Hey Guys,

A few months ago I came accross a post which lead me to a website that described how to make a new timing mark on your main pulley. IIRC it had a blue background and may have been done by an australian.

I know I saw it here, but after an hour of searching the forum, I can't find it anywhere. It seems like something I'd archive, but perusing the archive didn't bring it up either.

Anybody know the website I'm talking about? They take the pulley, put it on paper, draw two lines through it and a bunch of other things involving a protractor that I can't remember.....

Basically I think I've found one of my two timing marks, but I can't for the life of me figure out which one it is. If I can figure out which mark it is (if it is indeed a timing mark) then I can re-mark the other one by measuring 20* further or previous to it.

Jon

 

I may have it at home comp. but here's paul yaw's just in case. http://personal.riverusers.com/~yawpower/pultime.html

 

Jon, if you have a cloth metric tape measure, iirc, the pulleys are 360mm in circumference. It that's the case, mark 20mm on each side of the mark you found, then hit it with the timing light.

 

i know this has nothing to do with our cars but it does with the board, since changes aare gunna eb happening if im correct why not add a section with just websites that sell parts and stuff to do with rotaries and what helps us out...... just a thought ill find that suggestion place lol

 

Hey Jon,

Check your pm box. I sent you that link awhile back because I remember you were trying to mark your pulley. So you did read it here, just not as a post. Anyway, here it is again. It may help others as well.

http://ausrotary.dntinternet.com/for...ic.php?t=57491

Kent

 

Awesomeness.

Thanks Kent. I knew it was here *somewhere*. No wonder I couldn't search it up. I'm usually pretty l33t with my search skillz.

Jon

 

trochoid is talking about the cloth metric measuring tape pulley marking method or CMMTPMM (another seven letter acronym oh noes!1). It beats the pants off of the caliper masking tape method. The problem with masking tape is that it stretches, and since the pulley is 360mm in circumference, 1mm is equal to 1°. No need to convert to inches. A cloth measuring tape is a lot easier to handle than steel. Look for it in a fabric store.

 

I've done the pulley (ala Paul Yaw) many times. I just scribe the measurements directly to the pulley, then use a thin hacksaw blade.

 

Yeah, that makes sense. I'd already read the site thoroughly, but I needed to find my two original marks before I could make more. I found one mark, but didn't know whether it was leading or trailing and couldn't find the other mark.

Once I find my leading mark (TDC) I can start the process of making other marks and hack-sawing them. As it is, I only managed to find one of the two original marks and hacksaw'd that, but didn't know if it was TDC or 20* ATDC.

Needless to say, if I followed Yaw's instructions and made extra marks, but used the wrong starting point, all my marks would be 20* off!

Jon

 

You won't have to worry about it soon.

 

lol, true enough!

*still* haven't found a source for FD alt pulleys! Gah!

Jon

 

http://www.yawpower.com/pultime.html
So I thought I'd update this and post my struggles here. has anyone gone to mark thir pulley and ntoiced that their stock timing marks are off. Mine are 16mm instead of 20mm apart. Something is clearly wrong with my pully. I'm kinda pissed actually. I don't know of my TDC or 20*ATDC mark is the one that's off by 4 ******* degrees. This is terrible. If it's the T no biggie as i'm setting timing to 27btdc off of the leading mark, but if its the leading then my leading timming would actually be 23*btdc. fawk this is stupid!!

 

Well I found my answer... Paul yaw and many others are wrong.
https://www.rx7club.com/showthread.p...=timing+pulley
The yellow mark is infact not TDC. It is 5*ATDC and the red mark is 20*ATDC. This is the clearest thread explaining the issue. There are many other threads that point it out as well. Make sure you tell your friends.

 

You have an FC engine, right? You are right. They did have 5° and 20° ATDC marked on the pulley, and one bolt is offset a little.

 

here, some pics of what I did

the oem marks seem to be just 15 degrees apart, so they could be 20 and 5

 

It's a GSL-SE engine.

 

DONT YOU KNOW!

marks on the gsl-se engine are 5ATDC and 20ATDC, 15 degree split. all the FC's are marked like that too.

12A's are TDC and 20ATDC, which is 20 degrees.

also if you have had the pulley apart, theres like 2-3 degrees of slop in there, so there is a tolerance to the timing mark...

 

SA rivet-indexed pulley FTW. Escapes SO much confusion!

 

Damn I'm such a noob! me FTL! interweb sp3ak! yezzzz. I feel like a kid again talking like that.

 

Mine is a 1980 12A euro spec and seems to be 15 degrees apart

 

not all are true. the pix I showed is a 12-A pulley so TDC is correct. Besides, what you have to look at is the bolt at 12:00.

 

bolt at 12 o'clock key way at 90* and the timing mark is not at TDC. Iam leaning toward believing that 12a pullies are 20 and 0 and 13b ones are 20 and 5.

 

Per FSM, 12A's are 0 and 20, yes. Leastwise the early ones.

 

As you can see in the pics, I believed that.... but no, its not 0 and 20

 

If my car was home I'd take pics of the pulley I made. It's amazing what a bit of patience, some colourful paint and accurate measuring instruments can do. My 12a pulley was indeed at 0 and 20 stock... or at least the one I used was.

In the end I didn't go with FD pulleys, I stuck with the original v-belt style... but had to use one of the pulleys off the 3 12a's I took apart later as a reference point for the timing marks because my stock one really didn't have marks left on it.

Jon