Timebelt tensioner

When you turn the crankshaft on the opposite direction of the normal operation , if the motor doesn't have manual tensioner then , the tensioner slugs . How do we baypass this issue ?

Are you running the engine backwards, or just turning it backwards for cam timing etc?

If the former, you will need to have a serious look at the position and type of tensioners in use...good luck!

If the latter, I was always taught never to turn the engine backward anyway (risk of valve to piston contact).

Thank you for your answer . I should better rephrase it ...

As per course "How to degree a cam" , in some points we have to turn the crankshaft backwards for cam timing (to find the absolute top dead center ) .

But in case the motor has hydraulic or spring , etc tensioner then you cant, cause the tensioner is slugged and the reading will be False and misleading.

So is there a way to bypass this issue ?

If you are reversing the engine and it hasn't got gear driven camshafts, you aren't ever going to get an accurate TDC reading.

Here is the process I was taught.

1. Get the engine near cam lobe TDC

2. Fit the dial gauge in place

3. Run it past TDC a few times to get the dial gauge to zero at approximately TDC. You CAN reverse the engine at this part.

4. Get the engine back close to cam lobe TDC (if you reverse the engine to do this, when going forward give yourself enough rotation to get the belt/chain nice and tight!).

5. Rotate it to 0.1mm (or whatever you use) lift BEFORE cam lobe TDC and mark the cam timing

6. Rotate it to 0.1mm (or whatever you use) lift AFTER cam lobe TDC and mark the cam timing

7. The cam timing at TDC is the average of the two figures.

8. Repeat the check a couple of times just to be sure

The alternative is to use something like the Xmm lift should be at y degrees method. Which is generally more accurate. However this requires knowing this figure from either the cam manufacturer or having measured it previously prior to disturbing the cam timing.

A lot of people will argue against the cam lobe TDC method. They are right that it isn't as accurate. HOWEVER it should be consistent if done properly and if that is the only figure you have from either the cam manufacturer or previously measured, it is a good starting point ready for swinging it on the dyno.

Hope that helps.

Denis , thank you once again for your reply .

I am already timing my cams the way you described . However in the video is showing a non manual adjusting tensioner on B16 engine ( which is not a gear driven ) . That is why i was wondering if there is a trick for such like tensioners not to slug .