When will Ted use his talents for good, instead of evil...The world may never know, sigh......
It is sensationally easy, wanna watch my build-up, I mean bolt on. I will post everything needed for 700rwhp today, I need to do an inventory anyway before I start. Ted, with half the suoras out there doing it, you must be in a serious case of denial, Seek help, there are doctors that can help

 

okay, this has got to be the funniest thing in that thread:

"Uh no my friends DO know a lot about rotaries; I know a lot of people claim this or that; but one of my friends ate and slept rotaries... trust me; he knows his ****... he definitely knows more than you and 99% of the other toolboxes from rx7club (he got kicked off of there because the canadians pissed him off bigtime)... you'd have to know this guy to know what i'm talking about... but he knows his **** and is one of the two best drivers in any type of race i've ever met"

i especially love the comment about canadians...


back to the original topic (Ted i respect you and your knowledge, but i think you need to start providing more than just one liners ), i don't want to get into too much discussion, but i think the issue is not about heat, as some composite compounds can withstand the heat, but i think there would be issues with engine dynamics and strength. the characteristics of it would be totally different than conventional engine internals. how i can't say for sure, but i suspect things such as microfractures and combustion surface hot spots come into play if you aren't using conventional composites.

and one thing people aren't realizing is that if ever rotors or pistons were to be made of an exotic material, it is not going to be the same as that 'carbon fiber' shift **** you bought off eBay. we can see examples of carbon composites in things like Formula 1 brake rotors, but i think what is feasible is GRAPHITE internals. i read an article not too long ago that Diamler AG was researching graphite pistons. these pistons showed lower emissions in test vehicles and also had advantages of lower noise and vibration. apparently this is due to the pistons having a damping effect. also, get this: the pistons actually were able to ABSORB oil and were more heat resistant than conventional pistons. they were actually no disadvantages mentioned other than costs, which were pretty crazy, but it HAS been tested in actual vehicles...
anyways, that's my little bit of input.

 

carbon fibre piston out of a Porsche 912 ceramic piston rings

 

i can't seem to find any actual info on the custom porsche block that you are showing that piston from ^
it'd be nice to read an article about it rather than just see the picture.
and as i had mentioned, they are most like not using the conventional woven carbon fiber that you may find on your car exterior/interior parts

 

Yeah, I am pretty sure CF can take the heat. Carbon is already burnt .

Seriously, it is all about the carrier that is used in the composite process, right. It would still be a Carbon Fiber piece if it was a composite of carbon fibre weave in ceramic carrier.

I just watched a show on the X-prize winning privately funded/built space ship and I believe they used CF for the skin and they were able to make it hold up to re-entry by slowing the craft down a bit as opposed to using ceramic tiles and punching into the atmosphere like the shuttle. Cool stuff.

 

I agree more info on that engine, I found it a while ago doing research for my masters project, the carbon fibre may not be woven but alot of carbon fibre parts only have a woven layer on top for looks and use strands and bundles in specific directions for strength

 

Why not make them out of carbon fiber then have them coated.

 

You sure that's "carbon fiber" or "carbon-carbon"?
There's a BIG difference!


-Ted

 

it could be done
the main prob would be the cost of the resin for that temp (2500 gallon i think) and the ceramic fibres you would need for the combustion face

and the whole aircraft grade injection mould you would need machined

 

We have experimented with "Carbon Carbon" pistons here at work (NASA) on a small block Chevy and a v8 diesel of some sort (both n/a). These were carbon carbon and NOT carbon fibre/fiber. They all had a ceramic-coated tops to prevent them from self destructing themselves. We had one of the pistons on the diesel engine go bad one day during testing. The ceramic top or piston face had cracked from thermal shock or not adequate clearances, I don't remember (was a cold 28 *f morning when we started up the engine). Once the thermal ceramic top coat failed, the piston quickly deteriated. I still have the piston somewhere here, its got a HUGE hole in it from were the diesel fuel was injected and burned. This project died, so I don’t know how much this type of research has progressed, it was 6 years ago for us here. I tried to talk them into doing a rotor...LOL.. that was a no-go. I don’t have a whole lot of info on it (but I still am friends with the now retired employees that did work on it), I was a grunt for that particular project and just set up the water brake, mountings, wiring, fuel, etc and running the engines, I stayed out the engineering bit of it. All the stuff mentioned by other posters were found, tighter clearances (less expansion) which resulted in quieter smoother running, the oil temps dropped ( the carbon carbon held in oil much better, was a thermal barrier (non thermal conductive), and the ceramic top coat further kept combustion temps in the chambers and not absorbed by the pistons. Reciprocating mass of coarse dropped dramatically in the diesel (heavy iron pistons to begin with). Both engines gained effiency resulting in more power with better mileage and running cooler (I dont recall how the EGT's reacted)

~Mike.........

 

just a quick note, are the carbon-carbon composite pistons people are mentioning here similar to the graphite pistons i was mentioning in my post?
really graphite is just carbon (an allotrope), i am going to guess this is what everyone is referring to...

 

so the verdict on carbon is: better, but more expensive and less reliable........???

like rx7's need anything more exensive and less reliable. lol

 

thats what i see

and ill take teh nasa testing as the word on it

 

Carbon-carbon is carbon fibers in a carbon matrix

 

That's a very general description of it...
So what happened to temperature and pressure?


-Ted

 

Not trying to get into an argument, was just trying to point out that this material is a similar structure to an epoxy or polyester carbon fiber composite ie a carbon matrix instead of thermoset plastic or a metal matrix.
Yes the temperatures and pressures are generally high in the range of 2000 deg C for long periods of time-weeks depending on the exact process being used. On the other hand it is also possible to make carbon-carbon at low temperatures (500) and low pressures using PVD equipment.