Doing a subaru timing belt... each full rotation of the belt = 1 more skipped tooth?

Soo I don't get it.

I'm reinstalling the timing belt that came with my subaru SVX motor. I'm assuming it's the correct belt, as it came with the motor.

I get everything lined up and pull the grenade pin on the tensioner... everything is still lined up. Then I turn it one full timing belt rotation, and all three timing marks are back consistently one tooth? One more full timing belt rotation, and all three timing marks are back TWO teeth (one more full tooth). Another rotation, another tooth. As you might imagine, if you spin it backwards, the opposite happens.

Yet all three timing marks seem to be oriented perfectly. IE, when the crank pully is at TDC, both cam pulleys line up with their stamped marks.

Soooooooooooooooooooo. WTF?

You said the belt "came with your SVX motor". Was it RUNNING when you got it?

Sure it's the right belt?

What is a "full timing belt rotation"? Do you mean a full crankshaft rotation bringing it back to TDC? You said all three marks are aligned but back one tooth. I'm not sure I know what that means. Sounds like everything is aligned but you haven't completed the rotation. Has anything changed in terms of the engine components relation to each other?

i think you're actually OK here. as i recall subaru designed the timing system so that the belt continually spins around the gears and pulleys at a slow "orbit" to prevent the same spot on the pulleys touching the same spot on the belts and contributing to odd wear patterns....i.e. if there's some weird nick on a cam gear for instance, and it cuts into the belt slightly, the rotation pattern will spread this damage over the entire belt instead of focusing on one spot.

if you have the right belt, the timing marks are correct, and you're not finding any resistance throughout the piston travel (hitting valves) while turning the motor over with a breaker bar you should be fine.

thread's a bit of a E36 M3-show, but some more information here from a fairly recent post on NASIOC: http://forums.nasioc.com/forums/showthread.php?t=2153845&highlight=timing+belt+teeth

I don;t see where even the wrong belt would cause these problems...

I would keep turning it over by hand to see if it gets worse and worse.. or starts going back?

ignore the belt, ScottyB is right here, manufacturers design it to "orbit" around. Do your cams line up with the marks on the block/cover/whatever after TWO complete rotations of the crank shaft?

oh! I misread... as long as the pulleys line up, you are golden. All the timing belts I have done over the years.. I have NEVER looked that belt for marks.. just the pulleys

Done a couple of Scoobs in my time, peter is right on the money. Don't worry about the belt marks, they are only for quick initial alignment.

Thanks all. And just to be clear when I say a full rotation of the belt, I mean rotating the crank enough times for the belt marks to come full circle.

It seemed to me that this was not an issue, since the pulleys all line right up when the belt makes a 'full circle'... but the belt timing marks are retarded one notch (consistently on all pulleys) after a single belt rotation.

It makes perfect sense why they would do this, I just wanted to be sure that this was correct! I couldn't find any mention online about this. So I figured, GRM would know, and in fact, you did! So thank you.

For what it's worth, my engine bay now looks like this:

i didn't realize this engine wasn't actually in an SVX

yes sir. i like it.

Now, I have to ask this question, just because its a Subaru, You ARE using the correct crankshaft marks, right?

Hint: (4 cylinder) Subs are not timed at TDC.

The crank pulley comes off to do the job, so only the timing mark remains which is located on the crank sprocket.

Also it's a non interference engine, so I do not run the risk of damaging components.

(The intake and exhaust valves are interference by nature, however, they are gear driven, so this is a moot point unless one of the gears obliterates itself)

Streetwiseguy wrote: Now, I have to ask this question, just because its a Subaru, You ARE using the correct crankshaft marks, right? Hint: (4 cylinder) Subs are not timed at TDC.

He's not using a 4 cylinder Suby engine

mad_machine wrote:

Streetwiseguy wrote: Now, I have to ask this question, just because its a Subaru, You ARE using the correct crankshaft marks, right? Hint: (4 cylinder) Subs are not timed at TDC.

He's not using a 4 cylinder Suby engine

I understand that. I also don't know the procedure for timing a 6 by heart. Its also a Subaru, which automatically make it weird. RTFM. Just sayin...

The SVX is actually easier than the 4 cyl soob's to get lined up.