Chris1966

Hi all.



I'm slowly progressing with my 12a/13bt hybrid engine. I have to find some good stationaries but in Australia that isn't an easy prospect, especially when they're for a 12a. This got me thinking last night.



What would happen if I setup the front and rear irons in the lathe and put a groove in the stationary gear locating bore that lined up with the oil passage? Will it appreciably weaken the iron or let the stationary move around at all? The groove would only be 0.3" wide and 0.1" deep with radii in the groove corners. I could then drill some extra holes through the stationary gears to line up with the bearing groove and the groove I'd put in the iron.



I can't help but think this would allow greater oil flow into the ecentric shaft bearings and journals and for rotor bearing oiling.



To be honest I'd prefer to use RX-8 stationary gears front and rear seeing as how they are hardened and multiwindow already. What worries me is machining off the gear teeth to allow use in a 12a. I can't use a 13bt as my car has a engine size restriction in my state.



At the moment its a decision between which is harder and safer to do. Face off hardened gear teeth and expose soft metal on the gear, or groove the irons and possibly weaken them as well as trying to drill through stationary gears.



Opinions would be appreciated.



Chris.

Lynn E. Hanover

You are talking about several things at once here. Do you need hardened gears for a 12A? You can buy those, and if there is a heat treater near you, he can harden the gear teeth for you. You may have to hone the hole a bit after it cools, as they shrink a bit.



If you just need to put a groove inside a stationary gear, no problem. They are very hard and carbide or diamond or ceramic tooling will be needed, but the work is then easy.



I am told that the oil hole in the RX-8 stuff is off index a bit, so you would need to grind that oil hole over a bit to line it up with the gallery.



If you want to shorten a stationary gear, it is also easy on the lathe with carbide tooling. Go back and chamfer the hard edges to avoid burrs from flaking off the teeth. It works just fine.



I used to grind my irons so many times, the engine would start getting too short and the rear bearing would run up onto the radius on the rear crank throw. You can also add a thick gasket under the rear stationary, and the next time add one under the thrust plate. I havn't done that in years.



In any case, a racing rear bearing has extra clearance already and has the three windows and the deep groove. So just a bit of a groove under the windows is all that is required.



If you plan on turning it up that tight, narrow the rotors a bit and jack the oil pressure up over 100 PSI, and add an external oil line to the front main bearing.



From years ago, this is my rotary powered Camel Lights car.



Lynn E. Hanover



I used to groove the stationaries, and deepen the groove inside the bearings, and even drill and grind the stock bearings, because of having no money at all. But I just buy them now.

Chris1966

Hi again Lynn



I would have bet money that you'd be the one to answer this thread. Anyhow, I'm not sure if I need hardened gears or not but I'm going use them to be sure. The engine will use turbo ll irons and cut down rotorhousings. I went with the turbo ll irons to take advantage of the bigger oil pump and structural rigidity for a turbo engine. Not to mention not having to worry about recutting water seal grooves after cutting the housings down.



I'm going with a 115psi rear oil pressure relief and 180 jets in the eccentric shaft. Loop line mod is done. The irons are stud kitted, secodary bridgeported, and I'm expecting to turn it to around 9000RPM.....but I'm covering all bases in case it wants to go further and still make power. Expected power is around 450hp at the flywheel. I'll machine the 12AT rotors when the housings get back and I can measure them to calculate required clearance.



Looks like I'll get the RX-8 high performance stationaries for it then if machining is no problem. That is by far the most cost effective way.



Thanks again for your guidance Lynn.



Chris.

C. Ludwig

The RX-8 rear gear oil galley lines up fine. The front galley I've found to be about half shadowed on FC irons. You need to pull the opening about .060" to the rear of the bearing.



I just built an FD with RX-8 gears and they lined up fine front and rear.



For the price of the comp or FD bearings plus machine work you can buy RX-8 gears and bearings and save money.

nismo convert

The rear does not line up properly, when I built mine I used a flashlight in the bearing, and looked through where the oil filter pedestal and I could see how much material I had to remove, I wish I had taken pics of this.

C. Ludwig

I've got one in the shop right now. Lines up fine. In what way did it not line up for you? Front, back, radial?

nismo convert

I had to bring the hole down about 1/8", the hole was HALF covered by the hole being towards the rotor more, I think the back of the Renesis has a thicker land for the gear flange. I had pics of the RE gears beside the RX8 Gears; but now I can't find them.

C. Ludwig

I've built two engines and studied both closely and didn't find what you're describing at the rear. What's even more odd is that one of the bearing sets went into an FC and the other an FD. On the FC the front galley was off by .060". On the FD the galleys lined up. Both bearings were the same part number.

nismo convert

I've built one with these gears, but know a builder that has built multiple with them, and has had to take a dremel to them aswell.

j9fd3s

makes you wonder how well that lines up in any engine!