Knock Knock...

[blueskies]

Here's the clip for your listening pleasure.

The first part of the clip is taken under the hood, and unless you listen carefully, it's hard to hear the bad noise over the other noise. It helps to turn the bass down on your speakers. The video camera pics up and amplifies lots of stuff that you don't notice with your ear, like the air sucking down the carbs. Another noise the engine has had since the first time I started it is a sort of lunka-lunka-lunka sound when it is idling. You can hear this in the clip too. Not sure what is normal, as I've only heard one other flathead six in person (and wasn't paying attention at the time ).

The second part of the clip is taken inside the car, and the knocking sound is much more apparent because the camera doesn't pick up all the other sounds under the hood. You can't see the tach because of sun glare on the guage, but the noise comes in about 2100 rpm and stays there, and is much louder under acceleration, and almost goes away completely under deceleration.

Must be a bearing? Any thoughts?

I didn't get a chance to pull the pan yet, but hoping to do so in the next few days. I'm going to do a compression test first, just to get some baseline info.

More to come, armchair diagnostics welcome...

Pete

[Phill Powell]

Before you start looking for terminal problems, check the following.

1. With the sump off, check for shiney spots on inside of the sump that corispond to the big ends, only takes one to be touching & it sounds like a big end bearing gone. Could be the big end bolt/nut. I've seen this on 218 motors converted to 230.

2. Also with sump off check crank counterweight to dizzy shaft clearance. I recall you saying your dizzy was moving sideways on a previous post. Not all dizzy shafts are created equal, early & late, long & short block, long stroke & short stroke - some are interchangible. Have also seen this problem on 218 to 230 conversion.

3. With the head off check piston & valve clearance to head. Everything has worn a little & stretched a little.

All of the above may only occur when the engine is running so may not be obvious turning over by hand.

Hope this helps

[Young Ed]

Phill's post reminded me of something Pete. After rebuilding the 218 in dads 54 is had an odd noise. We had to drop the pan and reverse that cross pipe for the oil. It was backwards and touching the crank just a little.

[blueskies]

Phill's post reminded me of something Pete. After rebuilding the 218 in dads 54 is had an odd noise. We had to drop the pan and reverse that cross pipe for the oil. It was backwards and touching the crank just a little.

Ed-

I dug through my photos, and unfortunately I don't have a pic of the oil cross pipe during the rebuild. I was hoping to compare with this pic to see if they matched.

The noise has not always been there, so I'd be surprised if it was the tube, but you never know. Stranger things have happened...

Pete

[1947PLEVY]

Blueskies,

If you still have the oil pan off, take a small ballpeen hammer and tap on the rod caps and main bearing caps and see if they sound the same, if not could be a bearing failure... Hopefully not and crossing my fingers for you.

God Bless Us All.. John Ennis 47 Plevy

[Don Coatney]

Pete;

I am on the road and both my laptops dont do sound clips very well. Wish I could be more help. If I were home we could do a phone call and listen to eash others engines. I did not know that you had never heard another flatty 6 run.

[blueskies]

Phill-

Before you start looking for terminal problems, check the following.

1. With the sump off, check for shiney spots on inside of the sump that corispond to the big ends, only takes one to be touching & it sounds like a big end bearing gone. Could be the big end bolt/nut. I've seen this on 218 motors converted to 230.

Not sure I understand what you mean... Are you talking about the lobes on the crank touching the pan? Something to consider also, is that I have about 6500 miles on the engine since it's rebuild, and the noise has occured in the last 1000-1500 miles, and has gradually gotten worse to the point now where I'm not driving it at all until I get to the bottom of it. I think if it was an assembly issue, like the crank hitting the pan, or the oil crossover pipe hitting the crank, it would have been there from the get go.

2. Also with sump off check crank counterweight to dizzy shaft clearance. I recall you saying your dizzy was moving sideways on a previous post. Not all dizzy shafts are created equal, early & late, long & short block, long stroke & short stroke - some are interchangible. Have also seen this problem on 218 to 230 conversion.

This is a possibility, I'm using a Langdon HEI. The head of the dizzy does wobble ever so slightly. I checked my original distributor, and it too does the same thing. It could be because of the 230 crank, not sure. At first I thought it was because of the oil pump. I found that the tighter the tolerances between the oil pimp and the tang on the end of the dizzy shaft, the worse it got. It seemed that the tang on the shaft was binding in the slot of the pump. I messed with it on the bench till I got the shape of the tang to not bind at an angle as it rotated. This made the wobble almost go away. It seems like the bore in the block for the dizzy is not true to the oil pump. I will be very interested in checking the clearance of the crank lobe to the dizzy shaft when I get the pan off. In the process of troubleshooting the wobble, I coated the shaft of the dizzy with heavy blue ink, and ran the engine for a bit. I pulled the dizzy back out, and the ink was untouched. This lead me to believe that the shaft was not contacting the crank as there were no rub marks in the soft ink.

3. With the head off check piston & valve clearance to head. Everything has worn a little & stretched a little.

I'm hoping that I don't need to take the head off... But if I do, this will be the first thing I look at. My valve are very noisy. I set them cold at .014"/.014" at the recommendation of the cam grinder. I have not adjusted them since. I'm going to have to do it cold again though, because of the tube header design... ugh.

It was my understanding, from conversations with the mechanics at Vintage Power Wagons, Advisors on the POC, and folks on various forums, that the 218 and 230 engines were identical internally aside from the stroke (crank,rods), and the flywheel. The 230 parts (crank,rods) went into the block just like the the 218 stuff came out, and there wasn't any weird binding or anything when I turned it by hand before the pan went on.

I don't think I'll really know what is going on till the pan comes off, but keep the ideas coming!

Pete

[blueskies]

Blueskies,

If you still have the oil pan off, take a small ballpeen hammer and tap on the rod caps and main bearing caps and see if they sound the same, if not could be a bearing failure... Hopefully not and crossing my fingers for you.

God Bless Us All.. John Ennis 47 Plevy

John-

I don't have the pan off yet, but I will be giving your technique a shot as soon as the pan comes off.

Pete

[blueskies]

Pete;

I am on the road and both my laptops dont do sound clips very well. Wish I could be more help. If I were home we could do a phone call and listen to eash others engines. I did not know that you had never heard another flatty 6 run.

I suppose I should have stated, "hear another in person"... I've heard yours run over the phone, back when you had it on a stand, and have your exhaust clip on dropshots.

I don't know if you could really hear the noise over the phone anyway, it's hard to hear it in the clip too.

I'm thinking it's got to be a bearing, for what ever reason. I have another set of rod bearings. If it turns out to be a rod bearing, and the rod and crank are ok, it may be as simple as a quick swap for another.

Pete

[Normspeed]

Pete, another armchair opinion, you may remember that my machinist installed a bum valve guide and the #1 valve was loose in the guide. It was quiet at first but after 500+ break-in miles, it got progressively noisier. It was hardly noticeable at idle, but at 2,000 or more rpms it sounded kinda like what you are hearing. Pretty darned loud, and with the side covers off it was a heckuva lot louder. That valve was also impossible to adjust properly and it could be moved sideways while adjusting. I'm not suggesting you have the identical problem but it could be in the valve train. Before you tear it down, you might try removing the valve covers and running it to see if you can pin down the noise to that area. These motors are not at all messy when run with the side covers off. Could be a broken valve spring, bad guide or who knows what. If it's in that area it's gonna get a whole lot louder with the covers off. Oh, and my cam grinder suggested .012 for all. Frankly I'm thinking of going to stock clearances of .010 hot for all valves. Did you know you can buy kevlar heat proof sleeves to keep from burning your arms on the headers/manifolds?

I can only hear the first part of the video where you're under the hood. Can't hear the second part you mentioned.

Just my dos centavos.

[blueskies]

Pete, another armchair opinion, you may remember that my machinist installed a bum valve guide and the #1 valve was loose in the guide. It was quiet at first but after 500+ break-in miles, it got progressively noisier. It was hardly noticeable at idle, but at 2,000 or more rpms it sounded kinda like what you are hearing. Pretty darned loud, and with the side covers off it was a heckuva lot louder. That valve was also impossible to adjust properly and it could be moved sideways while adjusting. I'm not suggesting you have the identical problem but it could be in the valve train. Before you tear it down, you might try removing the valve covers and running it to see if you can pin down the noise to that area. These motors are not at all messy when run with the side covers off. Could be a broken valve spring, bad guide or who knows what. If it's in that area it's gonna get a whole lot louder with the covers off. Oh, and my cam grinder suggested .012 for all. Frankly I'm thinking of going to stock clearances of .010 hot for all valves. Did you know you can buy kevlar heat proof sleeves to keep from burning your arms on the headers/manifolds?

I can only hear the first part of the video where you're under the hood. Can't hear the second part you mentioned.

Just my dos centavos.

Norm-

Since I have to pull the oil pan to replace a bad gasket, I'm going to start there and have a look a the bearings while the pan is off. If all is well in the bottom end with the crank, rods, and cam, I'm going to get into the valves.

Unfortunately, the side covers cannot be removed without first removing the tube headers that I have. And, along with the headers, the intake since they are bolted on together. This is a major PIA with the Langdon tube headers, and if I were to start over, I would not use them because of this. I can not run the engine with the side covers off, unless I remove the headers/intake, then the side covers, and then put the headers/intake back on to run the engine, and then do it all again to put the covers back on... And, the rearmost header bolt takes an hour in itself .

With the heater installed, I can barely see the headers under the intake, and that will have to come out too...

I'm really hoping that it is not in the valves, because I don't want to take the EDGY head off. I've been paranoid about the head gasket not sealing from day one, and don't want to disturb it since it has been fine for 6500 miles. It may have to come off anyway...

Pete

[jd52cranbrook]

I'm sending my motor to the machinist today. Hope you find your problem before I drop mine back in.

BTW Langdons has different exhaust/intake set up now. The valve panels can be removed without disturbing them.

[BobT-47P15]

Pete, here is a thought about the exhaust/intake thing.....do you still have the original setup that you could use for a temporary substitute while doing this project?? That way you would only have to remove and reinstall the Langdon setup once.

[bob westphal]

If you haven't dropped the pan yet, it is quite easy to diagnos main noise and rod noise. The main bearing is the easiest. Just apply the brakes and rev the engine with it in high gear clutch out. If you hear a deep thudding, one of the mains is bad. A rod is also easy. Just jazz the engine to about 1500, hold there for just a moment and drop the rpm. If you hear a rattle it could easily be rod noise. You can isolate the errant rod by shorting out the plugs one at a time and do the above until the culprit/s stops making noise. A wrist pin won't short out with the above test.

[blueskies]

I'm sending my motor to the machinist today. Hope you find your problem before I drop mine back in.

BTW Langdons has different exhaust/intake set up now. The valve panels can be removed without disturbing them.

Yes... I know... I wish Tom had had these available at the time I bought the tube headers I would not have gone with the tube type. The cast iron headers he now sells are a modern version of the old Fenton design, with better header to pipe seals.

If I hadn't already gone through the wringer getting my exhaust done (thrice), I would sell the tube headers and mount the cast iron type while I had them off for the valve adjustment.

Pete

[blueskies]

Pete, here is a thought about the exhaust/intake thing.....do you still have the original setup that you could use for a temporary substitute while doing this project?? That way you would only have to remove and reinstall the Langdon setup once.

Bob-

Nope, I sold my split factory exhaust when I got the tube headers...

Pete

[blueskies]

If you haven't dropped the pan yet, it is quite easy to diagnos main noise and rod noise. The main bearing is the easiest. Just apply the brakes and rev the engine with it in high gear clutch out. If you hear a deep thudding, one of the mains is bad. A rod is also easy. Just jazz the engine to about 1500, hold there for just a moment and drop the rpm. If you hear a rattle it could easily be rod noise. You can isolate the errant rod by shorting out the plugs one at a time and do the above until the culprit/s stops making noise. A wrist pin won't short out with the above test.

Bob-

The sound seems to come on under load, and go away under no-load. I've tried to get the noise to go away by taking one plug wire off at a time. I couldn't hear the difference, and I've done this test three times. My gut tells me it's a main bearing.

Pete

[Niel Hoback]

I had an Olds with a noise that occured under the circumstances you describe and couldn't come up witha definite reason for. I took it to an old guy that I trusted and told him I thought I had a rod knock. He said if I did, it wouldn't run but a few miles before it came loose, so that couldn't be the problem. I told him I could hear in through the floor when I was in the car. He listened to it and said "I think you have a loose flywheel bolt or two." Dang if he wasn't right. I know its a long shot, but considering the cost of repairs, I think I would look into it before I began taking things apart. Looking is free.

[jd52cranbrook]

Bob-

Nope, I sold my split factory exhaust when I got the tube headers...

Pete

I have my original set up if you want to use it. Let me know.

[blueskies]

I have my original set up if you want to use it. Let me know.

Thanks for the offer, but I think I'll just work with what I've got. Getting the stock manifold in there with the exhaust pipes may be more work than it's worth.

I'm thinking that I can replace the tappet cover bolts with studs, and use nuts to hold them on. There may be enough room to get the covers on and off with the headers in place, with the nut and stud setup. I still will have to pull the headers though, to get the bolts out that are in there now.

Pete

[TodFitch]

. . .I'm thinking that I can replace the tappet cover bolts with studs, and use nuts to hold them on. . .

With your black painted block, aluminum head secured with studs and nuts and now your valve cover plates secured with studs and nuts, you are reverting the engine back to how they shipped them in 1933/34.

I haven't got a clue about your knock but I like the way your engine looks.

[blueskies]

With your black painted block, aluminum head secured with studs and nuts and now your valve cover plates secured with studs and nuts, you are reverting the engine back to how they shipped them in 1933/34.

I haven't got a clue about your knock but I like the way your engine looks.

I guess that makes me retro

Pete

[Jim Saraceno]

Try these methods, hope they help...

[blueskies]

Try these methods, hope they help...

http://img.photobucket.com/albums/v76/JImCno/Fix%20Plymouths/Page66.jpg

http://img.photobucket.com/albums/v76/JImCno/Fix%20Plymouths/Page67.jpg

Thanks Jim.

From the description on this page, it sounds most likely to me that it is a rod bearing. the sound is dull, as described in the main bearing section, but comes in above idle and stays there under load, instead of coming and going between acceleration and deceleration.

Can't wait to get a couple of hours and dig in there...

Pete

[Johnny 5]

I had the exact same thing happen in my 400 Ford motor several years back. It would knock under load and then ease off when you let go of the throttle. One more tap on the gas produced a large thud and stopped it cold. It was a broken rod bolt. I never replaced them when I rebuilt the engine. Ever since then I replace all rod, main and head bolts when I do a rebuild regardless of how much power the engine will make.