The Stovebolt Site Forums The Shop Area Engine Shop 216 rocker adjustment

im getting ready to pull the head on this 216 which has a bent push rod...broken rocker and stuck valve......all i have to do is to unscrew the nuts on top of the rockers to remove the rockers......do i have to unscrew the rocker set bolts that are on the drivers side of the rockers........and when i re-install it all i have to do is drop the rockers back over the bolts and tighten them down.........and because the rocker setscrews are already adjusted just start it up and fine tune it.........is the setscrew on each rocker the only adjustment point for the lifters and valves? ........this rocker system different from late model 6 cycliders like a 250 chevy......opening up the can of worms........shame i cant post pictures here.......you should see number 4 intake port.....sludge...i think the pushrods been bent for a long time..........thanks everyone for your help.......

If you are removing the cylinder head to deal with the stuck valve, yes, remove the complete rocker arm assembly- shafts and all, but leave the adjustments alone for now. You should have two cap screws and two threaded studs with nuts that hold the rocker assembly to the head. You can leave the studs in the head if you want to. Also, leave the bolts in the two supports at the center of the assembly, to keep things together while you handle it. When you remove the bolts/studs from the head, the shaft assembly will separate in the center when you lift if off the engine, so handle it somewhat carefully, not that it matters much if it comes apart, but that is avoidable complication if it happens. There are two thrust washers, or there should be, one at the center end of each 'half' shaft; those will fall off along with the oiler connection in the center- none of that is a serious matter if it happens.

Depending on the location of the broken arm, lay out the arms, the springs, and supports in their proper order so you put them all back in the correct location. Again, it is not unmanagable if you mess up the locations, but that is also an avoidable complication. I'm not sure what you are refering to with the "rocker set bolts on the driver's side"; are you refering to the adjustment screws and jam nuts on the passenger side? Leave those alone for now- that comes later.

For your other questions, yes, this rocker setup is vastly different from the 250 CID engines and the derivatives- for the most part, those have hydraulic lifters; yours has solid lifters- or it did originally. Yes, the set screw and jam nut on each rocker arm is the only valve adjustment. Yes, to install the assembly, put it back into position and tighten the bolts/nuts, but NO, you have to readjust the tappets/lifters after this operation. Yes, probably everything will be all right if you don't adjust the valves, but you risk future trouble if you don't adjust the valves after the job- that doesn't mean you can't start the engine before adjusting the valves, that just means you need to adjust the valves before you are finished. Valve clearance is .008" intake and .015" exhaust, engine hot. Original specifications are .006 I and .013 E, hot, but the larger clearance was more commonly used.

Don't forget to connect the rocker arm oil line after everything is in place. It can be troublesome with your engine, so be careful not to cross-thread the fitting. The fitting is a standard tube fitting, and the oil line is a standard size, but avoid trouble if you can. Its preferable to use a tubing wrench on the fitting.

The only can of worms you will encounter is if you aren't watchful with the disassembly. But if you do get into trouble, there is plenty of help here.

Harvester

thanks harvestor.......i forgot to mention that the brass line that connects to the rockers in the middle was broken...and i can only imagine that the rockers have not received oil for some time........the line is broken right at the nut.......can i replace this without removing the side cover on engine or will i have to pull the cover off and disconnect the brass oil line and replace the whole piece.........thanks again for the information...it helps alot..........i will be pulling it in a couple hours

You'll have to pull the side cover to replace the oil line. You'll also have to drain the coolant since the line runs through the water jacket. One way you might be able to avoid replacing the whole line is to use a compression union to splice enough new tubing to be able to make up the connection at the rocker shafts. I've not had the opportunity to try that so it may or may not work but just thinking about it I can't see why it wouldn't. If you decide to replace the complete line you can get kits at any of the vendors that have the necessary tubing and connections.

You have to replace the whole line. It passes through the block and attaches to the oil galley on the other side. If I remember correctly, the line goes through the water jacket, so drain the cooling system before you loosen the block fittings. And use tubing wrenches. I suppose you could use a coupler of some kind if you can find one of the proper size- hardware store item maybe, or a parts house that deals with the service trade, rather than the consumer market; NAPA would be a good place to look- but don't tell the counter man what the vehicle is- he'll first say they don't have parts. Just take the broken fitting for size. Its a compression fitting, so something should be available. The risk with adding a coupler in that line is that there is no support for the line between the block and the rocker arm connection, and the extra weight on the line may cause fatigue and break it again.

If the engine has been run long without oil to the rocker arms, the rocker arm bushings and the shafts may be badly worn. They wear enough even with oil up there, but that was a common problem with those engines. Parts are fairly readily available, but fairly costly for the whole assembly. It may be possible to re-bush the rocker arms; in the past, no one bothered with that- new arms and shafts were the order of the day. I don't know if anyone at this site has tried re-bushing the arms, but that would be worth looking into. Maybe someone else can add insight to that.

Good luck with the job.

Harvester

well guys the heads off.....pistons look nice.....cylinder walls are nice.......pulled off sidecover to find the mech. lifters all working and looking well.....that oil line runs right by them so i will replace the whole line...........now its on to the valve.......darn thing is stuck like its in cement......since i have the old girl apart i thought about replacing the lifters......any thoughts.........other than that its off to the machine shop monday to clean the head up and hopefully head done by within 5 days........thanks again for all the help guys...........your keeping me out of trouble.....these 216s are pretty basic but i can see now why they are swapping 216s for 235s........wink wink

If you havn't already thought about it, hardened valve seats. Running unleaded can cause valve seat recession in older vehicles. Generally, ones that ran for an extended period on leaded before the change are apparently relatively safe, but exposing new metal may open up a new problem.

Anyone out there agree/disagree? Please chime in, I'm only repeating what I have read.

I have to disagree. Unless you work the engine quite hard the unleaded will never hurt the seats. In fact you can cause problems by changing the seats if one comes loose (it does happen). I regularly run my 38 on unleaded without problems. I ran my '70 HD FLP (leaded gas engine) on unleaded for many tens of thousands of miles without problem. Just clean & lap the valves, clean the guides (replace if necessary) & put the head back on.

There is supposedly no need to worry about non-leaded gas used in 216/235/261 engines. The compression is so low and the rpms so low that there is no need to be concerned for normal driving conditions.

I can't add much to the question of unleaded gasoline for your truck. My only experience with 'unleaded fuel' was a '54 or '55 235 engine in a truck that used propane fuel, and there wasn't a lot of experience with that fuel at that time. The head was good for about 10,000 miles, then a valve job. After the second head (third valve job), we put in hard seats. I lost track of the truck after that, but hard seats seemed to cure the trouble. That truck ran loaded all the time- it was a propane delivery truck, and the tank was pretty much a full load, even empty. I'll defer to the wisdom of others on this question.

Harvester

If the lifters are worn thru the hardened wear surface , then yes , replace them.

BUT if they are still nice , put them right back where they came from.

The wear surface on the cam and lifters takes a lot of force during operation and is very hard when run in. It is a big deal to get that hard polished wear surface back again , dont mix them up. Dont replace them just because you can , only if they are worn thru.
If the bottoms of the lifters are worn thru the hardening , then the cam needs to be checked also. Then the cam gears . . .

And so the job grows .......

i always use aviation fuel 100LL which has lead.......but who knows what the people before me used on this 1941 216 engine....well looks like i have to replace 2 valves and the cracker rocker on #7 intake as well as the push rod.......placed the order with jim carter today...........it doesnt take long to spend 100 bucks does it........can i reuse the copper head gasket or replace with a composite one............

I don't think head gaskets are designed to be used more than once.

Replace the head gasket. No question. Replacements for the original head gasket sometimes were sheathed with copper, but they were still a composite inside. No matter- replace it. And replace all the other gaskets that are part of removing the head.

Harvester

Butch, I'm just across the river in Il. and am going to be pulling a running 51 216 if you would be interested. I just need to get it out and put the 235 I have in. Just throwin this out there. Thanks

sounds good......send me a email [email protected] or send me your phone number and i will give you a call.........

well it seems 75% of the items i ordered through jim carter were out of stock.........and it will take 2-3 weeks for shipment of the items in stock..........is this the 1920s or 2008....just a little reminder for you guys ordering parts........shell out the cash and wait 3-4 weeks..........thats why you will see 15k-25k for these trucks totally restored.......very time consuming

Try Obsolete Chevy Parts.
or
The Filling Station.
Both carry loads of truck parts. You might find them in stock.

well its all put back together........all cleaned up....new push rod......rocker arm........fixed oil inlet to rockers which was broken off.....rocker bar was in good condition...lots of sludge though.......clean as a whistle now.....made some basic adjustments to rockers pre flight.......cranked her up......ran a little rough so im going to fine tune it tomorrow when i can open up the doors......thanks again to everyone on the board...the old girl should be running like a sewing machine tomorrow after i fine tune the valves

well tiny.....the old 216 is fine tuned....its amazing how these old girls keep on a truckin.......i didnt have to adjust the valves very much after the cold settings.........i adjusted the valves per 216 specs .006 intake and .013 exhaust....then after a nice warm up i twicked a couple rockers and that was it.....thanks again for all the help as well as everyone else on this board......

Butch,

Fantastic success story! Helps me stay motivated just to hear others makin' progress so quickly!

Congrats on a job well done.

-Michael