The Stovebolt Site Forums The Shop Area Engine Shop 216 Questions

First off this is my first 216 enginge to have ever worked with so take it easy on my ignorance.

My truck seems to run five, but will pop in the carb every so often as if it is misfiring. I think this is a timing issue, but I noticed that the timing is adjusted via a vacume (a first as well for me). How do you adjust the timing? The poping increments increase as the rpms increase. Also I have an electric fuel pump if this has any bearing on the issue.

Is there a good maintenance book you recomend? The assembly manual just isn't cutting it.

sounds like the timing needs to be advanced a bit. You'll need a good timign light or vacuum guage (depending on method you use) to set it. I prefer using a light mself. You'll need to disconnect the vacuum line to set base timing. The timing marks are on the flywheel, and can be seen through a port on the bellhousing, just above the starter. It's basicly a matter of loosening the clamp on the dizzy, pointing the light at the timing port, squeeeze the trigger and turn the dizzy housing until the pointer and the ball in the flywheel line up. You may want to consider getting a timing light with an advance knob on it so that you can keep track of where you set it if you advance it beyond 0 degrees. Then tighten the clamp.
As to the manual issua, best one is the factory shop manual. The assembly manaula comes in handy, especially when getting into body and frame disassembly, but not real good for maintanace and repairs. Another sorce would be Keith Hardys Online Chevy Manual Project, http://chevy.tocmp.com/ . especially since you can print the pages you need and take them to the project and not mess up your books. There's many of the Chevy and even some GMC manauals on there.

Sounds like a sticking intake valve to me.

I would suggest setting the timing the static way. First, adjust the points to spec. Then, turn the motor over to where the small steel ball on the flywheel lines up with the pointer which is in the hole above the starter. The steel ball is tiny, maybe 1/8" in diameter. Now loosen the clamp on the distributor and turn it until the points are just breaking contact. You can test this with a meter. Tighten the clamp and you are good to go.

If you have a worn lobe on the cam it will idle ok but when you excelerate it will pop back through the carb

I believe that these are all 4 bolt units but are they the same dia. and ring gear.

Sounds like a valve thing to me. Could be tight valve lash, sticking valve or guide.

My bet is that a push rod has bent and is out of place. If it sat a while that valve may have stuck and bent the push rod.

Pull the valve cover and make sure all the push rods are in place.

That would be the pushrod cover but we know what you meant.

I finally found this post again. As it turns out, static timing at the steel ball results in too much advance when it is running. Next time I install points I will static time it at UDC where the triangle is. I will then use the timing light with the steel ball at idle.

Nope. Said it right. Valve cover is somewhat easier to pull on the 216 than the pushrod cover. If a pushrod were bent or broken, then the valve cover would have to come off anyway. So start there, make sure everything topside is moving as it should. If all is okay there, time for another idea.

Have to disagree. You don't have to pull the valve cover to access the pushrods (unless the pushrod cover is stuck tight and then you only have to loosen it) and if you did you couldn't remove the pushrods without removing the pushrod cover. A pushrod could be bent but not be noticeably loose at the rocker arm if it's on top of the lobe. IMHO it's best to just pull the pushrod cover when in doubt & know for sure.

The only problem is, when installing a new pushrod, the valve lash has to be adjusted. That has to be done with the valve cover off. Both jobs can be done topside. The push rods will come out the top when the rocker is out of the way. And they will go right back down into the lifter.

Pulling the push rod cover would let you eyeball the push rods better, but is a good bit more work than removing the valve cover.

Maybe there is a trick to installing pushrods frm the pushrod cover I don't know about. But it must be tricky to set that valve lash.

If I ever have to pull the pushrods again (heaven forbid) I'll try it your way & see how it works.