Cam belt don't line properly, stroker project

[staffeee]

Hi everyone!

I have a big issue with my stroker project
and need fast help.
My previously engine was a 3b block, 3b head
Aat crankshaft, custom piston and rods,
3b crankshaft sprocket, cat cams
Camshaft sprocket, AAT pulley (251C)
147 Cam belt, 3b waterpump as tensioner.

My current engine build is exactly like above,
The only change is that I use an AAT engine block
and a 151 Cam belt, and offcourse other rods and pistons.
Now my cam belt don't line properly, it will
almost scrape the head.
I didn't use the Diamond washer before
and I don't use it now.
The belt lines on the same spot on both
my 3b pulley on the oil pump cover and 3b
waterpump..
What the heck is wrong?
How have you others build it together that
use the waterpump as tensioner??

[AndyP]

Where on the head is it scraping? Do you have any pictures?

I've used the 3B waterpump on mine and had no problems, I don't use the diamond washer either.

[staffeee]

Here are photos:

[staffeee]

Another one:

[staffeee]

How thick is the ADU Diamond washer?
But I'm afraid it don´t lining properly my
waterpump and pulley if I use a washer.

If I use a Diamond washer
on the crankshaft and use a spacer
behind the pulley is it possible to
pull out the waterpump sprocket by
let say 1,5-2mm ?

Just brainstorming :/

[AndyP]

Do you have both the dowel pins in the head? I've seen something similar before on an AAN engine where the rear dowel was missing, the head was a fraction out of line and it caused the cambelt to 'walk' to the rear of the pulley like yours.

[AndyP]

Are the cams and cylinder head all torqued down correctly?

Edit : Looking at pic 2 I can see that the cam is not torqued down yet. I'd torque everything down to ensure it's all lined up correctly

[tajgreidotu]

Diamond washer, had same issue last week

Good luck!

[staffeee]

Do you have both the dowel pins in the head? I've seen something similar before on an AAN engine where the rear dowel was missing, the head was a fraction out of line and it caused the cambelt to 'walk' to the rear of the pulley like yours.

- Both dowel pins are in place
- The camshaft is torqued properly, I have no followers mounted so I can turn the engine without having the cam(s) in the right place.
- The cylinderhead is only torqued down easy with 4 arp bolts in each corner
with a used headgasket.

[staffeee]

If I use a diamond washer I´m afraid the cam belt don´t
line properly to my WP and pulley.
I have ordered a washer at Audi so I will try it tomorrow, but
is it possible to pull out the WP sprocket 1-2mm. ?

[AndyP]

I've just had a look at mine and the belt runs right at the front of the cam sprocket, waterpump and tensioner roller. I'll try and get some pics and measurements tomorrow, it's dark now!

Is the bottom end all bolted up? Have you checked end float on the crank?

[tajgreidotu]

U can see if ur problem is that u need the washer by looking at the pulley. If u have the same problem as mine, the pulley should make pressure to the metallic belt cover, and this will make the cam belt go to the block.

The washer just moves the pulley a bit out, so the cambelt has more space.

Is it a 3b pulley?


EDIT: take a look to this

http://www.s2forum.com/forum/showpost.php?p=633082&postcount=14

[tajgreidotu]

this is the metallic cover is making your cam belt go to the block.

[staffeee]

I've just had a look at mine and the belt runs right at the front of the cam sprocket, waterpump and tensioner roller. I'll try and get some pics and measurements tomorrow, it's dark now!

Is the bottom end all bolted up? Have you checked end float on the crank?

Some pics would be great,
And some measurments.
The bottom end is completely assembeld, the only changes from my previous
engine build is that I use kolbenschmidt main bearings with integrated
axial bearings now, Before I used ACL trimetal with separated glyco axial bearings.
The end float was good, don´t remeber the measurment but I have checked it.

[staffeee]

U can see if ur problem is that u need the washer by looking at the pulley. If u have the same problem as mine, the pulley should make pressure to the metallic belt cover, and this will make the cam belt go to the block.

The washer just moves the pulley a bit out, so the cambelt has more space.

Is it a 3b pulley?


EDIT: take a look to this

http://www.s2forum.com/forum/showpos...2&postcount=14

I don´t have that belt cover so I can´t compare
I use the AAT pulley with 3b crankshaft sprocket.
As I´ve written above I will fit a diamond washer tomorrow and
see how the belt travels on my Waterpump.

EDIT: I use the 251C and should not use the washer in normal case.


Appreciate all the help guys, very valuable !!!