Author Topic: installing cams (Read 2870 times)

logger · « **on:** April 05, 2007, 08:50:20 PM »

When installing new cams is it ok to tighten down the cams to put pressure on the valves ? Does any one know what I mean ? or have any info ?

badboypolar · « **Reply #1 on:** April 05, 2007, 10:47:36 PM »

Accordingto the bentley you use some special tool to slowly apply pressure while checking the specific time it takes to compress the lifters. Then after all the lifters are compressed you move the crank back to TDC then install the chain.

Look here:
http://ee1394.com/bmw/docs/factory/repair/en/index1.htm
Specific Page:
http://ee1394.com/bmw/docs/factory/repair/en/extra/htm/0137.htm

D. Clay · « **Reply #2 on:** April 05, 2007, 11:50:08 PM »

How do you get hold of a tool like that(without bleeding money)? Anyone have any experience with gradually tightening bolts in sequence. Any other way to do it? I have heard that you can actually break a cam just cranking down on it.

badboypolar · « **Reply #3 on:** April 06, 2007, 12:02:51 AM »

I don't know how you would break a cam since it is cast alum, however since it is hollow I suppose it could in cold temps. With installing OHC I've always just slowly screwed down from the middle. So

7 - 3 - 1 - 5 - 9
10 - 6 - 2 - 4 - 8

If you do it slowly enough at the right temps (above 65) and it should be okay.

2002maniac · « **Reply #4 on:** April 06, 2007, 01:52:41 AM »

just go around and loosen each nut 1/2 turn at a time. No special tools required.

And the cams are not cast aluminum, they are hardened steel and they are brittle. They will break if you are not careful.

badboypolar · « **Reply #5 on:** April 06, 2007, 08:11:13 AM »

My mistake on the aluminum. I don't know why I said that. The book even says they are hardened steel. Whoops.

Alpine003 · « **Reply #6 on:** April 06, 2007, 11:42:58 AM »

I've replaced a couple camshafts without any special tools and haven't had any issues. Just make sure you gradually tighten the nuts in proper sequence and spread the load evenly like people have said. Use a torque wrench for your final tightening or else you WILL eventually have a busted camshaft.

The previous owner forgot to do this critical step: