Rotor Housing Hardening
02-09-2010, 10:47 PM
#1
Rotor Housing Hardening
I stumbled upon this bit of information while skimming through this article in Autoblog.com.
It has to do with a process called Plasma Transferred Wire Arc (PTWA) process.
Here are a few points that stuck out while reading.
"The heart of the PTWA process involves feeding a steel wire into a device that heats it up to 35,000 degrees Fahrenheit and then sprays it onto the aluminum cylinder bores."
"Using the PTWA process allows the block to have a thinner surface coating – only 150 microns deep – that is just as tough as one with cast or pressed-in iron or steel liners. However, using less material results in lower weight. According to Hameedi, the GT500 block is 8.5 pounds lighter than the sleeved GT version. Overall, the complete engine is 102 pounds lighter than the 2010 cast iron engine. The steel coating has also helped Ford reduce the internal friction of the engine, aiding both efficiency and power production."
As I was reading this article, I thought of our rotor housings and the possible application of this process. Considering the current process of rotor housing hardening dates back to 1974 and as far as I know, no significant change to the process has changed yet, this technology might have some use in designing a better rotor coating that has better friction characteristics.
Any thoughts from the rotary gods?
It has to do with a process called Plasma Transferred Wire Arc (PTWA) process.
Here are a few points that stuck out while reading.
"The heart of the PTWA process involves feeding a steel wire into a device that heats it up to 35,000 degrees Fahrenheit and then sprays it onto the aluminum cylinder bores."
"Using the PTWA process allows the block to have a thinner surface coating – only 150 microns deep – that is just as tough as one with cast or pressed-in iron or steel liners. However, using less material results in lower weight. According to Hameedi, the GT500 block is 8.5 pounds lighter than the sleeved GT version. Overall, the complete engine is 102 pounds lighter than the 2010 cast iron engine. The steel coating has also helped Ford reduce the internal friction of the engine, aiding both efficiency and power production."
As I was reading this article, I thought of our rotor housings and the possible application of this process. Considering the current process of rotor housing hardening dates back to 1974 and as far as I know, no significant change to the process has changed yet, this technology might have some use in designing a better rotor coating that has better friction characteristics.
Any thoughts from the rotary gods?
02-10-2010, 06:29 AM
#3
02-10-2010, 06:46 AM
#4
02-10-2010, 06:48 AM
#5
As an engineer I have to say it sounds like an interesting process although I'm a wee skeptical over the numbers, 35k to melt it? Doesn't take more than 1/10th of that to melt steel depending on the alloy/grade let alone the effect of that temperature all the sudden sprayed on aluminum instantly. Wonder how they control it without having serious damage occur and smooth over the internals to . I'd had to read into how they control that process.
02-10-2010, 07:02 AM
#6
02-10-2010, 08:50 AM
#7
Mazda has made significant changes to the surface, well, of course its not as good as some exotic surface like carbon metallic. and Mazda knows it, if they can sell the car at 2-3 times more ... they can even use Aluminum Rotors.
You can still send your housing to have some company to do the surface, the process cost about I think 300 bux each, and when you use it with Dr. I's seal ... w00t
You can still send your housing to have some company to do the surface, the process cost about I think 300 bux each, and when you use it with Dr. I's seal ... w00t
02-10-2010, 10:14 AM
#9
How would all this expense and the use of Ianetti's seals make any difference? Do you think the Renesis has THAT much blow-by?
02-10-2010, 10:34 AM
#10
BDC Motorsports
There was a guy back in about 2003-2004 in the Rx7 community that was exploring this. He figured out a way to produce the plasma arc and all that, posted up a video of it, etc.. then poof. Lost interest or something. He was trying to come up with a way of re-chroming the rotor housings to try and help repair damaged ones.
B
B
02-10-2010, 10:41 AM
#11
but for ultimate performance people or racing, its not bad I guess.
Last edited by nycgps; 02-10-2010 at 10:44 AM.
02-10-2010, 10:53 AM
#13
Great information and thanks for some of the corrections on the evolution of the chroming process on our rotor housings. I did some casual searching on rotor housing coating to see if anyone/any company has had experience in rotor housing re-chroming/plating. I came across this site called JHB Performance where they offer a "cermet-coating" process for 13B rotors housings.
I'm not in the market for such a process...just curious as to what others are doing to improve on Mazda's rotary engineering.
I'm not in the market for such a process...just curious as to what others are doing to improve on Mazda's rotary engineering.
02-10-2010, 07:02 PM
#14
a "brand new" engine cost about 6K, a Brand new engine + those crazy stuff can easily double the cost. so is it worth it ? maybe. matter of opinion I guess.
Great information and thanks for some of the corrections on the evolution of the chroming process on our rotor housings. I did some casual searching on rotor housing coating to see if anyone/any company has had experience in rotor housing re-chroming/plating. I came across this site called JHB Performance where they offer a "cermet-coating" process for 13B rotors housings.
I'm not in the market for such a process...just curious as to what others are doing to improve on Mazda's rotary engineering.
I'm not in the market for such a process...just curious as to what others are doing to improve on Mazda's rotary engineering.
Mazda has tried a lot (if not all) of different materials and process. In fact, a lot more than we imagine. one example is Aluminum side housing and Aluminum Rotors. Mazda has tried them like 20 something years ago. It ran very very good, it shows little to no where in their lab test. but it cost too much for production car, thats why they went back to Cast Iron.
02-10-2010, 07:16 PM
#15
Guys in PR have started coating the rotor housing surface with Cermet which is an extremely hard tooling coating used for machining of hard metals. they are even able to fix housings with slight grooves and imperfections.
I think it will start to come to light in the next year or so.
Best regards,
Chris
I think it will start to come to light in the next year or so.
Best regards,
Chris
02-10-2010, 07:52 PM
#16
Guys in PR have started coating the rotor housing surface with Cermet which is an extremely hard tooling coating used for machining of hard metals. they are even able to fix housings with slight grooves and imperfections.
I think it will start to come to light in the next year or so.
Best regards,
Chris
I think it will start to come to light in the next year or so.
Best regards,
Chris
http://www.jhbperformance.com/products.php
02-11-2010, 08:16 AM
#18
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As an engineer I have to say it sounds like an interesting process although I'm a wee skeptical over the numbers, 35k to melt it? Doesn't take more than 1/10th of that to melt steel depending on the alloy/grade let alone the effect of that temperature all the sudden sprayed on aluminum instantly. Wonder how they control it without having serious damage occur and smooth over the internals to . I'd had to read into how they control that process.
The process has been around for a long, long time, it's how they coat medical tooling.
02-11-2010, 01:04 PM
#21
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Depends what you spray on there, I'd bet that if you switched to TiALN being plasma sprayed on there, you'd go through a lot of rotor tips/piston rings before you wear through it...
02-11-2010, 02:20 PM
#23
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On topic this reminded me of the recented news about the new shelby gt500
In addition to being lighter, the new engine should also be more efficient thanks to Ford's Plasma Transfer Wire Arc (PTWA) cylinder coating system that reduces friction between the engine's pistons and cylinders. If this tech sounds familiar, it's because Ford licensed the PTWA tech to Nissan for the GT-R. The engine's slippery plasma-coated internals--along with a move from pneumatic to electric power steering--help the GT500 achieve a projected of 23 MPG highway and 15 MPG, which makes the GT500 one of only a handful of 500-plus horsepower cars that doesn't get slapped with the gas guzzler tax.
02-11-2010, 05:37 PM
#24
02-11-2010, 07:42 PM
#25
The whole purpose of this technology was to make sleeving unnecessary on aluminum blocks for piston motors.
One of the main problems with rotor housings is retaining the oil film from the OMP (which affects oil consumption and housing life). I don't see how coating an aluminum housing with steel is going to solve that unless there is some material property that we are unaware of.
One of the main problems with rotor housings is retaining the oil film from the OMP (which affects oil consumption and housing life). I don't see how coating an aluminum housing with steel is going to solve that unless there is some material property that we are unaware of.