j9fd3s

um it might make scrap! the two rotor is easy, the rotors are 180 degrees apart. the muti-rotors are different as they actually need to run in a certain firing order to balance out



this info is actually in the rotary engine book.



not a big deal though, the shaft is still very simple, relative to the apex seal, which has to be hard on the wear surfaces, and soft on the sides

Maxt

You'd also have to try and machine in the convex, thats also what all the aftermarket seals are missing to, without they sag in the middle.

sen2two

What do you mean by this?



The rounded edge where the seal meets the housing? or something else?

sen2two

Not if you mate the two together with the the 1st and 3rd rotor identical, making the 2d and 4th also identical. Yeah, it will sound like two 2-rotors, but it will still be a 4-rotor.



Also, it's been done. I will not be the first here. Little info is out there on it. But I'm pretty sure I can pull it off...

GreyGT-C

If you are hell-bent on making your own parts... why not make your own aluminum side housings? I've held a set of the RB ones... they are SILLY light. I could probably pick up a 3 rotor built from these and walk around with it. (the engine wasn't put together yet) As far as i know, RB does not make the odd housing for a 3 rotor yet either...





Just a thought......

sen2two

Making plates, e-shafts, ect. will come in time. But for right now I'm more interested in making apex seals, The only other thing I have been working on is making housings. But every design I come up with for making the steel liner and chrome surfacing just dosnt seem right.



There are 2 or 3 companies that make the thick plate for the 3 rotor also.

j9fd3s

something else, look in the FSM

sen2two

I'll take a guess..



while measuring a stock Mazda 3 piece seal, I noticed it gets slimmer towards the center. Not sure if this is what you are talking about, or my seal was in bad shape?

Lynn E. Hanover

The apex seals are concave in the center. They come to flat at operating temperature. The center of the seal is heated by the exhaust gasses. The Renesis may even be convex due to the exhaust gasses heating the sides of the rotor. But I have read nothing on that yet. The wear surfaces are hardened by exposure to electron beams similar to the welding process.



You could put a segment in a shadowgraph and get the radius.



Milling machines have become more accurate through the years but really close tolorance stuff is ground or lapped to finish size. When you get down to .0001" or less you are grinding or lapping to real close then hand selecting to an air gaged bore size for example. As in small 9 piston hydraulic pump. You measure as close as is possible then install the piston you hand select to fit in the bore and pressurize to say 100 PSI with the oil at 100 degrees, then count the drops of oil that leak past the piston (Called case drain)to calculate the clearance.



So a nine piston pump the size of a .30 pistole cylinder may be produced with 9 holes all different sizes. So you sit at a station and hand fit one of a big selection of pistons graded by diameter sitting in trays. You put in a piston and stick the cylinder into a fixture and pressurize it with oil. Then a laser counts the drops of oil leaking past the piston, and you are looking for 5 to 7 drops in 15 seconds. You get 9 drops. So you pull out that piston and select a larger diameter piston and try again. This is the kind of pump that powers the flight control rams (cylinders) on aircraft. They produce 3,000 to 9,000 pounds of pressure. They run off of the engine accessory section.



You could build pumps for years and never handle a part that was more than .0002" out of spec.



Apex seals have side clearance to prevent sticking in the groove. What happens when you burn sump oil in the combustion chamber. Too much clearance lets the apex seal vibrate across the chrome. Producing evenly spaced lines in the chrome.

A small number of heavy dents below the ramp is just the apex seal ski jumping the ramp from too many revs. Better oils than in the 70s and for those who mix there own top oil allows three piece zero clearance seals with little danger of gumming or sticking.



Lynn E. Hanover

sen2two

The material I plan on using has a melting point of almost 5000 °F and it has one of the lowest coefficient of thermal expansion of the top metals. It also has a Brinell hardness of 1500 MPa. Which is more than double Titanium.