just a Sunday driver. I still enjoy watching your video and knowledge. I do have a question. Did you notice any oil consumption prior to the engine teardown?
Nope nothing. And still had great leak down numbers under 8% on every cylinder.
Those wear marks on your pistons are burnishing.