Need some advice. having trouble setting timing.

[progman]

I was finished the last few things to get my engine ready to run from being rebuilt. I installed the timing belt set my cas in the middle and started the car. Everything seemed fine until I went to set my timing. I have to advanced my CAS all the way to get to about 8 degree btdc. So first I thought my timing was off. I double checked everything and then went back to set the timing again and same thing. so now I went back and checked it about 5 more times. I spun the crank around the checked thing and counted the cogs over and over again and everything seems to line up perfectly.

Take a look at these pics? is it off? I'm I blind?



Why is the exhaust slightly off? is this normal. I don't remember this on my other build but I never looked so closely before.

[themadscientist]

ALL SLACK must be on the tensioner side. You will need to rotate the exhuast cam sprocket clockwise just enough to engage the belt tooth which should leave both sprockets lined up to the notches when the tensioner is released and the belt pulled fully taut.

[progman]

Thank you for the advice. I'm going to go redo it.

[progman]

Just finished redoing it.... same thing . I must be doing it wrong. I'm going to reread the FSM and try again. I've done this fine two or three times before..

One thing I didn't do is turn the crank around two times holding tension on the tensioner and then tighten it up. I guess this works the tension out. I'll try this....

[themadscientist]

Did you have the head or the block decked as part of the rebuild? What thickness is the head gasket?

[progman]

Both were done. The block should have been very minimal and I don't know how much was taken off the head. But I have used that head on a different block and it was not re-decked for this block. The head gasket is oem.

So if it's too short then the space between my exhaust cam and crank is shorter than normal... time for adjustable cam gears? thicker head gasket (of course I'd rather not so this) Maybe I should set the crank off by a pin and see if that moves everything the opposite way.. hmm, that's not enough to hurt anything I don't think. judging by how far off the timing is I think I need a whole cog's worth of adjustment because the most advance i get get is 8 degrees btdc.

[themadscientist]

It looks like that is the problem. Just get some adjustable sprockets and degree the cams and you will be fine.

[bentvalves]

8 degrees btdc with the CAS fully advanced?

I doubt its your head/block being skimmed.

Try another CAS, then try another. They are like almost 300 brand new from autozone I believe. Order one, put rubber gloves on and try it out real quick, then return it if you dont have access to another.

Do not get a thicker headgasket and negate the benefits of your bumped compression. If anything try advancing the exhaust cam 1 tooth. I remember a guy on SXOC and NICO from Poland? I believe having much experience with these engines and swearing by advancing the exhaust cam 1 tooth. Im going to have a look for the thread and post a link later on to make absolute sure it was the exhaust cam.

Greg

[progman]

Thanks for the advice. I ordered tomei cam gears but they are on back order for 3 weeks so I canceled the order (240sxmotering).

I'm pretty sure that it's the intake you want advanced. and the exhuast retarded. After adding a free flowing exhuast you want to seperate the over lap time because you don't need it as much anymore. I read that in a tuning book somewhere (nissan specific)

I was just thinking about it. and it wasn't even this far off when I did have the exhaust off by a tooth.

I think it may be my cas. Because When I first set the timing I can set it to 15 degrees and it revs awesome and builds boost. but then it starts to bog down and the timing stays way off the chart. (I can't remember if it actually chnages... i think it does, i thought maybe the slack was working out)

Time to find a new cas. If i have to buy a new one. screw that. mega squirt here I come!

If anyone reading this would be willing to ship me a working cas I could try on my engine that would be awesome, I'll cover shipping both ways + some if you would be willing to help me out.

Thanks.

Oh, BTW, is the 88 pulsar 1.8 de have the same CAS? I'm pretty sure but just want to check.

Thank you.
Modified by progman at 5:39 PM 5/12/2008

[bentvalves]

yes it does, same thing.

[progman]

Autozone: $348 no returns.website:Unit Price: $227.99*Core Value: $50.00Total Price: $277.99

Pepboys: ~$378 no core, no returns.

advanced auto parts: ~348 dollars, no core, no returns

Napa auto parts wesbite: $509.00

[bentvalves]

damn ix-nay on the returns huh?

[progman]

I just got a working used CAS and that was the problem. Now I just need to tune this thing and get it back on the road.