can't get cams timed....help

**njm23** · 12-18-2008 12:23 PM

Okay, well i'm trying to put my head back together. I've taken it apart about 15 times now trying to figure this out.

1- the cam doesn't wanna line up perfectly, it's always slightly off to the side(referring to the timing mark on the actual camshaft, the other cam is fine) and the chain seams off too because of that, like it is 1/2 a tooth off?

2- when I feel like it is as close to correct as I can get it the chain is tight on the top but loose on the bottom of the tensioner and it still seams like it is a tiny bit off. Like the gear on the cam has moved or something...?

if anyone can help, this doesn't make any sense to me...

I know the picture is blurry sorry..this is as close as I can get it and the bottom of the chain is loose when it is like this. BTW the chain is marked from when it was taken out of the head, which ran perfect. maybe i'm just paranoid? idk.. just worried mostly the fact that the chain is loose on the bottom of the tensioner, and yes the cap is loose, I had 2 and 4 tight just to see.

**pac1085** · 12-18-2008 12:44 PM

i don't remember if it was the intake or the exhaust cam, but one of the notches doesn't line up 100% .

go read the bentley, it tells you

**njm23** · 12-18-2008 12:53 PM

yeah I know, but my problem isn't that. if you look at the cam the "notch" is offset form the arrow, the other cam is the same way.. I can't figure out why and I dont remember it being like that, I only remember the chain being off, the notch should be in the middle, or so i think.. and then the chain not being tight on the bottom of the tensioner... Just wondering if someone can correct me and maybe there is nothing wrong or what. I don't get how it could come out of the engine timed and everything fine but then not want to go back together correctly, all the markings i did on the chain ect.. were correct, also might add that it doesn't line up with the valve cover perfectly either...but there is no other way, this is the closest I can get it, makes zero sense to me..

**t1demont1** · 12-18-2008 12:55 PM

16 teeth apart, after you install them, spin them and they will line up.

**dougyfresh** · 12-18-2008 12:55 PM

CAT cams? Adjustable cam TB gear? OEM cam TB gear?

BobQ should have marked TDC on the cams. I think it is aligned with the keyway notch like the OEM cams. Set the exhaust cam dead nuts on the marker. Count 16 pins on the chain over to the intake cam and line up that pin with the TDC marker (keyway). It will most likely be off a hair. I'll post up photos of my CAT cams 3651s when I get home tonight to show you what I mean. I went back and forth with Bob a few times when I installed them.

PM'd you my # if you need to call me about this.

EDIT: That is the exhaust cam photo. Re-adjust. Its not aligned. The Intake cam most likely will look like the photo you posted. Not the exhaust.

Also, tighten those bearing caps down. You are stressing the bearing surfaces with them loose and tension on the cams with the chain. With the tensioner and tensioner tool you can re-adjust the chain. Cams should be torqued down regardless. 7ft-lbs if I recall correctly.

**njm23** · 12-18-2008 01:30 PM

I have the cam tensioner tensioned, there is no stress on the cams, I had 2 and 4 tightened down for about a minute to take the photo..the bearing cap you see is just sitting there, it isn't held in..i'm gunna give you a call doug, because I tried everything and can't get this ot lign up right..btw there oem cams, no adjustments or anything.

**njm23** · 12-18-2008 02:14 PM

Wow I don't even know.. After talking to ya doug I just managed to get everything timed up correctly and it is EXACT.. luck? who knows lol but I didn't anything from ther last time where it refused to line up.

Now onto a new problem... How is this even possible? Everything is timed PERFECT. at TDC cyl.1 and cyl.4 both have 1 exhaust valve that isn't completely closed (i see light through the port) and same thing for the intake valves. I really can't even begin to understand how a cam could do that. so i guess i'm asking is it possible my springs are kinda "stuck" or something? I'm bringing it over to the machine shop tomorrow he's gunna look at it, this is crazy..

**t1demont1** · 12-18-2008 02:34 PM

how far open is the valve?

could be a number of things

1) valve is slightly bent
2) lifter has air in it
3) dirt or something keeping the valve form seating.

Put that valve all the way open and leave it there for like an hour irrc and taht should settle the lifter if its that.

If your machine shop is good then they caught any bent valves. I had a bent valve that was so slightly bent, it would settle after time and close but when the car was on it would stay bent and missfire. My machine shop found it.

**njm23** · 12-18-2008 03:12 PM

yeah t1, I think you were right, assuming the lifters had air in it or something cause now the valves are fine and every once in a while there will be a valve that'll not close all the way but it is so minimal, only way I could tell was by having my light come through it. seams like everything is good now. guess its expected to run into problems when it is the first 20v 1.8 head I have worked on. thanks for the help guys, appreciate it.

**dougyfresh** · 12-18-2008 08:01 PM

Brenden is thinking what i was thinking... Lifters (as mentioned). Talk to your machine shop tomorrow to confirm. Will those valves close if you take out the cam and lifter?

What did you do after we spoke to get them to line up?

I don't have any photos of my cams on my flickr account. Well, none that show TDC and the markings. Let me look through iPhoto.

**njm23** · 12-18-2008 08:10 PM

Yeah, if I pull the cams the valves close. Which is why i am thinking it is the lifters doing it, it has gotten progressively better the more the lifters have had pressure. This is why i didn't wanna do it when I had it on the engine already, ha.

and i didn't do anything, which is the weird part. I mean all i did was take it apart again and did it all over again. But nothing changed that I could see, chain stayed in the same spot..who knows, but it is spot on. earlier I couldn't get the cam gear and valve cover lined up and if i did the key ways on the cams were a good 1-2mm out. perfect know..whatever i'll take it.