The Stovebolt Site Forums The Shop Area Engine Shop Noise in "new" 216

The (long) sad story:

For about two weeks I have been enjoying the fruits of years of labor while driving my stock '46 3/4 ton. Then it happenned - a horrible noise from the engine. My engine(Serial number LBA735549) which had been rebuilt some years ago (but had never run) started grinding and rattling badly so I immediatly shut it off. (Oil pressure had been good at about 15 pounds.)

Towed him home, took the valve cover off. Yikes, the exhaust valve for number 1 had dropped because the keepers fell off. Found the old mangled keepers and got new ones and, with a friend, we fixed the valve in 10 minutes. With great anticipation, we fired it up. It started right up and the top end seemed perfect. My friend suggested that the problem of the sucked valve was becuase I had adjusted the valves a few thousandths too loose.

Then the second whammy. There was a knocking rod sound from what appears to be the back part of the engine. Coincidence?

I am now in process of removing the pan to see what will give me my next challenge.

Any advice here? If it is a rod, can I drop it from below or do I need to take the head off to get to the problem rod? The enine was rebuilt by Four Star Engine Rebuilders in Hutchinson, Kansas. Does anyone know a connection there? Can I repair just one rod? Should I convert that rod to inserts? If indeed it is a rod bearing as I suspect, can I prevent other rod bearings from failing?

Thanks for any help. :confused:

First off haveing the valve set a little loose would not cause the keeper to come out. It either was not put in good or the grooves &/or keepers are wallered out. Also watch for the rocker arm hitting the retainer. Some of the rods on a 216 can be removed without pulling the head. No. 1 is one of them. Drop the piston down enough so the wristpin will clear & loosen the clampbolt slide the pin out enough to remove the rod. The crank is probably scorred though.

I can't imagine a valve dropping down, riding the piston and not doing damage. You won't know what's up until you get in there. In any case, there was some problem the way the head was put together and you really don't want to keep running that way.

You may have bent the valve or at least whacked the piston with it. Usually you get a damaged rod and piston when you do that.

I'd reccomend you pull the cylinder head and drop the oil pan, and do a thorough inspection of everything. If there's much of a rod knock, the crankshaft has probably been damaged too badly to take another rod without being reground. Many years ago, we used to grind crankshafts in the engine, but it left a lot of abrasive debris behind. If the shop that did your buildup was not familiar with fitting bearings and setting clearances, they could have built in some problems. I learned to fit babbit bearings in the late 50's, and I'm probably one of the last mechanics who dealt with poured-bearing rods on a regular basis. There's definitely as art, as well as a science to making them live!
Jerry

Hey gang,

I am not sure this is the right way to do an update to the problem with my 216, but here goes: I have pulled the pan and everything looks tight and clean. I jiggled every rod bearing and main bearing with some force and there is no movement except the necesary front to back play.

I pulled the head. The dropped valve looked fine to me. I took the offending valve back out and checked it for flatness and for a bent shaft and it still checked out well.

However, there was a lot of cast chips in cylinders 1, 2, and 5. In cylinder 1, the chips had even scored and dented the top on the piston a bit.

I examined the head carefully of anything broken, or even unusual, and can find nothing. The cylinder walls look great.

Help. Any thoughts?

Michael

Got a couple of ideas- - - - -
It sounds like something has gotten on top of a piston, probably #1. Are all the valve seat rings still in place? I had a problem with a brand new MOPAR 383, when an exhaust seat came adrift on a dyno run. It ended up getting pieces into 4 cylinders, and necessitating a full teardown to get all the chips cleaned out. I'd reccomend the same thing with your engine. Once chips start moving around inside, it's almost impossible to account for all of them without doing a full disassembly. You'll save yourself a lot of grief in the long run if you do a detailed teardown now!
Jerry

Jerry,

Thanks for your response.

I have the top and bottom off the engine and have cleaned up the debris that I found on top of the pistons. First, I collected all of the chips, then I wiped the tops to get the smaller pieces, then I sprayed WD40 around the edges of the cylinder walls and wiped again with cotton swabs. Tomorrow, I'll vacuum then blow out. Is there another way to clean? And is there another place the debris might be hiding other than on top?

I am not exactly sure what a valve seat ring is, but I will ask someone here and then check to see that all of them are in place. Since most of the debris was in No. 1, I'll look there. Or can you describe it well enough for me to look tonight?

Thank you again.

Michael

The valve seat is what the valve seals to. It looks like part of the head but it's actually just pressed into the head. I think I would send the head in for an inspection by a machine shop,
Scott

Debris from a foreign object in a cylinder has a habit of wedging itself into the gap between the piston and the cylinder wall, on top of the top piston ring. If it's metallic, it can create score marks in the cylinder walls, leading to compression loss and blowby. I'd suggest pulling the pistons and checking for debris imbedded around the piston rings. I'd also reccomend a full teardown of the cylinder head, and an inspection of the valve seats, etc.
Jerry

Does a 216 head also have valve seats?

I'm not sure about original-equipment heads, but if it's ever been rebuilt, it's possible seat inserts were installed. A competent machinist should be able to determine if seat inserts have been fitted, and if they're in good shape. Other sources of metallic debris in the cylinder might be pieces of a piston ring that had been broken while installing the pistons. The only way to be absolutely sure nothing is damaged is to do a complete teardown, including pulling the pistons and rods. If the rings don't have more than a few miles on them, and aren't damaged, it should be OK to reinstall them. They might have to "break-in" again, but that shouldn't cause any long-lasting problems. Good luck!
Jerry

Jerry,

Thanks again.

Michael

216,235 and 261's don't have valve seat inserts as original ,but machining in new exhaust seats is common.
It's hard to believe the piston and valve aren't mangled lumps being that the exhaust valve is angled or canted about 20 degrees and hard to believe an exhaust seat fell out and and fell back in with no drastic damage.But the exhaust valve sits in a deep pocket,so just maybe.......
Why did the valve locks fall out in the first place?Is the top spring retainer ok?
I dropped a single lock washer by accident into a V-8 intake manifold once,when the engine was started,the single washer broke a ring land on one piston then managed to migrate into 2 other cylinders leaving fresh marks on the piston crowns.Perhaps ypu have loose hardware floating around in the combustion chambers,got an aircleaner on that engine?

You ask some good questions.

First, the valve that fell into the cylinder was vertical and because of that I thought that it might could travel up and down for a few hundred RPM's without destroying itself, the cylinder walls, or the piston. I thought that it was the exhaust valve because it is the second from the front of the engine.

As to your second comment/question as to what caused the valve locks to fall off, I don't know. Perhaps the valve was defective or the locks were not put in properly. The retainer seems fine to me. The valve seems fine to me. The new locks went in easily and help when I tapped them with a socket to be sure that they were seated.

The last commnet that you made is to me the most interesting. I did indeed have something floating around in No.1 cylinder. It appears to have been cast iron becuase the pieces are cast. I thought that it was related to the sucked valve - but maybe the two items (debris and failing valve) are not related.

Yes, I do have an oil bath air cleaner that I will look at again to see if it has any junk in it. I do not think that I left anything in the intake (or wherever) that may have worked its way into the cylinder, but who knows.

Thank you for your time and thoughts. Any other ideas?

Michael

Gang,

I brought my head to a friend who suggested that we remover another intake valve. Lo and behold, we discovered that the valve guide on the broken valve broke at its base just inside the top of the combustion chamber. This broken part was the source of the chips in at least No. 1.

My questions: What would cause this guide to break? Is it possible that the valve springs are too weak? Do the intake and exhaust valve springs have the same "strength?" My exhaiust valve springs seem to be a lot stronger.

Michael

Stovebolt valves have a really nasty habit of sticking in the guides. it's possible the guide broke instead of letting the valve slide through it freely when the engine was first fired up. Once it broke, it would just be a matter of time until pieces found their way into the cylinder, or back into the intake manifold where they could go into any, or all the cylinders. Make sure the guides have enough clearance when the head is reassembled. I'd rather deal with a slight amount of oil consumption due to sloppy guide clearance than the possiblilty of stuck valves and/or parts breakage!
Jerry

What now appears to be the problem in my 216 head may be of interest to some, especially Jerry.

The intake valves in the 216 "wear" metal "hats" to keep too much oil from being sucked down into the valve guides. These "hats" are intended to be in direct contact with the top of the valves so that when the rocker pushes down the force is transferred through the "hat" to the valve below. Kinda like being tapped on the head when you are wearing a baseball cap that has some space above it - first the cap compresses and then you would feel the tap on your head.

Using the wrong keepers not only keeps a lessenned tension on the spring, it also causes a gap inbetween the "hat" and the top of the valve. The hat is now pushing first on the valve spring caps and then on the top of the valve. This constant jarring of the valve spring caps caused the taperred keepers to come loose and hence the sucked valve.

Thought that this might be of interest as a note of caution for those who are machining their heads.

Thanks again to all.

Michael