dreadseb

Hey guys, I'm having some serious problems here. I've searched but haven't had any luck what so ever. I'm trying to set my initial timing on my 1986 N/A but just can't get anywhere close.

My first and biggest problem starts with my E-shaft pulley, The most bolts I can align is 3, and I know that the pulley only fits one way and have tried every position accordingly.

Next is I've set the timing 4 different ways by re-positioning the pulley a quarter turn and then stabbing the CAS as instructed by the fsm with the leading mark aligned to the timing mark. Even with the CAS cover off to make sure it doesn't turn out of place. It started once in my last position but after that nothing even close to being started.

So I lined up the timing marks and pulled the CAS to check it out and it was 180 degrees out now for some reason. The teeth look to be in good shape so I don't think it could be skipping teeth.

Has anybody had a problem like this, or does anybody have a suggestion or anything really that might help me out here. I'm at my wits end with this thing.

HAILERS

*****My first and biggest problem starts with my E-shaft pulley, The most bolts I can align is 3, and I know that the pulley only fits one way and have tried every position accordingly.
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It sounds like you have a first generation CARB, pulley or CARB hub, that your putting on the engine.

The hub has the four threaded holes for the pulleys. A first gen, CARB hub threaded holes are different than the series four. The series four have one hole offset, unlike the first gen hub.

Or? is it a case of you putting first gen pulleys on a series four??? It's one or the other.

Tell us more about this project. Just rebuild the engine? Bought from someone else? Or have the pulleys been taken off and now for some unknown reason the holes don't match?

dreadseb

The carb pulley problem would make sense. The pulley should be S4 since all the bolts were in when I pulled it. The motor was rebuilt and now it doesn't go on. The motor wasn't put built by myself so I'm not sure what hub it is. I do have a first gen pulley outside so I'll try see if that makes a difference for me. The new hub does have a dimply in it between two of the mounting holes if that tells anybody anything.

HAILERS

EDIT:I erased my fist response so if you read it, forget it.

I had written something that might be wrong so I cut it out of this thead.

A dimple. Well my series four hub has a dimple. I'll try to find my fist gen pulley sometime tomorrow and scan the first and second gen together along side each other. But it does SEEM to me the rebuilder put a fist gen hub on a second gen, especially if you KNOW the pulleys your putting on came off your second gen engine.

There must be some measurement I can make. I'll think about it.

IF memory serves, the first gen had a rivet b/t two of the mounting holes to locate the pulley with the hash marks for timing. I'm fairly sure of that, about sixty percent sure.

ATTACHED is a jpg of a first generation carb pulley. See the extra hole???? Yes. I think there was on some of them a rivet thru that hole that attached the pulley to the hub at one time. Fairly sure. I can't find the hub at the moment. Too cold right now.

HAILERS

Remember a couple of things you may not be aware of.

1. There is a keyway on the eccentric shaft that is located 90 degrees from TDC and this keyway holds the pulley HUB in place.

2. When that keyway is 90 degrees to the left when looking towards the engine, then TDC is at the top of the pulley and opposite the fixed pointer on the front cover.

3. If you had a first generation HUB on your eccentric shaft and put on a series four pulley on that hub, there will be one hole on the pulley that won't match the holes on the HUB. That misaligned hole will be to your right as you look into the engine, AND the keyway will just opposite on your left. So what I'm getting at, is if the misaligned hole is to your right as you look into the engine, then the timing marks will be at the top *close* to the fixed pin timing mark. That even applies if your using a S4 hub with a first gen pulley on it. Same situation.

4. On a first gen car, when the keyway is exactly 90 degrees to the left as you look into the engine, then the first mark on that first gen pulley will be opposite the fixed pointer. But keep in mind that Lead timing is at TDC unlike a S4 which is 5 ATDC

5. And if it was a fist gen pulley and the keyway was exactly 90 degrees to your left when looking into the engine, you can draw a straight line b/t the very bottom hole on the pulley thru the very top hole and that line will be in alignment with the fixed pointer.

6. BUT If you had a S4 hub on, and put a first gen pulley on with the three bolts that will match, you cannot draw a straight line thru the top and bottom holes of the pulley and expect them to align with the fixed pointer, because the holes in the hub of a fist gen are not located exactly as those on a S4. They will be close but won't align with the fixed pointer.

7. One of several ways to find TDC is to take the pan off the engine and set it on a flat surface (gotta remove that oil pressure control device from the front cover also plus the oil pickup also). Then measure the diameter of the eccentric shaft in the keyway area. Then measure from the flat surface the engine is on to the bottom of the eccentric shaft. Add half the diameter of the eccentric shaft to that and come up with a FIGURE/NUMBER. Then hold your 12" flexible scale with thousandths marks/32nd marks etc and turn the eccentric shaft til its keyway is to your left and the MIDDLE of the keyway is opposite your FIGURE/NUMBER on your scale. Then you have found TDC. So put the hub and pulley on the shaft and make a mark on the pulley opposite the fixed pointer. That will be TDC.

8. The you can use the pie are square routine and figure out the distance on the outer edge of the pulley to get to 5 degrees and 20 degrees from TDC.

9. This is similar to what that thread on OPTUPUSNET does except what they do isn' totally relevant to S4 because the threaded holes on the S4 hub are drilled in a different pattern.

I also realize all the above makes sense to me but not anybody else. Big deal. Jpm attached to help out a bit.

A BALLPARK way of finding TDC is found here: http://www.teamfc3s.org/info/articles/demystifying.html Bottom of that page.

Rx7_Nut13B

iTrader: (1)

Here is a trick i have, to find TDC if i need to with out a pulley

Take a plastic pen, insert it into the bottom plug hole on the front rotor. Turn the motor by hand untill the pen doesnt go out or in, In other words where the rotor is as close as it can be before it starts to move away for the housing.

dreadseb

Thanks a lot guys, I got it running pretty good over the weekend through a little bit of educated guessing and its running pretty good now but the pully is still in the wrong position so I can't time it with a light. I'm away from the car for the week because of school but when I get back to it I'll try to set tdc and line up the timing marks and see what I get. I'm also gonna try to stop by a wrecking yard and try to pull a pulley off an s4 because who knows maybe the car didn't have the s4 pulley to start with.

Now for a new riddle. After running the car a while when it was running good it has developed a howl from the engine bay. I figure it could be one or more of three things, first a vacuum leak, second a bad pilot bearing (its not this it happens in neutral when the pilot bearing "should" be stationary in its race), and third the starter gear staying engaged with the flywheel. Does this sound about right or could there be something missing.