Using Flywheel to determine timing?
 

Someone once posted about a mark on the FW that corresponds to a mark on the engine which when aligned, puts the engine at TDC. Can anyone post a pic of this? Or a detailed description?

im going to check my 12a on the bench when i get back to the shop, ill photo it for you, banana yellow donuts to those that help me figure out how to fuel this supercharger

Re: Using Flywheel to determine timing?
 

DO A SEARCH!

:D

I have an '83-'85 flywheel to look at, but I can't recall seeing any markings on. I'll glance at it in a few.

Re: Re: Using Flywheel to determine timing?
 

I DID SMARTGUY! :D Didnt find any useful info. However on teh way home I stopped by my storage place to look at some flywheels I have. Maybe someone can help with this info I have. On an 81-82 and an 84-85 FW the keyway lines up perfectly with the center of the notched portion of the CW. In the attached pics, the keyway is straight up at 12 o'clock. This must mean something. Where is the keyway when the engine is at TDC?

http://www.mazdatrix.com/faqpics/flywheel/81_12ar.jpg

http://www.mazdatrix.com/faqpics/flywheel/31r.jpg

I just checked the flywheel and didn't see any marks. All that's there are holes for balancing.

Hey Carl, I just looked at an E shaft and I can say the keyway in the rear of the shaft is on the same side as the rotor bearing journal (or whater the lobe-ish part is called). That means the keyway is 180º from TDC.

Thats ok though. If I can get an answer to where the keyway is at TDC, then I can use the center of the cutout as a guide, capice<sp>?

I just edited my post. :)

Maybe what I wrote is confusing. The rear rotor journal is what I meant to say. So when rotor #2 ir ready fire, the keyway is on the plug side of the engine.

Ok then, correct me if I'm wrong, but then this would mean when the keyway (center of the FW cutout) is at the 3 o'clock position (engine as viewed from the rear) Then the front rotor is at TDC. And that means you can remove the inspection plate aft of the exhaust manifold and line up the cutout at the 3 o'clock position, and your then at TDC.

I know that the front keyway is at 9 o'clock when the front rotor is at TDC, but I've never seen any marks on the flywheel's periphery, and I've looked for 'em, too.
If there is in fact a reliable way to determine TDC by simply removing the inspection plate and lining up some marks, that would be great. I'm gonna have a look at some other engines I have stored over at my friend Klaus' house and see if I can find anything.
This is starting to bug me.

I never heard of that either but out of curiosity, I've checked several of my old flywheels and found no mark. Morethan likely, he (whoever posted that thread) made his own marks on the flywheel. But isnt it easier just to check the key mark on the pulley like what Wankelguy mentioned.

Well to HELL with the mark! Look at the weight! You can clearly see teh cutout (and find teh center). Since it lines up perfectly with teh keyway guys, its an indicator of timing right? Or am I totally fucked up here? I'm looking for an indicator to reset teh engine when someone removes teh pulley from teh hub and isint sure how to reset it.

yeah just use the key notch on the front pulley. Its an easier process. Otherwise, if you want another pulley, let me know. I will send it to you.

i posted ... theres a line on the flywheel that will line up with a line on the rear plate when its @ tdc.... with a a stock flywheel and also the key in the front of the main pully will be @9 oclock (Exh side of the motor) when its tdc

Where did you see teh line at? In other words, how close to teh imbalance is teh line? :)

Badass, I never saw that line on any of the FW's I have. But I think I have enough to go on now using the balance weight cutout. Sound ok to you guys? Mel, cant see the front keyway if the hub is on. :confused:

just remove the pulley bolt. you will see it.

9 o'clock as viewed from the front or rear? And how does the front and rear keyways relate to each other on the e-shaft? Are they in line? 180* out? I dont have an e shaft handy to check. :confused: :(

Ahah! Looking at a rear housing I found this hole. I see no purpose for it. Maybe this is supposed to line up with what we thought were drilled balance holes, when they may be in fact timing marks on the FW. On the 81-82 theres only one drilled hole, but on the 84-85, theres 2. Maybe they are 20* apart? mebbe????? ANyone? Bueller?????

https://www.rx7club.com/attachment.p...postid=2456842

No offense Carl, but I think you're sending yourself on a wild goose chase.

When you disconnect the front pulley, put the keyway at 9 o clock and then line the yellow mark on the pulley with the timing pin. It's that easy. Done it a bunch of times now.

9 o'clock when viewed from the front. I'm not sure about the rear keyway's position relative to the front, sorry. And yeah, you can't see the keyway unless the pulley bolt is removed, which can be a bitch. That's why I was excited at the prospect of an alternative method.

The front and rear keyways on the E shaft are in the same position.

Aha! Now we're getting somewhere!

It is true. I looked at an engine today (it didnt have a FW on it though). The rear keway is indeed at approx 9 oclock at TDC as best I could tell. I think this alternate method will pan out for all of us. :)

I'm with you WG, pulling the front bolt is a PITA with all the stuff up front. This will be WAYYYY easier. ;)

PS- No offense taken Chris. :beerchug: :D

pulling the trans is way easier? :wtf: