Hoping someone can help me figure this out.



My friend bought an S5 NA that someone's turbocharged. It won't start and we're trying to set the timing.

Someone re-drilled the front pulley to fit the hub - it looks like the bolt pattern was a little different.

The hub that's on the engine (again, I believe it to be S5 NA) also has a small "notch" around the inner bit. Maybe something just hit it or something, or maybe it's a factory mark, I'm not sure.


I pulled every front pulley that I could find out of my shed (5 of them in total) and some are different than others but they ALL fit on every hub that I can find. And of course, NONE fit on the front hub on his engine.


So what's the deal here?

Are there two different front hub bolt patterns, and if there are, can we just swap a different hub on the engine? All the hubs I found (2 or 3 of them) seem identical.

 

I stopped by Terrh's house and grabbed all of the pulley's he had, according to him he's disassembled more S5 engines that S4's so some of these pulley's HAVE to be S5's, but none fit.

I have a few hubs that fit these pulley's, but if I swap out the hub and put on one of these pulley's, will the timing still line up?

the bottom pulley in this picture was the one modified to fit by the last owner. you can see one of the holes is ovaled out.

 

You can swap the S4 hub onto the S5 and vice versa. However, you NEED to keep hubs and pulleys together as a set because they are all drilled uniquely. I've seen S4 pulleys that don't fit other S4 hubs, SE pulleys that fit S4, and all manner of variation. So a hub needs to be kept together with it's matching pulley when removed from an engine.

To sort out this mess, turn the eccentric so that the front key way faces the side of the engine with the intake and exhaust ports. That is TDC. Now mark a set of hub and pulley appropriately.

 

and here is a picture of that mysterious notch on the hub, also if anyone can tell me why I'm leaking oil from the front bolt that would be great too

 

ok, yah I'm aware that the key way is 90 degrees to the left for tdc, but I was trying to avoid pulling out the front bolt.. because I can't get the damn thing out. If I remove the radiator I'll have room to get my impact gun in there.. I guess I'll get to work thanks.

also I've been told that I need to keep the clutch pressed to the floor when removing the front bolt to avoid some bearings from falling, is this true?

 

You're leaking oil there because the O-ring of that screw is damaged.

 

Maybe the mark on the pulley was put there to note the location of the keyway? No way to tell unless you remove the front pulley bolt with can be a PITA. I didn't want to pull the rad to get an impact on it, so I used a breaker bar and the starter to break it loose.

You can just put a little bead around the base after you pull it to find the keyway.

Just a guess, but could it be 12a hub? If many different S5 pulleys don't fit on an "S5" hub, I'd suspect the hub. Either way, you're probably going to make your own timing marks, so I'd just use the ovalled one that already fits.

 

I never ripped apart any 12a's. Do 12a's even break? I wouldn't know because I've never seen one that didn't run.


I think that's a factory mark I'm sure I've seen it before but of course I can't find any other hubs laying around that have that mark on them.

To make things even more confusing, all of those pulleys fit the hubs that I did find (only two hubs), and there are two different diameters. Some of them are a little smaller. And the ones that are different have timing marks in a different spot.

His crank bolt is on real, real good. I don't know if bob had any luck removing it today but we were unsuccessful in our attempts to remove it last weekend.

 

nope, I need to find a good torch.. That thing is on there good.

 

They do when they have an '83 front counterweight and an '80 flywheel. Shook itself to pieces. It was in a lemons car, so we weren't sure which vibration was coming from where.