Assuming the engine is sealed, and there is NO hub\damper marks, how can I tell that the front rotor is at TDC?



I know what TDC is on a rotary engine, but don't know how to tell without any hub\damper marks on a sealed engine https://www.nopistons.com/forums/pub...1047683561.gif https://www.nopistons.com/forums/pub...1047683358.gif https://www.nopistons.com/forums/pub...R#>/violin.gif

This would be a good thread for the FAQ if a solid answer can be given. I've heard all sorts of methods but the way I find it is by using a known good pulley and hub pair and lining it up just to the right of the 5ATDC yellow mark.



I think the key indexer on the front of the eccentric shaft sits at 9 o'clock (270 degrees), indicating TDC on the front rotor.. I think.



B

BDC is correct, the E-shaft key at the 9'o'clock position is TDC.

chuck

Thaks for the input, same to you B!



However on my ever quest to troubleshoot my current engine, the key @ 9 won't work if the rotor wasn't assemble properly. I won't dig into my current issues, but since this is my first rebuild engine, the front rotor might be a tooth or two offset.

if its a tooth off set you need to disasemble it, it will not turn like that, and may damage the rotor if you try to hard to turn it.

I think having a rotor off a tooth is a old wifes myth, or I have been one lucky fool with the last 40 or so rebuilds. Rotors only go in one way. I suggests looking for a problem elsewhere.

chuck

agreed

if the rotor was off a tooth it woudl get jammed in a few degrees of its rotation and the motor would be siezed.

That's right. The crank won't turn otherwise.



B

Thank You Guys!!



The offset tooth was just something I brought up to fuel the thread, my engine starts up every time https://www.nopistons.com/forums/pub...IR#>/smile.png