Plasma-moly rings
Le Mans Master
Joined: Feb 2000
Posts: 9,715
Likes: 27
From: Kempner Texas
Re: Plasma-moly rings (devilfish)
No, I there isn't. Plasma moly is just a way to identify the method used to apply the moly to the top compression ring during manufacture.
Most of use are accustom to using grit numbers to identify how coarse or fine a piece of sandpaper is; like 600 grit for the walls of an engine that's to run moly rings.
But the actual hones used in the honing machine uses a different numbering system that I'm not familiar with. Maybe someone with machine shop experience can fill in that gap.
The bore finish not only involves the smoothness of the bore, but the cross hatch pattern left by the honing process.
You could probably do a Google.com search and find tons of information on boring and honing cylinder walls.
Jake
Most of use are accustom to using grit numbers to identify how coarse or fine a piece of sandpaper is; like 600 grit for the walls of an engine that's to run moly rings.
But the actual hones used in the honing machine uses a different numbering system that I'm not familiar with. Maybe someone with machine shop experience can fill in that gap.
The bore finish not only involves the smoothness of the bore, but the cross hatch pattern left by the honing process.
You could probably do a Google.com search and find tons of information on boring and honing cylinder walls.
Jake
Le Mans Master
Joined: Feb 2000
Posts: 9,715
Likes: 27
From: Kempner Texas
Re: Plasma-moly rings (devilfish)
Like most things when first developed, when moly rings were first introduced, which I believe was back in the 70s, there was a problem with the moly chipping/breaking or falling out of the channel in the ring.
A new and different technique to install the moly in the channel was developed and that cured the problem. To my knowledge, the cylinder wall surface finish remained the same though.
The material needs a smooth surface, compared to the cast rings, but not so smooth as to prevent a certain amount of oil from remaining on the walls.
Moly rings seat almost instantly. As I posted before, I've built engines with new moly rings with only enough running time to set the timing and heat the fluids. Then headed straight to the burn-out box and the car ran the same times and MPH as expected.
In many 1/4 mile classes, if you're off a tenth, you're on the trailer headed home. If you entered the 8.90 class and run a 9.0, you might as well load up the tool box.
Jake
A new and different technique to install the moly in the channel was developed and that cured the problem. To my knowledge, the cylinder wall surface finish remained the same though.
The material needs a smooth surface, compared to the cast rings, but not so smooth as to prevent a certain amount of oil from remaining on the walls.
Moly rings seat almost instantly. As I posted before, I've built engines with new moly rings with only enough running time to set the timing and heat the fluids. Then headed straight to the burn-out box and the car ran the same times and MPH as expected.
In many 1/4 mile classes, if you're off a tenth, you're on the trailer headed home. If you entered the 8.90 class and run a 9.0, you might as well load up the tool box.
Jake
