Ive lost track of which rotor was in the front of the motor and which was in the back... Does it matter which is the front or rear rotor?

 

it doesn't really matter, the main reason for marking them is everything is seated up for that rotor, gear, seals, etc. moving them around just means they have to re-seat to their new environment.

supposedly there is a lip at the leading edge of the rotor for that rotor housing but most of the time i see or feel no lip, this was just what someone else speculated or was intent on them having.

 

But if you're rebuilding (replacing seals and what not) everything is going to be re-seating anyway.

 

Hey, I was just wondering, What engine work must go into a high hp/'boost build, like in a piston motor. For a high boost 7m youd need forged pistons, h beam rods, clevite bearings, arp bottom end kit, metal head gasket, arp head studs, etc. Can someone just calrify what must go into a rotary? I cant see that there is much to break other than wearing out apex or face seals or something to that effect. Would i have to have the rotors or housings polished or anything? Because i know with pistons if they are not polished the rough spots start to glow from the heat and can ignote the fuel? any help appreciated, thanks!

 

Here ya go:http://fc3spro.com/TECH/FM2W/power.htm
Basically, you just need to make sure you have enough fuel and cooling capacity, and your set. Once you get into crazy power and boost its a good idea to do some oil mods and possibly dowel your motor.

 

Alright ive got the front rotor and the intermediate iron on HOWEVER ive got a gap between the intermediate iron and the front rotor housing. No matter how hard I press on the housing, it will not close the gap! Nothing appears to be binded up on the rotor ( I turned the e-shaft about 1/4 a turn) but the gap between the iron and the housing is about 2mm. Is this a typical thing that will be taken care of when I tighten down the tension bolts or do I need to pull the iron off to see what the problem is?

Ive shined a light between the gap and cant see anything that may have gotten in the way.... not sure what to do at this point.

 

Nevermind! The motor is together and it MAKES COMPRESSION!! WOOOOOO


Now I just hope when its in the car nothing leaks..

 

even in stock form a 13B engine is capeable of handling upwards of 500RWHP with proper tuning, fuel and boost. now you know why piston guys hate rotaries.

 

Another problem: the engine is difficult to spin over by hand. Both rotors make strong pops when turning over, its just that it takes alot more work to spin the flywheel than it does on my N/A motor. Could this be because ive got all new bearings installed as well as a whoollllleeee lot of assemble lube on the contact surfaces of the e-shaft, rotor, etc?

 

it shouldn't be difficult to spin by hand, you should still be able to turn it by hand at the front pulley. you could have put the front thrust bearing stack in wrong.

 

If everything is on correctly and the plugs out you should be able to spin it with 2 fingers on a flywheel dowel.

Another check is if you have the plugs in if you spin it forward and let go, it should kick back a little. If it is any mor difficult than this then you either assembled the front thrust bearing wrong or a bearing may have been pressed in at a slight angle giving the bearing a tapered end.

Some engines when freshly assembled make some serious compression with everything fresh. You may have built a unicorn. Either way good luck.

Keep us posted on your findings.

 

It was difficult to spin right after I put the intermediate housing on (when you have to turn the eshaft lobe to face the intake/exhaust port). When this happend I checked to see if the eshaft contacts the intermediate housing but it does not. It does kick back a little when I turn it by hand with the plugs in. I assumed it was the amount of assembly lube I coated the bearing and eshaft with before putting it in. Im about to check endplay and see how that is.

 

Did you try spinning it freely without the plugs in? I would assume if they are in it would be hard to spin.

 

No this was with the plugs out and the front cover along with the pulley, torrington bearings, etc off. Just the housings, rotors, and irons were assembled-- with the front assembly stuffs of it makes it no more difficult to spin. I am going to take off the front stat gear tomorrow and see how that looks. Its the only thing that I think could have caused this issue.

 

From what you described earlier, I suspect the inner O-ring fell out of its groove in the center iron & got pinched into the rotor path.
I did a test spin on my last rebuild with a cordless drill on the front pulley nut.

 

Take it back apart you screwed something up.

 

So I took off the front cover and all that crap inside and found that although I had taken care not to crush one of the torrington bearings, I forgot about the other one. But despite all of that stuff off, the motor was still hard to spin over. So I took off the rear iron, rotor, and housing and the motor was STILL hard to spin! I took off the intermediate housing and the front rotor housing... turns out the outer coolant seal had twisted at the intake side and somehow got caught between the rotor housing and the front housing which nearly got it cut in half. I took out the e-shaft and inspected all of my bearings (which were fine) and as a test I lubbed up the e-shaft and bearings, put them together and put the intermediate housing on... now I am able to spin the front rotor just by gripping the front lobe and turning it despite having my hands covered in motor oil.

I dont know how its easy to spin now (all of the seals and such are on the front rotor, all coolant seals were removed for the test since they need to be replaced) as I dont think the outer coolant seal being pinched would make the front rotor hard to spin over. The only thing I did differently was coat the bearings and e-shaft in motor oil instead of assembly lube. The lube comes out as a kind of paste that is almost as thick as RTV. Its called Sta-lube engine assembly lube with moly-graphite.

I was going to leave the motor together and try to run it anyway but when I called a friend of mine who is an experienced piston engine builder he was pretty sketchy that the assembly lube would cause the motor to be so difficult to spin over. Regardless of what it was, I am glad I didnt try to run the motor with that pinched coolant seal. Just a word of advise for other first time engine builders reading this post:

If something does not feel right, then its not right.