x19 Cam Timing

[daving]

Hey, you might remember me from this thread:
http://xwebforums.com/forum/index.php?threads/5973/

We took out the engine and resealed most of it. It's back in now, with the new head attached and torqued down, as well as the cam housing. When we changed the seal on the cam shaft we didn't pay attention to the orientation of the gear as we reattached it. The cam housing is now torqued down with a new gasket / RTV, so we don't want to take it off.

We are sure the engine is at top dead center so we need to figure out how to get the belt over the cam gear, with proper timing. Oh in case you didn't check the other thread it's a 1986 x19.

Ideas?

HD Pix of the current cam location:

 

[halojm]

Cam Timing

Since it looks from your posts that you have a stock cam and stock, it should be easy to get the cam timing on. Easy, because you have a non-interference fit engine and the valves shouldn't contact the pistons anywhere in their travel (If it was me, I would still turn the crank maybe a quarter turn from TDC just to make sure there was no interference). Anyway, timing is usually done off cylinder #4 (although #1 will be up at the same time). Pull off your dist cap, figure out where the rotor lines up to fire cylinder #4, mark that point and aim the rotor there. Next, turn over the cam until the marks on the rear timing cover bracket and the cam sprocket line up (should be a "V" shave pointer on the rear timing cover bracket and a notch on the back side of the cam sprocket). If you still have your cam cover off, you can verify that the cam is at TDC for cylinder #4 by looking at the cam lobes; both should be "up" about the same amount. (If you were paranoid like me, bring the crank back to TDC now) Make sure the crank is on TDC, put the timing belt on, loosen the tensioner nut, make sure everything still lines up, carefully turn the engine about 1/2 turn over with the tensioner nut still loose, then snug it down. Your engine should be timed. Good luck,
Dave

 

[Sport]

Well...

Right now in your pictures the camshaft is set up to TDC cyl. #1, and cyl. #4 is on overlap. If you look in your distributor, the rotor is probably set to #1. Before the belt goes back on you should turn the camshaft to be on TDC #4 and have the distributor rotor set to fire for #4.

Also, I like to rotate the engine over by hand twice to center the belt on all the cogs and get the slack on the tensioner side. Once this is done loosen the bolt and let the tensioner take up the slack, torque the bolt and you're done.
Rolf.

 

[daving]

problem...

(should be a "V" shave pointer on the rear timing cover bracket and a notch on the back side of the cam sprocket).

The problem is, the Cam sprocket was reattached to the cam shaft with out attention to where it belongs. So the markings on the cam sprocket aren't useful.

Also, the cam housing is already torqued down and RTV'd. We don't have an extra gasket. Thus it would be a pain to try to change the orientation of the sprocket.

How can I make sure the cam is aligned properly as possible, not considering markings on the cam sprocket?

Also thanks for the tips on TDC #4 and the distributor rotor.

-Greg

 

[budgetzagato]

Not advised

In stock configuration, the cam sprocket is indexed to the camshaft with a small dowel or pin. If you fit the sprocket without the dowel, not only is it no longer indexed to the camshaft, but it could spin on the bolt.

If the sprocket is not accurately indexed, the cam timing could be off by at least 1/2 a tooth no matter how you place the timing belt. That's about 3º of error that would lead to some "interesting" timing issues.

I recommend removing the sprocket and refitting the alignment dowel, and then the timing marks will be useful. You should be able to do this without removing the cam box from the head.

 

[daving]

Nice, I didn't know about that dowel at all, there wasn't one when we removed the sprocket in the first place.

I guess I can find a similar fitting pin and get that sprocket properly aligned.

Thanks
-Greg

 

[yugoracing]

For future if you dont knew ... just put your pistons on top No1/4 look and on mark on flywheel and your cam on cylinder No1 is bout valves open just put dial gage on inlet follower and pus to inlet valve is open 0.4mm (for OE 244* cam ) and put your cam belt that is factory timing if you like some "free power" from cam timing put your valve to open 0.8mm and put you cam belt (that is on cup racing yugo ) you put your cam in advance few deg. If you have racing cam you dont knew nothing from cam you can installed like this : cam installed same height opened inlet and exhaust some look haw mm is opened exhaust valve and same mm inlet valve in TDC than like "info" 2,5mm + 3.8mm =6.3mm than divide with 5=1.26mm . Inlet valve you can put to have 3.78mm and ex valve 2.52 on dial indicator and put-installed cam belt control again rev complete engine and look again in dial indicators . That is starting point than you can change some with adj.cam pulley ....Sorry my mother language is not English ...

 

[Chris Obert]

Also, the cam housing is already torqued down and RTV'd. We don't have an extra gasket. -Greg

Cool, I hope you got it on nice & thick so all the extra strings off & ends up on your oil pump pickup causing cavitation & loss of oil pressure.
Just joking.
But I would not have used RTV for exactly these reasons. I would however get a new gasket, take it apart, clean off all traces of RTV, & use a better quality sealant better suited for the job.

Sorry I am not addressing the question on your post, looks like others got that taken care of.