Why is this thread posted on the single turbo section?????

 

Titanium is silly material. Peejay, I´m sure you´ve seen update on billet rotors, they are being tested on circuit race car, also on 500whp+ street car.

I also want to see outcome of these rotors, as they hasn´t cooling passages. But I really think its not needed in these. I would be concerned rather about apex seals slots...Only time will tell...

 

Really. Well, that IS interesting. I'll have to wander over and pay more attention to them, then.

 

also about CGI , it would help apex seal frictional drag in the SLOT or GROOVE( higher graphite content) .
a well known apex problem is not contactng rotor housing thru its cycle,(aka, blow back and deton. because apex drags in the groove,and dont return fast enough to surface) strong springs have been tried,with some results. not a cure all.
lighter seals, has some merit,,Ceramic,etc.

but nobody has tried a groove where(with hi combustion pressure is pushin the seal hard against the side of the groove,and draggin. or in worn grooves breakin in half, tryin to bend the seal.
personally it sounds like a mess.\,IMO
anyway less friction, may-could help!

 

That's not why the seals leave the surface. The seals bounce back. I'm certain that inertia plays a large part of it given that lighter seals don't bounce nearly as much, but the rest is...

The springs are mainly there for starting, combustion pressure on the backside of the seal does most of the force pushing the seal against the rotor housing. Just like a piston ring.

That's why seal to rotor clearance is so critical.

AFAIK the slot wear (in iron rotors anyway) isn't wear so much as it is the tips of the rotor getting hammered apart. The seals really "rattle" around in those slots. The engines I've had apart where the slots were trashed didn't look worn so much as peeled apart.

 

Peejay, i agree ,also we dont have perfect engineering, with apex seals,YET!

thats why i think some drag on seal in groove may be a trouble spot, Graphite is a good hi-temp friction reducer.
combustion press, could and will get behind,but also pushes seal against rotor causing some drag.

I am reseaserchin, a beveled wedge shaped Apex seal configuration, with a low friction coating.
we gotta get that seal to move faster!

somthin i noticed with a lot of blowups,they quite often happen around the same RPM,
maybe some type of reasonating harmonic, that upsets the seals movement.
just some thoughts, im on my third engine, and not a happy camper.
THX Ron

 

Consider that the sealing problem is the housing not the apex seals themselves.

Remember how Mazda recomends we test the seals for flatness/wear by putting the faces together?

Ronbros, look carefully at the seal face and you should see wear nicks from the spark plug openings.

Some thoughts,
Barry

 

Mazda have already made and tested titanium rotors in the 1970s. Its old news. It is better then the cast iron rotors. They are lighter. They absorb less heat.


AND PLEASE PEOPLE.
JUST CAUSE YOUR EGTS are 1900 F dosnt mean any part of your engine is at the temperature.

Youll find most parts dont get anywere near that hot. NOT EVEN HALF.

Mazda tested temperatures on apex seals and showed that they dont really get hotter then 300 degrees celcius, the actually showed the oil injection bring down the temperature by around 75 degrees celcius.

As for billet aluminium rotors. They are a great thing. Only bill gates can afford them at this point in time. And testing something in a 500rwhp street car is a waste of time or any street car for that matter. Its not a real test of reliability for an engine.
and the problem with testing them on so called race cars, we dont get to see any of the real info in testing, too many variables, too much secrecy, alot would happen that the people testing wont tell you.

Best way in the industry of aftermarket parts, especially with parts like rotors, face plates etc. IS BUY THEM AND TEST THEM YOUR SELF, IF THEY ARE **** WELL THEN TUFF LUCK, if they are good WELL THEN GREAT. Dont recommend something you havnt tried just cause they tested it "on a circuit car that you know nothing about".

 

Ron: Good to see you're always thinking. I need to come down to from Dallas, and catch up!

 

HI YA,, Johan,, anytime im retired, and got plenty time, while your here i can show you some 1000-1400hp STREET cars. YUP, they bad.

 

I hate to be "that guy" but can you cite that?

 

can TI. be cast hollow,for oil cooling, if not ,then i dont think TI. would be the answer.

also i heard if it drags against the plate irons it can gall and dig in, and cost would be in outta space too.


YUP, i think CGI cast is a usable way!! as costs come down and the tech goes up!

 

I agree, I wouldnt consider buying parts at that price for starters, It would be nice to see some real results. Maybe run a fully tuned 1,000+HP 2 rotor with factory rotors take it apart, Install the "Bill Gates Rotors" and show us the results

 

I know i have the article write up somewere around.

If you do some research youll find that it has be done and tested. I have a picture of them somewere.

For the guy saying that if titanium was to touch your plates it would damage the plates, WELL DEH. Steel rotors would do this as well.


I still think if someone cast steel rotors with slightly different design principles in mind etc then that would be plenty. Them being in steel isnt a problem. They need to be slightly thicker behind the apex seal slot area so they dont dimple, and side seal needs to be closer to the edge like rx8 rotor so we can make ports bigger. Would have one hell of a street port then.

 

when a rotor touches the plates ,the CGI hi content graphite is a friction reducer would not dig in as easy as regular grey cast iron ,steel(aluminum would slide like a bearing material tho),,
plus CGI can be cast to any specs required, and it transfers heat more uniformly.

anyway(as usual with hi-output rotories) gotta keep the Eshaft from bending, and rotors wont touch,, a lot of time is spent on clearencing rotors and shafts only to end up with loose and sloppy motors.

I have a LOVE-HATE relationship with the little devils!

 

of course all this may never happen! how and,who, we gonna get someone to make molds and cast them,then machine a custom rotor,PLUS get a formula for the proper material.

HEY! i only said it was an IDEA.

and MOST improtant, much of the rotory guys just aint got the money for Exotic stuff, if you talk Ceramic seals they run and hide etc.

 

Ron, I wonder how much the eccentric shaft would bend if the rotors were a third of the weight (Titanium or Aluminum).

What would become the critical rpm with light-weight rotors?

You could lighten the shaft and the counterweights. It would rev like a motorcycle!

Barry

 

Probably much more than what will limit us-apex seals. Even at only 6,000 rpms, apex seal sliding velocity on major axis in 13B geometry is 30 m/s, even motorcycles revving to 17,000 rpms doesn´t overcome 24 m/s mean piston speed. Hardly imaginable that apex seals would follow trochoid surface at these velocities.

 

all good info,, but i think we should try to make more torque,, and not rev the crap outta them.

say 9,000max rpm,, but get thr torque up in the mid ranges,, like 425lb.ft. at 4500-8000rpm.

HEY! that even sounds cool.

leborek, you could convert, that torque number to metric

 

576 Nm
-- which is already realistically within grasp of the 13b motor with extend ports choked on a small ( 0.96 ) turbine housing with 0.70 front
( i have tuned one to 1700 pounds of TE running a 326 mm R and 4.5 final drive = 548 Nm on a DD dyno )
[ = 404 lb.ft ]

saying that ,, it would be a mean feat to see 576 Nm from an NA 13b
-- which is exactly why the trochoid and stroke is revised for the 16x

 

seems as tho the 16X is gonna change most of what we know about 13Bs.

or a whole new set of R&D, hope it dont take 10yrs like the last.

and will 16X put the 13 to rest,, time will tell, and im open to new stuff anyway!