1st Generation Specific (1979-1985) 1979-1985 Discussion including performance modifications and technical support sections

Timing Mark Website (I know it was here somewhere)

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Old 04-17-06, 05:34 PM
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Timing Mark Website (I know it was here somewhere)

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
Old 04-17-06, 06:21 PM
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I may have it at home comp. but here's paul yaw's just in case. http://personal.riverusers.com/~yawpower/pultime.html
Old 04-17-06, 07:04 PM
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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.
Old 04-17-06, 08:19 PM
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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
Old 04-18-06, 03:32 AM
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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
Old 04-18-06, 09:48 AM
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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
Old 04-18-06, 01:03 PM
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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.
Old 04-18-06, 01:53 PM
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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.
Old 04-18-06, 02:10 PM
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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
Old 04-18-06, 03:59 PM
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You won't have to worry about it soon.
Old 04-18-06, 06:56 PM
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lol, true enough!

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

Jon
Old 03-12-09, 02:19 AM
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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!!
Old 03-12-09, 03:36 AM
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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.
Old 03-12-09, 04:22 AM
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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.
Old 03-12-09, 12:03 PM
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here, some pics of what I did

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






Old 03-12-09, 04:11 PM
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It's a GSL-SE engine.
Old 03-12-09, 04:19 PM
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Originally Posted by Hyper4mance2k
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...
Old 03-12-09, 05:07 PM
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SA rivet-indexed pulley FTW. Escapes SO much confusion!
Old 03-12-09, 07:15 PM
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Damn I'm such a noob! me FTL! interweb sp3ak! yezzzz. I feel like a kid again talking like that.
Old 03-12-09, 08:17 PM
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Mine is a 1980 12A euro spec and seems to be 15 degrees apart
Old 03-16-09, 08:32 AM
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Originally Posted by Hyper4mance2k
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.
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.
Old 03-16-09, 01:55 PM
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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.
Old 03-16-09, 03:01 PM
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Per FSM, 12A's are 0 and 20, yes. Leastwise the early ones.
Old 03-16-09, 03:42 PM
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As you can see in the pics, I believed that.... but no, its not 0 and 20
Old 03-17-09, 07:02 PM
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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

Last edited by vipernicus42; 03-17-09 at 07:05 PM.


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