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Stainless steel rotors.

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Old Sep 1, 2009 | 08:35 PM
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Stainless steel rotors.

Hey guys, I have a 88 t2 and im tired of the gas prices going up. So i've decided to turn my car into a hydrogen car. Im planning on running only hydrogen and i've gotten everything planned out except for the engine internals. Im worried about the inside of the engine rusting from the hydrogen turning back to water after combustion. Is there such thing as Stainless Steel Rotors or any other way I can prevent rusting on the inside of a 13bt???
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Old Sep 2, 2009 | 11:51 AM
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I seriously doubt anyone makes stainless rotors. There is a shop making aluminum rotors for drag racing, but you're talking many thousands of dollars for them.

Look up the hydrogen powered RX-8.
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Old Sep 2, 2009 | 02:52 PM
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Not an expert but possibly getting some stock rotors coated with something? IDK just a thought.
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Old Sep 2, 2009 | 03:43 PM
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Get a nice coating vapor deposited on some stock rotors. Silicon carbide or silicon nitride should be good to about 2500 F. There should be other higher temp options available if you ask a vapor deposition specialist.
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Old Sep 2, 2009 | 04:52 PM
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http://www.poeton.co.uk/coatings-motorsport.htm this is a UK shop but there will be people in the US who can do the same for you.
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Old Sep 2, 2009 | 05:37 PM
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http://www.globalspec.com/local/4284/NV

Check with vendors 2,4,6, & 7 if you are actually in the Vegas area.
See if any can do CVD of Silicon Carbide or Nitride in your area. Easier to explain requirements in person than ship off and hope they get it right.
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Old Sep 2, 2009 | 10:23 PM
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gas is mad cheap.... but id love to see how this turns out
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Old Sep 3, 2009 | 05:09 AM
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Originally Posted by GhostRotor
Hey guys, I have a 88 t2 and im tired of the gas prices going up. So i've decided to turn my car into a hydrogen car. Im planning on running only hydrogen and i've gotten everything planned out except for the engine internals. Im worried about the inside of the engine rusting from the hydrogen turning back to water after combustion. Is there such thing as Stainless Steel Rotors or any other way I can prevent rusting on the inside of a 13bt???
Nobody is making them and you'd have to pick absolutely the perfect grade of stainless to even work properly. In other words, very expensive.

Dave
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Old Sep 3, 2009 | 10:05 AM
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dude spend 2g on a Miata with 35 mpg and have a daily.
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Old Sep 6, 2009 | 10:30 AM
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Originally Posted by GhostRotor
Hey guys, I have a 88 t2 and im tired of the gas prices going up. So i've decided to turn my car into a hydrogen car. Im planning on running only hydrogen and i've gotten everything planned out except for the engine internals. Im worried about the inside of the engine rusting from the hydrogen turning back to water after combustion. Is there such thing as Stainless Steel Rotors or any other way I can prevent rusting on the inside of a 13bt???
As an experiment or project car, this sounds like a fun idea. As a practical vehicle to save money on fuel, not so much.

You don't need stainless steel rotors or any coating. Regular old cadmium plated Mazda rotors (they are plated from the factory) will work fine. Combustion temperatures are high enough that it's all steam and the oil coating from the metering oil pump will protect the rotors. Remember, quite a lot of water is produced through burning gasoline, though not as much as hydrogen, obviously.

The real problem you are going to have is making the system actually efficient. In order to store enough hydrogen to travel more then about 60 miles (remember, the energy density of hydrogen is abysmal compared to gasoline or batteries) you need to keep it liquid. Which means extremely high pressures (20,000+ PSI) and lots of insulation. Such a storage tank will not be cheap, and must be rated for on road use.

Then you have to actually fill it, which means a high pressure pump and a supply of hydrogen. If you expect to use cylinders purchased at the welding store, forget it. Even the largest particle size is only 360 cubic feed and weighs over 100 LBs. It also costs 10x the money as gasoline for the same distance driven.

If you expect to make the hydrogen at home, forget it. It will be an enormous cost to acquire the compressor and storage tank, and electrolosys is very inefficient.

We have not even covered actually running the engine with the stuff and already it's not worth the hassle by several orders of magnitude.
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Old Sep 8, 2009 | 02:29 AM
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Originally Posted by 13BT_RX3
Get a nice coating vapor deposited on some stock rotors. Silicon carbide or silicon nitride should be good to about 2500 F. There should be other higher temp options available if you ask a vapor deposition specialist.
But does this coating prevent rust?
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Old Sep 8, 2009 | 02:35 AM
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Originally Posted by 13BT_RX3
http://www.globalspec.com/local/4284/NV

Check with vendors 2,4,6, & 7 if you are actually in the Vegas area.
See if any can do CVD of Silicon Carbide or Nitride in your area. Easier to explain requirements in person than ship off and hope they get it right.
Wow, as long as ive lived in vegas ive never heard of those shops. thank you.
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Old Sep 8, 2009 | 02:38 AM
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Originally Posted by Dltreezan
dude spend 2g on a Miata with 35 mpg and have a daily.
Gas prices are rising man. I'm more looking for something permanent so thats why I'm doing a hydrogen rx7. I might consider haing an extra fuel cell for e85 though.
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Old Sep 8, 2009 | 02:43 AM
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Originally Posted by Aaron Cake
As an experiment or project car, this sounds like a fun idea. As a practical vehicle to save money on fuel, not so much.

You don't need stainless steel rotors or any coating. Regular old cadmium plated Mazda rotors (they are plated from the factory) will work fine. Combustion temperatures are high enough that it's all steam and the oil coating from the metering oil pump will protect the rotors. Remember, quite a lot of water is produced through burning gasoline, though not as much as hydrogen, obviously.

The real problem you are going to have is making the system actually efficient. In order to store enough hydrogen to travel more then about 60 miles (remember, the energy density of hydrogen is abysmal compared to gasoline or batteries) you need to keep it liquid. Which means extremely high pressures (20,000+ PSI) and lots of insulation. Such a storage tank will not be cheap, and must be rated for on road use.

Then you have to actually fill it, which means a high pressure pump and a supply of hydrogen. If you expect to use cylinders purchased at the welding store, forget it. Even the largest particle size is only 360 cubic feed and weighs over 100 LBs. It also costs 10x the money as gasoline for the same distance driven.

If you expect to make the hydrogen at home, forget it. It will be an enormous cost to acquire the compressor and storage tank, and electrolosys is very inefficient.

We have not even covered actually running the engine with the stuff and already it's not worth the hassle by several orders of magnitude.
Thanks but like I said I've already have everything covered for all that. But right now I'm getting all the parts to do it. I'll be sure to post a build thread when I start to let everyone know all the details and how it turned out.
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Old Sep 8, 2009 | 03:15 AM
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if you are still looking for coatings http://jhbperformance.com/
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Old Sep 9, 2009 | 09:18 AM
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Originally Posted by GhostRotor
Thanks but like I said I've already have everything covered for all that. But right now I'm getting all the parts to do it. I'll be sure to post a build thread when I start to let everyone know all the details and how it turned out.
Those are considerable problems, and to hear that you have solved them makes me very curious about your project.

Where are you getting your hydrogen? Are you producing it? If so, how are you compressing and storing it?

Where did you get your storage tank?

What EMS are you going to run? Injector sizes?

Inquiring minds want to know...
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Old Sep 9, 2009 | 12:29 PM
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Inquiring minds want to say WTF? Are you nuts, this surely will not work. The cake is waiting for the pounce.

I would definitely love to see this storage tank that can hold 20,000 PSI of hydrogen.

Seriously your gas prices versus your cost of build for what you are putting it into are insane. Very much not worth the effort.
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Old Sep 9, 2009 | 02:30 PM
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well w/21 posts he could be a particle physicist that just so happened to acquire an rx7... lets watch and see what happens...
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Old Sep 9, 2009 | 03:37 PM
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Originally Posted by Aaron Cake
As an experiment or project car, this sounds like a fun idea. As a practical vehicle to save money on fuel, not so much.
as a project, i encourage you. as a way to get better fuel consumption, i must agree with Aaron.

please don't take this as me shitting your parade, but if you want better gas mileage, a TURBO rotary is not the ideal tool for the job. you should have had a Prius or something.

in the long run, i think it would be cheaper to just wait until you get a second car as a daily driver (Corolla, Camry, Civic, Accord, etc.) and just leave your Rx-7 Turbo for the days you want to have fun. obviously, the technology exists, but adapting it for your own personal use will more than likely prove to be grossly inefficient.
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Old Sep 9, 2009 | 03:55 PM
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I hope he doesn't live in my neighborhood if something in the "experiment" goes wrong...

I did a little google on natural gas rotaries with out much luck. (If you live in Utah NG is way-cheap.)

I would think going all electric would be easier as well.
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Old Sep 9, 2009 | 05:23 PM
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Originally Posted by GhostRotor
Hey guys, I have a 88 t2 and im tired of the gas prices going up. So i've decided to turn my car into a hydrogen car. Im planning on running only hydrogen and i've gotten everything planned out except for the engine internals. Im worried about the inside of the engine rusting from the hydrogen turning back to water after combustion. Is there such thing as Stainless Steel Rotors or any other way I can prevent rusting on the inside of a 13bt???
I dont think rust in the rotors will be your major problem, Ive disasembled engines running with an internal water leak and that doesnt seems to be a problem for the engine running. They have temp issues, thats why they finally rebuild the engine.
I think the only seal that can give you trouble is the side seal which really gets rusty and can get stuck. the corner seal is more like stainless and the apex seal solution is simply: carbon or ceramic seals.
I remember the engines running LPG (liquid petroleum gas) in the ´80s and they use to start the engine with gasoline in the morning and then use a switch to change to LPG and do the reverse at night, before ending the day. Maybe that is a solution...

Good luck with the proyect.

p.d.

I recently assambled an engine with aluminum rotors, they look great but they dont have oil cooling capability, so, thats why they recomend them just for drag racing
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Old Sep 10, 2009 | 04:26 AM
  #22  
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Originally Posted by Aaron Cake
Those are considerable problems, and to hear that you have solved them makes me very curious about your project.

Where are you getting your hydrogen? Are you producing it? If so, how are you compressing and storing it?

Where did you get your storage tank?

What EMS are you going to run? Injector sizes?

Inquiring minds want to know...
Hey aaron I love your interest in this. But for sake of critisizing comments I'm going to save the details for the build post. But the build won't start for another month or two due to money issues I've been having lately with work. But I'll be happy to give you all the details of this project once I get started.
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