engine built by bankrupt shop.. need an accurate way to find TDC ideally without taking off the front cover.. there are no markings anywhere.

any ideas? i took off the transmission, clutch, flywheel, then took some photos.

thanks for any help!

http://www.rx7club.com/attachment.ph...8&d=1230693406
http://www.rx7club.com/attachment.ph...9&d=1230693406
http://www.rx7club.com/attachment.ph...0&d=1230693406

btw, does that look like guru shaft? or stock e-shaft from the rear?

 

 

just looked for one last time, can't see any keyways of eshaft anywhere.

it looks like I may have to take off that front bolt. i'm guessing lay the engine by the fly wheel side, then just unbolt it with a torque wrench? how would I lock down the flywheel, so eshaft doesn't move? i guess a friend with a crawbar would work somehow heh..

btw, what's the torque spec for 20b front nut? i was thinking of just setting my torque wrench to max and just tightening it as much as i can at around 550ftlb.

 

look in a spark plug hole

 

ok too simple a post and i have just enough time before i have to go. on a 20b when rotor 1 is at 0 the others are at 120 and 240 respectively.

remove the plugs so you can see in the plug holes or rotor 1. rotate the e shaft until you see the apex split the plug hole. mark that point on the timing wheel. rotate the shaft more until the apex crosses the other plug hole. mark that- the mid point between the two is TDC.

 

wait thats not right and i gotta go

 

could someone tell me which is TDC--A, B, or C?

the picture are meant to show the first rotor housing (front rotor housing).

thanks!

this is for 20b.

 

"B" on rotor #1.

 

thanks mm! so i'm guessing if I go with zoom's retracted idea, i have 33% chance of getting it right?

i probably end up taking off the eccentric bolt. could you confirm the method below?

1. i'll clamp down a thick piece of wood in the rear of the engine so that the e-shaft will be pushed toward the front (so that eshaft won't be moving towards the rear of the car).
2. unbolt the screw
3. make sure the keyway points towards the exhaust side
4. align distributer style CAS with the factory marking
5. put it in very carefully...
6. bolt back on to ~200ftlb

thanks! and happy new years!

 

I'm not understanding the dilemma.
Why are you checking this from the rear of the motor?
The e-shaft is always in the same position when the #1 rotor is in your "B" configuration above.
Just get it close then look at the keyway on the front of the shaft.

 

my way works on a two rotor because the rotors are 180 degrees apart. when you use my method on the rear rotor it puts the front at TDC. this wont work on the 3 rotor because the offsets are different.

since the offsets between rotors on a3 rotor are different you would have to do it slightly differently. on the front rotor leading plug watch for the apex to just clear the plug mark that. then put a feeler(peice of wire) in the trailing and turn until you can just feel the apex about to cross the hole. mark that- bisecting THAT angle gives you TDC on the front. the others will be 120 and 240 out respectively.


you should be able as jeff says to look at the key way to see the position of the shaft

 

hi jeff, i was told that i can look at the rear of the shaft for the keyway by a member on the rx7 club. i couldn't find any keyway in the rear of the shaft, so i snapped some pics.

now i realize i need to take the front eshaft bolt off to visualize the keyway.

i just wanted to know whether the precaution everyone talks about is jamming the e-shaft toward the FRONT of the car, so that shaft won't move toward the rear of the car during the unbolting process. something about some bearing coming out of place... kevin at rotaryresurrection was really nice to talk through the process with me before, but i hate to call vendors cell phones on new year just wanted to double check that keyway should point toward the exhaust side, and that shaft should be jammed toward the front during the entire process.

and happy new year everyone!

 

ok after reading on the rx7club.com, i see what you guys are saying now. config "B" has to be TDC because of the eccentric rotor rotation geometry. as long as there's equal distance from each spark plug hole to the rotor surface in "B" configuration in housing #1, that must be TDC. thanks!

now is there any good way I could put in that CAS into the hole and ensure the gear didn't turn accidentally?