Timing chain stretch question
 

When measuring timing chain stretch how do you align the marks? I know its the little arrow on the cam mount near the sprocket and the space in the ring but where does the point of the arrow line up? The leading edge, middle or rear edge?

Aligning the marks is NOT the way to measure timing chain stretch. You can do it, and if there is LOTS of stretch you will be able to tell, but it is not the correct procedure.

You need to consult the factory service manual. It will tell you to put a dial indicator on one of the number one valves and turn the engine to a certain posiiton. This is the only procedure that has adequate accuracy.

Hope this helps,

I just wanted to see if I was in the 3degree ballpark or if I need to get a dial indicator. Which apparently I am going to have to get.

I don't think anyone should condone aligning the marks to check chain stretch.

That said I don't think you need to break out the dial indicator every time you have the valve cover off. As long as you check properly once or twice a year.
When you align the marks they should align dead center.

Danny

What arrow are you talking about? If you're talking about on the cam tower, then those things need to be lined up EXACTLY in the middle dead on to get any sort of accurate reading down below on the crank. Those little marks up top from my understanding are there for general reference i.e. to be within 18 deg. But I will tell you this, before I replaced my timing chain, I got the marks lined up three times, and each time showed I had more than 6 deg. stretch, which is all the info I needed to decide on a new chain. If I had done it and couldn't conclude from that, I'd just move on to the more accurate dial method.

The dial method is more acurate, but you can do the cam marks in a pinch. The 2 lines need to be perfectly lined up like this --.

Having a hard time getting my car timed,have followed the service manual process... but I am still getting contact of piston to valve on the second turn over.
I have 86 190 diesel 2.5 in line non turbo...
What am I missing??What are the timing marks on the camshaft to line up with. Got the TDC , but what am I lining up to??? Tried multiple times and still getting contact..
thanks
Doug

Use the 2mm method is the concensus.

I assume you just replaced your chain? What happened or was the reason to change it? If you broke your chain while running there is damage. A bent valve for example. With the cam timing marks lining up and bottom pulley a 0 degrees you should be experiencing no interference. A little more information would help. Do not force it.

With the crankshaft damper at the specified mark such as 20 degrees BTDC, the camshaft mark should line up AND the IP number one should be dripping.

I though it was the =- ?

- being the cam housing and = being the space in the ring?

You're correct.

DG is saying the same thing...........

I just wanted to make sure. Looks like I am going to push off doing IP timing until I can afford a dial indicator at HF next weekend. Looks like this weekend is prep for manual tranny swap!

The dial indicator won't help you time the IP.........:confused:

I thought that time chain stretch should be attended to before attempting IP timing?