820 valve setting

What are the valve setting on my 820? According to the book, it says that is .020 for both but I also see a not that talks about the intake valve being .015 for intake after serial #801852. So does my 820 need to be both set at .020 or intake at .015 and exhaust at .020. Thanks

The setting isn't that critical. Better a little extra clearance than too little.

The purpose of that little bit of clearance is to ensure that the valves still close as the engine and all components heat up and grow. Your cam rolls around and opens and closes the valves... So think about it. The purpose of that gap being to be certain the valves close... how much difference is .005 gonna make and what will it effect?

In these big old things I really can't think of any component that extra clearance isn't a better thing or lesser of the evils as compared to too little clearance.

Anywho... regardless. Shoot for the .02 and you'll be fine. Odds are you'll vary a little in your readings anyway. And cam bearing clearances that won't be apparent when rolling over and checking without a real load will give variation. Better to be certain that valve closes and get all the compression and avoid frying a valve and seat than to come up short on clearance.

Have a good one...
Bob

Hi again Toby,

Another thing to add to this since seeing that you were the guy with the injector sleeve issues and all...
Make sure you get back in there and re-torque ALL the head bolts after you've had a few heat up and cool down cycles. Two re-torques would be better yet. Second re-torque you could probably skip the bolts in the injector compartment. I've never had them move after the first re-torque.

Also... all the more reason not to get to worked up about your initial rocker clearance numbers as the rocker assembly will be coming back off at least once. And you'll need to re-set them anyway. If you keep pushrods and orientation all the same you're first setting should be good when you go and re-check them.

Also when tightening the towers and rocker assembly... You don't need to go with head torque on those bolts. I forget what head torque is right off? Something around 175-ish? whatever it is (check your book as it sounds like you do indeed have one) ... I'd suggest you back off on the bolts holding the rocker assembly on. It is possible to crush the towers and crack them at the gapped area where they grab the rocker shaft. (hmmm... how do I know that one...?) They don't need to be super tight. Also... I seem to recall not being able to find the recommended torque for those two bolts. They don't have the job to do that the head nuts do. Just give 'em a good healthy grunt with a half inch ratchet and no cheater bar on it and you'll be good to go. If you torque to same as head nuts with your big 3 foot torque wrench you'll have a good chance of craking the towers.

Last but not least... don't permatex your cover gaskets until you've done your re-torques. I've used my old gaskets in the past until I'm happy with my re-torques then put the new ones on and goop them up.

Have fun,
Bob

set your valves at .022 cold and leave them be