engine and drivetrain Rebuilding an A4S engine and have an issue

[Rustyfe]

Per subject, have and A4S Alpina that I am having an issue with regarding the timing chain. New chain and tensioning arm and tensioner is fully extended to where the tensioning arm is hitting the front cover wall. The head height measure 127.4mm (E12). I cannot find specs on the sprockets, but that will be my next step, i. e., new sprockets.

Are different thickness head gaskets available for such an application?

Different chain lengths?

Any ideas or experienced persons that could help with this issue.

I have found that Korman offers degreed sprockets.

Thanking all in advance, Love these 2002s

Rusty

[c.d.iesel]

not clear what your describing:

(photos always cut to the answer quicker)

all M10 timing chain, tensioner, guide rail

and chain sprockets are the SAME.

Only (1) timing chain for all M10 's

(unless you have a Twin-Cam head?)

Sounds like your saying the chain and

guide rail is too far away from the front

of the block and touching the inside

of the timing cover ????

i read your question for the 4th time:

-your timing chain is stretched badly?

-all your t-chain gear teeth are worn badly?

-using a USED worn chain guide rail?

-only (1) length timing chain

-yes, cutting the head too much might

retard cam timing - can you give the measurement

for the thickness of the head?

(min. cyl. head thickness = 128.5 mm)

re-read a 5th time:

YIKES! you state:: "The head height measure 127.4mm "

i'll let someone else give you more input on the negative

effects of 2.6mm machined off of the original 129.0mm head

thickness can cause..........

also - Watch yer valve to piston top clearance

[FB73tii]

If I read it right you are saying the timing chain is too long, correct? I'd pull it out and count the links for a start. Some time ago I remember a post about an Alpina or Schnitzer-type timing chain tensioner that is a gear on an arm with a hydraulic buffer, mounted in a different location. I did a quick search but can't find it. Perhaps somehow that timing chain is longer and that is what you ended up with? Or, more likely, the factory put the wrong chain in your box. How many links do you think it is long by?

Fred '74tii & '69

[c.d.iesel]

M10 duplex roller timing chain = 3/8" x 7/32 x 94 links

[Rustyfe]

Update: opened the link to Ireland E. They offer a custom head gasket for heads that have been machined. I had a second gasket and put 2 head gasket and torqued to check chain tension. So 1.3 mm for each gasket the tension is good. So next step is to have Ireland mfg a custom head gasket.

I'll also replace the cam gear with one that can be adjusted for cam timing.

Thanks for the replies and I apologize for not making my problem more clear.

Long day.

I'll keep this forum posted on the build progress.

Rusty

[FB73tii]

Ireland's price of $200 for a custom MLS gasket is pretty good. I will be interested to hear if they can match your exact thickness (2 * 0.051" = 0.102"). The thickest MLS gaskets offered directly from Cometic are 0.098", 0.120", and 0.140". Part number and price for the 0.120" M10 B18/20 gasket are:

C4293-120

$205.27 @ jayracing.com

$208.49 @ Autoplicity

$219.99 @ JEGS

Obviously best to work with Ireland as they have a lot more knowledge than other "we sell everything" retailers. Let us know how this works out. --Fred

[Hans]

A thicker head gasket is available from BMW - check real OEM . !.8mm as I recall.