RX7 allnight

i searched and didnt find anything.
do i remove the 1st rotor housing leading spark plug and wait till i see rotor tip (apex seal) and this is TDC? iam installing a new engine and putting the front pullys on and need to line up the timing marks thanks

ivegonemad

hmm timing gun??

RX7 allnight

timimg gun is used when the engine is running. iam installing front pulleys on a rebuild. the CAS is already installed

2fast2rotar

When rebuilding the motor you dont have to worry about TDC. The rotors only fit in one way, same as the flywheel b/c it is keyed. Just make sure the main pullys are installed correctly, but as for the rebuild, the rotors only go in one way to where the apex seals are always touching the rotor housings.
~andrew

HAILERS

The pulley is held on the hub with four bolts. The bolt pattern is offset, so the pulley will only go on one way, unless, unless you wallow the four holes out.

TDC in GENERAL(not counting looking at the marks on the pulley), can be found by removing the rear two sparkplugs. Look into the top sparkplug hole while turning the engine. Use a mirror and flashlight. Look to see a apex seal in the hole. Now make a mark on the pulley just opposite the fixed pin.

Now keep turning the engine until the apes seal shows up in the bottom hole. Make a mark on the pulley opposite the fix pin on the front cover.

Now measure the distance b/t those two marks. In the middle will be APPROX TDC. NOT TDC but approx TDC. I don't care what they say in that article that explains what I just wrote. It is NOT TDC.

So lets say you found APPROX TDC. Here's what you can do to make it more accurate. Buy a two foot piece of clear vinyl tubing of 1/2 inch outside diameter.

Remove the two front sparkplugs. Cut that tubing in half and SCREW half of it in the top hole and half of it in the bottom hole. It WILL screw in the threaded hole. Just three or four threads will do. And that will seal the hole also.

Now, with the engine at APPROX TDC, pour or squirt oil in the vinyl tubing in the bottom hole. Common 30 wt oil will do fine. Keep squirting til oil appears in the tubing in the top hole. And keep filling til the both tubes are about three quarters full or there about..

Now, carefully rotate the engine a tash clockwise then anti clockwise. Only a inch or so will do. Notice how the oil first might rise in the tubing and then starts to fall? At that point b/t rising and then falling, IS TDC. Do this rockiing back and forth a few times and each time make a mark on the pulley opposite the fix pin on the front cover. You'll find that each time you do this, you'll get the same results.

Wondering about this and why it works?????? Well pretend you have a piston engine with the sparkplug at the top of the head. If you pour oil in the sparkplug hole with the piston at the bottom of it's bore, and fill it up to the top, then turn that engine to make the piston come up to the top, you'll displace oil until the piston reaches the top and then starts downwards. At that point of transition will be TDC. Same thing with a rotary as described above.

Other TDC methods require dismemberment of the engine. I'm talking about an engine in the car already and the marks on the pulley being in *dispute* so to speak. And please, nobody make the remark about how if the keyway for the timing gears is pointing to the exhaust side, that that is TDC. There is NOWAY to get that keyway exactly 90* to the right side of the engine while the engine is sitting in the car.