Gas 2600 Ping/knock

[Bluegill Bill]

I have a 77 Ford 2600 that has a slight knock or ping when cold and first cranked. After warm it sounds smooth with no unusual noise and runs and operates great. The tractor only has 906 hours on it and I was wondering if my timing could be off a little or is this normal upon cold start up for an older gas motor? Thanks
 

[Dean]

Spark knock upon cold start up is not normal. If spark knock, check the ignition timing.

Are you sure it is not piston slap?

Dean
 

[Bluegill Bill]

If it were piston slap wouldn't it do it all the time and not just at start up? I'm not sure what the timing should be set on, but I do have a timing light and could check but need to find out the correct timing.
 

[David G]

No, slap will diminish as the cylinders get splash oiling and the pistons warm and expand. I have never heard of a fast timing issue with a cold engine.
 

[Bluegill Bill]

If it is piston slap maybe I should go to a multi-grade oil like a 10W30 or 15W40 so that the oil pump wouldn't have to work so hard at start up and would coat the cylinders quicker. I've been using a straight 30 weight, any suggestions would be great and thanks for the replies.