finding "TDC".... (racing beat flywheel/counterweight)
 

i would like to start by saying i have searched the forum for about a day looking for this info with no avail...

that being said,

i have a fresh engine, it came with no pulley(the one that should have the timing marks)

i have a racing beat flywheel/counterweight.

i should be able to find TDC using the flywheel sight on the top of the engine, right?

right now, what i believe to be TDC, looking down the top flywheel sight, i see the counterweight is all the way on the drivers, side. the little(1/2") divet, that is on the counterweight is facing up.

any other good schemes for finding TDC?

i will take a pic looking down the sight when there is a break in the rain :-(

Hold on a second...I have been talking to RB on the phone for a bit, and stumbled on this thread :)

I take it you have a 12a?

EDIT: The guy I talked to said you have to buy a RB pulley, as there is no mechanical way you can find TDC.

I feel like throwing the BS flag.

mine is a 13b... repu "block"
dizzy and front cover are gsl-SE.(so it fits)

i just talked to someone at racing beat also,
he seemed to think that under the pulley, there is a key for the pulley installation.
i am not seeing any kind of keying.

there are four positions the pulley can be installed(can be clocked in 3 hour increments

does it sound right, that TDC would put the counterweight all the way(standing up) on the drivers side?

Must not have search too hard, this thread in the archives should get you thru it.

https://www.rx7club.com/showthread.p...ht=finding+TDC

Yes thats a load of crapola. He wants to sell you a pulley dude.

he sure did try to sell me a pulley...;-)

thanks for the link TG!
i admit i might suck at searching, but i did try... maybe using wrong vocabulary though...

maybe cuz i only searched first gen section... wasn't sure if it would be the same... thanks

more to come!

after reading the link above(great thread, wish i found that first...)
i think i had TDC the whole time...

the thing that is throwing me off is when in this configuration, it is almost impossible to crank over. if i start moving teeth on the dizzy gear it gets easier. it will fire after moving several teeth

thoughts?

so... just to make sure i got this right...
 

please see attached pic..
i am using the RB flywheel/counterweight.

looking down the top sight(at the flywheel)
the part of the counterweight marked in red should just become visible?

it come into visibility from the passenger side.

thanks for the help, trying nt to damage my new motor...

i'm beginnin gto wonder if my ignitors are cabled incorrectly...

did it come with the dizzy already in it? of so just rotate the engine til the rotor button points to L1 on the cap.

did not come with dizzy in, i rebuilt the one i had...

BTW... just ran to sears...
got a new battery and batt cables...
i really wish it would stop raining...
i am working in short spurts do to weather

before, trying to start it the voltage was dropping down to about 5v with a starter box on it.

so... with new battery and cables.. it turns nice and hard now.
but still doesn't catch.

i have tried moving the distributor around by a tooth at a time, moving the rotor clockwise.

no change.
it at least fired over yesterday...

Some engines and pulleys have a small key where lead is placed and mushroomed. Notice in the picture where the white circle is. Not all pulleys will have the hole.

http://pages.sbcglobal.net/cerneric/...nginefront.jpg

^aluminum

mine does not have this...
looking at the pulley through the site, i think i have TDC...
now i think i am fighting something else.

i replaced battery, and cables. turns very nicely now.
will recheck for spark again in the morning
maybe i knocked something loose when i rewired...

tow that bitch to me and i will get that thing running in no time. Im in LA near Dodger stadium.

ok...
so, in going over my wiring i have found a small wire with no home.
it has a smallring fitting. it seems to be attached to the part of the loom that comes from the fire wall. looks like it should be a ground(maybe ECU ground???)
the ring fitting (like small battery terminal) would fit on the starter solenoid, but i do not see this in any wire diagrams. it is hanging in the vicinity of the starter.

what could this be?

If that ring fitting is attached to a wire that has funny looking fabric insulation then it is the fusible link that provides power to the hot start assist.

Edit: I just realized I replied to a post from LAST January!!!LOL oh well .......

There's no mechanical way you can find TDC with an assembled engine. You can try to see an apex seal in each of the #2 rotor's spark plug holes and then split the difference, but this will only get you to within ten degrees or so because the spark plug holes are asymmetrical.

This is good enough if you're just trying to find out how to orient an OE crank pulley on an OE hub. (And starting with the FC, the pulley only goes on one way anyway)

Another way you can try to find where the general vicinity of TDC is involves removing the dust shield on the right (manifolding) side of the engine, and line up the cutout/depression so that it is pointing 90 degrees from vertical. When rotor #1 is at TDC, the light spot on the flywheel/rear counterweight points towards the ports and the heavy spot points to the spark plugs.

But the only way to find exact TDC is with various improvised jigs on a partially assembled engine.

if you have a standard flywheel on,,
( view from rear )
then the bite missing from the back ring will be pointing at the exhaust at 3 oclock

if you have an auto counterweight ,,
then the bumps will at 9 o'clock ( view from rear ) down the spark side
( look down inspection cover )

=================



take off the clutch inspection cover and take note of the position of the counter weight wings or conversely the missing bite from the OEM flywheel balance

line the engine up to the right position and install the pulley so the timing mark matches

you will find 1974-82 the pulleys have an alum rivet extra to the bolt holes to help align
83-85 will have a pulley that can fit on 4 different ways
and the 1986-91 have an asymmetric bolt hole that allows them to align only one way

all these pulleys bolt to a hub and hub to crankshaft with big bolt and key-way that allow only one position for the hub

align the TDC or 5 ATDC ( pulley depending ) mark with the timing pin and then align the dizzy dot and mark on shaft and drop it in holding the button

- secret trick is actually to stop the pulley 5 degrees short ( clockwise ) [ 5 BTDC]

it allows the dizzy to stab easier without being on the crux of jumping forward or back as you stab
rotate the engine to the proper mark and align the pickup with the reluctor vane

=============

when you are happy with that and the polarity of the pickups to coil wiring
you can try starting
some rebuilds with s/h parts and superglue may need an initial tug/tow/bumpstart start ( if manual )
set idle high and allow engine to half warm before stopping it and allowing cooling system to depressurise to burp and refill it
most budget rebuilds will by now key start,, but some may require one or two more tugs till engine beds in

if u have a pulley that's still bolted to the hub, just put that one on it.