Disappointed - R112 (long post)


IHC in the early to mid-fifties.

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Golden Jubilee
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Post Wed May 15, 2019 6:00 am

Re: Disappointed - R112 (long post)

Have you run the engine long enough to get it warm? Even with .030 oversize pistons, if the wear is excessive, what you might be hearing is piston slap. Most common on high-mileage engines with a lot of piston skirt wear, and it usually goes away or minimizes when the engine is fully warmed up.

Long-distance diagnosis is SUCH an inexact science...
My posts contain my own opinions...your mileage may vary, void where prohibited, objects in the mirror may be closer than they appear, and alcohol may intensify any side effects.

Rusty Driver
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Post Wed May 15, 2019 7:54 am

Re: Disappointed - R112 (long post)

I will have some more experienced people listen to the noise. I will have to document what I'm hearing better. I haven't run it too much because I know the valves need adjusted and I'm waiting for my friend to have time to come over. There is plenty of valve train noise but that is clearly distinguishable from the knock. This is what I've noticed so far and yes it has been run up to operating temperature. Time before last that I ran it I was focused on a few different things and not just the knock but a friend that was there said it sounded like a knock in the engine. This last time I ran it, it wasn't making the noise cold but started making the noise as the engine warmed up. From what I can tell it sounds louder on the driver side but there could be other variables making me think that. I got underneath and it sounded like it was coming from the rear end of the oil pan. There also seemed to be quite a bit of vibration when I gave it gas but I assume that could also be many different things. The knock also didn't seem to be consistent as it would come and go. It is pretty loud though. I didn't take notice if the knock changed when rpms changed. When the head was off, the cylinders looked really good as far as we could tell.

My friend said he is going to try and come this evening to adjust valves and if he does I will be more comfortable letting it run longer and I can try taking it for a drive for the first time.

I'm not giving up, really. Just in a moment of frustration and frankly I think I've spent too much time and am getting burnt out on it. I estimate I easily have about 350 hours into it over 6 months while working full time, kid in sports, family, etc. Again back to the impatient thing. That's why the thought of pulling the engine when I thought I was so close has me commenting the way I am. If needed, pulling the engine will just be another thing under my belt over the past 2 years of antique auto mechanics (bought a 65 Mustang 2 years ago).

Golden Jubilee
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Post Wed May 15, 2019 9:42 am

Re: Disappointed - R112 (long post)

Do you know someone with a stethoscope that knows how to use it? That would be the best way to figure out just where your noise is coming from.
52 L110
61 C112
68 Cadillac Coupe DeVille

Rusty Driver
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Post Wed May 15, 2019 11:17 am

Re: Disappointed - R112 (long post)

waltesefalcon wrote:Do you know someone with a stethoscope that knows how to use it? That would be the best way to figure out just where your noise is coming from.


The shop I use is pretty old school and once I can get this thing to drive down the road I will take it to him to have a listen. He has a couple vintage autos himself and has had Gen 1 Camaros for years.

Golden Jubilee
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Post Wed May 15, 2019 1:23 pm

Re: Disappointed - R112 (long post)

Noise can be a symptom, but not a diagnoses. I had a pick-up come into the shop I was working at with a bottom end knock. It had a 292 Chevy 6 and auto trans. The owner said his wife had driven the truck for 2 1/2 hrs on the hiway with the trans in "2" and not drive. She claimed it wouldn't go over 60 MPH.
I listened to the knock and concluded it came from the crank area, it wasn't until I pulled a few bearings to inspect that I found them all good! There was a definite knock from the oil pan, but it turned out to be a loose torque converter on the flex-plate.
You need someone who can not only know what to listen for, but who will follow through and confirm the diagnoses. In the case above, the owner had been warned it might need a new crank, and was over the moon to learn all it needed was a new flex-plate (the holes had wollowed out) and new bolts.
There are plenty of things that can make a noise, some have been listed, and some have not (carbon, sparkplug wires out of order etc)
Rod bearings tend to get louder as speed increases and the inertia in the rod causes it to knock at both ends of the stroke, mains tend to knock more a low speed. Bad main will wipe out the rod attached to it in short order,as it dumps the oil and little makes it through the drilling to lube the rod.

Rusty Driver
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Post Wed May 15, 2019 1:42 pm

Re: Disappointed - R112 (long post)

cornbinder89 wrote:Noise can be a symptom, but not a diagnoses. I had a pick-up come into the shop I was working at with a bottom end knock. It had a 292 Chevy 6 and auto trans. The owner said his wife had driven the truck for 2 1/2 hrs on the hiway with the trans in "2" and not drive. She claimed it wouldn't go over 60 MPH.
I listened to the knock and concluded it came from the crank area, it wasn't until I pulled a few bearings to inspect that I found them all good! There was a definite knock from the oil pan, but it turned out to be a loose torque converter on the flex-plate.
You need someone who can not only know what to listen for, but who will follow through and confirm the diagnoses. In the case above, the owner had been warned it might need a new crank, and was over the moon to learn all it needed was a new flex-plate (the holes had wollowed out) and new bolts.
There are plenty of things that can make a noise, some have been listed, and some have not (carbon, sparkplug wires out of order etc)
Rod bearings tend to get louder as speed increases and the inertia in the rod causes it to knock at both ends of the stroke, mains tend to knock more a low speed. Bad main will wipe out the rod attached to it in short order,as it dumps the oil and little makes it through the drilling to lube the rod.


I think this is where I'm at. Once I get the valves adjusted, my old school mechanic is only a couple miles away so I'll just take it to him and hang out while he looks at it. Even if he can't tell me in a couple hours what it is he will have a lot more insight into it than what I can tell.

Golden Jubilee
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Post Thu May 16, 2019 9:43 am

Re: Disappointed - R112 (long post)

"I think this is where I'm at. Once I get the valves adjusted, my old school mechanic is only a couple miles away so I'll just take it to him and hang out while he looks at it. Even if he can't tell me in a couple hours what it is he will have a lot more insight into it than what I can tell."

Hopefully you will get an answer and can move forward again with your project. As has been pointed out it is nearly impossible to accurately diagnose an engine without having it in the shop.
52 L110
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68 Cadillac Coupe DeVille

Golden Jubilee
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Post Thu May 16, 2019 4:07 pm

Re: Disappointed - R112 (long post)

Some guys do it this way. Scroll up a couple of posts.
viewtopic.php?f=25&t=7640&p=57761&hilit=valve+lash#p57761

Golden Jubilee
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Post Thu May 16, 2019 10:44 pm

Re: Disappointed - R112 (long post)

I have a 1940 Ford blocking my shop. I had thought I could have this car in and out of the shop in less than five years. This is year 15. Am I disappointed? Yes I am. Did I plan on spending as much money as I did? Absolutely not. I have had to learn to enjoy the journey and let the project develop. Money for the project has never been a stalling point. When I had several serious health issues to deal with, the calendar did not stop to wait for me. I had to learn patience. Asking for and paying for professional help with a project is something I had to learn to deal with.
I am closer to having a driving car today than last week. When? I cannot say for sure. Soon, I hope.
I would rather have tools I do not need than to need tools I do not have

Golden Jubilee
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Post Fri May 17, 2019 5:24 am

Re: Disappointed - R112 (long post)

A leak down test can help you pinpoint the source of the oil consumption. If the overall diagnoses of the motor including rod knock is bad consider finding a replacement motor it can end up being a lot cheaper than a rebuild. I was fortunate to find a nice one from a member on this site (Yay Terrell!). V8 motor swaps are popular these days which ups the percentage of good used sixes out there.

Any old truck can turn into a money pit.The more you can do yourself the more you will save. I estimate an expenditure of about $3,000.00 on top of the purchase price and a lot of hours on my current Binder to get it back on the road. Granted it is a rustoration but with elbow grease and judicious parts sourcing it's been a fun project that has not put me in the poor house. This has included wiring, glass, brakes, drive train and misc.
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