Valve timing off a little

[wwheeler]

I installed a new timing chain and chain tensioner and wanted to see how close the valve timing was. I made my own bracket to hold a dial indicator and worked well. I will post pictures of it tomorrow when I down load them. Bracket took 45 minutes to make and a 1" travel dial indicator can be had for $15 or so from Harbour Freight and the likes. Easy to do and not expensive.

I installed a .004" shim to take the slack out of the #1 intake valve. I set the dial to zero and turned the crank CW. I watched as the dial moved to 4/10mm or .0157". The reading on the crank balancer was 9 degrees btdc. I made sure the valve gap was right and went through the test again. Same result 9 btdc and not 11 which is what it should be. I tried one more time and got that same result. I guess that is 2 degrees LATE which I think should be fine and not worth adding a bushing to the cam gear. I have heard never, never be early.

What do you think? 

[glenn]

'Time' for an offset key on the cam sprocket?

[Atazman]

Anxious to see the pictures of how you were measuring.  I already have the Harbor Freight dial indicator.   

I have wondered about this myself.

Thanks.............

[wwheeler]

Here are pictures of my bracket. I have the dimensions that I can try to scan. It works well and is very easy. The only change I need to add is a radius to the lower corner where the dial indicator mounts. That would allow it to swivel more. Once you screw it down, it is rock solid. You have to get the indicator with the mounting stub on the back side.

To answer Glenn, I am not sure if they make a 2 degree offset. I think it might be 2-1/2?

 If you want to add the bracket to the tech manual, I can try. Not great at that sort of thing!

[280SE Guy]

Wallace,

The new chain looks nice. You did put on a new cam sprocket didn't you? The old ones get worn and the points on the sprocket get very pointed.

Regards,

280SE Guy

[Benz Dr.]

I use a degree wheel on the cam shaft but I suppose either way would work. With .003'' rocker clearance it would actually subtract from the total number a small amount. I've installed offset keys before and you have to pay attention to how they're mounted. I also check when the valve closes to make sure it's timed right.
 The cam gear will wear and it's easy to replace but the crank gear is always worn and it's not so easy to replace. New gears will generally pull the chain forward and you might be able to get it a bit closer to stock settings.
Late cam timing means your IP will also be a bit late but only half as much as the cam shaft. Expect all gears to be worn if the cam gear is that way.

[wwheeler]

Thanks for the thoughts on sprocket wear Benz Dr. I did not replace the cam sprocket because it can be one of those domino things were you don't know where to stop. The old chain really wasn't bad but I was doing all of this work in the area anyway and decided to replace it. It was supposed to be replaced with the PO's engine rebuild. I decided to replace it for peace of mind.

The cam sprocket still has a small flat on the top of the sprockets and about the same as the idler sprocket. Certainly not sharp like I have seen on very worn out sprockets. So I think it is OK, but thanks for the thought!

[Benz Dr.]

By the time the teeth on the cam gear were pointed it would be really worn. They don't have to come to a point t be worn. I'll measure a new gear and get back to this.