Knock Knock is back, and then some.

[jd52cranbrook]

Well, I spoke too soon. From this thread,

http://www430.pair.com/p15d24/mopar_forum/showthread.php?t=9816

I thought I had a fix, ran about 70 miles on it no problem. Then went for about 10 mile run, stopped and heard my bracket for the Alternator hitting the little fan blade in the front of it. It is happened before and a quick fix to unbolt and lift the bracket a bit, and tighten up. But

Having done that, I was giving it low revs to make sure the problem was gone,,,,,,,,,,,,,,,,,,,,,,,,,,,,, and a knock,, or what I sense to be a knock appeared. Was not too happy,

Long story short, It sounds to me like its coming from the timing chain area. And it is not a knock exclusively, sounds more like marbles in a glass jar rolling around also. Happens about 1500. I ended up pulling the pan, and some rod caps, plus two main caps. And to be honest they looked pretty uniform to me. Then I thought the fuel pump spring could be bad, so I put it all back together, pulled out the pump, fired it up with what fuel was left in the line, etc. Noise still there.

So, put the pump back in, torqued and tightened everything, and drove it to the builders place.

The scene, one builder, one old parts guy, one parts supplier, and me all around the car scratching our heads No one thought it was rod or bearing knock. Got stethoscope out, no luck.

Last idea was;

We have been squaring the alloy head each time it is come off. Thought was from the builder that has probably been shaved one to many times. The valves must clear, as it ran for about 75 miles with no problems. He said, to much compression and it is detonating or pre igniting, (I forget which he said). I run 87 fuel, and had about 2/3 of a tank in it. So I filled the rest with 90 octane and drove it home. When I got it in the garage it sounded more from the head than the front timing cover. The fuel did not help.

I have a stock head cleaned up, and had it shaved about .040 just for kicks. But it square and flat.

This is my last resort, ( I think ). I will put the stock head on in the next day or so as soon as I find fitting for the holes, etc. If the noise is still there after that, I guess the engine come out, I really don't want to do that in the summer,,, man.......

I did pull the finned head, hoping for some clue, none. All the valves seem to function right, I am at a loss, and tired, and bummed...

If anyone has any experience in finding some lost noise, please jump in.....

[Normspeed]

JD I can sure believe the part about being tired. That's a lotta work. Stay at it, you'll hit on it soon.

Edit: One of the forum folks a while back had a main bearing in the wrong position so the oil hole did not line up with the one in the block. I think it was #1 main. Any chance that's happened to yours?

[jd52cranbrook]

Hi Norm,

Yes, that certainly would be me to do something like that, but I did go back when I installed them to be sure. I even pulled off each one to double check.

I tell ya, I'm finding out more and more, that I am less and less of a mechanic. I am not sure what I did, if anything at all. If swapping the head does not do it, the engine would have to come out I think, and that is something I really do not want to do in such good cruising weather.

One thing I did notice during the bearing replacement. When pulling the rear main, the crank could move back n forth a bit. In fact I did have to pull if forward a hair to line up for the new rear bearing. I mentioned this to the builder and he seemed to think it not being a issue.

The engine has about 15,000 miles since the rebuild I am thinking.

I'm hitting the hay early tonight to try and re group a bit. I have spent way to much time on this already with little or no results.

[Normspeed]

Some things I might try, take off the drive belt and see if the sound goes away. Eliminates the water pump and generator from the loop. Also pull one plug wire at a time with insulated pliers, motor running, to track it down to one cylinder. If you have the bare metal connectors on the plugs, just short them out to the block instead of yanking each wire off. Once you find the noisy cylinder, if you haven't checked the wrist pin bushing on that cylinder I'd do that. And try either the cast iron head or maybe the aluminum one with two gaskets. Good luck.

[blueskies]

Unless the valves are hitting the head, I can't think of any reason that the stock head will make any difference.

As you might remember, I chased my tail in circles for months trying to get to the bottom of the noise in my 230. Turned out to be a wrist pin bushing that had come loose and spun in the rod.

The test that eventually gave it away, was pulling plug wires one at a time. At first, the noise wasn't significant enough for this test to tell me anything, as the rest of the engine was noisy enough so that I couldn't tell the difference. Once the problem had matured to the point that the noise was fairly loud all the time, the wire test isolated it to one cylinder.

It will probably be a process of elimination, and you already know that it isn't the bearings or the fuel pump. I can't imagine that it is the head, unless it has been shaved to the point that the valves are contacting when they are open. You can measure the lift with a dial indicator (w/ head off) to see if they are even close. That leaves the tappets, cam, water pump, timing chain, and distributor.

Have you checked your timing? Aren't you running a Langdon HEI? I think the initial advance that Tom advises is too much. You might be getting detonation from timing, not octane. This could cause pounding on your wrist pins and bearings... which is what I think caused the problem I had.

Hope you track it down, and I hope you can keep the polished head.

Pete

[Don Coatney]

I agree with Pete that you have a timing issue. A couple years back I was on a road trip driving through the southern Tennessee hills. My engine developed a knock. Like you the first thing I did was add some high test gasolene. This did not help. I then retarded the timing and the noise disappeared. Forum member Christopher has the same issue on one of his engines. He retarded his timing and the noise was gone. Follow this link.

http://www430.pair.com/p15d24/mopar_forum/showthread.php?t=4525&highlight=timing

I recommend you retard your timing first. If that fails then pull the pistons and check all the wrist pin bushings.

[jd52cranbrook]

All good advice.

Think I should add a bit more. The builder, and my friend live about 17 miles away via highway. So by the time I get there the car is warmed up fine. This is where I started hearing things.

It seemed like a timing issue to me too. We did turn the distributor with no difference. And with the HEI you can turn it alot and the car will still run. I normally set the advance to 5 degrees.

I pulled the wires one by one, on Sunday it seemed like number 1 was the culprit, that is when I dropped the pan and the bearings were checked. After I found no change while checking the bearings, I put it all back together and drove to the builder yesterday. When we did the wire test it did not matter what plugs we pulled, in fact we pulled two at a time even with no change in the marble sound.

The thought of the builder was the head was shaved so much the compression is too high. The valves have to clear as it ran for about 70 miles before this noise started up. And they look fine after pulling the head last night.

The only other change I did was to add some stop leak in the radiator when I put it all back together a few days ago. I could not seem to stop a small leak at the water neck no matter how much sanded it flat, put on RTV, etc.

When I drained the water to pull the head the water was brown, the stop leak color. Could it be the properties of the stop leak lowered the boiling point of the water?

I am at a loss right now. I need to do regular work at my job for a bit then tackle this again. I have never heard this sound before. I do have another distributor I can put in compare I guess. I will check the timing first when I get it back together.

I forgot to add, I did pull the belts off, the noise is still there.

[Christopher]

Thats right,, retarded the timing, noise went away. ,,also all the power.I dinked with my rattle problem for months. different dizzys, plug wires, vacume checks.its comming out [when I get the time]and Im going to shoot it.!!!!! just kidding, I believe it is the wrist pin bushing,, won't know for sure,until after the autopsy.putting in a 251.. enough of these little wussey engines...Christopher from the high and lonesome... ..

[Don Coatney]

I normally set the advance to 5 degrees.

Five degrees sounds like too much advance. My timing was set at five degrees when I had the knock. I reduced it to two degrees advance and the knock went away. And I still have plenty of power.

[jd52cranbrook]

If I remember, Langdons wants to set them at 12 or more, Id have to look it up again. I've had it set at 5 ever since it has been in the car, many miles.

I do think the distributor could be the issue however.

I dont know either why the head would make a difference. But it is off now, so it would not hurt to put the stock one back in for a run. Going to use the same gasket for now.

[martybose]

I tried setting my HEI at 12 degrees and it knocked like crazy every time I stood on the gas. Cut the initial (less vacuum) to 3 degrees, then it was okay around town, but heated up on the highway. I wound up tiewrapping the counterweights to see if the centrifugal advance was too much, and found it eliminated that problem. Right now (if I had the head back on my engine, which I don't right now) I woudl be running 3 degrees initial with manifold vacumm to the vac. advance, and no centrifugal advance at all.

Later on I wil experiment with springs etc. to see about adding a little centrifugal advance higher up in the RPM range.

All of this is on a 230 bored out .072" with a mild cam, dual Carter-Webers and an Edmunds head running about 9 to 1 compression.

Marty

[Tim Frank]

Diagnosing engine noises from text descriptions in a forum such as this can be a challenge....

You weren’t sure whether the rebuilder blamed detonation or pre-ignition.

Pre-ignition is less likely than spark knock (detonation) and is caused by a hot spot developing in the combustion chamber and firing the mixture before the spark plug does. Biggest culprit used to be carbon deposits, which aren't so common any more. If you are using too hot a plug, that could contribute and if you have machined that Alum head, you may have sharp edges in the combustion chamber. I had an Austin that "pinged" after I machined the head until I broke the edges in the combustion chamber.

Not sure if you can accurately determine what the effective CR of your engine now is, but you might have to use a thicker head gasket and/or a spacer to reduce it a bit.

Also if you are running too lean that can be a factor.

~or detonation, spark knock ~

Detonation can usually be solved by using higher octane fuel. If that is not a solution, which you said it wasn’t for you, there may be several factors compounding the problem. Compression ratio may be one. Your rebuild may have o/s pistons and with the non-stock head you may be flirting with c/r issue. You did have head gaskets blowing at a higher than expected rate. Still, why suddenly after LT 15K miles?

Timing could be the problem, but again, why suddenly?

If it is really either pre-ignition or spark knock that you are suffering, I would first rule out a lean mixture (unless you already have and I missed it) ...vacuum line leaks....etc.

I think you said somewhere in the thread that the knock starts after it has warmed up.

Could it be “after the choke shuts off?”

The fuel angle does mesh with the chronology of events.

Good luck, rgds, Tim

[jd52cranbrook]

Thanks Tim,

Detonation was the word.

I don't believe its a choke issue, it warms correctly, then idles down after hitting the throttle sightly, but will look further.

I will put the head on this afternoon and cross my fingers.

Being that it is a dual carb set up, I can shut one down for test purposes if the knock is still there.

by the way, what is c/r and LT that you refer too?

Thanks, John

[Don Coatney]

Detonation (sometimes called dieseling) will occur after the ignition is killed in a "hot" engine as the engine will continue to run once the key is turned off. Pre-ignition is a timing related issue and will not be the cause of an engine not stopping once the ignition switch is turned off. I do not believe detonation is the problem here.

[Don Coatney]

by the way, what is c/r

c/r is compression ratio. This chart will help in finding out what your

compression ratio is from a compression check. However there is a

mathmatical formula (it is the ratio between the volume of the cylinder

and combustion chamber when the piston is at the bottom of its stroke,

and the volume of the combustion chamber when the piston is at the

top of its stroke) for finding out your true compression ratio.

Shaving a head several times will increase the compression ratio

[jd52cranbrook]

Well the head try did not work. I have a older head then what was on the car. And it doe not cover the by pass hole on the block. I could pull the water pump and change plates I guess. Thought I had one around here that had that hole blocked.

I didn't want to get into doing that cause this was only to be a test with the older head.

So, I put two gaskets together to take away some of the compression. Still had a banging rapping somewhere, but less than yesterday. Retarded the timing and it got less, but not gone completely. And the marble in a jar noise was gone, but the motor did not get as hot as yesterday driving 25 miles or so.

So,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,, I'm going to pull the head once again. Look for any sharp edges where it might be getting red hot enough to fire the fuel. De burr where I can in the chamber to get smoother edges. Thats for the alloy head. For the other older cast iron I will dig up where I had the other water pump with that hole blocked. If I find it, will swap it in and try the other head also.

The sound does not sound like a rod or main at all to me. It's coming from the top of the head it seems to me.

I was told by Earl these heads have somewhere around 9:1 compression, with all the shaving this one has I am sure it's more.

As for detonation and pre ignition. I guess what I mean is inside the cylinder is getting so hot, any edge on the head could be glowing, thus igniting the fuel before its time. That's my thought anyway.

The saga continues.

[jd52cranbrook]

Thanks for the compression page Don, good reading.

And as always, opinions, advice welcome........

[KINGSWAY52]

Thanks for the compression page Don, good reading.

And as always, opinions, advice welcome........

Hi!

I've the the same sound on my engie also.I change the sparkplugs to a colder range and retarded the timing and most of the sound gone away,there is still a little knock when driving uphill with campingtrailer behind but on flat road or downhill nothing,the engine is running in the upper heatrange (95 to 105 degree celsius).I m also runnig mini hei from langdon and a crter weber carburator from him.at first it was not easy to set the timing correct but it helpt with cooler plugs.

Kiinsway52 from Norway

[Don Coatney]

JD52;

Try another distributor (non HEI) and set the timing at TDC with no advance.

[jd52cranbrook]

I think I still have a non HEI around somewhere. I know I do have another HEI for sure.

We did retard last night, the knocking got less, but not gone.

Regular work is getting in the way now, dang.

And so it goes,

[Tim Frank]

JD,

Was not suggesting that it was a choke issue, I am asking if the mixture could be too lean. The choke would cover for the lean mixture while it was on and that might account for why you get a bit of time after startup before the knocking starts.

I still have not been into the carb on my wife's Dodge, bu it should be possible to richen the mixture "some" and reverse the adjustment if no effect.

Kingsway52's post is a classic case of troubleshooting and having to make small improvements in a a number of factors that could all be contributing to the problem. Pulling a trailer is a textbook cause of knock.

What are your plugs like? That is one other thing that I don't recall being covered in your post. They should give a picture that tells whether you might be on the lean side.

Rgds,

Tim

[martybose]

I think I still have a non HEI around somewhere. I know I do have another HEI for sure.

We did retard last night, the knocking got less, but not gone.

Regular work is getting in the way now, dang.

And so it goes,

Or you could try what I did. Get a small tiewrap or two; you'll find that if you position it correctly you can put it around the outside of the counterweights and the cap will still fit on. Leave the initial advance at 3-4 degrees BTDC and leave the vacuum advance working.

This was the combination that finally stopped my motor from pinging on my torque test hill.

Marty

[jd52cranbrook]

Well today I thought more while working, and tried a couple of other things.

Tim, I am sure I'm not running lean, in fact I am pretty sure I have too much fuel. The oil turns black sooner than I would expect. It smokes a little, I always knew about that. And there is a odor of fuel more that I would expect. I'm running the Landon's set up, dual carter/webber 2 barrels.

My builder always thought it was way over carberated, (sp).

Today I took one out of the system, and let it warm up. At first I was happy, then the frown came back, lol. The knocking was there, just less. This was with the back one connected. Then I swapped, and back some more. Turns out what was really happening was the car was just getting more warmed up. Warmer, or hotter the engine, the louder, and ease of creating the noise.

So that didn't work, next.

I pulled the alloy head, got some JB Weld and covered the bypass hole in the block. Did this so I could run the stock head from a older block I have. Figured I could take it out latter if need be. Anyway, put the stock block head on, with the compression more like 9:1 and fired it up with no water as yet, was waiting for the JB to set overnight before the water.

Sound still there.

I should add this no longer is a slight sound,, it raps pretty good.

So my options are getting less.

Could be in the valve train. (it's a job and a half to get to them, let alone do any work in there with the engine in the car)

Could be in the timing chain assembly, (I swear if I had to point,thats where the sound is coming from ) But to get to the timing chain assembly with my set up, the radiator and shroud comes out. Plus I am not sure what repair, if any can be done with the engine in the car still.

Could be a wrist pin. ( I inspected them on the first tear down when I had the pistons out of the engine, and tried them from below on the second time I pulled the bearings for inspection)

I could not find a original distributor, I do have another HEI one that I can try I guess. But my thinking is with the lower compression head, and retard of the one in the car, this is not the cause.

I'm reluctantly leaning to pulling the engine out, and taking it back to the builder for him to inspect. I mean I feel I should get some relief from him. The engine has about 15K miles on it since rebuild. I have put lots of hours already into it, following leads, advice from him and you good people. I could spend a day to pull it, and take it to the builder, have it entirely gone though. During that time I could be doing other things. I really do think I need smaller jets on these carbs for one, have some painting to do, and misc items. I will probably do some looking around myself before I take it to the builder. Pull the front cover, (look for a nut or bolt flying around)

I don't feel like I'm giving up, I think this is the most logical step. Even if it is one of the items I mentioned above, it would so much easier to fix it out of the car than in.

Like sand through a hour glass, so goes,,,,,,,,,,,,,,,,,,,, (anyone? )

[steveplym]

At this point I think I'm with you. If I paid a guy good money to rebuild my motor and after 15k mi there is a problem, and he is willing to warranty it, I would definitely have him fix it. Pulling the motor again is a pain I know, but you may work on it another week and have to pull it out anyway.

Pull it and let someone else figure it out.

[Normspeed]

Sounds like you're not afraid to tackle the motor R&R, so I say that might be the best way to track it down. Anything that sounded like you describe has gotta be corrected.

After I got mine back from the machine shop with the block all assembled, I finished up with all the external stuff. I checked and found the oil pump had not been properly indexed, the timing cover bolts not in their correct spots, head bolts in the wrong spots and worst of all, a tapping that appeared after 500 miles and turned out to be a way oversized valve guide in #1. Machine shop replaced the guide with the motor in the car but dinged up my firewall and got some of the intake/exhaust fasters and washers in the wrong spots. If I did it over I would have pulled the motor and taken it to them, or would have done the guide myself.