350 Engine Damage

[cppursell]

I am in need of advice for my ~1970's 350. It's in my '67 chevy C10. Yesterday I was driving home when I suddenly heard a knocking noise from my engine, quiet at first, then steadily louder until I experienced a loss of acceleration, then the engine died after I let off the gas (the whole process from noise to die was about 2 minutes). I was able to pull over, and when I opened the hood, there was oil spilled everywhere on the firewall and in that general area. After a tow, I looked at it today and, thank God, the problem was the copper tube for the oil pressure valve snapped, causing all the oil splatter. I repaired the tube, and the engine drank 1 gallon of oil (that's how much I lost).

After this repair I started up the truck again and it is running. However after it warmed up a bit there is now a moderate knocking sound. It sounded like it was coming from lower part of the engine. I don't know what to do! I dare not run it any longer until I get some advice. All I can think of is that damage was caused due to the lack of oil. Does anyone have any ideas? I appreciate any and all comments you give.
Thank you,
Christian

[too much stuff]

Sounds like you wiped out some bearings on the lower end. Not good. I wouldn't run it anymore until you open it up and find the problem. I hate to say it, but you should have shut it down when you first noticed a problem. Good luck, Eric

[Todd Hepler]

+1 on a spun bearing.

I did the same thing in my 67 fury with the original 383. I felt it happen right away and gingerly drove it to my shop about a mile away.

1 main bearing and one rod bearing were toast.

Tiny metal particles made it through most of the oil system in that short period of time (i didnt have an oil leak, just a weak pump), and decided to build a 440 instead and sell the 383.

I was able to save the cam and lifters - they were a pretty new edelbrock set - I just took each lifter apart and cleaned 'em out.

The bad news is you are probably looking at an engine rebuild.

The good news is that 350 parts are dirt cheap!

Sorry to hear about your bad luck,
Todd

[cppursell]

Well, I talked with my cousin, and it seems you two are about right. My cousin's recommendation is to buy a cheap but running small block v8 and swap the two so I can get back on the road faster, then diagnose the problem at leisure. It could either require a whole engine rebuild, or *hopefully* replace bearings and put in a reground crank. I have hope toward the latter because the engine does run "smooth", so I don't think everything got ruined.
On too_much_stuff's comment, no hard feelings; I do wish I knew what to do, however I'm a rookie at 20 and my cousin tells me I also should have looped the copper tube next to the hole to absorb the vibration... great.
Let me know what you think of this engine swap idea.

[tasian]

engine swap is a good idea you can find some pretty good deals on decent low mile 350's just remember a used engine is always a little bit of a gamble just try to find one you can hear run as far as your engine goes the problem with just replacing the bearings is if all the metal particles are left it'll just ruin the bearings again now a lot of people will say you can get by without a full rebuild and people have in the past but its a pretty big risk if it was mine i wouldn't chance anything short of a full rebuild and having EVERYTHING hot tanked

[GRX]

Agreement on the engine swap. But as has been said, it will be a crap shoot.

In my experience you will need to completely disassemble the engine after such bearing failures. This includes removing all the oil galley plugs & cleaning the passages. And replace the lifters of course. Only way to be sure you've removed the particulates.

And your cousin is right about looping the copper line. Or you could go to plastic.

[BADPURPLE70CHEVY]

Originally Posted by GRX

Agreement on the engine swap. But as has been said, it will be a crap shoot.

In my experience you will need to completely disassemble the engine after such bearing failures. This includes removing all the oil galley plugs & cleaning the passages. And replace the lifters of course. Only way to be sure you've removed the particulates.

And your cousin is right about looping the copper line. Or you could go to plastic.

x2...you need to disassemble it completly. If you didnt there is no telling what might be lurking in other parts.

[treveiger]

Sounds like a bearing burned up, when any noise comes up or something dont feel right always shut the truck off right away(my brother learned that the hard way lol) i would look into crate motors from GM thats what im going to get next year hopefully, dont buy one from the auto parts store ive heard bad things from them and with GM you get a nice warrenty. That sucks that happen but maybe something good will come out of it.

[cppursell]

Yes, it looks like I'll be rebuilding the engine in the future. My cousin (the person who I seem to always refer to) is helping me out by putting in one of his motors in my truck. He has apparently done the impossible and has a 350 with 283 heads, and it runs without pinging. He says it's got like an 11.5:1 compression ratio.

I certainly did learn the hard way on how to react when something didn't sound right, but I guess the moral of the story is that I can take this as a challenge and build my skills.

Thanks again your support! I love this truck forum :')

[QKENUF4U]

11.5:1 compression WILL NOT run on pump gas..... just askin for more problems trying to use that on the street..

[cppursell]

Originally Posted by QKENUF4U

11.5:1 compression WILL NOT run on pump gas..... just askin for more problems trying to use that on the street..

Well it ran for him and he drove it, so ask him. I will mention it though... Is higher octane a solution? 91 with booster or something?

Edit: I called my cousin to get my facts straight.
He says the compression is between 11 and 11.2. He thinks it has an RV cam, and he smoothed the inside of the combustion chamber.
He ran it and drove it around a few times on cheap pump fuel.

[GRX]

Originally Posted by QKENUF4U

11.5:1 compression WILL NOT run on pump gas..... just askin for more problems trying to use that on the street..

Depends on the cam really. Static & dynamic compression are two different animals.